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

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.