Abstract
The gelatin agglutination test (GAT) and the tray slide agglutination test (TAT) for antisperm antibodies may yield equivocal titers in a number of cases when sera from infertile men are tested. The question is whether these equivocal titers represent true immunological activity or whether other factors such as .beta.-spermagglutinins are responsible. The sera from 24 infertile men with moderate or equivocal titers were tested using the TAT after absorption with protein A-producing staphylococci to remove IgG. Only 2 of the 24 sera showed activity which may have been due to .beta.-spermagglutinins; the majority of the sera showed no activity following absorption. Even at low titers, the GAT and TAT are detecting immunological agglutination when male sera are tested and by inference that antisperm antibodies in male sera only become clinically significant at higher titers, as it is well known that men may father children in the presence of lower or equivocal serum GAT or TAT titers.