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4106
BLOOD, 1 MAY 2007 䡠 VOLUME 109, NUMBER 9
CORRESPONDENCE
To the editor:
Why make a diagnosis?
I read with interest Dr Evan Sadler’s commentary regarding the
papers by Goodeve and colleagues and James and colleagues in a
recent issue of Blood.1
Since 2 large studies failed to associate a mutation with people
followed in bleeding disorder clinics who have mild type 1 von
Willebrand disease, why give them a diagnosis? Fair-skinned
people are more at risk of sunburn and melanoma than darkskinned people. Do they have “premelanoma syndrome”? We just
advise (prescribe) sun block. Similarly, if a person has a mild
bleeding history, bruises easily, is blood type O, and their ristocetin
cofactor is slightly low, why all these machinations about “making
a diagnosis”? Just write a note in their medical record about your
rationale for prescribing DDAVP before their dental extraction.
In certain clinical situations, we should consider other therapeutic paradigms than making a diagnosis before treating.
Richard Lipton
Correspondence: Richard Lipton, Hemophilia Treatment Center, 270-05 76th
Ave, Oncology 350, New Hyde Park, NY 11040; e-mail: [email protected].
Reference
1. Sadler EJ. VWD data worth 10 000 words [Inside Blood]. Blood. 2007;109:3.
Response:
Diagnosing VWD type 1: when is it useful and when illogical?
Dr Lipton raises an important question about the best strategy for
managing patients with moderately decreased levels of von Willebrand factor (VWF). One need not medicalize every small predisposition to a future adverse event by giving it an eponymous
diagnosis. I like the comparison to fair skin as a risk factor for skin
cancer, and I’ve used it myself in discussing von Willebrand
disease (VWD) type 1. We also take a similar approach to high
blood pressure, managing it empirically as a modest risk factor for
cardiovascular events. With respect to low VWF levels, the
community is still figuring out the best approach. The problem was
discussed in some detail in the revised guidelines for diagnosing
VWD that were published recently on behalf of the International
Society on Thrombosis and Haemostasis.1 This paper prompted a
similar exchange of letters about how to define VWD type 1 and
which patients should be considered simply to have “low VWF”
instead.2,3 On one hand, VWF levels lower than 20 IU/dL usually
are associated with VWF mutations, significant bleeding symptoms, and a high likelihood of transmitting the condition to
progeny. A diagnosis of VWD type 1 seems appropriate in such
cases. On the other hand, VWF levels closer to 50 IU/dL have none
of these properties, and a label of “disease” is illogical. For the
troublesome intermediate levels, we need more information, espe-
cially about the risk of bleeding and the benefits of treatment. Is
there a threshold, a natural boundary that separates patients into
useful categories? If so, then we could treat those below as VWD
type 1 and those above as possessors of low VWF, a risk factor for
mild bleeding. The ongoing studies of VWD in Europe and in
Canada are starting to provide this information and should help to
define a more satisfactory approach to diagnosing, treating, and
advising our patients with modest, quantitative decreases in VWF.
J. Evan Sadler
Correspondence: J. Evan Sadler, 660 S. Euclid Ave, Box 8022, St Louis, MO
63110; e-mail: [email protected].
References
1.
Sadler JE, Budde U, Eikenboom JC, et al. Update on the pathophysiology and
classification of von Willebrand disease: a report of the Subcommittee on von
Willebrand Factor. J Thromb Haemost. 2006;4:2103-2114.
2.
Nurden AT. Interesting variations on how a disease is defined: comparisons of
von Willebrand disease and Glanzmann thrombasthenia. J Thromb Haemost.
2007;5:647-649.
3.
Sadler JE. Interesting variations on how a disease is defined: comparisons of
von Willebrand disease and Glanzmann thrombasthenia. Reply to a rebuttal.
J Thromb Haemost. 2007;5:649-651.
To the editor:
Myelofibrosis evolving during imatinib treatment of a chronic myeloproliferative disease
with coexisting BCR-ABL translocation and JAK2V617F mutation
Among the more than 100 published cases of Philadelphia chromosome–positive chronic myelogenous leukemia (Ph⫹ CML) investigated for the 1849G ⬎ T mutation of the Janus kinase 2
V617F 1
(JAK2
), no mutated cases have been found so far.2,3 Selected
patients with Ph⫹ CML with marked thrombocytosis also proved to
be negative for the JAK2V617F mutation.3 We report for the first time
a case of coexisting JAK2V617F mutation in Ph⫹ CML evolving to
myelofibrosis during imatinib treatment.
