Celebrating 10 Years
ASH NEWS AND REPORTS®
MARCH/APRIL 2013
Volume 10 Issue 2
2013 Marks the Beginning of a New Era for Blood, the Official Journal of ASH
Succeeding Dr. Cynthia Dunbar as Blood editor-in-chief is Bob Löwenberg,
MD, PhD, professor of hematology at Erasmus University Medical School,
Rotterdam, The Netherlands. Dr. Löwenberg is the journal’s first nonNorth American editor-in-chief. Another change for 2013 is the addition
to the editorial board of the journal’s first-ever deputy editor, Nancy
Berliner, MD, chief of hematology at Brigham and Women’s Hospital and
Professor of Medicine at Harvard Medical School in Boston. Dr. Löwenberg
and Dr. Berliner assumed their positions on January 1 and marked the
beginning of their tenure with a new article type – Blood Spotlight. Blood
Spotlights are brief articles (less than 2,000 words) that focus on emerging
scientific and clinical developments or on a recent burst of advances within
a circumscribed area. The first Spotlight article (“Sense and nonsense
of high-dose cytarabine for acute myeloid leukemia” authored by Dr.
Löwenberg) appeared in the January 3, 2013, issue. Going forward, Blood
Spotlight articles will be solicited and published based on the editors’ view
of their relevance and impact. A number of other new Blood features will be
introduced to readers over the next few months including a series of review
articles that highlight particularly significant advances in biomedical and clinical/translational
research. The four review series to be published in 2013 will focus on the
following topics: epigenetics in hematology, cancer-related thrombotic
disease, genome sequencing and its impact on hematology, and blood
cells in vascular inflammation. Additionally, readers are now introduced
to “Blood Hubs.” The idea behind this feature is to make available for
the convenience of journal readers micro-websites that can be used to
aggregate content and services around a particular topic or theme. Blood
Hubs will be complementary to the Blood journal website and will provide
a centralized place for readers to find content, including journal article
lists, images and slideshows, and relevant multimedia. Visit the first Blood
Hub on Pediatric Hematology at http://pediatric.bloodjournal.org. The next
Blood Hub will focus on thrombocytopenia.
Read more about these new article types and products, and learn about
the new editor and deputy editor in the continuation of the Blood editor
interview on page 6. Dr. Jose Bufill, 2012 ASH News Daily contributor, sat
down with Dr. Löwenberg and Dr. Berliner to discuss their vision for the
future of the world’s premier hematology journal and what inspires their work.
D I F F U S I O N
Features
Platelets Reveal a New Weapon in the Fight Against Malaria
McMorran BJ, Wieczorski L, Drysdale KE, et al. Science. 2012;338:1348-1351.
4
Ask the Hematologists –
6
A Conversation With the
New Editors of Blood –
Dr. P. Brent Ferrell and Dr. Mark
Koury review their approach to diagnosis
and management of the anemia of
chronic inflammation.
ASH News Daily contributor Dr. Jose
Bufill continues his conversation with
recently appointed Blood editors Dr.
Bob Löwenberg and Dr. Nancy Berliner.
The first part of their conversation was
published in ASH News Daily, the official
newspaper of the annual meeting of the
American Society of Hematology.
14
Embedded in the Red
Cell – Dr. H. Franklin Bunn’s
long, distinguish career in hematology is
the subject of this memoir.
15
In Memoriam, Karl G.
Blume, MD (1938-2013) –
Dr. Robert Negrin pays tribute to the
career achievements and legacy of
Dr. Blume.
DE P ARTMENTS
2 President’s Column
2 News and Reports
5 The Hematologist Advocate
8 Diffusion
13Clinical Trials Corner
16 WHAT’S ON THE WEB
Love MS, Milholland MG, Mishra S, et al. Cell Host Microbe. 2012;12:815-823.
P
latelets are increasingly recognized for their role in innate
immunity. Their capacity to detect erythrocytes infected
with malarial parasites and kill the invading organism is a
remarkable example of this function. Studies evaluating
the physiologic significance of platelet-mediated killing in controlling
malaria have demonstrated that both thrombocytopenia and inhibition
of platelet activity increase mortality in mouse models of the disease.1
These observations raise the question of how platelets recognize
infected red cells and destroy the invading parasites.
Studies from the laboratory of Dr. Simon Foote at the Menzies
Research Institute in Hobart, Tasmania, now demonstrate that
platelet factor 4 (PF4, CXCL4) mediates malarial parasite killing via
interactions with Duffy antigen on erythrocytes. In a follow-up study
of their work showing that platelets kill P. falciparum,1 Dr. Foote’s
group found that activated platelets use CD36 to bind to erythrocytes.
Platelets then release PF4, which is highly concentrated in platelet
granules. Immunofluorescence of red cells infected with P. falciparum
demonstrates colocalization of PF4 with dead intraerythrocytic
parasites following exposure to platelets. Subsequent studies
found that PF4 binds to the chemokine receptor Duffy antigen. The
investigators showed that purified PF4 killed P. falciparum within
erythrocytes expressing Duffy antigen, but not in red cells that lacked
this surface antigen. These results support a model in which platelets
bind to infected red cells and release PF4, which then kills the
intracellular parasite (Figure).
Working independently at the University of Pennsylvania,
Melissa S. Love and colleagues screened a panel of
human defense peptides to discover circulating proteins
that possess activity against P. falciparum. The screen
identified PF4 as the most potent inhibitor of parasite
survival. PF4 is made up of an N-terminal domain, a
central domain, and an amphipathic C-terminal domain.
The authors localized the antimalarial activity of PF4
to a 12-amino-acid amphipathic helical domain at the
C-terminus of the peptide. Based on this analysis,
they screened a library of small molecules capable of
adopting amphipathic secondary structures to identify
compounds capable of killing P. falciparum. Two
compounds, PMX1207 and PMX207, demonstrated
potency at nanomolar concentrations against both
chloroquine-sensitive and chloroquine-resistant
strains of the organism. The two compounds were
subsequently tested in mouse models of malaria. Both
Robert Flaumenhaft, MD, PhD
Dr. Flaumenhaft indicated no relevant conflicts of interest.
PMX1207 and PMX207 decreased parasitemia as measured by the
number of erythrocytes containing lysed parasitic digestive vacuoles.
In a murine malaria model, PMX207 totally reversed P. bergheiinduced death.
Nearly half the world’s population is at risk for malaria, and 216
million cases were reported in 2010. The parasite is so prevalent
and so lethal that it has created a selective pressure that has altered
the genetic composition of the human population in the at-risk areas.
Among the genes that have been selected against is the Duffy
antigen, which serves as a receptor for the parasite. The work by
McMorran et al., however, reveals the flip side of this story. The Duffy
antigen on erythrocytes serves as the binding site for platelet-derived
PF4 that mediates killing of the parasite. Whether Duffy-negative
individuals have an alternative mechanism for controlling parasite
growth is not known. However, this new understanding of the
role of PF4 in killing parasites within erythrocytes has informed
the development of drugs based on PF4 structure, directing the
design of a new class of antimalarials capable of killing chloroquineresistant P. falciparum. If converted to orally available drugs, this
novel approach to treat malaria could have a significant impact on an
enormous global health problem.
1. McMorran BJ, Marshall VM, de Graaf C, et al. Platelets kill
intraerythrocytic malarial parasites and mediate survival to
infection. Science. 2009;323:797-800.
PF4 kills intraerythrocytic P. falciparum. A) Platelet CD36 enables recognition of infected
erythrocytes. B) Once bound to the erythrocyte, platelets release PF4 from their stores.
C) PF4 subsequently lyses the parasite digestive vacuole, killing the parasites within.
Engwerda and Good, Science. 338:1304 (2012). Image: K. Sutliff/Science. Used with permission by AAAS.
President’s Column
“The mind is not a vessel to be filled, but a fire to be kindled.”
This quote is attributed to Plutarch (born 46 A.D.) as a variant translation
of his statements in On Listening to Lectures. Plutarch was a Greek historian,
biographer, and essayist and an excellent observer of societal values. To me,
this metaphor captures the pragmatics of mentorship: the why we mentor
and how we mentor.
Mentors were critical to my career success. My mentors shared their
excitement about hematology with me but, more importantly, encouraged
and believed in me, even when the path ahead was muddled or difficult to
navigate. At our annual meeting this past December, both Drs. Tim Ley,
2012 E. Donnall Thomas lecturer, and Jim George, 2012 Wallace H. Coulter
Lifetime Achievement recipient, credited mentors for their successes. As
most members feel similarly about their mentors, supporting mentorship is
and should be a core mission of ASH.
In 2003, Drs. Jim George and Bev Mitchell helped establish and co-directed
ASH’s first Clinical Research Training Institute (CRTI) for fellows and junior
faculty interested in patient-directed research or outcome studies. Then and
in each subsequent year, 20 trainees and 20 faculty mentors participate in an
intense week-long program that combines lectures with small group sessions
that refine the participant’s clinical research protocol. Each participant is
assigned a faculty mentor and mentorship continues throughout the year
and often longer. A recent evaluation of the program revealed that nearly 90
percent of CRTI graduates were active clinical investigators and some early
trainees had tenured faculty positions. The vast majority felt that the CTRI
experience was an important contributor to their career success and that
mentorship and the active networking that developed among participants
were the reasons for this. As former trainees now return as enthusiastic
mentors, the program’s ongoing success is secure.
Building on the success of this mentorship effort, ASH, in conjunction
with the European Hematology Association, established a program for
Translational Research Training in Hematology (TRTH) in 2010. And this
year, in association with the Highlights of ASH® in Latin America (HOA-LA)
meeting in Santiago, Chile, ASH will host a one-day workshop on clinical
investigation strategies. Each program has a different focus to fit different
needs and each has metrics for expected accomplishments that will be
prospectively evaluated. TRTH is a yearlong program that is formatted
like CRTI but focuses on translational research as well as academic career
development. The HOA-LA workshop will target hematology faculty
members, not trainees, with the intent of improving the infrastructure for
clinical hematology research in Latin America by strengthening the skills of
established faculty. However, key to both programs is establishing one-toone connections between instructor and participant and the concept that
mentorship will empower (kindle) the next generation of investigators.
Similarly, ASH’s Minority Medical Student Award Program (MMSAP), an
eight- to 12-week research experience for first- or second-year medical
students, prioritizes mentorship by pairing each participant with an ASH
member who serves as a career-development advisor during medical school
and residency. In addition, ASH supports underrepresented minority junior
faculty hematologists through the partnership with the Harold Amos Medical
Faculty Development Program of the Robert Wood Johnson Foundation, and
thus partners with this extraordinarily successful mentorship effort.
ASH also highlights mentorship each year when awarding the ASH Mentor
Award to one basic scientist and one clinician. These awards were
established in response to a proposal by the hematology fellows of ASH’s
Trainee Council in 2004 and annually remind us that it is the quality of
mentoring relationships that counts – being trustworthy and honest, but not
judgmental; having time to talk; and providing insight into work-life balance.
As colleagues we also mentor each other. ASH facilitates this with programs
such as Consult-a-Colleague. Last year more than 50 volunteers who are
at the top of their field provided insights to 421 clinical queries from
colleagues. Less formal mentorship also abounds. Most importantly, the
annual meeting provides an ideal opportunity to make and renew our one-toone connections, and the fire, once kindled, is thus sustained.
Janis L. Abkowitz, MD
2
a nd
r e p o r t s
Volunteer and Make a Difference in
Patients’ Lives in Uganda
In partnership with Health Volunteers
Overseas (HVO), ASH members
provide consultative training in the
clinics, classrooms, and laboratories
of health-care institutions in the
developing world. In Kampala,
Uganda, the need for hematology
support is especially dire. The full
spectrum of hematologic disorders
is observed at Mulago Hospital in
Kampala, Uganda. Daily rounds
are conducted on the wards, and
Dr. Ana Oton, Denver Health Medical Center
and the University of Colorado, gives a lecture
an outpatient clinic, with a census
to hospital staff and medical students while
of approximately 50 patients, is
volunteering at Mulago Hospital in Kampala,
held weekly. The expertise of ASH
Uganda, in 2009.
members is crucial for appropriate
diagnosis and management of this large cohort of hematology patients. Education
and training of local personnel are core components of the program that ensure
sustainability. Volunteers at Mulago Hospital spend time with medical students from
the affiliated Makerere University and provide clinical and classroom teaching while
school is in session. Formal lectures held at the hospital are attended by medical staff,
residents, and medical students.
Photos courtesy of HVO
Mentorship is a Core Value of ASH
n e w s
Current training needs at Mulago Hospital include the following:
• Diagnosis and treatment of chronic myeloid leukemia
• Diagnosis and treatment of chronic lymphocytic leukemia
• Management of sickle cell patients
• Training in differential diagnosis
• P
reparation and interpretation of
peripheral blood films and bone marrow
aspirates
Volunteers have the option of living in
the HVO apartment or in the Mulago
Guesthouse. The accommodations are
basic but comfortable and well-kept
and include Internet access. Cleaning
and laundry services are available for a
minimal fee.
To find out how you can make a difference
as a hematology volunteer in Uganda,
please contact Danielle Stonehirsch at
[email protected].
*
Dr. Oton with a patient who has Burkitt
lymphoma.
Volunteer at New ASH-HVO Site in Tanzania
Tanzania was recently added to the current list of ASH-HVO sites, which includes
Uganda, Peru, and Cambodia. Go online (www.hematology.org/volunteerinTanzania)
to read about why Tanzania was selected as the next site and to learn more about how
to volunteer. The volunteer initiative at Muhimbili National Hospital represents a special
opportunity for ASH members to share their time and expertise to advance patient care
in an exceptionally high need area of the world. If you are interested in learning more
about Muhimbili National Hospital in Dar es Salaam, Tanzania, or volunteering your time
and expertise, please contact Chase Willett, ASH International Programs Specialist, at
[email protected].
Honor Your Mentor by Nominating Him or Her
for a Mentor Award
Mentorship, as ASH President Dr. Jan Abkowitz writes about in her column, is one of
the most important determinants of a successful career in hematology. In recognition
of the value the Society places on mentorship, the ASH Mentor Award was created
to reward outstanding mentors in the hematology community. Superb mentors from
any of the different branches of hematology are eligible for this award, including adult
or pediatric hematologists; academic or community practitioners; basic, clinical, or
translational researchers; hematopathologists; transfusion medicine specialists; and
individuals working in industry or government. Each year an award of $5,000 and a
plaque will be presented to two outstanding mentors. Nomination packages are due
April 4. Get more information at www.hematology.org/Awards/Mentor/2505.aspx.
