At what level of Hb should I be
worried?
Not a single figure but the whole picture that is
important
eg
– 60 year old male/female
– Hb 180 MCV 92 six months ago
– Hb 120 MCV 80 now
eg
– 30 year female with menorrhagia
No test substitutes history and examination
Reticulocyte count
If production is normal – anaemic patient
should have high reticulocyte count
Low or normal reticulocyte anaemia
= production failure
LACK OF BONE MARROW
STIMULATION
– DEFICIENCY OF EPO (CRF) OR OTHER
HORMONES (THYROID)
– REFRACTORINESS TO EPO (SYSTEMIC
INFLAMMATORY PROCESS)
Bone marrow dysfunction
Generally associated with abnormality in
WCC and platelets
Blood film often provides diagnostic clues
Physical examination may be abnormal
INCREASED RED CELL LOSS IE HIGH
RETICULOCYTE COUNT ANAEMIA
HAEMOLYTIC ANAEMIA
– IMMUNE MEDIATED
– NON IMMUNE
ACUTE BLOOD LOSS
ANEMIA
NOT ALWAYS A PRIMARY
HEMATOLOGICAL
CONDITION
ANEMIA
45 YEARS OLD MAN
TIRED AND NOT FEELING WELL
MILD EXERTIONAL SHORTNESS OF
BREATH
NO FOCAL SYMPTOMS
NO CO-MORBIDITIES
ANEMIA
HEMOGLOBIN: 100 GM/L
MCV: 89
WWC/DIFFERENTIAL AND PLATELETS:
NORMAL
WHAT OTHER ISSUES AND TESTS?
ANEMIA
NORMAL WCC AND PLATELETS:
– BLOOD FILM
– RENAL FUNCTION
– LFTs AND INFLAMMATORY MARKERS
– HEMATINIC STUDIES
– HAPTOGLOBIN
– PARAPROTEIN
– ENDOCRINE EVALUATION
Case 1
20 YR FEMALE
HB 70 RETICULOCYTE COUNT 200
FILM: RED CELL AGGLUTINATION +
SPHEROCYTES MARKED POLYCHROMASIA
RECENT GLANDULAR FEVER/MYCOPLASMA
INFECTION – RECEIVED PENICILLIN
HAPTOGLOBIN – UNDETECTABLE, COOMB’S
TEST POSITIVE
DIAGNOSIS – HAS AUTOIMMUNE
HAEMOLYTIC ANAEMIA
Case 2
20 YEAR FEMALE, RECURRENT SORE
THROAT
HB 70, WCC 2, N 1, PLT 30
RETICULOCYTE COUNT 20
FILM: UNREMARKABLE
FERRITIN 200 B12/FOLATE NORMAL
DIAGNOSIS: BONE MARROW FAILURE
?APLASTIC ANAEMIA
Red flags – abnormal film
Rouleaux
Leukoerythroblastic
film
Red cell agglutination
Fragmentation
Red flags
INVOLVEMENT OF OTHER CELL
LINEAGES
SYSTEMIC SYMPTOMS AND SIGNS
FAMILY HISTORY
ANEMIA
82 YEAR OLD FEMALE
NOT FEELING WELL
LETHARGIC, EXERTIONALLY SHORT
OF BREATH
ALSO NOTED EXERTIONAL CHEST
TIGHTNESS
ANEMIA
6 MONTHS OF CRAVING FOR ICE
CREAM AND RICE
INCREASING CONSTIPATION
NO OTHER CONCERNS
ANEMIA
FULL BLOOD COUNT:
– HEMOGLOBIN: 75 GMS/L (120-150)
– MCV: 68 Fl (82-96)
– Platelets: 680x109/l (150-400)
– WCC: 5.5X109/L (4-11)
– BLOOD FILM: MICROCYTIC
HYPROCHROMIC , ELONGATED RED
CELLS
DIAGNOSIS OF IRON
DEFICIENCY
FULL BLOOD COUNT
– MICROCYTIC HYPOCHROMIC RED CELLS,
PENCIL-SHAPED RED CELLS
– NORMAL WHITE CELL COUNT
– PLATELET COUNT NORMAL OR INCREASED
IRON STUDIES
IRON STUDIES IN IRON
DEFICIENCY ANEMIA
SERUM IRON: REDUCED
TRANSFERRIN LEVEL: INCREASED
FERRITIN: REDUCED
FERRITIN
THE STORED FORM OF
IRON
SERUM FERRITIN
CONSISTS OF TWO MOIETIES:
– APOFERRITIN: AN ACUTE PHASE
REACTANT
– IRON
FERRITIN ASSAYS DO NOT
DIFFERENTIATE BETWEEN
APOFERRITIN AND FERRITIN
ELEVATED FERRITIN LEVELS
MALIGNANCIES
INFLAMMATORY CONDITIONS
HEPATITIS
– A NORMAL OR HIGH FERRITIN
