Hypersegmentation in Iron Deficiency Anemia

Abstract

<h3>To the Editor.—</h3> Hypersegmented neutrophils, a hallmark of vitamin B¹²and folic acid deficiency, have also been found, for unknown reasons, in chronic renal disease and as a hereditary disorder. The neutrophil hypersegmentation observed in iron deficiency,¹usually ascribed to an associated vitamin B₁₂or folate deficiency, may also occur without laboratory evidence of deficiency of these vitamins. The reason for this morphologic change in iron deficiency is not known, but abnormalities in folate metabolism have been suggested. Thus, the urinary excretion of formiminoglutamic acid (FIGLU) is often increased in iron deficiency, and experimentally induced iron deficiency may lead to a secondary folate deficiency.^2,3 In patients with normal serum folate levels, it is possible that a subclinical folate deficiency exists, since iron therapy may induce a fall in serum folate concentrations. It has also been suggested that the enzymeFIGLU transferase is iron-dependent and, therefore, not functioning