Determination of anti-cardiolipin and other antibodies in HIV-1-infected patients.

Anti-cardiolipin antibodies (ACA) were determined by an ELISA assay in 116 HIV-1-infected patients. A positive test was found in 27 patients (23.3%) with a predominance of IgG ACA isotype. No significant difference in ACA positivity was observed between homosexuals (22.2%) and intravenous drug users (25.8%). The presence of different immunological markers was compared in ACA-positive and ACA-negative patients: ACA-positive patients had higher IgG levels (p less than 0.05) and a tendency to higher frequencies of anti-ss DNA, anti-ds DNA, anti-i antibodies, as well as circulating immune complexes. When patients were classified according to CDC criteria, no significant difference was observed for the prevalence of ACA in class II (21.2%), in class III (25%), and in class IV (21%). Our results indicate that ACA antibodies occur with other immunological alterations in HIV-1-infected patients, but do not confirm that ACA is a useful prognostic marker for development of AIDS.