The 55-year-old white man presented with splenomegaly,
leukocytosis (white blood cell [WBC] count of 163 ⫻ 109/L), a low
hemoglobin (Hb) level (115 g/L), and an elevated lactate dehydrogenase (LDH) level (1337 U/L). A total of 14% blast cells in
peripheral blood indicated acceleration. Peripheral blood smears
revealed typical features of a CML, and molecular analysis showed
a rare variant of bcr-abl fusion gene (e19a2). Imatinib therapy
induced normalization of the patient’s blood parameters within 11
From www.bloodjournal.org by guest on June 14, 2017. For personal use only.
BLOOD, 1 MAY 2007 䡠 VOLUME 109, NUMBER 9
CORRESPONDENCE
4107
Figure 1. JAK2VG17F allele frequency and bone marrow histology. (A) The percentage of mutated JAK2 alleles increased from 5% (prior to imatinib therapy) to 23% (after 23
months of imatinib therapy), while the initial BCR-ABL e19a2 fusion transcript became undetectable after 11 months of treatment. The dotted line indicates the JAK2 wild-type
status of 125 control volunteers (87 bone marrow biopsies from patients with Ph⫹ CML and peripheral blood from 38 healthy blood donors). For the Pyrosequencer assay
(Biotage, Uppsala, Sweden), 25 ng of formalin-fixed and paraffin-embedded (FFPE) bone marrow biopsy–derived DNA was used to generate a 102-bp JAK2 polymerase chain
reaction (PCR) product (JAK2 forward, 5⬘-TATGATGAGCAAGCTTTCTCACAAG-3⬘; JAK2 reverse, 5⬘-AGAAAGGCATTAGAAAGCCTGTAGTT-3⬘; GenBank accession no.
AL161450) and a 130-bp MPL product (MPL forward, 5⬘-ATCTCCTTGGTGACCGCTCTG-3⬘; MPL reverse, 5⬘-TGGTCCACCGCCAGTCTG-3⬘; GenBank accession no.
U68161). The Pyrosequencer detects the pyrophosphate release per wild-type G or mutated T incorporation at JAK2 position 1849 or at MPL position 1544, respectively, by a
connected enzyme cascade with a luciferase-induced light signal. The light signal intensity is proportional to the amount of G or T and allows a quantification of the mutated T
allele (positive/negative controls: JAK2 mutant cell line HEL, MPL mutated patient sample, and JAK2/MPL wild-type cell line HL-60). (B) Pretherapy bone marrow trephine
revealed increased cellularity with a prominent promyelocytic proliferation and typical micromegakaryocytes (Giemsa stain; original magnification, ⫻1000). (C) Posttherapy
bone marrow trephine showed predominant megakaryocytic proliferation with large and bizarre megakaryocytes arranged in clusters (Giemsa stain; original magnification,
⫻1000). (D) Megakaryocytic proliferation was associated with a marked increase of argyrophilic fibers (silver stain; original magnification, ⫻1000). Images in panels B-D were
produced with a BX51 microscope equipped with a 40⫻/0.8 Vplan/Apo objective, a DP50 digital camera, and DP3.1 software, all from Olympus (Hamburg, Germany).
months (WBC count, 5 ⫻ 109/L; Hb, 138 g/L; LDH, 232 U/L; and
0% blast cells), including cytogenetic and molecular remission,
with no detectable BCR-ABL fusion transcripts in the bone marrow.
Furthermore, splenomegaly was no longer present. Follow-up
biopsies of the bone marrow 11, 14, and 23 months after initial
diagnosis and onset of treatment revealed an increasing accumulation of megakaryoctes and focal deposition of argyrophilic fibers
(Figure 1). Whereas histomorphology suggested persistence or
relapse of the Ph⫹ CML clone, no BCR-ABL fusion transcripts
could be detected in the bone marrow. Consequently, a JAK2V617F
mutation was analyzed with a highly sensitive pyrosequencer
2,4
assay, and in the initial biopsy, 5% mutated alleles were found,
which increased to 15% and 23% after 14 and 23 months,
respectively (Figure 1). During the first 23 months of follow-up red
blood cell counts, Hb, platelets, and WBC counts remained stable
and within normal range. When the initial pretherapeutic trephine
was re-evaluated, minor focal fibrosis was obvious, but besides a
BCR-ABL fusion, there was evidence for a small JAK2V617Fmutated clone encompassing 5% of alleles. In rare cases, JAK2V617F
can occur simultaneously with the recently discovered thrombopoietin receptor point mutation in the oncogene of myeloproliferative
leukemia (MPL 1544G ⬎ T/W515L),5,6 but pyrosequencing and
direct sequencing revealed a MPL wild-type status in all biopsies.
