Erythroblast‐ and erythrocyte‐bound antibodies in α and β thalassaemia syndromes

Abstract

Summary. Thirty‐five Thai patients with various α‐thalassaemia (α‐thal 1/α‐thal 2, α‐thal 1/HbCS, HbCS/ HbCS) and yβ‐thalassaemia (β‐thal/HbE, severe and mild form, HbE/HbE) syndromes were examined for the presence of immunoglobulins and C3d on o‐tolidine positive erythroblasts in the bone marrow, and for the amounts of IgG of some specificities bound to circulating erythrocytes. In mild, but not in severe yβ‐thal/HbE and in α‐thalassaemia, the percentages of Ig‐positive erythroblasts were significantly higher than in controls and correlated well with the percentages of IgG‐positive erythroblasts. By contrast, the percentages of IgM and C3d positive erythroblasts were low and similar in thalassaemic and control marrows. A substantial proportion of thalassaemic patients showed more erythrocyte‐bound IgG than controls, but statistically significant elevations were seen only in severe β‐thal/HbE. Within a particular syndrome erythrocyte‐bound IgG was more abundant in splenectomized than non‐splenectomized subjects. It showed specificity for spectrin in some β‐thalassaemic patients and for band 3 protein in several individuals with α‐ or β‐thalassaemia. The results suggest that IgG antibodies play a role in the haemolysis of thalassaemia and that they are likely to be involved in the ineffective erythropoiesis in at least some of the syndromes studied. Copyright © 1991, Wiley Blackwell. All rights reserved