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MEGALOBLASTICANEMIAS

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MEGALOBLASTIC ANEMIASCauses

1. Vit. B12 deficiency

2. Folic acid deficiency

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VITAMIN B12 AND FOLIC ACID-PHYSIOLOGIC CONSIDERATIONS

Vitamin B12 Folic acid

Sources meat, fish green vegetables, yeast

Daily requirement 2-5 ug 50-100 ug

Body stores 3-5 mg (liver) 10-12mg (liver)

Places of absorption ileum 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

- Fish tapeworm

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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 deficiency1. 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

• 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:

• macrocytic anemia ( MCV>100fl )

• thrombocytopenia

• leucopenia (granulocytopenia)

• low reticulocyte count

2. Blood smear:

• 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 , hypertsegmentation)

• megakariocytes are decreased and show abnormal morphology

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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

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PERNICIOUS ANEMIADIAGNOSIS

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

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FOLIC ACID DEFICIENCY ANEMIA DIAGNOSIS

1. Establishing megaloblastic anemia

2. History: causes of folate deficiency okoliczności sprzyjające niedoborowi kw. foliowego

3. Absence neurologic symptoms

4. Low serum and red blood cell folic acid

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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.

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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. Leczenie podtrzymujące w zależności od przyczyny