Sperm agglutinins in seminal plasma and serum after vasectomy: correlation between immunological and clinical findings.

The development of sperm agglutinins in serum and seminal plasma in relation to vasectomy was studied in forty-seven men by testing samples taken before vasectomy and on five occasions during the first year after vasectomy. Thirty additional patients were tested only 1 year after vasectomy. One year after vasectomy, sperm agglutinins in the serum in titres from 4 to about 4000 had developed in 62% of the entire group, while antibodies in the seminal fluid detectable by the gelatin agglutination test were present in only 4% of the group, and apart from on unusual case the titres were low here (either 4 or 8). Analysis of the modes of agglutination revealed changing patterns in several patients during the observation period, with a predominance of tail agglutinins after 1 year. In some cases, mixed agglutination was seen with serum but pure tail-to-tail agglutination with seminal plasma. The total number of spermatozoa in a pre-vasectomy ejaculate was found to be correlated with an early immune response and with the titre values after 1 year. The group of patients in whom agglutinins had developed 1 year after vasectomy were found to have significantly larger nodules at the sites of operation than those without sperm agglutinins.