53 The Role of Folate and Vitamin B₁₂ in the Etiology of the Thrombocytopenia of Iron Deficiency Anemia

Abstract

Thrombocytopenia is an unexplained complication of iron deficiency anemia. Studies have suggested that the low levels of platelets may in some instances be related to a folate or vitamin B₁₂ deficiency. In order to pursue this possibility, neutrophile lobe counts, bone marrow examinations, serum folate and vitamin B₁₂ levels, and formiminoglutamic acid (FIGLU) excretion studies were performed on 55 iron deficient anemic infants and children both with and without thrombocytopenia. Similar studies were performed on normal children. There was an increased incidence of hypersegmentation in the iron deficiency patients and a number of these children exhibited increased lobe averages. Twenty-five of the anemic children showed abnormalities of the bone marrow consistent with megaloblastic dysplasia. The serum vitamin B₁₂ levels were within normal limits in all patients but the serum folate level was decreased in two of them, and three children excreted increased amounts of FIGLU.

Although there appeared to be a slightly greater incidence of bone marrow megaloblastoid changes in the thrombocytopenic children no clear separation on a morphologic or biochemical basis could be made between those with and without a platelet deficiency. These findings indicate that although a folate or vitamin B₁₂ deficiency at the bone marrow level may be involved in the causation of the thrombocytopenia of iron deficiency anemia, other factors may also be important in the etiology of the complication. (SPR)