DOES NOT RULE OUT IRON
DEFICIENCY
TRANSFERRIN RECEPTOR
ESSENTIAL FOR TRANSPORT OF IRON INTO
CELLS
80% OF CELLULAR TRANSFERIN RECEPTOR
IS ERYTHROID IN ORIGIN
A TRUNCATED FORM OF THE RECEPTOR
CIRCULATES IN PLASMA
SOLUBLE FORM OF
TRANSFERRIN RECETOR
ELEVATED LEVELS
– ERYTHROID HYPERPLASIA
– IRON DEFICIENCY
REDUCED LEVELS
– HYPOPLASTIC ANEMIA
– OTHER SITUATIONS WHERE
ERYTHROPOIESIS IS REDUCED
SOLUBLE TRANSFERIN
RECEPTOR
HELPFUL IN DIFFERENTATING IRON
DEFICIENCY FROM OTHER CAUSES
OF ANEMIA
LEVELS IS NOT INCREASED IN
ACUTE INFLAMMATORY STATES
TREATMENT OF IRON
DEFICIENCY ANEMIA
IDENTIFY THE CAUSE
REPLENISH IRON STORES
COBALAMIN DEFICIENCY
COBALAMINS ARE ESSENTIAL FOR DNA
SYNTHESIS, REPLICATION AND CELL GROWTH
TYPICAL DIET CONTAINS 3-10 UG OF COBALAMIN
RESERVE IS PRIMARILY HEPATIC >1.5 MG
USUALLY A 5-10 YEAR DELAY BETWEEN
INSUFFICENT INTAKE AND ONSET OF SYMPTOMS.
BETTER ASSAYS LED TO INCREASED
RECOGNITION OF DEFICIENCY STATES
VITAMIN B12 (COBALAMIN)
LOW COBALAMIN AND
NEUROPSYCHIATRIC PROBLEMS
SEVERAL REPORTS ON
NEUROPSYCHIATRIC SYMPTOMS AND
LOW COBALAMIN
PATIENTS DO NOT DISPLAY ANEMIA
OR INCREASED MCV
TRUE COBALAMIN DEFICIENCY CAN
OCCUR WITH LOW NORMAL B12
LEVELS
Neuropsychiatric disorders caused by cobalamin deficiency in the
absence of anemia or macrocytosis
J Lindenbaum, EB Healton, DG Savage, JC Brust, TJ Garrett, ER Podell, PD
Marcell, SP Stabler, and RH Allen
Among 141 consecutive patients with neuro-psychiatric abnormalities due to cobalamin deficiency, we found that 40 (28
percent) had no anemia or macrocytosis. The hematocrit was normal in 34, the mean cell volume was normal in 25, and
both tests were normal in 19. Characteristic features in such patients included paresthesia, sensory loss, ataxia,
dementia, and psychiatric disorders; longstanding neurologic symptoms without anemia; normal white-cell and platelet
counts and serum bilirubin and lactate dehydrogenase levels; and markedly elevated serum concentrations of
methylmalonic acid and total homocysteine. Serum cobalamin levels were above 150 pmol per liter (200 pg per milliliter)
in 2 patients, between 75 and 150 pmol per liter (100 and 200 pg per milliliter) in 16, and below 75 pmol per liter (100 pg
per milliliter) in only 22. Except for one patient who died during the first week of treatment, every patient in this group
benefited from cobalamin therapy. Responses included improvement in neuropsychiatric abnormalities (39 of 39),
improvement (often within the normal range) in one or more hematologic findings (36 of 39), and a decrease of more
than 50 percent in levels of serum methylmalonic acid, total homocysteine, or both (31 of 31). We conclude that
neuropsychiatric disorders due to cobalamin deficiency occur commonly in the absence of anemia or an elevated mean
cell volume and that measurements of serum methylmalonic acid and total homocysteine both before and after treatment
are useful in the diagnosis of these patients.
