MEGALOBLASTICANEMIAS

Nada Mohamed Ahmed ,MD, MT (ASCP)i

Contents • Definition • Causes • Function of B 12,folate • General feature • lab diagnosis

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MEGALOBLASTIC ANEMIASCauses

1. Vit. B12 deficiency

2. Folic acid deficiency

Functions of folate and vitamin B12

• folate and vitamin B12 are required for DNA synthesis and for maintenance of neurons and red blood cells.

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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 proxymalsegment of small intestine

Vit .B12

Plazma level of Vit. B12

• 200 - 900 ng/ L

Folate levels:

Normal ranges • Serum: 6 – 21 g/L (RBC volume)

• Red cell: 160 – 640 g/L (RBC volume)

Folate deficiency• Serum folate : <4g /L • Red cell folate: <140g /L

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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 utylisationDrugs: 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)

• 3-Glossitis :

Sore tongue, poor taste sensation, pain

Papill. atrophy-beefy tongue

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MEGALOBLASTIC ANEMIAS clinical features

1. Symptoms of anemia2. Symptoms associated with vit. B12 or Folic acid deficiency

• neurologic manifestations (exclusivly in wit. B12 deficiency)

- megaloblastic madness or psychosis, • 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 neutrophyles

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VIT B12 DEFICIENCY ANEMIA DIAGNOSIS

1. Establishing megaloblastic anemia

2. Clinical symptoms of vit. B 12

deficiency3. Low serum vit. B 12

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FOLIC ACID DEFICIENCY ANEMIA DIAGNOSIS

1. Establishing megaloblastic anemia 2. History: causes of folate deficiency3. Absence neurologic symptoms 4. Low serum and red blood cell folic acid

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MEGALOBLASTIC ANEMIAS TREATMENT(1)

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.

,

Vitamin B12

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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