7th Conference - Abstract 109

Mucosal Antibody Responses in HIV-1-Infected Individuals: Dominance of Anti-gp160 IgG Responses in Comparison to IgA

P. A. GOEPFERT*, M. J. MULLIGAN, S. SABBAJ, S. J. PRINCE, R. KULHAVY, L. R. BREWER, S. JACKSON, and J. MESTECKY. Univ. of Alabama at Birmingham

The mucosal immune response to HIV-1 infection is poorly defined. Few studies have compared mucosal immunity to HIV from various sites utilizing multiple assays. We studied a group of 50 HIV-1 infected individuals and 20 uninfected controls (equally divided between genders). Samples were obtained from parotid saliva, nasal washes, vaginal washes, seminal fluid, and rectal washes. All samples were tested by Western blot assay and all mucosal samples were tested by ELISA for both total immunoglobulin and anti-gp160 antibody. The total immunoglobulin levels in the mucosal secretions did not differ when comparing HIV-infected vs. uninfected controls. The total amounts of IgA compared to IgG were much higher in the rectal and nasal washes whereas similar levels were seen in genital tract secretions. The average anti-gp160 antibody and Western blot responses in infected volunteers were as follows:

Only one sample gave a false positive result (nasal wash, Western blot) and probably represented a mislabeled specimen. Interestingly the levels of HIV-1 specific IgG were consistently higher than the IgA levels in all mucosal secretions. This finding is clearly different from other viral infections (i.e. influenza, HSV) in which IgA has been shown to be the predominant response and may reflect differences in viral pathogenesis.

Key Words: antibodies, HIV-1, mucosal secretions