Abnormalities in the immune system of children with beta-thalassaemia major.

We have studied both the humoral and cell mediated immune systems of 23 children with beta-thalassaemia major. In children who had not been splenectomized, a 3-fold expansion in the number of circulating B cells and a modest polyclonal gammopathy was present. Of these patients 70% had decreased numbers of circulating T4 cells; 83% were unresponsive to skin testing with Candida albicans, and the majority had decreased lymphocyte proliferative responses in vitro. In children who had been splenectomized, there was a 10-fold increase in the number of circulating B lymphocytes and a 2-fold increase in the number of T4 and T8 cells present in peripheral blood. Additionally, these patients as a group were more responsive to both skin testing and lymphocyte stimulation in vitro with Candida albicans. Seven patients had an inverted T4/T8 ratio. One child has positive serology to HIV by ELISA and Western Blot techniques with a normal T4/T8 ratio. Thus, while children with thalassaemia are at risk for exposure to HIV, the immunological abnormalities associated with the disease and/or its treatment necessitates cautious interpretation of any AIDS-related immunological changes.