Variation of Secretory Antibodies in Parotid Saliva to Human Immunodeficiency Virus Type 1 with HIV-1 Disease Stage

The secretory immune response to pathogens of the gut-associated lymphoid tissue is often independent of the systemic response. We investigated and compared the presence of antibodies to human immunodeficiency virus type 1 (HIV-1) antigens in parotid saliva and serum by Western blotting in 22 HIV-1-infected individuals. Antibodies to the HIV-1 envelope antigen gp160 were detected in saliva samples from 21 of 22 individuals and in serum from all individuals who were classified as CDC Group II, III, or IV. Antibody titers to gp160 were approximately 3000 times higher in serum than in saliva. Antibodies to viral core antigen p24 were detected in 6 of 7 Group II individuals in saliva and in 7 of 7 in serum. Antibodies to p24 were not found in the parotid saliva, but were detected in the sera of 3 of 3 Group III and 11 of 12 Group IV patients. The absence of secretory antibodies to HIV-1 core antigen p24 was correlated with CD4⁺ cell counts of less than 200/mm³. The results suggest that loss of secretory anti-p24 antibodies may be an early sign of progression to higher CDC clinical stages in HIV-1-infected individuals.