Cell-mediated immunity in vasectomized rhesus monkeys

Does vasectomy have long-term effects on somatic and psychological health status?

All the major international articles on the somatic and psychological consequences of vasectomy published over the last 10 years have been reviewed and analysed. Although some experiments on animals have revealed harmful effects, none of the large-scale epidemiological studies has pointed to any increase in health risks (cardiovascular, hypertensive, psychiatric) in vasectomized men. The contradictions which arise between the clinical and large-scale epidemiological studies may be the result of methodological or experimental conditions. As our knowledge stands at present it can therefore be considered that vasectomy has no major effects on the physical or mental health of men.

Formation of antisperm autoantibodies in rats vasectomized at prefertile age

Bilateral vasectomy was performed in 40 inbred Lewis rats. Twenty prefertile rats were operated upon at the age of 2-3 weeks and 20 adult rats at the age of 10-11 weeks. Sera were sampled 16 and 8 weeks later respectively. Circulating antisperm antibodies were demonstrated in 90% of the vasectomized rats by means of the indirect immunofluorescence technique. No significant difference between the two groups could be found. Sham-vasectomy was performed in 20 rats age 2-3 weeks and in 20 rats aged 10-11 weeks. No antisperm antibodies could be detected in sera from either of these groups 16 and 8 weeks respectively postoperatively. Also, no antisperm antibodies could be demonstrated in sera sampled from 5 control rats at the age of 2-3 weeks or in sera sampled preoperatively from the 40 rats aged 10-11 weeks. Sperm granulomas were observed in 95% of the rats vasectomized at the age of 2-3 weeks, almost, all granulomas being located in the epididymis. 95% of the rats vasectomized at the age of 10-11 weeks also developed sperm granulomas. These were located in the proximal end of the vas deferens. The difference in distribution was significant (p less than 0.001).

A comparison of eight techniques for the evaluation of the auto-immune response to spermatozoa after vasectomy

The tray agglutination tests (TAT), gelatin agglutination test (GAT), side agglutination test (SAT), tube-slide agglutination test (TSAT), sperm immobilization test (SIT), ATP-release cytotoxicity test (ARCT), indirect immunofluorescence technique (IFT) on methanol-fixed, intact spermatozoa, and a lymphocyte transformation test (LTT) were compared using a maximum of 329 blood samples taken from 47 men before and after vasectomy. The TAT, GAT, TSAT, SIT and ARCT discriminated between the pre- and post-vasectomy samples, and the sensitivity for sperm antibodies decreased in that order. The activity in the IFT and the LTT did not change significantly after vasectomy. In the TAT the mode of agglutination varied with serum dilution; the results for the 1:4 dilution showed the best agreement with the SAT results. Almost all TAT activity was detected by a combination of GAT and TSAT. Sperm agglutinins were present in all serum samples positive in the two complement-dependent tests, SIT and ARCT. If improved in sensitivity, the ARCT, which lacks the subjective elements of microscopy, might be suitable for the screening of male sera in clinical work. For the present, we recommend the TAT.

Immunological and clinical consequences of vasectomy

Blood samples from 109 vasectomized and 100 non-vasectomized fertile men were tested for antisperm antibodies using Tray Agglutination Test (TAT) and Sperm Immobilization Test (SIT), Cell Mediated Immunity to sperm using Leukocyte Migration Inhibition Test (LMIT). Incidence of antisperm antibodies in vasectomized group was 76.2% by TAT and 13.8% by SIT whereas in control group was 11% (p less than 0.001) and 3% (P less than 0.01) respectively. Titre of TAT antibodies increased with post vasectomy period even beyond 20 years post vasectomy. High Incidence of TAT titre of greater than 1:250 was observed in vasectomized men with post operative complications. No significant incidence of positive LMIT to sperm antigens was detected in vasectomized group as compared to control group.

Immunological consequences of vasectomy

In more than 50% of men, vasectomy leads to auto-immune pathology. The auto-immune response to sperms following vasectomy is triggered by the phagocytosis of sperm in the epididymis. In the humoral immune response, sperm agglutinating, sperm immobilizing, and antibodies to sperm nuclear protamines occur, as early as 3-4 days after vasectomy. The incidence reaches 60-70% within 1 year and remains almost the same even after 20 years. Presence and effects of circulating immune complexes following vasectomy are discussed with reference to reported increased incidence of atherosclerosis and auto-immune orchitis in experimental animals. There is no positive conclusion whether vasectomy leads to cell mediated immunity to spermatozoa.

Primates: Their use in research on vasectomy

Studies based on experimental vasectomies clearly reveal marked species differences in response to vasectomy. In rats, vasectomy invariably results in granuloma formation at the surgical site. In rabbits, immune-complex orchitis develops. Allergic orchitis may also develop in guinea pigs, and the morphological lesions can be adoptively transferred. My co-workers and I have been able to study systematically, biochemically, hormonally, pathologically, and immunologically, primates vasectomized up to 14 years earlier and to compare them with age-matched controls. We have monitored antibody levels in vasectomized rhesus and cynomolgus macaques by sperm-agglutination, sperm-immobilization, and indirect immunofluorescence techniques. Antibodies develop in almost every monkey, in some as early as 10 days after vasectomy. About 50% retain such circulating antisperm antibodies. In men, antibody development is less rapid, and about half of vasectomized men reveal detectable levels. Testicular histopathological studies have revealed detectable levels. Testicular histopathological studies have revealed orchitis, aspermatogenesis, or both, resembling allergic orchitis in most of the vasectomized monkeys and in about one-fourth of the controls. Limited studies of human material reveal some testicular changes. Epididymitis and epididymal granuloma occur exclusively in the vasectomized animals. Use of immunofluorescence has revealed significantly more granular deposits of IgA, IgG, and/or C3 in the basal lamina of the ductus efferens and the caput epididymidis of the vasectomized monkeys. Similar studies on human material have not been done. Both cynomolgus and rhesus macaques have proved to be excellent models for research in atherosclerosis and so have been used to determine whether constant sperm antigen leakage causes immune-complex formation that might result in arteritis and atherosclerosis. Evaluation of the cardiovascular systems from such animals has revealed that vasectomized monkeys have more frequent, more extensive, and more severe arteriosclerosis than age-matched controls. Epidemiological studies are currently under way to determine whether such an effect also occurs in men after vasectomy.

Allergic orchitis lesions are adoptively transferred from vasoligated guinea pigs to syngeneic recipients

Histopathology typical of allergic orchitis developed in testes of inbred guinea pigs 16 months after vasoligation. A similar histopathology was found in unoperated testes after unilateral vasoligation. Peritoneal exudate cells from vasoligated guinea pigs transferred identical lesions to syngeneic recipients. The testicular lesions in long-term vasoligated guinea pigs have an immunological basis.