Prevalence and specificity of lymphocytotoxic antibodies in different stages of HIV infection.

Sera obtained from 27 HIV-infected persons were investigated for complement-dependent humoral cytotoxicity. Uninfected as well as HTLV-IIIB-infected H9 cells were used as cellular targets either before or after stimulation by phytohemagglutinin (PHA) or concanavalin A (Con-A). The degree of cytotoxicity was determined by 51Cr-release assay. Two different antibodies could be found in sera of HIV-infected persons, one being directed against HIV-induced cell surface component(s) and the other reacting with structure(s) present on activated T4 cells. Asymptomatic HIV-carries were found to have antibodies exerting complement-dependent cytotoxicity to HIV-infected T4 cells. These antibodies were reactive mainly after stimulation of HIV-infected target cells by Con-A. Sera of ARC and AIDS patients contained autoantibodies reactive with PHA-stimulated or HIV-infected T4 lymphocytes. These data suggest that HIV-specific antibodies represent an anti-viral immune defense, while autoantibodies may be important in destruction of the immune system in AIDS.