The Hematologist:
ASH News and Reports
n e w s
Hematologist
a nd
r e p o r t s
THE
A S H N e w s and R e p o rt s ®
ASH Opposes NCAA Policy Requiring Screening for Sickle Cell Trait
I SS N 1 5 5 1 - 8 7 7 9
Last March, we reported on the National Collegiate Athletic Association (NCAA) requiring screening for sickle cell trait
in Division I institutions. This issue continues to generate controversy, and on January 19, the NCAA approved a policy
requiring Division III institutions to mandate screening for sickle cell trait on all incoming student athletes. This policy is an
expansion of the screening policy already in place in Divisions I and II. Just as ASH opposed the policy for Division I and
II, the Society believes the NCAA policy is medically groundless and is focused more on protecting the NCAA from legal
liability than on protecting the health of student-athletes.
Editor-in-Chief:
Charles Parker, MD
University of Utah
Salt Lake City, UT
Contributing Editors:
Pamela S. Becker, MD, PhD
University of Washington
Seattle, WA
Prior to the vote, ASH worked with leaders of several Division III institutions in an effort to urge the NCAA to reassess the
policy and consider the recommendations outlined in ASH’s Policy Statement on Screening for Sickle Cell Trait and Athletic
Participation, including specifically mandating athletic programs to adopt universal preventive interventions in their training
programs designed to protect all athletes from exertion-related illness and death. ASH’s advocacy contributed to a very
close vote after a 45-minute debate.
John C. Byrd, MD
The Ohio State University
Columbus, OH
ASH will continue to engage in a dialogue with the NCAA about how both organizations can work together to protect
athletes, namely by supporting further research on the relationship between sickle cell trait and exertion-related illness and
by educating NCAA trainers, coaches, and athletic departments on how to protect all student-athletes comprehensively from
exertion-related injuries.
Robert Flaumenhaft, MD, PhD
Harvard Medical School
Boston, MA
Jason Gotlib, MD, MS
Stanford Cancer Center
Stanford, CA
Peter Johnson, MD
Southampton General Hospital
Southampton, United Kingdom
ASH Bridge Grant: Applications for Second Round Due April 5
In response to the impact of NIH funding cuts on hematology, ASH will assist unfunded R01 grant applicants through
one-year, $100,000 awards designed to help sustain the recipient’s research. In 2013 and for the next two years, the ASH
Bridge Grant program will provide at least 30 one-year awards annually. ASH members who applied for an NIH R01 grant or
equivalent but were denied funding due to budget cutbacks are eligible to apply. Applications for the second round of awards
are due April 5. Learn more about the ASH Bridge Grant program at www.hematology.org/Awards/Bridge-Grants/8669.aspx.
Mark J. Koury, MD
Vanderbilt University
Nashville, TN
Peter Kurre, MD
Oregon Health & Science University
Portland, OR
Xavier Leleu, MD, PhD
Service des Maladies Du Sang
Hopital Huriez, CHRU
Lille, France
20 Early-Career Hematologists Set to Gain Invaluable
Translational Research Tools
Pete Lollar, MD
Emory Children’s Center
Atlanta, GA
ASH and the European Hematology Association (EHA) have
selected 20 early-career hematologists in the Translational Research
Training in Hematology (TRTH) program. Now in its fourth year,
TRTH provides junior researchers from around the world with an
unique, yearlong training and mentoring experience with the goal
of fostering the next generation of global leaders in translational
research. The TRTH program begins with a week-long course held
March 16-23, at a learning center near Milan, Italy, followed by a
meeting at the EHA Annual Congress in June, and finally a meeting
at the ASH annual meeting in December, where trainees present
the status of their research. To learn more about the TRTH program,
visit www.hematology.org/Awards/TRTH/2632.aspx. Charles T. Quinn, MD, MS
Cincinnati Children’s Hospital Medical
Center
Cincinnati, OH
Margaret Ragni, MD, MPH
University of Pittsburgh
Pittsburgh, PA
David Steensma, MD
Dana-Farber Cancer Institute
Boston, MA
Gregory M. Vercellotti, MD
University of Minnesota
Minneapolis, MN
Heiko Becker, MD
University Freiburg Medical Center
Ami Bhatt, MD, PhD
Dana-Farber Cancer Institute
Onima Chowdhury, MD
Oxford University
Conrad Russell Cruz, MD, PhD
Baylor College of Medicine
Craig Eckfeldt, MD, PhD
University of Minnesota Medical School
Ann-Kathrin Eisfeld, MD
The Ohio State University
Caroline Furness, MD (BMBChir)
Institute of Cancer Research
Charles Gawad, MD
Stanford University
Managing Editor
Karen Learner
Patrick Hanley, PhD
Baylor College of Medicine
Graphic Designer
grayHouse design
American Society of Hematology
2021 L Street, NW, Suite 900
Washington, DC 20036
Maria Kleppe, PhD
Memorial Sloan-Kettering Cancer Center
[email protected]
Goldi A. Kozloski, PhD
University of Miami Miller School of Medicine
©2013 by the American Society of Hematology.
Moira Michelle Lancelot, MD
Children’s Hospital of Michigan
All materials contained in this newsletter are protected
by copyright laws and may not be used, reproduced,
or otherwise exploited in any manner without the
express prior written permission of The Hematologist:
ASH News and Reports. Any third-party materials
communicated to The Hematologist become its
copyrighted property and may be used, reproduced,
or otherwise exploited by The Hematologist.
Fabienne McClanahan, MD
Barts Cancer Institute
Contributing authors have declared any financial
interest in a product or in potentially competing
products, regardless of the dollar amount. Any such
financial interest is noted at the bottom of the article.
Daniel Pollyea, MD
University of Colorado
Klaus Metzeler, MD
University of Munich, University Hospital Großhadern
Teresa Mortera-Blanco, PhD
Karolinska Institutet
Lindsay Anne Rein, MD
Duke University Medical Center
Dr. Parker has no relevant conflicts of interest to
disclose.
Jamshid Sorouri Khorashad, MD, PhD
Huntsman Cancer Institute, The University of Utah
Frank Stegelmann, MD
University Hospital of Ulm
David Sykes, MD, PhD
Massachusetts General Hospital
The Hematologist:
ASH News and Reports
3
ASH does not recommend or endorse any specific tests, physicians, products, procedures, or opinions, and disclaims any
representation, warranty, or guaranty as to the same. Reliance on any information provided in this article is solely at your own risk.
Ask the Hematologists
P. Brent Ferrell, MD, 1 and Mark J. Koury, MD 2
1. Clinical Fellow, Division of Hematology/Oncology, Vanderbilt University
2. Professor of Medicine, Division of Hematology/Oncology, Vanderbilt University and Veterans Affairs Tennessee Valley Healthcare System
Patient History
A 64-year-old man had a history of two years of weight
loss and mild normocytic anemia, but over the preceding
two months, worsening polyarthritis, fatigue, and anemia
(Hgb 8.6 g/dL, Hct 25%, MCV 91 fL) were noted. The
reticulocyte count was 1.4 percent with a normal WBC and
normal platelet count. He had normal serum cobalamin,
methylmalonate, LDH, RBC folate, and negative hepatitis
serologies. Laboratory tests were consistent with normal
renal, thyroid, and liver function. Abnormal laboratory tests
included an erythrocyte sedimentation rate of 87 mm/h,
serum C-reactive protein (CRP) of 145 mg/L, haptoglobin
of 447 mg/dL, and serum albumin of 2.5 g/dL. Iron studies
showed a serum iron of 23 ug/dL, TIBC of 209 ug/dL,
transferrin saturation of 11 percent, and serum ferritin of
299 ng/mL. He was transfused with two units of packed
erythrocytes, begun on low-dose prednisone, and referred
for evaluation of anemia.
The Question
What is your approach to the diagnosis and management of
the anemia of chronic inflammation (ACI)?
Our Response
Overview
The traditional disease categories associated with ACI are
malignancy, infection, and connective tissue disorders.
When excess cytokine production is a pathologic
manifestation, ACI may be associated with such processes
as severe heart failure and poorly controlled diabetes that
fall outside of the customary listing of chronic inflammatory
diseases. ACI is often subtle and insidious in onset,
presenting as a mild, persistent anemia that may worsen
over time. Causes of the underlying inflammation such as
rheumatoid arthritis may be obvious, or the basis of the
inflammation may not be immediately apparent as in cases
of occult malignancy or chronic infection.
Pathophysiology
Multiple mechanisms are responsible for the development of
ACI.1-3 Although erythrocytes in ACI have slightly shortened
survivals, the following three mechanisms, mediated by
inflammatory cytokines, exert major effects in sequential
periods of erythropoiesis (Figure): 1) inhibited survival and
differentiation of erythroid progenitor cells; 2) suppressed
erythropoietin (EPO) production; and 3) hepcidinmediated sequestration of reticuloendothelial iron. Chronic
inflammatory states increase production of cytokines
such as IL-1, TNF-α, and interferon-γ that directly inhibit
the survival and differentiation of erythroid progenitor
cells.1,2 Inflammatory cytokines suppress EPO production,
decreasing plasma EPO concentration and increasing
apoptosis of erythroid cells in the EPO-dependent stages of
differentiation (Figure).4 Finally, the inflammatory cytokines
IL-6 and members of the bone morphogenetic protein (BMP)
family diminish serum iron concentration by inducing
transcription of hepcidin, the master regulator of iron
homeostasis.3 Hepcidin exerts its effects primarily through
interaction with the cellular iron exporter, ferroportin,
expressed on the basolateral surface of enterocytes and
on reticuloendothelial cells. Binding to hepcidin induces
endocytosis and degradation of ferroportin thereby
restricting gastrointestinal iron absorption and impairing
macrophage export and recycling of iron from phagocytosed
senescent erythrocytes. The trapping of iron in
reticuloendothelial cells accounts for the characteristic ironladen macrophages observed in ACI bone marrow aspirates
4
stained with Prussian blue. Because iron absorption and
iron recycling are impaired, plasma iron concentration is
low, and transferrin saturation is often subnormal (as in
our case), resulting in a functional iron deficiency state
with consequent suboptimal delivery of iron to maturing
erythroblasts. Interpretation of transferrin saturation must
also take into account the fact that transferrin is a negative
acute phase reactant, and as such, the serum concentration
is often subnormal or at the lower end of the normal range in
patients with ACI (as illustrated in our case).
Diagnostic Considerations
In most instances, ACI is normocytic, normochromic, but
approximately one-third of cases fall into the microcytic,
hypochromic morphological classification. In the latter
cases, functional iron deficiency as a consequence of excess
hepcidin production dominates the pathophysiology, and
review of the peripheral blood film reveals features similar
to other processes, such as iron deficiency or thalassemia,
that affect production of heme or globin. ACI is typically a
mild-to-moderate hypoproliferative process manifested as
grade I or grade II anemia. If more severe, (grade III or worse,
hemoglobin < 8.0 gm/dL), the anemia is likely multifactorial
with other processes, such as concurrent gastrointestinal
bleeding contributing to the etiology. Blood loss and
inflammation may coexist, especially in patients with renal
failure on hemodialysis, in patients with gastrointestinal
malignancy or inflammation, or in patients with arthritis
treated with corticosteroids or non-steroidal antiinflammation drugs. In those cases, determining the relative
contributions of absolute iron deficiency and functional iron
deficiency can be challenging without performing a bone
marrow analysis.
Serum ferritin concentration is less than 20 ng/mL in
uncomplicated iron deficiency anemia. Although as an acutephase protein, the ferritin concentration can be driven into
the normal range by the underlying inflammatory process, a
ferritin concentration greater than 150 ng/mL is rare in ACI
patients who have concomitant absolute iron deficiency. As
noted above, low serum iron is characteristic of ACI, and
low serum transferrin concentration and low transferrin
saturation are also observed routinely in ACI.
Transferrin receptor (TfR) expression is regulated posttranscriptionally by intracellular iron concentration through
the iron regulatory element (IRE)/IRE binding protein
(IREBP) system. When intracellular iron concentration is
low, the IRE/IREBP system stabilizes TfR mRNA, thereby
Figure
Inhibited Survival
and Differentiation
Supressed
EPO Production
increasing translation and protein expression. The effect
of intracellular iron concentration on TfR production led
to development of a clinical test of iron status. In this
case, the concentration of TfR in plasma (soluble TfR or
sTfR) serves as a surrogate marker of iron status (i.e., the
concentration of sTfR is elevated in absolute iron deficiency).
Subsequent studies suggested that the sensitivity of the
assay in distinguishing absolute iron deficient states from
inflammatory processes that affect iron metabolism can be
improved by calculating the sTfR index by dividing the sTfR
concentration by the log of the serum ferritin concentration.
Another proposed method for identifying iron deficiency
is to measure reticulocyte hemoglobin concentration
(CHr) by flow cytometry. As the most recently produced
1 percent of erythrocytes in the blood, the reticulocytes
are the subpopulation most affected by iron deficiency at
the time the blood sample is obtained, and decreased CHr
is a sensitive indicator of iron-restricted erythropoiesis.5
Combining CHr with sTfR index has been used to improve
the identification of absolute iron deficiency in patients
with inflammation.5 While these studies may have value is
some particularly problematic cases, their clinical utility is
relatively modest. This interpretation is based on the fact
that functional iron deficiency plays an important role in the
pathophysiology of ACI, and patients with functional iron
deficiency, without absolute iron deficiency, may benefit
from supplemental iron. Therefore, the practical value of
distinguishing functional iron deficiency from absolute iron
deficiency is arguable because iron supplementation can be
therapeutic in either case.
Treatment
Although many patients have mild anemia that does
not require treatment, establishing a diagnosis of ACI is
important as doing so implies an ongoing inflammatory
process, the etiology of which should be investigated.
