[An immunofluorescent study of circulating sperm antibodies in humans (author's transl)]

1. By means of an indirect immunofluorescent technique with reference to Weller and Coons (1954), modified for spermatozoal immunofluorescence we found antibodies against spermatozoa in the sera of: 6 of 35 female partners of couples with unexplained infertility, 5 of 35 male partners of couples with unexplained infertility, 8 of 40 prostitutes, 8 of 18 men after orchitis and vasoresection. In contrast to these findings the sera of 20 fertile women, 25 fertile men, and 20 virgins showed negative results with the test mentioned above. 2. The site of the antigen-antibody reaction was mainly the spermatozoal tail and in the second place, the equatorial segment. 3. The immunoglobulins primarily belonged to the IgG and secondly to the IgA class. 4. Our results differ partly from the findings made by other authors perhaps on account of methodical differences. 5. The clinical relevance and associated problems are discussed.