MEGALOBLASTIC ANEMIA – an emerging GLOBAL PROBLEM and it’s noteworthy ELEVEN – TITBITS
1 Megaloblastic Anemia is better viewed as a multi-system disorder with ANEMIA, centrally featured by large Erythrocytes bigger than 100 fL in terms of MCV ( macro-ovalocytes ) as the classic picture.
2 Nutritional Deficiency of Vitamin B 12 ( COBALMIN) is FIVE TIMES commoner than FOLATE deficiency. However, deficiency of both can also cause Pancytopenia and Osteopenia / Osteoporosis.
3 Vit. B 12 Deficiency is a worldwide problem, with Breastfed babies of B-12 Deficient mothers being at highest risk. Pure Vegetarian diet and cooking are other contributing factors.
4 FOLATE deficiency is less common but both Deficiency States can co-exist.
5 RDA for Vit.B 12 is 0.2 to 1 mcg. and that of FOLATE is 25-200 mcg. The former is absorbed in the ILEUM and the latter in DUODENUM – JEJUNUM.
6 LAB. TESTING of Serum Vit. B12 and FOLATE has little value . Serum HOMOCYSTEINE is increased in both deficiency states but MMA ( Methyl Malonic Acid ) rises only in VIT B 12 deficiency.
7 In Megaloblastic Anemia, there is defective DNA SYNTHESIS leading to poor Nuclear maturation, vis-a-vis Cytoplasmic Maturation.
8 Haematological Findings are HyperSegmented Neutrophills ( six or more lobes) + Macro-Ovalocytes, Reticulocytes less than 1 % , Leukopenia and occasionally Thrombocytopenia .
Nucleated RBCs are seen in Per. Smear, if Hematocrit is less than 20 % ( Since all Cell lines are down, it could easily mimic Aplastic Anemia )
Bone Marrow shows reversed M/E RATIO and giant Metamyelocytes.
9. NEUROLOGICAL SYMPTOMS can be either : Tremors, Hypotonia, Seizures, Parasthesias and Development Regression. However, Cognitive Dysfunction is likely to stay, despite therapy.
10 Skin changes are Hyperpigmentation of knuckles and terminal phalanges . ATP SYNDROME ( anemia+ tremor+ pigmentation TRIAD ) is a classic clinical pointer in children.
11 Treatment Priority is with B12 replacement and FOLATE supplementation comes after the former is managed. Parenteral Vitamin B 12 is better administered by IV injection , rather than IM route, in view of the likelihood of Thrombocytopenia and local bleeds.