Furthermore, effective treatment of the underlying disease
results in improvement or resolution of the anemia. In some
instances, however, the underlying disease may be resistant
to therapy (e.g., poorly responsive malignancy or refractory
connective tissue disease). In such cases, red cell transfusion
support and therapy that targets the pathophysiologic
mechanisms that underlie ACI (Figure) are the mainstays of
management. ACI may respond to recombinant human EPO
(rhEPO),6 but the response may be blunted by concomitant
functional iron deficiency. Iron supplementation, with a
goal transferrin saturation of > 20 percent, may increase the
effectiveness of rhEPO, and some patients respond to iron
supplementation in the absence of rhEPO support. Infused
Increased RES
Iron Sequestration
Stage of Erythroid Differentiation
HSC
BFU-E
CFU-E
Pro EB
Baso EB
Poly EB
Ortho EB
RET
RBC
l — EPO dependence — l l — Hemoglobin synthesis — l
Key
BFU-E: Burst-forming unit-erythroid
CFU-E: Colony-forming unit-erythroid
Pro EB: Proerythroblast
Baso EB: Basophilic erythroblast
Poly EB: Polychromatophilic erythroblast
Ortho EB: Orthochromatic erythroblast
RET: Reticulocyte
Mechanisms of inflammatory cytokine inhibition of erythropoiesis in ACI.
Three mechanisms (shown in red) that are mediated by inflammatory cytokines are
key elements in the pathophysiology of ACI and represent potential therapeutic
targets. The main period of erythropoiesis in which each of the respective
mechanisms has its major effect is indicated by arrows. The stages of erythropoiesis
begin with the hematopoietic stem cell (HSC) and extend through the mature
erythrocyte (RBC). The periods of erythropoietin (EPO) dependency and hemoglobin
synthesis are shown below those specific stages of differentiation.
The Hematologist:
ASH News and Reports
t h e
p r a c t i c i n g
h e m a t o l o g i s t
T H E
H E M AT O L O G I S T
A D V O C ATE
HEADLINES FROM
Washington
NIH Budget Situation Remains Uncertain
iron rather than oral iron supplementation is often needed
as hepcidin restricts gastrointestinal iron absorption. The
desired response (increase in transferrin saturation) to iron
supplementation, however, is relatively short lived, and
repeated iron infusion puts patients at risk for iatrogenic
hemochromatosis1,2 because the high hepcidin prevents
the recycling of this iron. Anti-TNF-α agents have been
shown to increase hemoglobin concentration in patients
with ACI independent of an effect on EPO concentration.7
Looking forward, suppression of hepcidin activity has
been examined in animal models. In a mouse model of
ACI, antibodies to hepcidin also required the concurrent
administration of EPO to reverse the anemia,8 whereas
inhibition of hepcidin transcription, by blocking BMP
receptor activation or downstream signaling, prevented
and reversed ACI without the need for exogenous EPO
administration.9,10 As more therapeutic options become
available, well-designed clinical studies will be needed to
determine the optimal pharmacologic approach to the
management of ACI.
The patient described in the introduction was diagnosed
with seronegative rheumatoid arthritis, and two months after
beginning therapy with prednisone and methotrexate, his
arthritis symptoms had improved and his Hgb was 12.5 g/dL.
1. Weiss G, Schett G. Anaemia in inflammatory rheumatic
diseases. Nat Rev Rheumatol. 2012. Epub ahead of
print.
2. Davis SL, Littlewood TJ. The investigation and
treatment of secondary anaemia. Blood Rev.
2012;26:65-71.
3. Ganz T, Nemeth E. Hepcidin and iron homeostasis.
Biochim Biophys Acta. 2012;1823:1434-1443.
4. Miller CB, Jones RJ, Piantadosi S, et al. Decreased
erythropoietin response in patients with the anemia of
cancer. N Engl J Med. 1990;322:1689-1692.
5. Thomas C, Thomas L. Biochemical markers and
hematologic indices in the diagnosis of functional iron
deficiency. Clin Chem. 2002;48:1066-1076.
6. Pincus T, Olsen NJ, Russell IJ, et al. Multicenter
study of recombinant human erythropoietin in
correction of anemia in rheumatoid arthritis. Am J
Med.1990;89:161-168.
7. Papadaki HA, Kritikos HD, Valatas V, et al. Anemia of
chronic disease in rheumatoid arthritis is associated
with increased apoptosis of bone marrow erythroid
cells: improvement following anti-tumor necrosis
factor-α antibody therapy. Blood. 2002;100:474-482.
8. Sasu BJ, Cooke KS, Arvedson TL et al. Antihepcidin
antibody treatment modulates iron metabolism and
is effective in a mouse model of inflammation-induced
anemia. Blood. 2010;115:3616-3624.
9. Steinbicker AU, Sachidanandan C, Vonner AJ, et al.
Inhibition of bone morphogenetic protein signaling
attenuates anemia associated with inflammation. Blood.
2011;117:4915-4923.
10. Theurl I, Schroll A, Sonnweber T, et al. Pharmacologic
inhibition of hepcidin expression reverses anemia of
chronic inflammation in rats. Blood. 2011;118:4977-4984.
Dr. Ferrell indicated no relevant conflicts of
interest. Dr. Koury is a consultant with Keryx
Biopharmaceuticals, Inc. and the Pharmaceutical
Division of Japan Tobacco, Inc.
The Hematologist:
ASH News and Reports
A
lthough Congress and the Obama administration reached an agreement to delay the automatic across-theboard spending cuts (“sequestration”) to the National Institutes of Health (NIH) and other federal agencies
and programs that were scheduled to take effect at the beginning of the year, federal funding for biomedical
research remains in jeopardy.
While the agreement reached in January protects the country from going over the so-called fiscal cliff until March
1, NIH and other non-defense discretionary programs are not safeguarded from either future cuts or the new cliff
deadline. As this issue of The Hematologist went to press, congressional negotiators were continuing efforts to reach
a deal to avert these catastrophic across-the-board spending cuts, but it was uncertain if a deal could be reached by
the March 1 deadline, if the cuts would be again delayed temporarily, or if the cuts would be allowed to take effect.
To complicate matters even more, fiscal year (FY) 2013 funding for NIH has only been provided through March 27,
and Congress must finalize the FY 2013 budget before the temporary funding expires. Additionally, as this issue
went to press, it was expected that the fiscal year (FY) 2014 budget request from the Obama administration would
be delayed. By law, the budget request is due before Congress by the first Monday in February. However, because
of ongoing uncertainty over the fiscal cliff and sequestration, it was expected that this year’s request would be
postponed until mid-March. The late delivery of the President’s request to Capitol Hill will likely mean a delay in the
entire budget process for FY 2014 and lingering budget uncertainty for NIH.
What’s the takeaway?
Key congressional decisions impacting biomedical research funding remain unresolved.
Advocacy by Hematologists Crucial to Safeguarding
Biomedical Research Funding
L
ast year, ASH launched an aggressive multifaceted strategy to protect research funding and take a balanced
approach to reducing the deficit without further cutting NIH and other core federal programs. This approach
involved enhanced advocacy efforts, including a “Fly-In Day,” advocacy leadership training, and online advocacy
campaigns, letters-to-the-editor; the creation of the ASH Bridge Grant program; and expanded communication
efforts to educate ASH members, the media, and the public about the value of research funding.
This year ASH will continue and expand its efforts. In the coming weeks, for example, ASH will:
• Initiate a campaign to educate newly elected Members of Congress about the NIH so that they understand
federal funding for NIH protects the well being of this country, generates jobs, and helps secure America’s
position as a global leader in science and medicine
• Conduct Capitol Hill Days with the ASH Government Affairs and Scientific Affairs Committees
• C
oordinate online advocacy campaigns so that all ASH members can quickly and easily contact their Members
of Congress and share ASH’s message
• Work in coalition with others in the research community to advocate for biomedical research.
What you can do:
• Join the ASH Grassroots Network (www.hematology.org/takeaction) so that you get advocacy alerts and updates.
• C
ontact your Representative and Senators by visiting the online ASH Advocacy Center
(www.hematology.org/takeaction).
• A
ttend a local “Town Hall Forum” with your Member of Congress and ask about support for research
(www.hematology.org/townhall).
• S
hare your story about how NIH funding impacts your research and/or your patients; visit
www.hematology.org/fightnow and click on the “Tell Your Story” link.
What’s the takeaway?
Advocacy by hematologists and members of the research community is critical to obtaining Congressional
support for biomedical research funding.
One-Year ‘Doc Fix’ Included in Fiscal Cliff Package
T
he fiscal cliff legislation passed by the Congress on January 1 includes a one-year payment patch for
physicians who treat Medicare patients. The deal blocks the scheduled 27 percent payment cuts to Medicare
physicians that were slated to start January 1 and keeps rates frozen at current levels for one year. The legislation
also defers, for two months, sequestration cuts that included an additional two percent reduction in Medicare
payments. ASH encourages all clinicians to join the Society in continuing to pressure Congress to
repeal permanently the Sustainable Growth Rate (SGR) formula by visiting the ASH Advocacy Center
(www.hematology.org/takeaction) and sending an email to your elected officials.
5
A Conversation With the New Editors of Blood
Editor’s Note: ASH News Daily contributor Jose Bufill, MD, sat down with the new editors of Blood to discuss
their vision for the future of the world’s premier hematology journal and what inspires their work. The first
part of this interview appeared in ASH News Daily, published in conjunction with the annual meeting, and is
available online (www.nxtbook.com/nxtbooks/customnews/ashnewsdaily2012_Tuesday); below is the remainder
of their conversation.
of the globe. The international perspective of the Journal
will require a considerable level of active involvement
of associate editors and editorial board members from
different parts of the world, which we consider essential.
I am in fact the first non-American editor-in-chief in an
American tradition of more than 60 years. I am convinced
that there is considerable and growing interest in Europe,
Asia, and South America in Blood. There is great growth
potential there!
Q: Will you reach out to more international physicians to
serve as editorial board members?
Dr. Löwenberg: The need for an internationalized
editorial board is a trend that has been actively initiated
by my predecessors at Blood. The treatment approach
in a patient with a particular subtype of leukemia is
fundamentally identical for patients in America, Asia, or
Europe. And scientific knowledge obviously has generic
value independent of geography. Blood as the premier
journal in hematology by virtue of its role, has acquired a
high-profile position as the leading journal of our field. We
have just begun to review and revisit various aspects of
the role of the editorial board, and in this respect we will
also pay attention to the challenge of Blood’s progressively
evolving international presence.
Q: You’ve served on the editorial boards of several journals
in the United States and Europe. Do you view the “role”
of the medical journal simply as a means to disseminate
new information – a neutral platform, so to speak – or as a
means to actively educate? Is there a difference?
Dr. Löwenberg: Dissemination and education should go
together. What Blood brings to the table should make
a difference to our readers. Our content and how it’s
presented should help them grow in their understanding
of the biology and pathology of hematologic disorders. We
aspire to serve Blood readers by offering a resource with
information that is right, novel, and impactful.
Dr. Berliner: And I might add, that we want to offer
context. When there are differences of opinion regarding a
research finding or clinical approach, we’ll try to present
both sides and let readers draw their own conclusions.
Q: Dr. Löwenberg, you’ve mentioned the notion of Blood’s
“impact” several times in your comments. How do you
feel about the “impact factor” and its effect on scientific
publishing?
Dr. Löwenberg: I would yield to the expert!
Dr. Berliner: The “impact factor” was originally intended
to keep track of how often a journal was requested from a
library. Librarians wanted to know how many copies of a
journal they needed so that readers would not complain!
It seemed to be a good idea at the time. Today it refers to
the number of citations a given article receives in other
publications. In a sense, it asks: “Do people pay attention
to the articles that appear in this journal?” The results
never used to be published. It has now acquired a level of
importance that requires us to take it seriously. It should
be recognized, however, that it is not a good measure of
quality, and also that it is subject to manipulation.
Q: What proportion of articles will report original research
versus review articles under your tenure?
Dr. Löwenberg: There is no rigid, predefined proportion
for this. An issue of Blood may contain from one to three
review articles, a special article such as “How I Treat,”
plus several original research articles covering any area in
hematology.
Q: Do you plan to make changes to the graphics in the
journal, both online and in print?
Dr. Löwenberg: Yes, this will be a continuous effort.
The developments in digital publishing and readership
6
behavior change so quickly! Currently there are plans
to redesign Blood’s website. Blood will launch hubs for
related aggregated content that will serve readers with
particular common interests (more about this below). Our
first two hubs will be concerned with pediatric hematology
and thrombocytopenia. The Blood app has been available
since 2012 and is actively used. And we will also develop
the print journal. I will refer readers to our website, but I
should also mention the new look of Blood in print in 2013.
Dr. Berliner: Yes! We’ll continue to draw from the articles
for cover art, connecting the cover with the content.
Hematology lends itself to beautiful graphics, and the
covers are a highlight of the journal. We’ll also add a
highlighted box of “key points” appearing next to the
abstract that summarize the most important take-home
lessons of each article.
Q: Is this an acknowledgment of our shortened attention
spans?
Dr. Berliner: Draw your own conclusions …
Q: What are you looking for in articles submitted to Blood?
What advice would you give to prospective authors?
Dr. Löwenberg: We are looking for articles that are novel,
original, and impactful. Those are the three ingredients,
the three legs of the stool. Proportions of each of these
ingredients might vary, but this is what we would like to
see.
Q: There is stiff competition not only for “eyeballs” but
also for quality articles. How can Blood attract high-impact
articles and authors?
Dr. Berliner: The best way to attract good articles is to
have a good journal. Blood has a very strong reputation as
a premier journal with excellent peer review that presents
outstanding clinical and basic research. But you are right,
competition is increasing. We will recruit outstanding
content and emphasize the advantages of publishing in
Blood. We have a rapid review process that can offer fast
turn-around. In addition, articles accepted to Blood are
made available online on a daily basis.
Q: Dr. Löwenberg, will the editorial board of Blood under
your tenure reflect this increasing “internationalization” or
“globalization” of hematology?
Dr. Löwenberg: While ASH as the publisher and owner
is American, Blood as a matter of fact is an international
journal. Our readers and authors represent all corners
Q: People do get sick in the same way around the world,
but access to care – to effective medications, to trained
physicians and support services – varies widely. How can
Blood address the needs of hematologists in developing
countries? Is this a priority for you?
Dr. Löwenberg: For Blood this is also a matter of
education. The American Society of Hematology through
its International Members Committee is actually playing
a major role in this area by making Blood available in less
privileged areas and by its outreach educational activities.
