Autoantibodies against spermatozoal antigens detected by immunoblotting and agglutination. A longitudinal study of vasectomized males.

Sera taken pre- and post-operatively at regular intervals within a year from 16 men undergoing vasectomy were analysed for autoantibodies against spermatozoal proteins by immunoblotting. The reaction patterns were compared with the results of sperm agglutination tests. Immunoblotting revealed the presence of autoantibodies against various spermatozoal polypeptides in all sera taken pre-operatively and post-operatively. On average, seven polypeptides showed reaction. During the post-operative period two patients developed spermatozoal agglutinins in moderate titers (greater than 16) but in immunoblotting no change in band reactivity was observed for these two patients. However, scanning of the immunoblotting results revealed that one of the patients, although without sperm agglutinins, during the post-operative period showed an increasing band colouring of a polypeptide of Mr 31,500, reflecting an increased level of the corresponding antibodies.