Pernicious anemia. The expected findings of very low serum cobalamin levels, anemia, and macrocytosis are
often lacking
R. Carmel
Department of Medicine, University of Southern California, School of Medicine 90033.
When patients are examined for possible cobalamin deficiency, great stress is often placed on the presence or
absence of macrocytosis and anemia and on how low the serum cobalamin level is. The present study, however,
shows that only 45 (64%) of 70 consecutively diagnosed patients with pernicious anemia, the most common cause of
cobalamin deficiency, had very low cobalamin levels (less than 74 pmol/L [or less than 100 ng/L]). Anemia was absent
in 13 (19%) of the patients, and macrocytosis was absent in 23 (33%) of the patients; such absence was particularly
common when cobalamin levels were only slightly or moderately low (74 to 184 pmol/L). Coexisting iron deficiency was
responsible for the absence of macrocytosis in nine patients. Of the ten patients with neither anemia nor macrocytosis,
neurological disturbance was prominent in six, including four whose only noticeable abnormality was cerebral. These
observations indicate that macrocytosis and anemia, two classic features of pernicious anemia, may be overstressed in
our diagnostic approach. All subnormal serum cobalamin results are best viewed as pathological until proved
otherwise. Emphasis on only very low cobalamin levels risks delaying the diagnosis of pernicious anemia in a
substantial proportion of cases, particularly in those without anemia or macrocytosis.
B12 DEFICIENCY IS COMMON
FLOOD VM, ET AL. PREVALENCE OF
LOW SERUM FOLATE AND VITAMIN
B12 IN AN OLDER AUSTRALIAN
POPULATION. AUST N Z J PUBLIC
HEALTH. 2006, 30(1):38-41
3,508 PERSONS AGED 50+ YEARS
COHORT STUDY SYDNEY
LOW SERUM B12 (< 185 PMOL/L) IN
22.9% OF PARTICIPANTS
B12 DEFICIENCY IS
COMMON
B12 DEFICIENCY
15% OF PEOPLE OVER THE AGE OF 60
HAVE B12 DEFICIENCY
– FOOD COBALAMIN DEFICIENCY: 60-70%
OF CASES
– PERNICIOUS ANEMIA 15-20% OF CASES
– DIETARY AND MALABSORPTION 10-20%
COBALAMINS
HYDROXYCOBALAMIN, METHYLCOBALAMIN
AND 5-DEOXYADENOSYLCOBALAMIN ARE
THE ACTIVE FORMS OF B12
ALL THREE COBALAMINS BIND TO PLASMA
BINDING PROTEINS
– TRANSCOBALAMIN II BINDS 20% OF TOTAL B12
– REMAINDER OF B12 IS BOUND TO R-PROTEINS
TC II IS THE PHYSIOLOGICAL B12 TRANSPORTER
HOLOTRANSCOBALAMIN: 20% OF
COBALAMIN IS BOUND TO TCII