This case demonstrates for the first time that BCR-ABL translocation and JAK2 mutation may be concomitantly detectable in
hematopoietic cells of a single patient. The suppression of the Ph⫹
CML clone beyond the level of detection by imatinib therapy while
the JAK2V617F-mutated alleles steadily increased argues in favor of
2 independently growing aberrant stem cell clones in this patient.
The clinical and histopathologic diversity of Ph⫺ chronic myeloproliferative disease (CMPD), encompassing polycythemia vera, essential thrombocythemia, and chronic idiopathic myelofibrosis, all of
which share the JAK2V617F mutation, is still unexplained. Recently,
it has been hypothesized by Kralovics et al7 that a varying
combination of different molecular defects in 1 pathologic stem
cell might be responsible for the phenotypic heterogeneity,7 but this
case indicates that at least in a subfraction of patients, heterogeneity might also be caused by independently coexisting abnormal
hematopoietic stem cell clones. Furthermore, persistent anemia or
evolving myelofibrosis during imatinib treatment of Ph⫹ CML despite
molecular suppression might be caused by a coexisting Ph⫺ CMPD
clone.
Kais Hussein, Oliver Bock, Anna Seegers, Michael Flasshove,
Felicitas Henneke, Guntram Buesche, and Hans Heinrich Kreipe
Correspondence: Hans Kreipe, Institute of Pathology, Medizinische
Hochschule Hannover, Carl-Neuberg-Strasse 1, 30625 Hannover, Germany;
e-mail: [email protected].
Supported by Deutsche Krebshilfe, Dr Mildred Scheel Stiftung 10-2191 (O.B.,
H.K.) and Deutsche Forschungsgemeinschaft—DFG BO 1954/1-1 (O.B., H.K.)
References
1.
James C, Ugo V, Le Couedic JP, et al. A unique clonal JAK2 mutation leading
to constitutive signalling causes polycythaemia vera. Nature. 2005;434:11441148.
2.
Jelinek J, Oki Y, Gharibyan V, et al. JAK2 mutation 1849G⬎T is rare in acute
leukemias but can be found in CMML, Philadelphia chromosome-negative
CML, and megakaryocytic leukemia. Blood. 2005;106:3370-3373.
3.
Bock O, Busche G, Koop C, Schroter S, Buhr T, Kreipe H. Detection of the
single hotspot mutation in the JH2 pseudokinase domain of Janus kinase 2 in
bone marrow trephine biopsies derived from chronic myeloproliferative disorders. J Mol Diagn. 2006;8:170-177.
4.
Hussein K, Brakensiek K, Buesche G, et al. Different involvement of the
megakaryocytic lineage by the JAK2V617F mutation in polycythemia vera, essential thrombocythemia and chronic idiopathic myelofibrosis. Ann Hematol.
2007;86:245-253.
5.
Pikman Y, Lee BH, Mercher T, et al. MPLW515L is a novel somatic activating
mutation in myelofibrosis with myeloid metaplasia. PLoS Med. 2006;3:e270.
6.
Pardanani AD, Levine RL, Lasho T, et al. MPL515 mutations in myeloproliferative and other myeloid disorders: a study of 1182 patients. Blood. 2006;108:
3472-3476.
7.
Kralovics R, Teo S-S, Li S, et al. Acquisition of the V617F mutation of JAK2 is a
late genetic event in a subset of patients with myeloproliferative disorders.
Blood. 2006;108:1377-1380.
From www.bloodjournal.org by guest on June 14, 2017. For personal use only.
2007 109: 4106-4107
doi:10.1182/blood-2006-12-061135
Myelofibrosis evolving during imatinib treatment of a chronic
myeloproliferative disease with coexisting BCR-ABL translocation and
JAK2 V617F mutation
Kais Hussein, Oliver Bock, Anna Seegers, Michael Flasshove, Felicitas Henneke, Guntram Buesche
and Hans Heinrich Kreipe
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