Transcript NIEDOKRWISTOŚCI MEGALOBLASTYCZNE

MEGALOBLASTIC
ANEMIA
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M. Kaźmierczak XI 2012
MEGALOBLASTIC ANEMIAS
Causes
1. Vit. B12 deficiency
2. Folic acid deficiency
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VITAMIN B12 AND FOLIC ACIDPHYSIOLOGIC CONSIDERATIONS
Sources
Daily requirement
Vitamin B12
meat, fish
2-5 ug
Body stores
3-5 mg (liver)
(liver)
Places of absorption ileum
Folic acid
green vegetables, yeast
50-100 ug
10-12mg
duodenum and proxymal
segment of small intestine
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MEGALOBLASTIC ANEMIAS
Causes of Vit.B12 deficiency(1)
1. Malabsorption
a) Inadequate production of intrinsic factor
- pernicious anemia
- gastrectomy, partial or total
b) Inadequate releasing vit. B12 from food
(partial gastrectomy, abnormality of stomach function,
chronic pancreatic insufficiency)
c) Terminal ileum disease (sprue, celiac disease, ilea resection, Crohn
disease, Imerslund syndrome)
d) Competition for intestinal B12 :
- bacterial overgrowth: jejunal diverticula, intestinal stasis and
obstruction due to strictures, blind-loop syndrome
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- Fish tapeworm
MEGALOBLASTIC ANEMIAS
Causes of Vit.B12 deficiency(2)
2. Inadequate intake
- vegetarians
3. Inadequate utylisation
Drugs: PAS, Neomycin, Colchicin, Nitrous oxide
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MEGALOBLASTIC ANEMIAS- Causes of Folic acid deficiency
1. Inadequate intake
- diet lacking fresh, slightly cook food; chronic alcoholism, total parenteral nutrition,
2. Malabsorption
- small bowel disease (sprue, celiac disease,)
- alcoholism
3. Increased requirements:
- pregnancy and lactation
- infancy
- chronic hemolysis
- malignancy
- hemodialysis
4. Defective utilisation
Drugs:folate antagonists(methotrexate, trimethoprim, triamteren), purine analogs
(azathioprine), primidine analogs (zidovudine), RNA reductase inhibitor (hydroxyurea),
miscellaneous (phenytoin, N2)
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MEGALOBLASTIC ANEMIAS
clinical features
1. Symptoms of anemia
2. Symptoms associated with vit. B12 or Folic acid deficiency
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neurologic manifestations (exclusivly in wit. B12 deficiency)
- megaloblastic madness or psychosis,
- subacute, combined degeneration of the spinal cord
( proprioceptive and vibratory sensation, spinal ataxia)
gastrointestinal compraints (vit.B12 and folic acid deficiency)
- loss of appetite
- glosstis (red, sore, smooth tongue)
- diarrhea or constipation
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MEGALOBLASTIC ANEMIAS
Diagnosis(1)
1. Blood cell count:
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macrocytic anemia ( MCV>100fl )
thrombocytopenia
leucopenia (granulocytopenia)
low reticulocyte count
2. Blood smear:
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macroovalocytosis , anisocytosis, poikilocytosis
hypersegmentation of granulocytes
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MEGALOBLASTIC ANEMIAS
Diagnosis(2)
3. Laboratory features
• indirect hyperbilirubinemia
• elevation of lactate dehrogenase (LDH)
• serum iron concentration- normal or increased
4. Bone marrow smear
• hypercellular
• increased erythroid /myeloid ratio
• erythroid cell changes (megaloblasts, RBC precursor a abnormally large
with nuclear- cytoplasmic asynchrony)
• myeloid cell changes (giant bands and metamyelocytes ,
hypersegmentation)
• megakariocytes are decreased and show abnormal morphology
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Megaloblastic erythropoiesis
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MEGALOBLASTIC ANEMIAS
Diagnosis
1. Diagnosis megaloblastic anemia
2. Establishing a type of deficiency (vit. B12 and/or folic
acid)
3. Establishing a cause of deficiency
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VIT B12 DEFICIENCY ANEMIA
DIAGNOSIS
1. Establishing megaloblastic anemia
2. Clinical symptoms of vit. B 12 deficiency
3. Low serum vit. B 12
4. Increased concentration of methylmalonic acid (MMA)
and total homocysteine
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PERNICIOUS ANEMIA
DIAGNOSIS
1. Establishing vit.B12 deficiency anemia
2. Absence of hydrogen ion secretion (achlorhydria) with maximal
histamine stimulation
3. Radiolabeled vit. B12 absorption test (Schilling urinary excretion
test) : very reduced absorption of the B12-isotope, corrected to
normal only when coadministered with a source of gastric IF.
4. Intrinsic factor, parietal cell and IF-vit.B12 complex antibodies
5. Chronic atrophic gastritis
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Atrophic glossitis
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FOLIC ACID DEFICIENCY ANEMIA
DIAGNOSIS
1. Establishing megaloblastic anemia
2. History: causes of folate deficiency
3. Absence neurologic symptoms
4. Low serum and red blood cell folic acid
5. Normal concentration of methylmalonic acid (MMA) and
increased of total homocysteine
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MEGALOBLASTIC ANEMIAS
TREATMENT(1)
PERNICIOUS ANEMIA
1. Vitamin B12 administration intramuscular in dose 1000 (100) μg per day for
a week , then 100 μg 2x per week for 2 weeks, 1 x per week 100μg for
month
2. Reticulocytosis begins 2 or 3 days after therapy started and maximal number
reached on day 5 to 8.
Serum iron monitoring, after 7-10 days of vit.B12 treatment,
if Fe deficiency is diagnosed we should start iron substitution
3. 100 ug vit.B12 i.m. every month, regimen that must be mainted for the rest
on the patients life.
4. Oral substitution of cobalamin at doses 1000-2000ug/d
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MEGALOBLASTIC ANEMIAS
TREATMENT(2)
FOLIC ACID DEFICIENCY ANEMIA
1. Oral administration of Ac. folicum 1 (5) mg per day, for
3 months, and maintance therapy if it’s necessary.
2. Reticulocytosis after 5-7 days
3. Correction of anemia is over after 1-2 months
therapy
4. Maintenance therapy if necessary
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