Abstrakt: |
Immunologic responses to spermatozoa were investigated in homosexual and heterosexual men. Ten of 18 (56%) of the homosexual men had serum levels of IgG antibody to spermatozoa that were at least 2 standard deviations above the mean level for the heterosexual men; only 2 homosexual men had IgA antibody to spermatozoa. Similar increases above heterosexual levels in sperm-related antigen were detected in the sera of 56% (10 of 18) of the homosexual men. Circulating immune complexes (CICs) were detected at high levels (>1000 μg/ml) in 61% (11 of 18) of the homosexual men. The CICs were relatively small (<14S), as determined by sucrose gradient analysis. Only 3 of 18 (17%) of the heterosexual men had CICs, and these were at a much lower concentration (≤700 μg/ml). In the homosexual men, CICs and sperm-related antigen levels were positively correlated (r=0.41, P<0.001), while IgG sperm antibody levels were negatively correlated with both CIC levels (r=−0.24, P<0.01) and sperm-related antigen levels (r=−0.24, P<0.01). CICs from six homosexual men were analyzed for composition. All contained IgG, and two had evidence of sperm-related antigen. The results suggest that intake of spermatozoa via the alimentary canal may lead to the development of a humoral immune response to spermatozoa. |