Blood is interested in studies on major health-care issues
in other parts of the world, and we will continue to publish
interesting reports about hematologic health-care issues in
developing countries.
Q: Your experience in medical practice and research spans
two continents. Can you contrast the pros and cons of the
European and American systems? Are clinical trials easier
to carry out one place or the other?
Dr. Löwenberg: In the 70s and 80s of the last century, the
major therapeutic clinical trials were conducted in the
United States by the leading cooperative groups and major
institutions. In the recent decennium there has been a
shift toward the major trials being conducted in Europe.
The latter trend reflects a highly unfortunate development
since clinical trials with adequate enrollment remain a
cornerstone for evaluating new diagnostic procedures
and novel treatment approaches. This shift is most likely
caused by differences in the health-care system that
keeps private physicians from referring their patients
to institutions that have the required infrastructure and
advanced know-how for clinical trials.
Q: Some physicians in the United States are concerned
about the growing “centralization” of health-care policy in
our country. Should they be? Is centralization of health-care
policy a problem or a solution?
Dr. Löwenberg: I grew up in a country where the health-care
system is socialized in the sense that it ensures equal access
to health care for the citizens and ensures a certain basic
quality standard throughout the society of the country. I see
that as an advantage. There is however also an economic
advantage. In such a regulated system, we spend a smaller
health-care budget than the United States does.
Q: Dr. Berliner, your new editor-in-chief works six time
zones ahead of you. How will this affect your collaboration?
What practical advantages or challenges arise from the time
differences?
Dr. Berliner: So far this hasn’t presented much of a
problem. I get up early; he seems to often stay up late! Our
The Hematologist:
ASH News and Reports
emails fly back and forth at all hours, and I often forget
that we are on separate continents.
remember a particular moment in time when I decided to
take the plunge and apply to medical school.
Dr. Löwenberg: I am grateful to Nancy for accepting this
position. We have been friends for years, and we make a
great team!
Dr. Löwenberg: Right after graduating from medical school,
I became a PhD student in one of the leading research
institutes in Europe in Rijswijk-Rotterdam. These were the
pioneering days of experimental hematology. I became
excited about the prospects and challenges of the newest
developments. This was in the early days of stem cell
research – the discovery of spleen colony-forming assay,
in vitro colony-forming assays, the media with colonystimulating activity that contained CSFs – and the very
first successes of clinical stem cell transplantation. There
was excitement all over the place. My supervisor, Dirk van
Bekkum, was involved in one of the first successful human
allogeneic bone marrow transplantations in an infant with
severe combined immunodeficiency disease. He worked
in radiobiologic research and stem cell research. I decided
then that I wanted to work at the interface of preclinical
research and clinical advances. This is how it happened, and
why and how I ended up in hematology.
Q: You’re a teacher working in both laboratory and
clinical settings …
Q: If not a physician, then what professional work would
you have chosen?
Q: Any other comments you might like to make?
Dr. Berliner: I enjoy patient care and research, and
the decision to go into academic medicine reflected
my desire not to give either of them up. My career has
morphed many times over the years, but I have always
loved being able to mix research, patient care, and
teaching, although the mix has changed over time. Most
of all, my passion is mentoring fellows and junior faculty.
Dr. Löwenberg: Probably in any field where I would meet
the challenge of innovation and also in a setting where I
would be able to work with people. Thus, I could have found
myself in another challenging academic area, but perhaps it
could also have been as an entrepreneur in business.
Q: What will your role be in editing Blood? How will you
and Dr. Löwenberg share the hard work of editorship?
How will your responsibilities differ?
Dr. Berliner: On a day-to-day basis, we are both
responsible for the triage of new submissions and
selecting which associate editor ought to review a given
manuscript. We both answer pre-submission inquiries.
The rest is a work in progress. I have to say that I’m
delighted to partner with Bob in this adventure. We’ve
been good friends and colleagues for many years.
Q: Dr. Löwenberg, you too are both a clinician and
a scientist in the field of myeloid leukemia. Can you
comment on a pivotal experience in your life that moved
you to enter the field of medicine? A defining moment or
experience?
The Hematologist:
ASH News and Reports
Q: Dr. Berliner, can you recall a decisive moment in your
life – a person or event – that moved you toward medicine?
Dr. Berliner: Well, I was a comparative literature major in
college. But my dad was my hero, and he was a physicianscientist, so I tried to keep options open in case I decided
for science rather than the humanities. But I don’t
Q: Was he a hematologist?
Dr. Berliner: Actually, he was a renal physiologist, who was
one of the scientists to describe the counter current multiplier
system by which urine is concentrated. After serving as the
deputy director for science at the National Institutes of Health,
he became dean at the Yale School of Medicine.
Q: And you attended Harvard for medicine residency. You
were the first woman chief resident there.
Dr. Berliner: But I went to Yale for college and medical
school. I was on the Yale faculty for more than 20 years,
and my husband still teaches in the School of Architecture
there. Yale is family.
Dr. Löwenberg: Blood is a monument, and it is a reference
point in the professional life of any hematologist. We are
well aware of this inheritance. I am particularly grateful to
Cindy Dunbar, my predecessor for the past five years. She
and her team have done an outstanding job! While science
and medicine are changing profoundly, we are committed to
take Blood forward in the interest of our field and serve the
hematology community worldwide in the best possible way.
We want to improve wherever we can. Therefore, I encourage
everyone to get in touch with us. Readers or authors,
clinicians or basic scientists, wherever you may live and work
anywhere in the world, we want you to share your creative
ideas and suggestions about the content and the future
direction of our journal! Don’t hesitate to speak out!
7
The Cat’s Out of the Bag: How Mitochondrial Heme is Exported
Chiabrando D, Marro S, Mercurio S, et al. The mitochondrial heme exporter FLVCR1b mediates erythroid differentiation. J Clin Invest. 2012;122:4569-4579.
B
“
etween animal and human medicine there is no dividing line – nor should
there be. The object is different but the experience obtained constitutes the
basis of all medicine.” – Rudolf Virchow (1821-1902)1
Figure
In support of Virchow’s perspective, a number of notable advances in hematology have
their origins in observations made in animals. For example, cats infected with feline
leukemia virus C (FLVC) develop red cell aplasia, and investigation of the pathobiology
of this process led to identification of the receptor for FLVC (FLVCR1) as a cytoplasmic
heme exporter.2-4 Free heme is toxic, and FLVCR protects erythroid progenitors from
injury by exporting, from the cytoplasm, heme that is produced in excess of that
required for pairing with globin, cytochromes, and other proteins that use heme as a
prosthetic group (Figure). But the heme biosynthetic pathway ends in the mitochondria
(Figure), so how does newly synthesized heme move from the mitochondria to the
cytoplasm? The answer to that question can again be traced to the study of cats,
as Deborah Chiabrando and colleagues, in the laboratory of Emanuela Tolosano at
the University of Torino, have identified an isoform of FLVCR1 that mediates efflux of
mitochondrial heme into the cytoplasm.
Examination of the DNA structure of FLVCR1 suggested to the authors the possibility
of alternatively spliced transcripts, and their hypothesis was confirmed when they
ultimately identified an isoform (that they named FLVCR1b) that consists of amino
acids 277-555 of FLVCR1 (renamed FLVCR1a in their paper to distinguish it from
the newly discovered FLVCR1b). In mice, Flvcr1b is ubiquitously expressed, with the
highest transcript levels in the brain, heart, muscle, spleen, and bone marrow. When
overexpressed in vitro, Flvcr1b shows a strikingly different sub-cellular localization
compared with Flvcr1a. Flvcr1b has a mitochondrial targeting sequence and is found
enriched in mitochondria, whereas Flvcr1a is a plasma membrane protein (Figure).
Overexpression of Flvcr1b leads to intracellular heme accumulation, while silencing
of expression results both in heme accumulation exclusively in the mitochondria and
in termination of erythroid differentiation. Thus, normal erythropoiesis depends upon
FLVCR1b-mediated regulation of mitochondrial heme efflux without which hemoglobin
and other hemoproteins cannot form (Figure). Remarkably, mice lacking Flvcr1a
but expressing Flvcr1b have normal erythropoiesis. The Flvcr1a-/Flvcr1b+ mice are
characterized phenotypically by edema, hemorrhage, and skeletal abnormalities. These
observations suggest that the block in erythroid differentiation observed in the original
Flvcr1-/- knockout model (that eliminated both isoforms)4 was due to aberrant regulation
of mitochondria heme regulation due to absence of Flvcr1b function rather than to
cytoplasmic accumulation of heme due to loss of Flvcr1a activity. On the other hand,
the edema and hemorrhage that characterizes the Flvcr1a-/Flvcr1b+ model may be a
consequence of endothelial cell injury due to cytosolic accumulation of heme. This
same process may account for the observed skeletal deformities as endothelial cell
injury could lead to tissue hypoxia, thereby impairing cartilage development.
The exquisite control of heme metabolism and the potential toxicities associated with
excess heme accumulation are highlighted by this paper (Figure). The hypochromic,
microcytic anemias that are familiar to all hematologists are due to abnormal of
production of heme (e.g., iron deficiency) or globin (e.g., thalassemia). But are there
anemias in humans that are due to dysregulation of heme trafficking? If so, what
is the clinical phenotype? Is there a human counterpart of the red cell aplasia that
characterizes infection of cats with feline leukemia virus? To answer these questions,
an understanding of the fundamental mechanisms involved in heme homeostasis is
essential. The rigorous, imaginative studies of Chiabrando and colleagues have further
defined the participants in this intricate process.
1. Klauder JV. Interrelations of human and veterinary medicine — discussion of some
aspects of comparative dermatology. N Engl J Med. 1958;258:170-177.
2. Quigley JG, Burns CC, Anderson MM, et al. Cloning of the cellular receptor for
feline leukemia virus subgroup C (FeLV-C), a retrovirus that induces red cell aplasia.
Blood. 2000;95:1093-1099.
3. Quigley JG, Yang Z, Worthington MT, et al. Identification of a human heme exporter
that is essential for erythropoiesis Cell. 2004;118:757-766.
4. Keel SB, Doty RT, Yang Z, et al. A heme export protein is required for red blood cell
differentiation and iron homeostasis. Science. 2008;319:825-828.
A model for FLVCR1 isoforms function. A) A schematic representation of heme biosynthesis
is shown. Transferrin-bound iron (Tf-Fe) is taken up by cells through transferrin receptor 1 (TfR1),
and iron is transferred to the mitochondrion for heme biosynthesis. It was reported that the
mitochondrial iron importer MITOFERRIN1 (MFRN1) and ferrochelatase (FECH, the enzyme that
catalyzes incorporation of iron into protoporphyrin IX to form heme) are part of the same complex in
the inner mitochondrial membrane. FLVCR1b could work in association with this complex to allow
heme export out of the mitochondrion for incorporation into new hemoproteins. Heme not used for
hemoprotein synthesis is exported out of the cell through the cell-surface isoform FLVCR1a.
B) During erythroid differentiation, the expression of FLVCR1b in the mitochondrion regulates heme
export into the cytosol, allowing hemoglobinization of erythroid precursors. At the cell membrane,
FLVCR1a regulates the export of heme in excess. The data reported by Chiabrando et al. suggest
that decreased expression of the membrane heme exporter FLVCR1a and increased expression of
FLVCR1b are fundamental for proper differentiation of erythroid progenitors.
The Mitochondrial Heme Exporter FLVCR1b Mediates Erythroid Differentiation. Chiabrando D, Marro S, Mercurio
S, et al. J Clin Invest. 2012; 122(12):4569–4579, doi:10.1172/JCI62422.
Gregory M. Vercellotti, MD
Dr. Vercellotti indicated no relevant conflicts of interest.
8
The Hematologist:
ASH News and Reports
Targeting Chromosome Loss in Down
Syndrome Cells
Irons in the Fire: Developing New Therapies for Iron
Overload
Li LB, Chang KH, Wang PR, et al. Trisomy correction in Down
syndrome induced pluripotent stem cells. Cell Stem Cell.
2012;11:615-619.
Schmidt PJ, Toudjarska I, Sendamarai AK, et al. An RNAi therapeutic targeting Tmprss6
decreases iron overload in Hfe-/- mice and ameliorates anemia and iron overload in murine
b-thalassemia intermedia. Blood. 2012. Epub ahead of print.
D
own syndrome (DS) is the most common viable trisomy
in humans, with several thousand affected infants born
in the United States every year. Patients with DS have a
wide spectrum of clinical problems dominated by cardiac
and developmental abnormalities. Up to 10 percent of DS infants
experience a transient myeloproliferative disorder that can progress
to a rare form of acute megakaryocytic leukemia, whereas pre-schoolage children with DS have an abnormally high risk of developing
acute precursor B-cell leukemia. DS patients with leukemia present
unique management challenges owing to a combination of organ
vulnerability and increased susceptibility to drug toxicity. Progress
in understanding the hematopoietic defects and the molecular basis
of leukemogenesis of DS has been hampered by a lack of a faithful
murine disease model and the problems inherent in comparing
results obtained using cells from different patients.
The recent study by Li and colleagues from the University of
Washington in Seattle now provides evidence for the feasibility
of deriving strictly diploid, induced pluripotent stem cells (iPSCs)
from the trisomic fibroblasts of DS patients. The paper is at once
a technical tour de force and an illustration of the effectiveness of
combining targeted genome engineering approaches with induced
pluripotency. The investigators initially generated iPSCs that were
confirmed to be trisomic for chromosome (chr) 21. Next, they used
an adeno-associated viral vector to insert a dual selectable marker
into a gene located on chr 21 via homologous recombination. By
using a strategy that selects against the vector-bearing chr 21,
clones that had lost a complete copy of chr 21, and were hence
disomic for chr 21, were generated. Subsequent experiments
showed that the derived chr 21 diploid iPSCs had a higher
proliferative rate than their trisomy chr 21 counterparts, but in vitro
hematopoietic differentiation was not consistently different.
As noted above, patients with DS have a several hundred-fold
increased risk of developing megakaryocytic myeloid leukemia in
infancy and acute lymphocytic leukemia in early childhood. In another
recent paper, this one by MacLean and colleagues from Dana-Farber
Cancer Institute in Boston, the authors used isogenic disomic
pluripotent stem cells to investigate differences in hematopoiesis
between stem cells with diploid chr 21 and stem cells with trisomy
chr 21.1 The Dana-Farber group did not engineer their diploid chr
21 cell lines as did the University of Washington group, but instead
isolated spontaneous disomic revertants from human embryonic
stem cell and iPSC clones. Differences in immunophenotype and a
significant increase in progenitor colony formation by chr 21 trisomic
cells compared with chr 21 disomic cells was observed, consistent
with developmental dysregulation of hematopoiesis in DS individuals.
