Longitudinal study of anti-Candida albicans mucosal immunity against aspartic proteinases in HIV-infected patients.

Oropharyngeal candidiasis (OPC), mainly caused by Candida albicans, is commonly observed in HIV-infected patients. Secreted aspartic proteinases (Saps) are virulent agents involved in adherence to the mucosal surface and in tissue invasion. The immune secretory response to these agents was investigated in 15 HIV-infected patients, during oral yeast colonization and episodes of oropharyngeal candidiasis (OPC), in a 1-year longitudinal study. We developed an avidin-biotin-amplified immunofluorometric assay for the detection of specific immunoglobulins G, A, and M against somatic, Sap2 and Sap6 antigens. We report increases in anti-somatic, anti-Sap2, and anti-Sap6 salivary antibodies in patients with OPC. Over the 1-year period, not only OPC episodes but also variations in yeast colonization levels were correlated with variations in salivary anti-Sap6 antibody levels. Our results show the ability of HIV-infected patients to produce high levels of salivary antibodies; however, these antibodies were not efficient in limiting candidal infection, probably because of cellular cooperation deficiency and the enhanced virulence of the infecting strain.