A high proportion of sera of heroin addicts possesses anti-HLA class I and class II reactivity.

The anti-HLA reactivity of sera from 210 heroin addicts was tested by the direct binding with 125I-labeled preparations of HLA class I and class II molecules purified from human B-cell lines of various HLA haplotypes. A high proportion (81.7%) of the sera tested possessed anti-HLA class I and II reactivity. The reactivity did not show any allospecificity and was apparently mediated by antibodies. The control included 100 healthy blood donors, 25 male homosexuals positive for anti-HIV (human immunodeficiency virus) antibodies, and 25 patients positive for HBsAg (hepatitis B surface antigen). Of these controls, only one of the healthy blood donors was positive for anti-HLA reactivity (P much less than 0.001). Among heroin addicts, the reactivity was independent of the presence of either HBsAg or anti-HIV antibodies in the serum.