Suppression of post-vasectomy cytotoxic sperm antibody formation in rats by a short-term pretreatment with cyclosporine

Early antibody response following vasectomy is related to fertility after vasovasostomy in glucocorticoid-treated and untreated Lewis rats

The influence of treatment with a glucocorticoid on antisperm antibodies and fertility after vasectomy and vasovasostomy was studied in Lewis rats. Animals received a bilateral vasectomy followed 4 weeks later by bilateral vasovasostomy. Treatment with methylprednisolone for two months beginning at the time of the vasovasostomy resulted in a decrease in antisperm antibodies compared with nontreated vasovasostomized animals, but there was no difference in fertility between treated and nontreated vasovasostomized groups. However, when fertile vasovasostomized animals from treated and nontreated groups were compared with infertile vasovasostomized animals, antisperm antibodies were found to be significantly lower in fertile rats 2, 4 and 8 weeks after vasectomy, while antibodies did not differ between fertile and infertile animals at the end of the study (12 weeks). The observation that differences in antisperm antibodies appeared shortly after vasectomy, preceding either vasovasostomy or treatment, suggests that changes occurring very early after vasectomy have far-reaching effects and are among the factors that influence future fertility after vasovasostomy.

Effect of early antibiotic treatment on the formation of sperm antibodies in experimentally induced epididymitis

This investigation was conducted to evaluate whether or not experimentally produced epididymitis could induce the development of cytotoxic sperm antibodies and if effective antibiotic therapy could reverse the development of immunity to sperm. Escherichia coli was injected into the tail of the epididymis in adult Lewis rats to induce epididymitis and was allowed to incubate for 24 h, 72 h, 8 days, or 15 days. Serum titers of cytotoxic sperm antibodies at these time intervals were determined. Sperm antibody titers began to rise 3 days after inoculation, peaked, and plateaued at 8 days. The titers were negligible in the control rats. Two other groups of rats were inoculated with E. coli in a similar manner and were treated with tetracycline 25 mg/kg/day starting at either 24 h or 8 days after inoculation, for 7 days. The antibody titers became negligible in these two treated groups, the results being statistically significant when contrasted with the infected but untreated groups (p < .001 and < .05, respectively, for the 24-h and 8-day groups). However, histological examination of the antibiotic-treated and untreated specimens revealed significant inflammation and infection of the epididymis in both treated groups. Testicular alterations were consistent in both groups. It is concluded that epididymitis consequent to infection with E. coli can induce cytotoxic antibody formation in Lewis rats. Treatment with appropriate antibiotics may suppress the antibody response either through a direct immunosuppressive effect of the antibiotic or through a decrease in the antigenic load of killed sperm secondary to eradication of the infection.

Oral immunization with sperm antigens: possible therapy for sperm antibodies?

Young adult male CD-1 mice were given intraperitoneal injections (IP) of saline (controls) and pooled sperm or seminal plasma of two autoimmune infertile men and two nonautoimmune fertile men (n = 40 per treatment). Other mice received only an oral challenge with the same antigens (oral controls; n = 20 per treatment). Three weeks after the booster challenge (day 36), 20 mice in each group were orally immunized with the antigens, whereas the other 20 were not (IP controls). Cytotoxic antibody titers (immunoglobulin M) to human sperm were significantly higher in mice IP immunized with sperm or seminal plasma from autoimmune infertile men or orally immunized with autoimmune men's sperm, in contrast to the controls. Oral challenge with sperm or seminal plasma of autoimmune infertile men after the IP immunization with the same resulted in significantly decreased cytotoxic sperm antibody titers (P less than 0.001 versus oral or IP controls in sperm immunization; P less than 0.001 versus IP controls in seminal plasma immunization). Fertility was unaffected by any mode of immunization. It is concluded that, in mice, sperm and seminal plasma antigens from autoimmune infertile men are more immunogenic than those from nonautoimmune fertile men, and oral challenge with the former after an IP establishment of cytotoxic sperm immunity desensitizes the immune mice. These findings may have practical implications in the diagnosis and immunotherapy of infertile men with cytotoxic sperm antibodies.

Pathological and immunological effects of surgically induced varicocele in juvenile and adult rats

The presence of a varicocele in adult men has been correlated with infertility. This study documents the effect of an experimentally induced unilateral varicocele in 21-day-old juvenile prepubertal and 51-day-old adult rats (n = 10 per group) on subsequent adult testicular function. Varicoceles were induced by partial occlusion of the spermatic vein. There were ten sham-operated and five nonoperated control rats in each age group. The rats were sacrificed 1 month after surgery. Intrascrotal temperatures were elevated in both groups with varicoceles. Histologically, the ipsilateral testes of rats in both age groups demonstrated a decrease in the numbers of functioning seminiferous tubules and germ cells, but the decrease was significantly greater in the juveniles than in the adult rats. No changes were seen in the contralateral testes. Significant titers of cytotoxic sperm antibodies were present in all animals with varicoceles, which is in contrast to controls. The juveniles had significantly lower antibody titers (mean log2 +/- SEM; 3.2 +/- 0.09 vs. 8.5 +/- 1.1, P less than 0.001) than the adults. The induction of a unilateral varicocele damaged spermatogenesis and testicular function to a greater extent in juveniles than in adult rats. This damage may be immune complex-mediated.

Temporal appearance of antisperm autoantibodies in Lewis rats following vasectomy

An indirect enzyme-linked immunosorbent assay (ELISA) was employed to monitor antisperm autoantibodies in 16 Lewis rats for up to 36 weeks following vasectomy. This assay was capable of discriminating all prevasectomy from postvasectomy sera at a 1:16 dilution. Weekly serum samples were obtained for the first 13 weeks and bimonthly samples thereafter. Half of the animals developed a positive antisperm autoantibody response by the end of the first postoperative week. By the end of the second week, 81% of the animals had positive responses. The greatest proportion (88%) of animals having a positive response over the course of the study was found at the end of the seventh postoperative week and the highest mean absorbance value for all 16 animals was observed at this time. Only 25% of the animals had positive responses for antisperm autoantibody at the end of the 35th week of the study. These findings indicate that circulating antisperm autoantibodies arise in the Lewis rat earlier than has been generally appreciated. The time course is similar to that of antibody titers to infectious agents or arising from inoculation of rats with spermatozoa. These findings on autoantibody levels in the Lewis rat are compared with the dynamics of antisperm autoantibody formation in man.