B12
TRANSCOBALAMIN II
OTHER TC R-BINDERS
B12 ASSAYS MEASURE ALL B12 IN THE PLASMA AND ARE NOT
ALWAYS A RELIABLE INDICATOR OF TRUE B12 STATUS
HOLOTRANSCOBALAMIN: 20% OF
COBALAMIN IS BOUND TO TCII
B12
TRANSCOBALAMIN II
OTHER TC R-BINDERS
VITAMIN B12 ASSAYS
LEVELS GREATER THAN 200 pMOL/L
USUALLY INDICATE ADEQUATE B12
STATUS
LEVELS BELOW 70 pMOL/L ARE
INVARIABLY ASSOCIATED WITH TRUE
DEFICIENCY
LEVELS BETWEEN 70 AND 200 MAY BE
DIFFICULT TO INTERPRET
DIFFICULTIES IN B12 ASSAYS
HOLO-TC ASSAYS ARE NOW AVAILABLE
THEY DETECT THE FUNCTIONALLY
IMPORTANT B12
HOLO-TC LEVELS CORRELATE WITH OTHER
FUNCTIONAL MARKERS OF COBALAMIN
DEFICIENCY
IF VITAMIN B12 LEVEL < 200 PMOL/L
LABORATORY INITIATES HOLO-TC ASSAY
PERNICIOUS ANEMIA
B12 MALABSORPTION SECONDARY TO
ANTIBODIES TO INTRINSIC FACTOR
INTRINSINC FACTOR ANTIBODY
ASSAYS SPECIFIC BUT NOT
SENSITIVE
GASTRIC PARIETAL CELL ANTIBODIES
SENSITIVE BUT NOT SPECIFIC
FOOD COBALAMIN DEFICIENCY
FIRST DESCRIBED IN 1995
INABILTIY TO RELEASE COBALAMIN
FROM FOOD
NORMAL B12 INTAKE
COMMONLY ASSOCIATED WITH
REDUCED GASTRIC ACID DUE TO
GASTRIC ATROPHY
FOOD COBALAMIN DEFICIENCY
CONTRIBUTING FACTORS:
– HELICOBACTER INFECTION
– ACID SUPPRESSANT DRUGS
– METFORMIN
– OCP
– CHRONIC ALCOHOLISM
– IDIOPATHIC
FOOD COBALAMIN DEFICIENCY
5-10% OF PATIENTS ARE
SYMPTOMATIC
HEMATOLOGIC ABNORMALITIES MAY
BE INCOMPLETE (MILD
PANCYTOPENIA)
MILD SENSORY NEUROPATHY
COMMON
CONFUSION, IMPAIRED MENTAL
FUNCTIONING
DIAGNOSIS OF FOODCOBALAMIN MALABSORPTION
LOW VITAMIN B12 LEVEL
HEMATOLOGICAL PROFILE
ABSENCE OF INTRINSIC FACTOR
ANTIBODIES
APPROPRIATE CLINICAL SETTING
RESPONSE TO ORAL THERAPY
TREATMENT OF FOOD
COBALAMIN MALABSORPTION
TREATMENT OF FOOD COBALAMIN
MALABSORPTION
VITAMIN B12 INJECTIONS
ORAL CRYSTALLINE VITAMIN B12
ONE MG FOR ONE MONTH:
– NORMALISED B12 LEVEL
– IMPROVED HEMOGLOBIN, MCV
READINGS
– TREATMENT EVERY OTHER DAY IS
SUFFICIENT
WHEN IN DOUBT:
SUMMARY AND TAKE HOME
MESSAGES
B12 DEFICIENCY IS COMMON
B12 DEFICIENCY CAN CAUSE
NEUROLOGICAL SYMPTOMS IN THE
ABSENCE OF CLASSICAL HEMATOLOGICAL
FINDINGS
FOOD COBALAMIN MALABSORPTION IS THE
COMMONEST CAUSE OF B12 DEFICIENCY
EARLY RECOGNITION OF B12 DEFICIENCY
MAY SLOW/PREVENT NEURO-PSYCHIATRIC
COMPLICATIONS
AUTOIMMUNITY
BREAKDOWN IN SELF TOLERANCE
MECHANISMS
THE GENERATION OF AUTOREACTIVE
LYMPHOCYTES
NORMALLY THESE CELLS ARE ELIMINATED:
– CLONAL DELETION: AT A CENTRAL LEVEL (E.G.
