Abstract

PIP: It is only recently that the adverse effects of vasectomy have become the subject of numerous scientific and at times speculative articles in medical and in lay periodicals. In this review of the literature on the immunological effects of vasectomy, attention is directed to the following: immunological response; cellular immunity; effects on testes and epididymis, and systemic effects of sperm autoantibodies. In 1970, 50% of vasectomized men were found to have circulating spermatozoal antibodies. A more recent survey provides confirmation for this finding and presents an incidence of only 2% of agglutinating antibodies and 0% of immobilizing antibodies in a fertile control population. Some recent and convincing studies have shown sperm agglutinating and immobilizing antibodies to remain either at the same titer level or actually to increase 5-12 years postoperatively. Titers range from 2 to 2048 among different patients. The highest incidence of titers is 1 year after vasectomy, but titers can be found as early as 6 months or as late as 20 years postoperatively. The wide range in titers can be explained in terms of technical problems in immune assays, since only immunoglobulins and not those antibodies part of immune complex systems can be measured. Since sperm antigens are in abundant supply in vasectomized men because of the continuous resorption of spermatozoa after vasectomy, possibly undetectable antibody titers actually reflect high levels of antisperm antibodies circulating in the form of immune complexes. Also it may be possible that the variety in measured titers of autoantibodies, as well as the nonuniversal (70%) antibody response in a vasectomized population, is a variable dependent on genetic content and, therefore, an individual characteristic. The fact that hormonal reponse takes place rather readily after vasectomy makes at least some degree of cellular response a necessary occurrence. Studies by Alexander and Anderson, which show delayed hypersensitivity skin responses to sperm antigens, indicate at least some degree of cell mediated response. A recent study draws a strong correlation between the presence of sperm agglutinins in the seminal fluid of vasovasostomized men and persistent infertility. It is likely that autoantibodies to sperm as a result of vasectomy have a significant role in persistent infertility in vasovasostomized individuals. The greatest controversy at present concerns the immunologic effect of vasectomy on various organ systems. The incidence and degree of atherosclerotic changes in lower primates are increased after vasectomy, but whether vasectomy has the same effect in men has not as yet been determined.