A Comprehensive Study of Candida-specific Antibodies in the Saliva of Human Immunodeficiency Virus-positive Individuals with Oropharyngeal Candidiasis

Oropharyngeal candidiasis (OPC) is a common oral opportunistic infection among human immunodeficiency virus (HIV)-positive individuals. Although most cases of OPC correlate with reduced systemic levels of CD4(+) T cells, the role of humoral immunity in protection against mucosal candidiasis, including OPC, remains questionable. In the present study, a comprehensive analysis of saliva from 33 HIV-negative and 68 HIV-positive individuals, stratified by OPC status and peripheral CD4(+) cell count, was conducted to measure levels of total and Candida-specific immunoglobulin A(IgA) and IgG antibodies, including subclasses and secretory IgA. Despite changes in total immunoglobulin levels, when levels of Candida-specific antibodies were normalized to total protein or total immunoglobulin of the corresponding isotype, no distinct differences in IgG (including subclasses), IgA (including subclasses), or secretory IgA levels were seen, regardless of HIV status, OPC status, or CD4(+) cell count. These data suggest that when a complete repertoire of antibodies is evaluated, with appropriate normalization of data, there is no evidence of appreciable changes in levels of Candida-specific antibodies in saliva that would account for the prevalence of OPC among HIV-positive individuals.