Acquired pure red cell aplasia.

Correspondence MEDICALTJOSRNAL 559 Acquired Pure Red Cell Aplasia SIR,-May we make the following observation about your article on acquired pure red cell aplasia and its treatment with steroids (6 April, p. 3) ? A pure red cell aplasia that responded to riboflavine or prednisone has been described in African adults and in children with marasmus and kwashiorkor.' In marasmus and kwashiorkor an erythroid aplasia is frequently present when the children enter hospital in a serious clinical condition, with low total serum proteins, reversed albumin/ globulin ratio, giant pro-erythroblasts in the marrow, but the haemoglobin not grossly reduced. This aplasia is associated with infection and remits spontaneously, or when the infection is treated with antibiotics. Later, when the children are clinically better and their serum proteins are normal, an erythroid aplasia may develop which is not associated with infection, does not remit spontaneously or respond to antibiotics, and has no giant pro-erythroblasts in the marrow. This later aplasia responds to either riboflavine or prednisone, and unless so treated the children frequently die suddenly, either in hospital or when they have been discharged, from what appears to be adrenal insufficiency. About 10%-20% of children with marasmus and kwashiorkor in Kenya develop this erythroid aplasia during the recovery syndrome. It occurs 6 to 16 weeks after the children have been admitted to hospital and will be missed unless their stay is prolonged and frequent serial marrow biopsies are taken over a long period of time.' Histological abnormalities in the adrenal cortex, and in serum steroids, have been described in marasmus and kwashiorkor.`' A similar pure red cell aplasia has now been produced in baboons (Papio anubis) fed on a synthetic diet adequate in calories and all the necessary mineral salts and vitamins except ribo-flavine.5 In children with marasmus and kwashiorkor, and in the baboons, aplasia was judged by the absence of reticulocytes and profound falls in the marrow red cell precursors as estimated cytologically, as well as by depressed marrow activity determined by decreased uptake and plasma clearance of "Fe.' As in marasmus and kwashiorkor there are histological abnormalities in the adrenal cortex of the riboflavine-deprived baboons, but whether these are associated with derangements in production or metabolism of steroids is being investigated.' In the aplasia of infection the marrow neutrophils are raised, and giant pro-erythro-blasts are present, but in aplasia not associated with infection it is the marrow lymph-ocytes that are increased …