BONE MARROW)
– CLONAL ANERGY: INACTIVATION BUT NOT
DELTED
AUTOIMMUNE HEMOLYTIC
ANEMIA
ANTIBODIES AGAINST THE RED CELLS
RED CELL SURVIVAL SHORTENED
BONE MARROW COMPENSATION
ANEMIA DEVELOPS IF
COMPENSATION CANNOT KEEP UP
WITH THE DESTRUCTION
AUTOIMMUNE HEMOLYTIC
ANEMIA
IDIOPATHIC
DRUGS
AS PART OF A MORE GENERALISED
AUTOIMMUNE DISEASE
SECONDARY TO OTHER DISEASES
– LYMPHOMA/CHRONIC LYMPHATIC
LEUKEMIA
– HIV
– IMMUNE DEFICIENCY STATES
AUTOIMMUNE HEMOLYTIC
ANEMIA
DEVELOPMENT OF ANTIBODIES AGAINST
RED CELLS
TAGGED RED CELLS ARE REMOVED IN THE
SPLEEN OR LIVER
RED CELL SURVIVAL IS SHORTENED
BONE MARROW COMPENSATES FOR
INCREASED DESTRUCTION
ANEMIA DEVELOPS WHEN PRODUCTION
FAILS TO KEEP UP WITH DESTRUCTION
AUTOIMMUNE HEMOLYTIC
ANEMIA
SPHEROCYTE
HAEMOLYTIC ANAEMIA
ANEMIA SECONDARY TO REDUCED
RED CELL LIFE SPAN
MANY OF THE FEATURES ARE
SECONDARY TO INCREASED RED
CELL TURNOVER
INCREASED RED CELL
TURNOVER
HEMOGLOBIN
– HEME: METABOLISED TO BILE
– GLOBIN RECYCLED
HAEMOGLOBIN TURNOVER
HEME CONVERTED TO BLIVERDIN IN
MACROPHAGES
BILIVERDIN REDUCED TO BILIRUBIN
(ALBUMIN BOUND)
BILIRUBIN TAKEN UP BY THE LIVER
AND CONJUGATED
CONJUGATED BILIRUBIN IS WATER
SOLUBLE
FATE OF BILIRUBIN
CONJUGATED BILIRUBIN SECRETED AS
BILE AND USED FOR FAT DIGESTION
BILIRUBIN ABSORBED BY SMALL BOWEL
– ABSORBED BILIRUBIN RE-SECRETED AS
BILE
– BROKEN DOWN BY GUT BACTERIA AND
ABSORBED AND EXCRETED AS
UROBILINOGEN
BILIRUBIN METABOLISM
NORMAL URINE CONTAINS:
– NO BILIRUBIN
– SMALL AMOUNTS OF UROBILINOGEN
HAEMOLYTIC ANEMIA
DIAGNOSIS:
– BLOOD FILM:
POLYCHROMASIA, SPECIFIC FINDINGS
– EVIDENCE OF INCREASED RED CELL
DESTRUCTION
INCREASED LEVELS OF BILIRUBIN,
UROBILINOGEN, LDH,
REDUCED HAPTOGLOBIN
– EVIDENCE OF INCREASED RED CELL PRODUCTION:
RETICULOCYTOSIS
BONE MARROW FINDINGS
AUTOIMMUNE HEMOLYTIC
ANEMIA
72 YEAR OLD MAN
EXERTIONAL SHORTNESS OF BREATH
TIRED
SLIGHTLY JAUNDICED
SPLEEN ENLARGED
AUTOIMMUNE HEMOLYTIC
ANEMIA
HEMOGLOBIN: 70 GM/L (130-150)
– MCV: 115fL (82-96)
WHITE CELL COUNT: 7.2X109/L
PLATELETS: 356X109/L
BLOOD FILM: SPHEROCYTES,
POLYCHROMASIA
AUTOIMMUNE HEMOLYTIC
ANEMIA
BILIRUBIN: 46 uMol/L (up to 21)
LDH: 360 IU (UP TO 250)
HAPTOGLOBIN: <0.1 G/L (0.3-2)
COOMBS TEST (DIRECT
ANTIGLOBULIN TEST): POSITIVE FOR
IgG AND COMPLEMENT
AUTOIMMUNE HEMOLYTIC
ANEMIA
AUTOIMMUNE HEMOLYTIC
ANEMIA
TREATMENT:
– STEROIDS
– OTHER IMMUNOSUPPRESSANTS
– HIGH DOSE INTRAVENOUS
IMMUNOGLOBULIN
– SPLENECTOMY