The study by Li offers a unique perspective on advances in genome
engineering, and publication of their strategy for high-efficiency
generation of disomic iPS cells provides investigators with a
valuable tool to use in exploring the pathobiology that underlies the
potentially fatal hematopoietic complications of DS. Looking to the
future, the ability to engineer disomic isogenic iPSCs offers the
possibility of generating autologous hematopoietic grafts for stem
cell transplantation. While much additional work will be needed
to accomplish this futuristic goal, the studies of Li and colleagues
provide a strategy by which the power of stem cell biology can be
harnessed for the benefit of patients with DS.
I
ron is highly toxic because it generates tissue-damaging reactive oxygen species by the Fenton
reaction. Thus, although necessary for life, careful regulation of all aspects of iron metabolism is
critical. A key regulator of iron homeostasis is hepcidin, a peptide hormone produced by the liver.
Hepcidin negatively regulates cellular iron export from macrophages, duodenal enterocytes, and
hepatocytes by promoting degradation of ferroportin, a transmembrane iron exporter. Human diseases
that involve primary or secondary dysregulation of hepcidin include hereditary hemochromatosis (HH)
and b-thalassemia intermedia, respectively. HH is an autosomal recessive disorder caused by mutation
(C282Y homozygosity) in HFE, a key regulator of hepcidin expression. The iron overload of HH is the
result of failed upregulation of hepcidin despite ongoing dietary iron loading, while hepcidin synthesis
is suppressed due to ineffective erythropoiesis in b-thalassemia intermedia. The mechanism whereby
ineffective erythropoiesis suppresses hepcidin expression is largely speculative although trans acting
factors produced in the bone marrow (e.g., GDF-15 and TWSG1) are candidate signaling molecules.
The result of dysregulated suppression of hepcidin is iron overload. Hypothetically, patients with such
seemingly disparate diseases as HH and b-thalassemia intermedia could be treated by pharmacologic
manipulation of hepcidin expression. Indeed, genetic studies using animal models of HH showed
that constitutive expression of hepcidin or deletion of Tmprss6, a negative modulator of hepcidin
expression, could reverse iron overload. In models of b-thalassemia intermedia, targeted deletion of
Tmprss6 decreased iron loading and also reduced ineffective erythropoiesis.
Based upon these and other observations, Schmidt et al. sought to demonstrate that systemic
administration of lipid nanoparticle (LNP)-formulated siRNAs designed to silence Tmprss6 (LNP-Tmprss6)
could increase hepcidin expression and diminish iron uptake in murine models of HH and b-thalassemia
intermedia, while also reducing ineffective erythropoiesis in b-thalassemia intermedia. The first set of
experiments showed that they could, in fact, silence Tmprss6 using LNP-Tmprss6, thereby upregulating
hepcidin mRNA expression in a dose-dependent fashion. A single infusion of LNP-Tmprss6 decreased
Tmprss6 for 14 days, increased hepcidin levels for seven days, and decreased transferrin saturation for
nearly a month. Next, these investigators administered LNP-Tmprss6 to Hfe-/- mice to determine whether
the HH phenotype could be ameliorated. They found sustained decreases in serum iron, transferrin
saturation, and non-heme hepatic iron. There was also an increase in splenic iron, attributed to hepcidininduced sequestration of iron in splenic macrophages, and all of the mice developed a hypochromic,
microcytic, iron-deficient anemia by six weeks after onset of therapy. Notably, patients with Tmprss6
deficiency due to inherited mutations of the gene have a similar phenotype as the treated mice (i.e.,
high serum hepcidin and iron refractory, iron deficiency anemia). The final set of experiments tested the
effects of LNP-Tmprss6 in a murine model of b-thalassemia intermedia (Hbbth3/+). These mice have iron
overload, similar to humans with b-thalassemia intermedia, due to suppression of hepcidin by ineffective
erythropoiesis. As anticipated, LNP-Tmprss6 silenced Tmprss6, increased hepcidin, and decreased
serum iron and transferrin saturation. Most interestingly, however, LNP-Tmprss6 decreased ineffective
erythropoiesis, as evidenced by higher hemoglobin concentration; prolonged red blood cell (RBC)
lifespan; lowered the reticulocyte count; decreased erythropoietin concentration; and reduced splenic
volume. Splenic iron was lower, unlike the Hfe-/- mice, likely because of the reduction in splenic volume.
RBC membrane-bound a-globin, a pathophysiologic consequence of b-thalassemia, was also markedly
decreased, and peripheral blood morphology nearly normalized except for a modest increase in central
pallor. Together, these results suggest that iron plays an important but as yet incompletely understood
role in the pathobiology of thalassemia.
These experiments show the potential of novel therapeutics that manipulate hepcidin expression
for a number of disorders characterized by iron overload, both primary (e.g., HH) and secondary
(e.g., b-thalassemia intermedia). Here, Schmidt et al. explored RNAi therapeutics, but others have
investigated biomimetic “mini-hepcidins”1 and exogenous transferrin in similar animal models.2
Ultimately, such therapies will need to meet a very high standard to supplant phlebotomy, which is both
inexpensive and effective, for the resolution of iron overload in typical HH patients. Most intriguing
is the therapeutic potential of reducing hepcidin expression in b-thalassemia intermedia, where
amelioration of both iron loading and ineffective erythropoiesis is observed.
1. Preza GC, Ruchala P, Pinon R, et al. Minihepcidins are rationally designed small peptides that
mimic hepcidin activity in mice and may be useful for the treatment of iron overload. J Clin Invest.
2011;121:4880-4888.
2. Li H, Rybicki AC, Suzuka SM, et al. Transferrin therapy ameliorates disease in β-thalassemic mice.
Nat Med. 2010;16:177-182.
1. MacLean GA, Menne TF, Guo G, et al. Altered hematopoiesis
in trisomy 21 as revealed through in vitro differentiation of
isogenic human pluripotent cells. Proc Natl Acad Sci USA.
2012;109:17567-17572.
PETER KURRE, MD
Charles T. Quinn, MD, MS
Dr. Kurre indicated no relevant conflicts of interest.
Dr. Quinn indicated no relevant conflicts of interest.
The Hematologist:
ASH News and Reports
9
A New Ripple for Mpl: Eltrombopag for Aplastic Anemia
Olnes MJ, Scheinberg P, Calvo KR, et al. Eltrombopag and improved hematopoiesis in refractory aplastic anemia. N Engl J Med. 2012;367:11-19.
T
hrombopoietin (TPO) is the growth factor that stimulates platelet production through
interaction with its receptor, Mpl, on megakaryocytes. Surprisingly, patients with
immune thrombocytopenia (ITP) exhibit a relative deficiency of TPO and respond to
exogenous stimulation by TPO receptor agonists with increased platelet counts. Two
TPO mimetics, romiplostim and eltrombopag, have been FDA-approved for the treatment of
ITP in patients with an insufficient response to corticosteroids, intravenous immune globulin,
or splenectomy; both bind to c-Mpl at a site distinct from the TPO binding site, and neither
shares homology with TPO. Eltrombopag is an oral drug that activates the Jak-Stat and
MAPK pathways (Figure). A phase III trial of eltrombopag versus placebo demonstrated its
capacity to improve platelet counts, reduce bleeding occurrences, and improve quality of
life in patients with chronic ITP.1 Eltrombopag was also recently granted FDA approval in
November 2012 for patients with hepatitis C, as it effectively supports platelet counts during
treatment with interferon.
1. Cheng G, Saleh MN, Marcher C, et al. Eltrombopag for management of chronic
immune thrombocytopenia (RAISE): a 6-month, randomised, phase 3 study.
Lancet. 2011;377:393-402.
In contrast to patients with ITP, patients with aplastic anemia exhibit markedly elevated TPO
levels, but they still have thrombocytopenia. There are few options for patients with aplastic
anemia who have relapsed after immunosuppressive therapy (IST) with anti-thymocyte
globulin, cyclosporine, and steroids. The salvage therapies include a second course of IST or
an allogeneic stem cell transplant. The former has a poor response rate, and the latter, a high
mortality rate, especially for those who do not have a matched family donor.
5. Ballmaier M, Germeshausen M, Krukemeier S, et al. Thrombopoietin is essential
for the maintenance of normal hematopoiesis in humans: development of aplastic
anemia in patients with congenital amegakaryocytic thrombocytopenia. Ann N Y
Acad Sci. 2003;996:17-25.
As has been extensively studied, thrombopoietin receptors are expressed by primitive
hematopoietic stem cells, and TPO is a critical cytokine for ex vivo stem cell expansion and
lentiviral gene therapy.2 In addition, eltrombopag successfully expands cord blood stem cells in
vitro.3 Together, these observations suggested that TPO agonists could be therapeutically active
in diseases such as aplastic anemia in which the hematopoietic stem cell pool is depleted.
7. Kantarjian HM, Mutfi GJ, Fenaux P, et al. Treatment with the thrombopoietin
(TPO)-receptor agonist romiplostim in thrombocytopenic patients (Pts) with low or
intermediate-1 (int-1) risk myelodysplastic syndrome (MDS): Follow-up AML and
survival results of a randomized, double-blind, placebo (PBO)-controlled study.
Blood. ASH Annual Meeting Abstracts. 2012;120:421.
Dr. Cynthia Dunbar’s group at the National Institutes of Health conducted a non-randomized,
phase II study of eltrombopag in patients with severe aplastic anemia and severe persistent
thrombocytopenia who had failed to respond to immunosuppressive therapy. They
successively enrolled 25 adult patients and initiated eltrombopag at a dose of 50 mg daily,
the typical starting dose for ITP. The dose escalated every two weeks by 25 mg if the
platelet count remained below 20,000/mm3, until a maximum daily dose of 150 mg was
reached. All but one patient reached this maximum dose. Response was assessed at 12
weeks as follows: 1) platelet response defined as an increase in platelet count by 20,000
or freedom from platelet transfusions for eight weeks if previously dependent; 2) red cell
response defined as an increase in hemoglobin by 1.5 g/dl or reduction by four units of red
cells transfused in eight weeks as compared with the eight weeks prior to enrollment; and
3) neutrophil response defined as a rise in count to ≥ 500/mm3 or if < 500 then at least
doubling the count. Forty-four percent of the patients responded with improved production
in at least one cell lineage. All 25 patients were dependent on platelet transfusions prior to
treatment, and nine were able to discontinue them. The average increase of the platelet count
was 44,000/µl. Nine patients had a neutrophil response, and six had an erythroid response.
Higher reticulocyte count was one characteristic that predicted a favorable response. Of the
four patients who had a response of at least eight months, three attained normal bone marrow
cellularity. None of the patients’ bone marrows exhibited the reticulin fibrosis seen in some
ITP patients treated with eltrombopag. The severe adverse events included abdominal pain
due to gastroparesis, skin rash on cephalosporin, febrile neutropenia, and gingival bleeding.
Seven of 11 patients with a response remained on treatment for 16 months. One patient
who stopped treatment after nine weeks because of development of a cataract exhibited a
continued response for 16 months.
2. Uchida N, Hsieh MM, Hayakawa J, et al. Optimal conditions for lentiviral
transduction of engrafting human CD34+ cells. Gene Ther. 2011;18:1078-1086.
3. Sun H, Tsai Y, Nowak I, et al. Eltrombopag, a thrombopoietin receptor agonist,
enhances human umbilical cord blood hematopoietic stem/primitive progenitor
cell expansion and promotes multi-lineage hematopoiesis. Stem Cell Res.
2012;9:77-86.
4. Heckl D, Wicke DC, Brugman MH, et al. Lentiviral gene transfer regenerates
hematopoietic stem cells in a mouse model for Mpl-deficient aplastic anemia.
Blood. 2011;117:3737-3747.
6. Walne AJ, Dokal A, Plagnol V, et al. Exome sequencing identifies MPL as a
causative gene in familial aplastic anemia. Haematologica. 2012;97:524-528.
8. Pulikkan JA, Madera D, Xue L, et al. Thrombopoietin/MPL participates in initiating
and maintaining RUNX1-ETO acute myeloid leukemia via PI3K/AKT signaling.
Blood. 2012;120:868-879.
Figure
Mice deficient in mpl (the murine thrombopoietin receptor) exhibit bone marrow aplasia, 4 and
humans with congenital amegakaryocytic thrombocytopenia develop multi-lineage marrow
failure.5 Moreover, patients with familial aplastic anemia have recently been found to have a
defect in Mpl.6
The other thrombopoietin mimetic, romiplostim, has also been investigated in a randomized,
double-blind, placebo-controlled trial for low or int-1 risk myelodysplastic syndrome with
thrombocytopenia.7 There was sustained improvement in platelet counts among the
romiplostim-treated patients, but the study was stopped prematurely due to possible
increased incidence of progression to acute myeloid leukemia. The most recent analysis of
the data, presented at the 2012 ASH Annual Meeting, however, did not show a statistically
significant difference in progression to AML between romiplostim and placebo. Nonetheless,
the hypothetical risk of transformation induction remains, as another recent study
demonstrated elevated Mpl expression in some leukemia cells with t(8;21) that produces
the Runx1-ETO fusion gene, and thrombopoietin-mediated signaling via PI3K-Akt led to
development and maintenance of AML in a mouse model expressing Runx1-Eto. 8 In fact, two
non-responding patients in the eltrombopag trial exhibited clonal evolution with development
of monosomy 7, and one of them progressed to AML. Thus, a key objective in utilizing
thrombopoietin mimetic therapy for aplastic anemia will be to stimulate normal hematopoiesis
without potentiating leukemogenesis.
Thrombopoietin (TPO) and eltrombopag bind to distinct sites on Mpl. TPO
binding leads to activation of the JAK/STAT, PI3K/Akt, MEK, and MAPK pathways, and
eltrombopag binding leads to activation of the JAK/STAT and MAPK pathways.
