A simple method for detecting HIV antibodies hidden in circulating immune complexes

A method previously used for studying the specificity of antibody components of circulating immune complexes in different diseases has been applied to analyse circulating immune complexes in HIV-infected patients. Antibodies against HIV antigens hidden in circulating immune complexes were studied in 14 sera from 13 patients with asymptomatic HIV infection (group 1) and in 11 sera from seven patients with HIV symptoms (group 2). HIV antigen-coated wells from the Vironostika kit as well as core and envelope antigen-coated beads from the Abbott confirmatory kit were used as solid-phase antigen. Using the Vironostika plates, HIV antibodies were demonstrated in circulating immune complexes in three and five sera in groups 1 and 2, respectively. Anti-core antibodies hidden in circulating immune complexes were present in three out of eight and two out of nine sera, respectively, in groups 1 and 2, whereas anti-envelope antibodies were present in circulating immune complexes in one out of eight and six out of nine sera in the same groups. These findings demonstrate that not only core-anti-core but also envelope-anti-envelope immune complexes are present in the sera of HIV infected patients.