Inverse correlation between age related abnormalities of T-cell immunity and circulating thymosin alpha 1 levels in haemophilia A.

T-cell immunity and serum levels of thymosin alpha 1, beta 2-microglobulin, circulating immune complexes, serum immunoglobulin levels, antibodies to hepatitis surface or core antigen, and to cytomegalovirus, and Epstein-Barr virus were investigated in 51 patients with haemophilia A ranging in age from 2 to 52 years. All patients had received commercial U.S. lyophilized concentrates of antihaemophilic factor (AHF). The mean helper/cytotoxic-suppressor (OKT4/OKT8) ratio of 11 pre-adolescents (1.6 +/- 0.4 SE) was not significantly different from that of age matched normal controls. In contrast, the mean OKT4/OKT8 ratios of 13 adolescent (1.2 +/- 0.2 SE) and 23 adult (0.8 +/- 0.1 SE) haemophiliacs were significantly reduced. Abnormalities of lymphocyte mitogenic responses were found only in adult haemophiliacs. Nine individuals treated with commercial U.S. prothrombin complex concentrates for antibodies directed against AHF or for haemophilia B had normal mean OKT4/OKT8 values. The mean serum thymosin alpha 1 levels for each age category was similar to that of age matched controls; however, regression analysis revealed a significant relationship between elevated thymosin alpha 1 levels and decreased OKT4/OKT8 ratios in adult haemophiliacs (P = 0.012). Although the mean serum level of beta 2-microglobulin was significantly increased in the adult haemophiliac group, there was no correlation between OKT4/OKT8 ratios and any of the other serologic parameters studied.