Abnormalities of circulating lymphocyte subsets in haemophiliacs in an AIDS-free population.

Markers of the immune system were examined in 47 patients with haemophilia A and B who had been treated exclusively with blood products from a population apparently free from acquired immunodeficiency syndrome (AIDS). In haemophilia A the absolute number of T helper cells was depressed, resulting in a reduction in the helper/suppressor ratio in about half the patients. The serum IgG and IgA concentrations were raised and the serum IgG correlated with serum alanine aminotransferase. In haemophilia B, the helper/suppressor ratio was also depressed but this was attributable to a slight increase in the mean suppressor cell number and a slight decrease in the helper cells. These observations suggest that the abnormalities result from transfusion of foreign proteins and not from a specific infective agent and, further, that individuals may differ in susceptibility to the induced disturbances of immunity.