DETECTION OF HIV-GAG P24-SPECIFIC ANTIBODIES IN SERA AND SALIVA OF HIV-1-INFECTED ADULTS AND IN SERA OF INFANTS BORN TO HIV-1-INFECTED MOTHERS

Secretory immunoglobulin A (IgA) is known to play an important role in the mucosal defense against a variety of pathogens. Although the role of IgA antibodies during sexual transmission of HIV is not clear, HIV -specific IgA antibodies have been detected in various mucosal secreti ons of HIV-infected individuals. Using a monoclonal antibody against h uman IgA, we established an ELISA system to detect anti-HIV p24 IgA an tibodies in sera and saliva, We have analyzed the levels of anti-HIV p 24 IgG and IgA antibodies in sera and saliva of 107 and 119 adults, re spectively, with HIV infection at different clinical stages, and in th e sera of 13 infants born to HIV-infected mothers. The level of anti-H IV p24 IgA antibodies was lower in sera and higher in saliva as compar ed to that of anti-HIV p24 IgG antibodies, Where the percentage of HIV -specific serum antibody-positive cases decreased with disease progres sion, that of saliva antibody-positive cases increased in AIDS patient s, Among the 13 infants born to HIV-infected mothers, 7 infants were H IV-p24-specific serum IgA positive. These sera were negative for anti- HIV p24 secretory IgA, suggesting that some infants develop their own immune responses against HIV infection, Thus, the detection of HIV-spe cific IgA antibodies, especially in saliva, could be a simple and reli able test for the diagnosis of HIV infection.