The thrombopoietin receptor’s expression by hematopoietic stem cells provides a new
therapeutic target for acquired aplastic anemia. Eltrombopag’s potency in enhancing blood
cell production in this setting may enable broader applications of the thrombopoietin mimetics
in acquired and familial bone marrow failure. Additional studies are needed to optimize patient
selection and establish long-term safety given the theoretical and experimental potential for
expansion of dysplastic or leukemic clones.
Pamela S. Becker, MD, PhD
Dr. Becker indicated no relevant conflicts of interest.
10
The Hematologist:
ASH News and Reports
A New B Cell With a New B-Cell Function
In Polycythemia Vera, 45 Is the Number
Rauch PJ, Chudnovskiy A, Robbins CS, et al. Innate response activator B cells protect
against microbial sepsis. Science 2012;335:597-601.
Marchioli R, Finazzi G, Specchia G, et al. Cardiovascular events
and intensity of treatment in polycythemia vera. N Engl J Med.
2013;368:22-33.
T
he colony-stimulating factors, granulocyte/macrophage colony-stimulating factor
(GM-CSF), macrophage colony-stimulating factor (M-CSF), and granulocyte colonystimulating factor (G-CSF), were originally defined as hematopoietic cell growth factors.
Subsequently, CSFs have been found to have complex, pleiotropic effects in inflammation
and in other states.1 In most murine models of inflammation and autoimmunity (e.g., experimental
autoimmune encephalomyelitis, nephritis, and arthritis), CSF depletion results in the suppression
of the disease state. These findings, which are consistent with a proinflammatory function of
CSFs, have led to clinical trials of anti-GM-CSF and anti-M-CSF antibodies in rheumatoid
arthritis.
Prior to the present study by Rauch et al. from the laboratory of Filip Swirski, GM-CSF was
thought to be produced by non-hematopoietic cells, macrophages, or T cells. However, the
authors examined murine GM-CSF expression by flow cytometry and made the surprising
observation that in response to lipopolysaccharide (LPS), GM-CSF was found mainly in a
splenic B-cell subpopulation. Consistent with this interpretation, immunofluorescence of spleen
sections from LPS recipients co-localized GM-CSF expression to red pulp cells that coexpressed the B-cell markers, IgM, B220, and PAX5. Subsequent extensive characterization by
flow cytometry revealed that GM-CSF expressing cells were IgMhigh, CD43high, CD93+, CD138+,
VLA4high, LFA1high, CD284+, CD23low, IgDlow, and CD21low. In addition to GM-CSF, the cells under
investigation secreted IgM and IL-3, but not pro–IL-1β, IL-6, or tumor necrosis factor–α. This
set of phenotypic markers defined these cells as a unique mature B-cell population. The authors
named the cells “innate response activator B cells” (IRA B cells) because of the known role of
GM-CSF in activating innate leukocytes.
After maturation, B lymphocytes either recirculate through secondary lymphoid organs as part
of a long-lived pool (follicular cells) or join more static compartments in the marginal zone of
the spleen (MZ B cells) or peritoneal and pleural cavities (B1 B cells).2 The authors performed
transcriptional analysis on isolated IRA B cells and using hierarchical clustering and principal
component analysis found that IRA B cells fit into a population separate from transitional,
follicular, marginal zone, B1, or plasma cells. Adoptive transfer and parabiosis experiments
demonstrated that peritoneal B1 cells give rise to IRA B cells (Figure), of which B1a cells were
the dominant precursor. B1a cells in culture produced multiple cell types, including IRA B cells.
MZ B cells use the adhesive ligands VLA-4 and LFA-1 to remain lodged in the spleen. Similarly,
IRA B cells, which express VLA-4 and LFA-1, are dislodged from the spleen upon injection of
anti-VLA-4 and anti-LFA-1 antibodies. These and other experiments described by the authors
are consistent with a model in which IRA B cells are the progeny of peritoneal B1a B cells and
migrate to and take up residence in the spleen.
To assess the functional
Figure
significance of IRA B cells, the
authors employed a murine
cecal ligation and puncture
(CLP) sepsis model. They
produced mixed chimeras by
reconstituting lethally irradiated
mice with bone marrow from a
B-cell-deficient mouse called
µMT and from a GM-CSF–
deficient (Csf2–/–) mouse.
The B cells of these mice
(called GM/µMT chimeras)
cannot produce GM-CSF. The
mortality of GM/µMT mice was
significantly greater than that of
normal mice in the CLP model.
Additionally, the peritoneal
IRA B-cell development. NF, newly formed; TR, transitional;
cavities of GM/µMT chimeras
FO, follicular; MZ, marginal zone; B1, B1 cell; memB, memory
had more neutrophils, and the
B cell; and PC, plasma cell.
mice developed an IL-1β, IL-6,
Adapted with permission from Martin F, Kearney JF. Immunol
and TNFα cytokine storm. This
Rev. 2000;175:77.
cytokine profile is associated
with a defect in bacterial
clearance. Neutrophils from the GM/µMT chimeras also phagocytosed bacteria poorly and had
higher levels of bacteremia.
The paper by Rauch et al. describes the discovery of a novel B cell, the IRA B cell, which
expresses biologically significant levels of GM-CSF in a proinflammatory setting. The results
indicate that, while inhibition of GM-CSF may be beneficial in some settings, such as chronic
inflammatory states, GM-CSF may be protective in other settings, such as sepsis. The study
also raises the question of how IRA B cells may participate in other infectious and inflammatory
diseases.
1. Hamilton JA. Colony-stimulating factors in inflammation and autoimmunity. Nat Rev Immunol.
2008;8:533-544.
2. Martin F, Kearney JF. B-cell subsets and the mature preimmune repertoire. Marginal zone and
B1 B cells as part of a “natural immune memory.” Immunol Rev. 2000;175:70-79.
A
n increased red blood cell mass distinguishes polycythemia
vera (PV) from other myeloproliferative neoplasms (MPNs)
and is associated with an increased risk of thrombosis and
cardiovascular death. Elevation of the platelet and white
blood cell count are shared features between PV and other MPNs; while
an association between the degree of thrombocytosis and thrombosis
has not been established, an emerging body of data suggests a link
between leukocytosis and an excess risk of thrombosis. Risk stratification
and management of PV is primarily based on reducing thrombosis, the
complication that imposes the greatest morbid burden and risk of death.
Data from prospective and retrospective trials of PV (and essential
thrombocytosis) indicate that age > 60 or prior history of thrombosis
identify individuals with a high risk of vascular complications; lower-risk
patients exhibit neither risk factor.1 Lower-dose aspirin (e.g., 81-100
mg daily) with phlebotomy is the cornerstone of therapy for low-risk
patients, and cytoreductive therapy with hydroxyurea is added to this
regimen in high-risk individuals. While current guidelines recommend
that phlebotomy be undertaken to maintain a hematocrit < 45 percent
(and by inference, a target goal of < 42% in women), post-hoc analyses
of studies from the Polycythemia Vera Study Group and the European
Collaboration on Low-Dose Aspirin in Polcythemia Vera (ECLAP) have not
reinforced this hematocrit threshold; for example, thrombosis rates were
not increased in the hematocrit range of 45 to 50 percent.2,3
Dr. Roberto Marchioli and investigators from the Cytoreductive Therapy in
Polycythemia Vera (CYTO-PV) Collaborative Group conducted a multicenter, randomized trial of PV patients in order to test the hypothesis that
a hematocrit target of < 45 percent confers a lower rate of cardiovascular
death and major thrombosis than a target of 45 to 50 percent.
Stratification of 365 patients was partly based on age (< 65 years or
≥ 65 years) and on absence or presence of a history of thrombosis.
Baseline patient characteristics were well-matched. Individuals were
randomized to treatment with phlebotomy and hydroxyurea, with intensity
of therapy geared toward maintaining a target hematocrit < 45 percent
(low-hematocrit group) versus 45 to 50 percent (high-hematocrit group).
With a median follow-up of 31 months, the primary composite endpoint
of death from cardiovascular causes or major thrombotic events occurred
in five out of 182 patients (2.7%) in the low-hematocrit group and in 18
out of 183 patients (9.8%) in the high-hematocrit group (hazard ratio
3.91, P=0.007). Total cardiovascular events occurred in 4.4 percent
of patients in the low-hematocrit group and 10.9 percent of those in
the high-hematocrit group (hazard ratio 2.69, P=0.02). There was no
significant difference in adverse events, including bleeding, or in evolution
to myelofibrosis and myelodysplastic syndrome, or leukemia. In the lowand high-hematocrit groups, the median hematocrit level was maintained
at 44.4 percent and 47.5 percent, respectively, and 75 percent of patients
in each arm maintained the hematocrit in the assigned target range. While
the platelet count was not significantly different between treatment arms,
the leukocyte count was significantly higher in the high-hematocrit group.
The evidence provided by this landmark study justifies the current clinical
practice of maintaining the hematocrit < 45 percent, a target that is
associated with a significant reduction in the rates of cardiovascular death
and major thrombosis. Similar to prior studies, this trial spotlights the
potential role of leukocytes in promoting thrombosis given the significantly
higher white blood cell count in the high-hematocrit group. The higher
white blood cell count likely has functional consequences – leukocyte
activation has been associated with activation of endothelial cells and the
pro-coagulant response at sites of vascular injury.4 Randomized studies
are now needed to parse out whether a particular leukocyte threshold
imparts a significant difference in rates of thrombosis/death and is
additive to the target hematocrit.
1. Barbui T, Barosi G, Birgegard G, et al. Philadelphia-negative classical
myeloproliferative neoplasms: critical concepts and management
recommendations from European LeukemiaNet. J Clin Oncol.
2011;29:761-770.
2. Di Nisio M, Barbui T, Di Gennaro L,et al. The haematocrit and platelet
target in polycythemia vera. Br J Haematol. 2007;136:249-259.
3. Berk PD, Goldberg JD, Donovan PB, et al. Therapeutic
recommendations in polycythemia vera based on Polycythemia Vera
Study Group protocols. Semin Hematol. 1986;23:132-143.
4. Falanga A, Marchetti M, Evangelista V, et al. Polymorphonuclear
leukocyte activation and hemostasis in patients with essential
thrombocythemia and polycythemia vera. Blood. 2000;96:4261-4266.
PETE LOLLAR, MD
JASON GOTLIB, MD, MS
Dr. Lollar indicated no relevant conflicts of interest.
Dr. Gotlib indicated no relevant conflicts of interest.
The Hematologist:
ASH News and Reports
11
On Distressed Wood and the Origin of Acute Leukemia
Predicting Clinical Outcome in Patients
With Hodgkin Lymphoma
Welch JS, Ley TJ, Link DC, et al. The origin and evolution of mutations in acute myeloid
leukemia. Cell. 2012;150:264-278.
Scott DW, Chan FC, Hong F, et al. J Clin Oncol. 2012. Epub
ahead of print.
L
U
ong ago, in the guest bedroom of my grandparents’ summer cottage, there stood a battered
19th century French Provincial oak dresser so massive that if Atlas himself had been asked to
lift it, he might have shrugged and walked away. Faux-weathered wood with its rustic, vintage
connotations is all the rage in the decorative arts world these days, but that old dresser came by
its shabbily genteel appearance honestly, through a lifetime of heavy use – every nick and dent silently
bearing witness to a history of laborious relocations and close encounters with chairs, each chip and
scrape memorializing the trajectory of an impatiently shoved vacuum cleaner or an errant John Deere toy.
Data from the Genome Institute at Washington University in St. Louis indicate that just as a wellloved piece of furniture accumulates wear and tear over the years, the DNA of hematopoietic stem
and progenitor cells (HSPCs) endures a similar lifelong steady beating. Whole-genome sequencing
(WGS) of HSPCs from umbilical cord blood, septuagenarian marrow, and healthy volunteers
from every age cohort in between demonstrates age-dependent acquisition of somatic mutations,
most commonly C>T/A>G transitions resulting from random deamination of methylated cytosine
nucleotides. Other classes of mutations were shown to emerge with aging at the expected rate for
DNA replication infidelity.
When, on a very bad day, one of these mutations arises in a particularly unfortunate location,
malignant transformation to acute myeloid leukemia (AML) or another neoplasm can result. The cell’s
genomic signature, at that inauspicious moment, captures its idiosyncratic history of nucleic acid
trauma. The characteristic malignant behavior of the neoplastic clone might be driven by a FLT3 or
DNMT3A mutation, but all of the other genomic scars – private mutations located in genes encoding
proteins consequential only in, say, the retina or the ovary, or sited in meaningless intronic space far
from the coding and regulatory bits of the genome – are still there, in their hundreds, bearing a silent
story the way a manatee’s scarred hide tells tales of close encounters with long-gone ship propellers.
John Welch, Tim Ley, Dan Link, and their Wash U. colleagues further explored the origin and clonal
evolution of AML by WGS of 12 patients with normal karyotype AML M1, as well as 12 patients with
acute promyelocytic leukemia (APL) who have a clear disease-initiating molecular event, PML-RARA
translocation. An average of 10 to 11 mutations with translational consequences was present in the
AML cases, but most mutations were not recurrent (Figure). The differences between the M1 and
APL results are also interesting and could have filled another paper; briefly, mutations more common
in M1 AML than APL (e.g., NPM1, IDH1, DNMT3A – 13 recurrently mutated genes were found
only in M1 and not APL) might represent initiating events, while the nine recurrent mutations (e.g.,
FLT3) common to both subtypes are likely to be cooperators. This hypothesis is supported by mouse
models in which FLT3 mutations are not enough to initiate leukemia.
As with all good science, this new work raises as many questions as it answers. Are some of the
mutations that at first blush appear to be inconsequential “passengers” actually important cooperative
events? The 15 detected recurrently mutated non-genic regions, for instance, are attractive candidates
for exploration. What determines which subclones contribute to relapse? And, mechanistically, how
do newly described recurrent mutations contribute to leukemogenesis, such as those in the cohesin
complex? In his E. Donnall Thomas Lecture at the 2012 ASH Annual Meeting, Dr. Ley stated that all
of the AML-associated mutations present in at least 5 percent of patients have probably already been
described. But while the gateway to the garden of discovery for common recurrent mutations in AML is
rapidly closing, there are plenty of new wilds awaiting energetic explorers.
