Anti-cardiolipin antibodies and HIV infection.

Anti-cardiolipin antibodies of IgG class were found in 48% of intravenous drug users, 38% of homosexuals and 14% of heterosexuals (with no other risk factor) infected with HIV. Anti-cardiolipin antibodies were not increased in HIV-negative heterosexual partners of HIV-infected patients, but mildly elevated levels were detected in HIV-negative drug users, relative to healthy controls unselected for HIV status. Among HIV infected drug users, anti-cardiolipin antibodies were not associated with thrombocytopenia, Pneumocystis carinii pneumonia, disease progression or clinical stage. Anti-cardiolipin antibodies appear to be another non-specific marker of HIV infection which may be particularly common in male intravenous drug users infected with the virus.