Differences in the antigen pattern recognized by antisperm antibodies in patients with infertility and vasectomy

Antisperm antibodies may impair sperm fertilizing capacity. They are found in infertile patients and in men after vasectomy. Little is known to date of the biochemical nature of the antigens that induce the production of antisperm antibodies.

Sperm membrane proteins were prepared from donor spermatozoa, separated by 1-dimensional polyacrylamide gel electrophoresis and exposed to seminal plasma samples of 36 infertile men and 34 after vasectomy containing antisperm antibodies.

Ten antigenic protein bands with different molecular weight were recognized by antisperm antibodies. Antisperm antibodies binding to the antigen band at 55 kDa. were significantly more common in infertile men, while those binding to the 72 kDa. band were more common after vasectomy. Significant differences also occurred in the incidence of detecting the 55 kDa. antigen band by the antisperm antibodies of patients with and without varicocele. Comparing antisperm antibodies from patients with or without a history of genital diseases or trauma did not reveal significant differences in the antigens detected.

It seems likely that the development of antisperm antibody binding to different antigens is related to the mode of antibody induction. Since the antigenic properties of spermatozoa change during passage through the epididymis, the antigens detected by antisperm antibodies from men with vasectomy are mostly related to epididymal passage. The identification of human sperm antigens is essential for understanding the mechanism by which antisperm antibodies influence the fertilization capacity of spermatozoa. It is also necessary for the potential development of reliable diagnostic methods for antisperm antibodies that are relevant to infertility.