M1 initiating mutations
progression mutations
(NPM1, DNM3A, IDH1, TET2 and others)
(FLT3 and others)
subclone 1
founding AML
clone
HSPC
M3 initiating mutation
(PML-RAMA)
X: age-dependent passenger mutations pre-existing in HSPC
Y: passenger mutations gained between initiating and progression events
Z: passenger mutations gained during progression to subclones
subclone 2
Integrated model for the origin of driver and passenger mutations during AML evolution.
Hematopoietic stem/progenitor cells (HSPCs, shown in green) accumulate random, benign background mutations
as a function of age. “X” represents these background mutations in the HSPCs and may range from ~100 to
1,000 events, depending on age. The initiating mutations are different for M1 AML cases and M3 AML cases.
Because the initiating event provides an advantage for the affected cell, clonal expansion ensues, so that all of
the preexisting mutations in that cell are “captured” by cloning. Each cooperating mutation gives the expanding
clone an additional advantage; our data suggest that one to five events contribute to progression in most cases
of AML. Each cooperating mutation is expected to capture all mutations that occurred between the initiating event
and the progression event (designated as “Y” in the yellow cell). Although this number is unknown, the analysis of
clonal progression of secondary AML suggests that each cooperating mutation may capture dozens to hundreds
of mutations. The “founding” AML clone is designated in red. Subclones arise from the founding AML clone by
acquiring a small number of additional mutations that confer an advantage to that cell, along with any additional
background mutations that may have occurred in the interim (represented as “Z”).
ntil recently, the systems for predicting outcome in
patients with Hodgkin lymphoma have been based upon
relatively straightforward clinical criteria such as age,
gender, anatomical stage, and routine measurements,
including the sedimentation rate, blood count, and serum albumin
concentration. These parameters reflect indirectly on the biologic
heterogeneity of the disease, but only at one remove. Such
baseline prognostic indices, however, have proven inferior to
predictors based on functional imaging with FDG-PET performed
as a measurement of response during chemotherapy. Despite
this shift toward using in-treatment imaging as the prognostic
benchmark, the recent description of the clinical implications of
macrophage infiltration has revived interest in pathobiology both
as an indicator of outcome and as a potential target for therapy.
But enumeration of macrophages is difficult to reproduce using
immunohistochemistry, especially on tissue microarrays that may
sample only a small region of each biopsy. Now, a collaboration
between the Department of Pathology and Experimental
Therapeutics of the British Columbia Cancer Agency and four
North American cooperative groups has tested a method of multigene expression analysis to derive a prognostic score from routine
diagnostic biopsy material. This approach holds the prospect
of a new means of predicting outcome based upon molecular
phenotype.
In this study, requiring as little as 200 ng of RNA extracted in
most cases from a single 10 mm section of formalin-fixed, paraffinembedded tissue, the authors used a new technique called
NanoString technology to examine the pattern of expression of
259 genes. Cases for a training set were drawn from the recently
reported intergroup E2496 trial that showed equivalent outcomes
in patients with advanced Hodgkin lymphoma treated with either
ABVD or the Stanford V regimen. From a total of 794 available
biopsies, 290 were studied, and based on overall survival of
the patients from whom the samples were derived, a 52 gene
prognostic set was developed. Next, this prognostic set was
tested on a validation cohort consisting of 78 patients treated with
ABVD. This validation cohort was enriched for treatment failure
but was otherwise similar to patients treated with ABVD in a
population-based registry. From the original 52 gene set, analysis of
expression of 23 genes was found to generate a robust prognostic
index. Of those 23 genes, 20 were overexpressed and three were
underexpressed in the group at highest risk of death. The genes
overexpressed reflected the presence of increased macrophage
numbers, such as CD68, IL15RA, and STAT1; genes indicative
of a Th1 response such as IFN-γ; the targets of IFN-γ such as
CXCL11, IRF1, and TNFSF10; genes of HLA class I; and genes
expressed by cytotoxic T cells or NK cells. The high-risk group
was found to have an excess of patients with a high international
prognostic score, positive Epstein-Barr virus-encoded RNA (EBER)
expression, and a histology other than nodular sclerosis, although
the molecular signature remained independently predictive in
multivariate analysis.
Gene-expression profiling, which is already making a significant
impact on our understanding of the molecular basis of non-Hodgkin
lymphoma, has until now given relatively little information about
the heterogeneity of Hodgkin lymphoma. It is clear to clinicians
that such heterogeneity exists, and, given the complex infiltrate
seen on histology, it is not surprising that the microenvironment
in general, and the presence of macrophages and NK cells in
particular, would play a central role in the natural history of the
disease. This study represents an important contribution to our
understanding of the key interactions that drive Hodgkin lymphoma
and suggests that therapies that specifically target the inflammatory
component of the disease may be capable of improving outcome
for those destined to fare poorly with conventional chemotherapy.
The NanoString technology used in this study holds the promise
of a broader application for gene-expression profiling because
RNA sufficient for analysis can be obtained routinely from a single
formalin-fixed, paraffin-embedded tissue sample, whereas the need
to acquire relatively larger amounts of RNA from formalin-fixed,
paraffin-embedded tissue has limited the applicability of standard
microarray analysis as a clinical tool. If the results of this study can
be replicated by other groups, it may be possible to apply this type
of analysis to more routine biopsy specimens in the future, bringing
the prospect of real-time molecular phenotyping closer to the
bedside.
Welch JS et al. Cell. 2012;150:264-278. Reprinted with permission of Elsevier.
12
David P. Steensma, MD
Peter JOHNSON, MD
Dr. Steensma indicated no relevant conflicts of interest.
Dr. Johnson indicated no relevant conflicts of interest.
The Hematologist:
ASH News and Reports
Clinical Trials Corner
A Point Nommé/Just in Time
Study Title: A Trial of Single Autologous Transplant
With or Without Consolidation Therapy Versus Tandem
Autologous Transplant With Lenalidomide Maintenance
for Patients With Multiple Myeloma (BMT CTN 0702)
ClinicalTrials.gov Identifier: NCT01109004
Sponsor: National Heart, Lung, and Blood Institute
(NHLBI)
Collaborators: Blood and Marrow Transplant Clinical
Trials Network and National Cancer Institute (NCI)
Participating Centers: 63 study sites throughout the
United States
Accrual Goal: 750 patients
Study Design: This is a phase III, multicenter trial.
There are three comparison arms: tandem autologous
transplants followed by maintenance therapy; a single
autologous transplant followed by consolidation therapy
with lenalidomide, bortezomib, and dexamethasone
followed by maintenance therapy; and a single autologous
transplant followed by maintenance therapy. Eligible
patients are those with symptomatic myeloma, age 70
years or younger, and have a Karnofsky performance
score of ≥ 70 percent who have received at least two
cycles of any regimen as initial systemic therapy and
are within two to 12 months of the first dose of initial
therapy. Comparisons will be made between the two single
transplant arms and between each single transplant arm
and the tandem transplant arm. The primary outcome
measure is three-year progression-free survival. Secondary
endpoints include myeloma-stable survival measured
at four years, three-year overall survival, incidence of
progression, incidence of toxicities, incidence of infection,
treatment related mortality, non-compliance with
medications, and quality of life.
Rationale: The focus of this study is on evaluating
the benefit of consolidation in patients with myeloma
who undergo high-dose chemotherapy with melphalan
followed by stem cell rescue. The following two types
of consolidation are included in the study: a second
round of high-dose chemotherapy with melphalan
followed by autologous stem cell rescue (ASCR) (i.e.,
tandem transplant) and the myeloma active regimen of
lenalidomide, dexamethasone, and bortezomib (i.e., RVD)
(lenalidomide 15 mg/day on days 1-14; dexamethasone
40 mg on days 1, 8, and 15; and bortezomib 1.3 mg/m2
on days 1, 4, 8, and 11 of every 21 day cycle; patients
will receive four cycles). Patients on the third arm of
the study receive no consolidation. Patients on all three
arms receive maintenance therapy with lenalidomide
starting at 10 mg daily for three months and subsequently
increasing to 15 mg daily for the duration of the study.
The study addresses two important questions about
management of patients with myeloma who undergo highdose chemotherapy followed by ASCR: Does consolidation
improve outcome? If so, which consolidation strategy is
better, tandem transplant or combination therapy with the
highly active myeloma regimen RVD?
The Hematologist:
ASH News and Reports
Comment: The use of a second course of high-dose
Comment: As hematologists, we have been mesmerized
chemotherapy followed by a second autologous transplant
(i.e., tandem transplant) as a form of consolidation therapy
for treatment of myeloma antedated the development
of highly active therapeutic combinations that include
immunomodulatory drugs such as lenalidomide and
proteasome inhibitors such bortezomib in combination
with dexamethasone. The current study investigates
the efficacy and safety of the RVD regimen when used
as consolidation therapy following high-dose melphalan
with ASCR and compares the results with the tandem
transplant as consolidation. The study will also examine
whether consolidation of either type is necessary given
the proven efficacy of maintenance therapy following
treatment with high-dose chemotherapy followed ASCR (N.
Engl. J. Med. 2012; 366:1770-1781 and N. Engl. J. Med. 2012;
366:1782-1791). Importantly, in ongoing trials, IFM/DFCI
2009 (NCT01191060) and DFCI 10-106 (NCT01208662), the
efficacy and safety of high-dose chemotherapy followed by
ASCR is being compared directly with the RVD regimen as
initial therapy for patients with myeloma 65 years old or
younger. The results of this study when combined with the
results of the current study should provide clinicians with
a consensus, evidence-based approach to treatment of
myeloma in transplant eligible patients, a point nommé.
by the transformative power of imatinib in the treatment of
CML. That CLL is not analogous to CML, in that there is no
single, common genetic aberration equivalent to BCR-ABL
that drives the disease, made the prospect of identifying
a targeted drug for CLL equivalent in efficacy to imatinib
unlikely. However, recognition of the importance of BCR
signaling in the pathobiology of CLL and subsequent
development of BCR signaling pathway inhibitors, such
as ibrutinib, has created a sense of optimism in the
field that effective targeted therapy is not only feasible
but imminent. Large, completed phase I/II studies with
ibrutinib in relapsed CLL have shown responses in
approximately 71 percent of patients with another 18
percent benefiting from disease control but with persistent
lymphocytosis.
– Xavier Leleu, MD, PhD
Dr. Leleu indicated no relevant conflicts of interest.
Ibrutinib for del(17p13.1) CLL Patients:
A Potential Bonanza
Study Title: A Multicenter Phase II Study of PCI-32765
(Ibrutinib) in Patients With Relapsed or Refractory
Chronic Lymphocytic Leukemia (CLL) or Small
Lymphocytic Lymphoma (SLL) With 17p Deletion
The toxicity of ibrutinib appears modest with the major
adverse effects being low-grade diarrhea, dyspepsia,
infection, and rash. Notably, patients have been dosed
beyond two years without observed late cumulative
events. While many therapies do not work well in relapsed
del(17p13.1) CLL, response to ibrutinib is similar (68%) to
that observed in non-del(17p13.1) CLL, and remissions are
durable with an estimated PFS at 26 months of 55 percent.
Although comparative, randomized data are not yet
available, this response rate and PFS duration are better
than any other single-agent therapy previously tested in
relapsed del(17p13.1) CLL. Physicians caring for patients
with relapsed del(17p13.1) CLL should encourage patients
to enroll in this study. Given that effective treatment of
relapsed del(17p13.1) CLL represents an unmet medical
need, the hope is that this trial will rapidly accrue patients
and meet its designated endpoints, and by doing so, gain
accelerated approval by the FDA for marketing of ibrutinib
for this indication.
– John C. Byrd, MD, and Sam Penza, MD
Dr. Byrd and Dr. Penza indicated no relevant conflicts
of interest.
ClinicalTrials.Gov Identifier: NCT01744691
Coordinator: Pharmacyclics
Participating Centers: This is an international,
multicenter study.
Accrual Goal: 111 patients
Study Design: This is a single arm trial of ibrutinib in
previously treated, relapsed, or refractory CLL patients
with del(17p13.1). The primary endpoint is IWCLL 2008
overall response (partial + complete) response, and
secondary endpoints are safety, progression-free survival
(PFS), and overall survival.
Rationale: The gene locus of the master tumor
suppressor, p53, is chromosome 17p13.1, and patients
with a CLL clone deficient in p53 because of deletion (del)
involving that locus have a particularly poor prognosis.
Although patients with del(17p13.1) often respond to
cytotoxic chemotherapy in combination with rituxan,
responses are usually not durable, and, typically, response
duration becomes progressively shorter with successive
treatments. B-cell receptor (BCR) signaling has been
shown to be an important driver of proliferation in highrisk CLL. The Bruton agammaglobulinemia tyrosine
kinase (BTK) is an essential component of BCR signaling,
and ibrutinib, an irreversible inhibitor of BTK, has
demonstrated significant activity in relapsed CLL, including
patients with del(17p13.1). The current trial builds upon
those observations by exclusively targeting treatment of
patients with CLL or SLL with del(17p13.1) with the aim of
identifying effective therapy for this poor prognosis group.
13
P r o f i l e s
in
H e m a t o l o g y
Embedded in the Red Cell
H. Franklin Bunn, MD
Professor of Medicine, Harvard Medical School; Physician, Brigham and Women’s Hospital
I have been a science nerd for as long as I can remember. My rite of passage began with
my first chemistry set and home laboratory, followed by a series of summer jobs in
industrial labs.
During my undergraduate years at Harvard College, I
became increasingly intrigued with medical science
and obtained an MD in 1961 from the University of
Pennsylvania School of Medicine. I then completed a threeyear medical residency at New York Hospital, Cornell
Medical Center. One of my first admissions was a very
gallant and courageous young teenager with Cooley’s
anemia (thalassemia). “Alfred” had all of the indications
of severe iron overload, including progressive congestive
heart failure and endocrine hypofunction that delayed
transition into puberty. After he was discharged from the
hospital, I saw Alfred in our clinic about once a month over
a two-year period, and we became quite close. I will always
remember a clinic visit at which he seemed particularly
upbeat. He took me aside and said “Dr. Bunn, there is
something I want to tell you. On Saturday night I am going
out on my first date!” He died about six months later.
Alfred and his illness impelled me to go into hematology.
