Sperm autoantibodies as a consequence of vasectomy. II. Long-term follow-up studies

Abstract

Thirty-four out of fifty-two vasectomized men studied previously were studied again about 5 years after vasectomy for sperm-agglutinating and sperm-immoblizing antibodies, and for antibodies to human protamine. Only one man lost his already weak antibody activity, whilst one out of eight men, negative at 1 year, appeared to be positive at 5 years. Slightly higher titres in one of the three sperm antibody tests were found in the sera of about 30% of the men. Only in three (9%) was there a rise of two or more steps in more than one technique. Agglutinins and immobilizins were shown to be strongly correlated, as was the case with antibodies to human protamine and head-to-head agglutinins. Seminal plasma sperm agglutinins were detected in the samples of only four (out of thirty) men, in low titres. Circulating immune complexes tested with various techniques were only found in a few sera and not consistently. This prolonged study shows that sperm autoantibodies formed within 1 year after vasectomy are persistent. Their role in remaining infertility after reanastomosis requires further study.

PIP: 34 of 52 men who had participated in a previous study of the occurrence of sperm antibodies 1 year after a vasectomy donated blood again 5 years later; from 30 of them a seminal plasma sample was also tested. Serum samples were investigated as well for the presence of circulating immune complexes, based on findings in experimental animal models. The antibodies tested for were sperm-agglutinating, sperm-immobilizing, and antibody to human protamine. To obtain an optimal comparison in the 1 year and 5-year postvasectomy serum samples, both samples were titrated at the same time with the same donor semen sample. Declines of antibody titers were rarely found between the 2 specimens. 1 patient lost an already weak antibody activity; in 1 man the agglutinin but not the immobilizin titer decreased 2 steps; and in 2 others the immobilizin titer decreased 2-3 steps without change in agglutinin titer. A few titer rises were seen. Of the 8 men with no agglutinins at 1 year, only 1 developed them later, and of the 22 patients having no immobilizin titer at 1 year, 5 had them at 5 years. Overall, slightly higher titers in 1 of the 3 sperm antibody tests were found in the sera of about 30% of the men. Agglutinins and immobilizins were strongly correlated, as were antibodies to human protamine and head-to-head agglutinins. Seminal plasma sperm agglutinins were detected in the samples of only 4 of 30 men, in low titers. Circulating immune complexes tested with various techniques were found in only a few sera and then inconsistently. It is concluded that sperm antibodies formed postvasectomy are persistent.