Dimorphic anaemia: Deficiency of iron associated with nutritional macrocytic anaemia

Abstract

1. 1. Anaemia in the tropics is usually regarded as secondary to some tropical disease, such as the haemolysis of malaria and the blood sucking of hookworms; nutritional (tropical) macrocytic anaemia is a deficiency anaemia but is regarded as uncommon apart from pregnancy. 2. 2. Three hundred and eighteen cases of anaemia in Uganda were classified along these lines, but many difficulties arose in the classification due to overlap between the groups. 3. 3. The anomalies chiefly concerned treatment: iron might improve cases of nutritional macrocytic anaemia and liver might improve the iron deficiency anaemia of hookworm disease. 4. 4. The above classification was therefore abandoned in favour of the following procedure:— 4.1. ( a) Define the deficiencies present. 4.2. ( b) Ascertain if possible what factors in the diet and also what disease might give rise to these deficiencies ( e.g., hookworms accentuating an iron deficiency in the diet) or might destroy blood ( e.g., malaria). 4.3. ( c) Ascertain what associated infections or diseases might impede blood regeneration ( e.g., tuberculosis, nephritis). 5. 5. To indicate what deficiencies were present, cases were classified by mean corpuscular volume (M.C.V.) and mean corpuscular haemoglobin concentration (M.C.H.C.). 134 cases were thus classified as:— 5.1. I. 27 cases of macrocytic orthochromic anaemia (nutritional macrocytic anaemia). 5.2. II. 63 cases of macrocytic hypochromic anaemia. 5.3. III. 27 cases of normocytic hypochromic anaemia. 5.4. IV. 5 cases of microcytic hypochromic anaemia (pure iron deficiency). 5.5. V. 11 normocytic orthochromic and one microcytic orthochromic (mixed aetiology). 6. 6. Cases which were in Groups II and III showed signs suggestive of a mixture of nutritional macrocytic and iron deficiency anaemias. The majority were cured by iron and liver, in others the response to these was tested separately. 7. 7. A detailed analysis of these two groups is given. 8. 8. In some of these cases both deficiencies appeared severe and needed treatment by iron and liver, which, given separately, induced a double reticulocyte response. 9. 9. In others one deficiency predominated and obscured the other, and cases appeared to recover, albeit slowly, if the major deficiency alone was corrected. The mechanism here is not understood, and it is not clear if they should be regarded as suffering from a dual deficiency. Much would, theoretically at least, depend on the diet received while the major deficiency was corrected, and whether curable intercurrent blood-destroying diseases were checked. 10. 10. No attempt is made to define clearly how these deficiencies arose, but it is suggested that a dietetic deficiency of iron and the presence of hookworms accounted for the hypochromia and that the liver principle deficiency is nutritional macrocytic anaemia. 11. 11. The dual deficiency group might be classified as:— 11.1. ( a) Iron deficiency anaemia complicated by nutritional macrocytic anaemia. 11.2. ( b) Nutritional macrocytic anaemia complicated by iron deficiency. 11.3. ( c) A new clinical entity. Since the peripheral blood, more particularly the blood smear, shows two aspects, the bone marrow shows different types of erythropoiesis, and two factors have been detected in its aetiology and in its treatment, it is thought that the term “dimorphic anaemia” may commend itself to other workers, more particularly those who have already described this anaemia in Indian pregnant women.