From 1964 through 1967 I was a hematology fellow at the
Thorndike laboratory at Boston City Hospital (now known
as Boston Medical Center) under the inspiring mentorship
of James Jandl, arguably the leading experimental
hematologist of that era. Jim’s research focused on the
red blood cell and disorders thereof. The intellectual
atmosphere at the Thorndike laboratory was transforming,
particularly so at a weekly conference in which cases were
thoroughly dissected and reassembled by Jim, along with
William Castle and Jane DesForges, abetted by younger
colleagues, Harry Jacob, Dick Aster, and others who have
left a solid imprint on hematology.
After two years in the army at a blood research lab in Fort
Knox, KY, I felt I needed an apprenticeship in a strong
that confirmed the proposed binding site. Thus began
close friendships with Helen and Max, who, with Jim Jandl,
were my most influential and generous scientific mentors.
In the 1970s, my lab worked on non-enzymatic glycation
of hemoglobin and other proteins. A minor component
Hb AIc was known to be elevated in red cells of diabetics.
Following earlier work of Bob Bookchin and Paul Gallop at
Einstein, we showed that glucose formed a stable adduct
with the N-terminal amino of b-globin by a ketoamine
linkage. In order to study the biosynthesis of Hb AIc in
vivo, I clandestinely infused myself with serum transferrin
bound to 59Fe of high specific activity and then monitored
the incorporation of radioactivity into the major and
minor hemoglobin components. This rather impetuous
foray into human experimentation showed that Hb AIc is
formed continuously during the red cell’s life span and
that the ketoamine linkage is virtually irreversible. Thus,
measurement of Hb AIc could be, and indeed has proven,
useful in monitoring therapeutic control of hyperglycemia
in diabetic patients independent of fluctuations of blood
glucose levels.
In 1980, I used my first and only sabbatical leave to go to
the National Institutes of Health and work first with Bill
Eaton and then with Art Nienhuis. Bill and I addressed a
seemingly simple but clinically relevant question: Why
is sickle cell trait (AS) benign, whereas sickle cell (SC)
patients have significant morbidity? Contrary to an early
report, Bill and I showed that polymerization of mixtures
of Hbs S and C was identical to mixtures of Hbs S and A.
However, we found that two other factors contributed
about equally to enhanced sickling in SC patients. First, the
level of Hb S in these patients is about 10 percent higher
The Society fosters a remarkable climate of collegiality and cooperation
that has been an enormous boon to hematology in an era when our
specialty has faced a variety of challenges that threaten its livelihood.
biochemistry lab before initiating an independent research
program. Ruth and Reinhold Benesch had recently
reported that the oxygen affinity of hemoglobin in human
red cells was tightly regulated by 2,3-diphosphoglygerate
(2,3-BPG), an abundant intermediate in the glycolytic
pathway. They were aware of experiments I had done
at Fort Knox on the impact of falling levels of 2,3-BPG in
stored blood, and they gave me the opportunity to join
their lab at Columbia University.
Six weeks after my arrival I faced the first and only bona
fide crisis in my career. I telephoned Helen Ranney at
Albert Einstein College of Medicine and told her that
Reinhold had just fired me from his lab, for reasons that
I was at a loss to explain. Helen, who at that time was a
heavy smoker, replied, “Wait a minute. Let me go get a
cigarette. I can see this conversation is going to take a
while.” She then arranged for me to join Robin Briehl’s
lab at Einstein. While there, I measured the effect of
the addition of 2,3-BPG on the oxygen affinity of several
human hemoglobins and, after reviewing papers by
Max Perutz, made an educated guess regarding sites on
deoxyhemoglobin that bind to 2,3-BPG. I communicated
these results to Perutz and several months later received
an indescribably gratifying handwritten letter telling me
that he and Arthur Arnone had x-ray diffraction patterns
14
14
than that in AS individuals because αβS dimers assemble
at about the same rate as αβC dimers but more slowly than
αβA dimers. In addition, and of equal importance, polymer
formation is favored in SC red cells because Hb C induces
water loss and thus higher intracellular hemoglobin
concentration.
My six months in Art’s lab provided me with sorely needed
hands-on tutelage in molecular genetic technology and
enabled my lab to switch its focus from hemoglobin to
erythropoietin. This transition was greatly facilitated by
the creative input of a research fellow Mark Goldberg,
who, during college and medical school, had worked with
me on sickle hemoglobin. After an exhaustive search,
Mark found two human hepatoma cell lines that produce
erythropoietin in response to hypoxia. These cells enabled
us and others to identify key elements in the Epo gene
that are important in hypoxic induction. Jean-Paul Boissel
and I prepared a large number of site-directed mutants of
erythropoietin that helped to confirm its three-dimensional
structure and also to determine the sites that bind to the
erythropoietin receptor.
the use of subcutaneous deferroxamine for treatment
of iron overload in transfusion-dependent patients with
myelodysplasia.
During my tenure at Brigham and Women’s Hospital,
I have tried to fulfill a meaningful role in patient care,
a task made a lot easier and more fun by having the
opportunity to work closely with remarkable colleagues.
My predecessor as chief of hematology was William
Moloney, a master clinician with uncanny wisdom
reinforced by boundless energy and wit. My successors,
Bob Handin and Nancy Berliner are also superb clinicians
who have not only taught me a lot about hematology,
but have also been supportive and tolerant of my
idiosyncrasies, geriatric and otherwise. I never found it
easy to remain viable in competitive areas of research
while hanging on to and hopefully enhancing my
clinical skills. However, this ongoing challenge has been
greatly ameliorated by exposure to two generations of
extraordinarily bright and effective fellows, house staff,
and students at the Brigham and Harvard Medical School.
I am also indebted to the American Society of
Hematology. I was fortunate to have helped in the
leadership of this wonderful organization, including
a role in enabling ASH to own and publish Blood and
a 10-year stint as an associate editor. For a while,
I was “impresario” of the musical events that were
previously such a haven of civility and repose at our
annual meetings. On one blissful occasion, prior to an
ASH concert in San Francisco, I had the opportunity to
play the piano in a movement of a Schubert trio with Yo
Yo Ma and violinist Lynn Chang! The Society fosters a
remarkable climate of collegiality and cooperation that
has been an enormous boon to hematology in an era
when our specialty has faced a variety of challenges that
threaten its livelihood.
I have also had the opportunity to oversee some timely
and fulfilling clinical research projects including one of
the early trials of hydroxyurea therapy for SC patients and
The
The Hematologist:
Hematologist:
ASH
ASH News
News and
and Reports
Reports
I N
M E M O R I A M
Karl G. Blume, MD (1938-2013)
K
arl Blume, a pillar of the bone marrow transplant community and the
American Society of Hematology, died January 9, 2013. Although he had
endured a long illness, his death was unexpected.
Thoughts From a Former Protégé
Mark A. Goldberg, MD
Senior Vice President of Medical & Regulatory Affairs, Synageva Biopharma Corp.
Clinical Associate Professor of Medicine, Harvard Medical School
Webster’s Dictionary defines a mentor as “a trusted counselor or guide.”
I would go a step further. To me a true mentor is someone whom you
can rely upon to give you sound, experienced direction that, above all
else, is in your own best interest, even if that conflicts with the mentor’s
best interest. By this definition, true mentors are a very rare breed. In
Frank Bunn, I have been fortunate enough to have been mentored by
one of the best of this rare breed for more than 39 years.
I first met Frank in the fall of 1973. I was a college sophomore with a
little lab experience that I gained during high school, and Frank was a
young assistant professor of medicine at Peter Bent Brigham Hospital
and Harvard Medical School. After interviewing with Frank, he offered
me a position in his laboratory. Little did I know how dramatically and
positively Frank would impact my personal and professional life.
I worked in Frank’s lab throughout college and during medical school
and then did my postdoctoral research with him. Under Frank’s
mentorship, I learned a tremendous amount about science, hematology,
and life. During that time he taught me how to rigorously approach
scientific problems and how to design and conduct well-controlled
experiments. I learned about the molecular basis of sickle cell disease
and how it leads to many of the clinical manifestations of the disease.
We studied the regulation of erythropoietin gene expression by hypoxia
and made a number of interesting observations.
After I had started my own lab as an independent investigator, Frank
remained very supportive. I still spoke often with him. Once when I was
preparing a manuscript for
publication, I discussed
with Frank having him as a
co-author. Frank felt it was
important for me to publish independently of him
and suggested that he not
be a co-author.
I worked in Frank’s lab
throughout college
and during medical
school and then did my
postdoctoral research
with him. Under
Frank’s mentorship, I
learned a tremendous
amount about science,
hematology, and life.
Throughout my formative
years as a hematologist,
Frank always made sure
to introduce me to leaders
in the field. Shortly after
I received my first R01
award, Frank told me that
Ernie Beutler wanted to
have lunch with me at ASH
to discuss recruiting me to Scripps. During lunch, Ernie shared with me
that when he told Frank about his desire to recruit me, Frank appeared
as if he was giving away his first born. Nonetheless, Frank made the
introduction because he wanted me to have every opportunity.
For close to four decades I have had the privilege of seeing firsthand
the hard work and innovative thinking that allowed Frank to make very
significant contributions to our basic understanding of hemoglobin
structure and function, as well as the regulation of erythropoiesis, and
to translate these findings to clinical applications that have helped
patients with diabetes mellitus and sickle cell anemia. I have also seen
Frank’s commitment to teaching, as he has assumed a leadership role
in teaching hematology to generations of Harvard medical students.
My career has evolved in ways that I had never imagined. While still
maintaining my academic appointment at Harvard and the Brigham,
I have spent most of the past 15 years working in the biotechnology
industry. I still frequently seek out Frank for his advice and opinions. We
get together regularly for lunch. I always look forward to these dates.
We still talk about science and medicine but much more about our lives
and our families. I have been extremely fortunate to have such a caring,
thoughtful mentor. I hope that I can pay forward what I have learned
from Frank about the meaning and value of true mentorship. I hope I
can be like Frank.
Karl received his medical education at the University of Freiburg, Germany. An
early interest in abnormalities of red cell enzymes led him to work with Dr. Ernest
Beutler at City of Hope National Medical Center in Duarte, CA, from 1971 to 1972.
That mentor-mentee relationship blossomed particularly, and Karl and Ernie became
life-long friends. Upon returning to Freiburg, Karl’s clinical responsibilities included
managing patients with acute leukemia. The high mortality rate that inevitably
accompanied disease relapse caused Karl to rethink the direction of his career
path, and the change in trajectory became fixed after a fortuitous one-day visit to
Fred Hutchinson Cancer Research Center in Seattle, WA, in 1974. There, Karl met
Dr. Donnall Thomas and became convinced of the concept of marrow ablative
chemotherapy followed by bone marrow rescue as a mechanism for curing patients
with acute leukemia. In 1975, Karl
was recruited to City of Hope by Dr.
Beutler to develop a bone marrow
transplant program. At that time,
bone marrow transplantation was
being performed at only a few
institutions, and as a pioneer in the
field, Karl interacted frequently with
colleagues at the Fred Hutchinson
Cancer Research Center and, in
the process, developed a number
of enduring friendships. When
the program at the City of Hope
began, times were a bit shaky,
and Karl once showed me a letter
that he received from hospital
administration stating that, because
he was doing such a good job,
they had decided to continue the transplant program for another six months. The
administrators’ judgment proved prescient, and Karl went on to lead the City of
Hope program to international prominence. He was particularly proud of the young
physician-scientists he mentored there, most notably Steve Forman, who took over
the program after Karl was recruited to Stanford and who continues to lead that
exemplary group.
Karl was recruited to Stanford in 1987 by Dr. Stanley Schrier and Dr. Ronald Levy.
They tell the story that when they went to City of Hope to interview him for the
position, Karl immediately took control of the meeting and described his vision of
a bone marrow transplant program at Stanford. Karl recruited Nelson Chao and
me to his team, and we shared every third night call. Those were heady times,
filled with new ideas and difficult challenges. Karl was a charismatic, visionary
leader who saw the importance of including all members of the patient care team
(nurses, social workers, dieticians, physical therapists) in management planning.
This team-based treatment model was new at Stanford at the time, but the concept
is now widely emulated. Nelson went on to become the head of transplant at
Duke University, and that program has thrived under his leadership. Therefore,
Karl contributed to development of three of the major bone marrow transplant
programs in the United States and, in the process, mentored a number of fellows
who have made important, independent contributions to hematology.
In 2003, late in his academic career and after stepping down as Division Chief,
Karl took on the formidable challenge of developing a National Cancer Institute
(NCI)-designated Cancer Center at Stanford. Working with Dr. Beverly Mitchell and
with the cooperation of colleagues from throughout the Medical Center and the
University, an outstanding group of clinicians and investigators was assembled,
and NCI designation was awarded in three years.
Karl was known for his dedication, discipline, compassion, and sense of humor.
He was a particular fan of Stanford sports and knew at all times the updated
scores of the competition for the Directors’ Cup that is awarded annually to
the top intercollegiate athletic program in the nation. Karl was a forceful and
effective mentor and took great pride in his mentees’ accomplishments. He was
a driving force behind both development of the American Society of Blood and
Marrow Transplantation (ASBMT) and creation of Biology of Blood and Marrow
Transplantation, the official journal of that society, serving as its first co-editor.
Karl became the first honorary member of ASBMT. He was devoted to the
American Society of Hematology, serving as the first chair of the Development
Committee and serving on the Executive Committee. He was also a member of the
Scientific Committee on Transplantation Biology. Karl received many awards and
honors both in the United States and Germany, but his legacy is the impact he had
on the thousands of patients that he treated and the hundreds of students and
trainees that he mentored.
– Robert Negrin, MD
Professor of Medicine, Chief, Division of Blood and Marrow Transplantation,
Stanford University
The Hematologist:
ASH News and Reports
15
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on
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May
• Ham-Wasserman Lecture
• E. Donnall Thomas Lecture
1Scholar Awards letter of intent due
Washington, DC www.hematology.org/awards
• Ernest Beutler Lecture
• ASH/EHA Joint Symposium
• Trainee Simultaneous Didactic Sessions
• S
pecial Symposium from the Quality of Care Subcommittee –
Quality Improvement: A Toolkit for Hematology Practice
• Practice Forum
2
Application deadline for Visitor Training Program
Washington, DC
www.hematology.org/awards
15-18
American Society of Gene & Cell Therapy Annual Meeting
Salt Lake City, UT www.asgct.org
*In order to submit an application for the Clinical Research Training Institute, you
must have submitted a letter of intent by January 8, 2013. For additional meeting dates and award deadlines, go to www.hematology.org/Calendar.
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