Sperm autoantibodies as a consequence of vasectomy. I. Within 1 year post-operation.

In a group of fifty-two vasectomized men, 1 year post-vasectomy, 73% showed sperm-agglutinating antibodies in the serum with titres of 8 to 1024 in the tray agglutination test, and 42% showed sperm-immobilizing antibodies with titres of 1 to 128 in a micro-immobilization test. 3 months post-operatively, about 75% of the men who were to develop antibodies within the year already possessed them. With sperm agglutinins there was a gradual increase in incidence in the period from 3 months to 1 year, with titres increasing up to the 9 month stage. At 1 year, 68% of the positive titres were 32 or higher. Although no increase in the incidence of sperm-immobilizing antibodies was seen beyond 6 months post-operatively, titres increased up to 1 year. A strong correlation was found between the titres of sperm-agglutinating and sperm-immobilizing antibodies, and all sera with an agglutination titre of at least 128 also showed sperm immobilization. Tail-to-tail agglutination was the most predominant type of agglutination observed. No correlation between the type of agglutination and the presence of sperm-immobilizing antibodies could be found. The total number of spermatozoa in a pre-vasectomy ejaculate (as a measure of antigen dose) could not be correlated with the incidence or titre of sperm-agglutinating or sperm-immobilizing antibodies. These results are discussed in the context of possible interference with fertility if vasovasostomy is to be performed.