The morphology of the blood in dimorphic anaemia

Abstract

1. 1. The modern approach to anaemia consists in stressing the deficiency aspect of anaemia even when this deficiency is occasioned by, or increased in, a certain disease. Anaemia is seldom regarded as entirely secondary to disease unless this disease causes severe haemolysis. 2. 2. This outlook has not been applied to the classification of anaemia in the tropics, where anaemia is regarded as due almost exclusively to the presence of tropical diseases. 3. 3. Most cases of anaemia in Uganda natives show evidence of a dual deficiency of iron and of that present in nutritional macrocytic anaemia. 4. 4. It is suggested that this should be called dimorphic anaemia. 5. 5. 174 cases of anaemia in Uganda natives were examined by estimation of M.C.V., M.C.H.C., peripheral blood counts, sternal puncture, test meal, van den Bergh reaction and the reticulocyte response to iron and to liver. 6. 6. 100 of these cases appeared to be cases of dimorphic anaemia. 7. 7. The commonest cause of severe iron deficiency in dimorphic anaemia appeared to have been a heavy hookworm load and a diet deficient in iron. 8. 8. The commonest cause of the nutritional macrocytic anaemia type of deficiency appeared to have been due to a diet poor in meat and possibly in green vegetables. 9. 9. The sternal dry smear has been examined in 162 of these 174 cases and in some 145 other cases of anaemia and the megaloblastic tendencies in erythropoiesis in nutritional macrocytic anaemia and the hypochromic regeneration in iron-deficiency anaemia are described in detail and compared with normal erythropoiesis studied in eight normal Africans. 10. 10. In dimorphic anaemia all three types of erythropoiesis can usually be detected, hypochromic, megaloblastic and normoblastic, the latter, however, usually predominating. 11. 11. The morphology of the peripheral blood is described. Hypochromic cells are concentrated in the central parts of the smear whereas orthochromic macrocytes are collected at the tail. This is usually so characteristic that a diagnosis of dimorphic anaemia can be made at once in most cases. 12. 12. These views must not be construed to deny the fact that in well-fed persons malaria produces a pure haemolytic anaemia and hookworms a pure post-haemorrhagic iron-deficiency anaemia, neither of which comes under the category of dimorphic anaemia.