Immunological effects of vasectomy

Antisperm antibodies: invaluable tools toward the identification of sperm proteins involved in fertilization

The identification of sperm proteins involved in fertilization has been the subject of numerous investigations. Much interest has been dedicated to naturally occurring antisperm antibodies (ASA) and their impact in fertility. Their presence in men and women has been associated with 2-50% of infertility cases. ASA may impair pre- and post-fertilization steps. Experimental models have been developed using sperm proteins as immunogens to evaluate their involvement in sperm function. Our team has pursued investigations to assess ASA presence in biological fluids from patients consulting for infertility and their effect on fertilization. We found ASA in follicular fluids with ability of inducing the acrosome reaction and blocking sperm-zona pellucida interaction and used them to identify sperm entities involved in these events. We generated and utilized antibodies against proacrosin/acrosin to characterize the sperm protease system. We implemented an ELISA to detect proacrosin/acrosin antibodies in human sera and evaluated their impact upon fertility by developing in vitro assays and a gene immunization model. This review presents a summary of ASA history, etiology, current approaches for detection and effects upon fertility. ASA (naturally occurring, generated by animal immunization and/or of commercial origin) are invaluable tools to understand the molecular basis of fertilization, better diagnose/treat immunoinfertility and develop immunocontraceptive methods.

Immune-related disease before and after vasectomy: an epidemiological database study

BACKGROUND

Vasectomy can be followed by an autoimmune-antibody response. We aimed to determine whether men with immune-related diseases were more or less likely than others to have a vasectomy and then to determine whether vasectomy is associated with the subsequent development of immune-related diseases.

METHODS

A database of linked records of hospital statistics was analysed. By comparing a population of men who underwent vasectomy with a reference population, we calculated the rate ratios for selected immune-related diseases before and after vasectomy.

RESULTS

Some diseases studied (e.g. asthma and diabetes mellitus) were a little less common, prior to operation, in the vasectomy group than in the reference group. Others were not different. The mean period of follow-up was 13 years. We found no long-term elevation of risk following vasectomy of asthma, diabetes mellitus, ankylosing spondylitis, thyrotoxicosis, multiple sclerosis, myasthenia gravis, inflammatory bowel disease, rheumatoid arthritis or testicular atrophy. There was a short-term elevation of risk of orchitis/epididymitis.

CONCLUSIONS

In this large study, with many years of follow-up, we found no evidence that vasectomy increases the subsequent long-term risk of immune-related diseases.

Immunological infertility among Nigerian men: incidence of circulating antisperm auto-antibodies and some clinical observations: a preliminary report

OBJECTIVES

To (i) establish the incidence of circulating antisperm auto-antibodies among infertile men; (ii) relate this incidence to the high prevalence of sexually-transmitted diseases (STDs) in sub-Saharan Africa and; (iii) elucidate the effect of steroid and other therapy on semen quality and subsequent fertility of the patients.

PATIENTS AND METHODS

Serum samples from 50 infertile men and 50 age-matched controls were assayed by two agglutination techniques for anti-sperm antibodies. Mean sperm concentrations were determined before and after steroid treatment of patients having antibody titres of 1:64 or above. Serum levels of follicle-stimulating hormone, luteinizing hormone, testosterone and prolactin were also determined by radioimmunoassay in 38 patients. Seminal fluid analysis and culture were performed in 35 patients and testicular histology determined in 21.

RESULTS

Agglutination was demonstrated in 22 of 50 sera (44%), whilst non-agglutinating cytotoxic antibodies were detected in two. Only two of the 50 control sera (4%) were positive. After steroid therapy, antibody titres were significantly decreased and there was a sixfold improvement in mean sperm concentration and a threefold improvement in motility and morphological characteristics. Bacterial (46%) and non-bacterial (17%) infection were recorded in 22 of 35 patients, 13 of whom showed the presence of antisperm antibodies in their sera. Staphylococcus aureus was the commonest single bacterial isolate. Overall, 13 of 29 patients (45%) improved, nine accounting for 12 pregnancies. Pregnancies and/or improvements in semen quality were observed only among patients with mild histological changes. Low testosterone and prolactinaemia occurred in 29% and 21% of the patients, respectively. Among these, anti-sperm antibodies were also recorded in 18% and 13%, respectively.

CONCLUSION

The incidence of antisperm antibodies among infertile men is high in Nigeria and may be related to high prevalence of STDs. Immunologically infertile men can be treated successfully with steroids. Concomitant antibiotic and hormone therapy may also be essential in appropriate cases. Clinicians are advised to adopt a multimodal approach to the treatment of male infertility in sub-Saharan Africa. The presence of non-agglutinating cytotoxic antibodies calls for further investigation of the role of complement in the pathogenesis of immunological infertility.

Risk factors for antisperm antibodies in infertile men

PROBLEM

The prevalence of anti-sperm antibodies (ASAs) in the general population is 0 to 2%; the prevalence in infertile men is much higher at 7 to 26%. However, the role of ASAs in male infertility remains controversial to date. Although several risk factors for ASA development have been defined (such as testicular torsion, varicocele, cryptorchidism, vasectomy, and genital tract infection), there are no specific indications for ASA testing.

METHOD

In order to examine if a single parameter exists identifying patients with elevated ASA titers, serum ASA testing was performed with an enzyme-linked immunosorbent assay (ELISA) in 226 consecutive male patients. The new assay, synchron ELISA (Synelisa) used in our study represents a new type of ELISA without fixation of the sperm surface antigens by formaldehyde or glutaraldehyde. Therefore, the quantitative assay is highly sensitive and reproducible since the structure of sperm surface antigens is not altered by the fixation process.

CONCLUSIONS

The prevalence of ASAs in this population was 14%, while the prevalence of the control group was 2.5%. Of all factors analyzed only a history of vasectomy, an acute epididymitis, and an abnormal result in the bovine mucus penetration test was associated with elevated ASA titers (P < .001). In addition, we could demonstrate a time related formation of ASAs in men after vasectomy.

Risk factors for male partner antisperm antibodies

The role of antisperm antibodies in human infertility remains controversial. Indications for antisperm antibody testing of male partners of infertile marriages have been based upon anecdotal reports and studies using outdated assays. In an effort to define the indications for antisperm antibody testing of the male partner, the immunobead assay for antisperm antibodies was performed upon 100 consecutive men referred for evaluation of male factor infertility. The prevalence of antisperm antibodies in this patient population was 18% and only 9% when patients with a history of vasectomy were excluded. Of all the factors analyzed, only a history of vasectomy and sperm agglutination on semen analysis were predictive of antisperm antibody status (p < 0.001). Use of the aforementioned parameters as an indication for antisperm antibody testing would have resulted in a sensitivity of 94%, specificity 73% and negative predictive value 98% in this patient population. The only way to identify all patients with significant levels of antisperm antibody activity (sensitivity 100%) would have been to test every patient.

A late post-vasectomy syndrome

A group of 20 surgical specimens in 18 patients with a previously unappreciated syndrome of unremitting epididymal pain and induration 5 to 7 years after vasectomy was collected during a 2-year interval. These symptoms uniformly were unresponsive to conservative measures, including empiric antibiotics. Total unilateral or bilateral epididymectomy and partial vasectomy led to complete relief of symptoms, usually within 24 hours. Pathological examination of the specimens revealed features consistent with sequelae of long-standing obstruction. Recognition of this late post-vasectomy syndrome, which represents a major complication of vasectomy, might be expected to increase as cohorts of vasectomized individuals age.

Increased frequency of autoantibodies in men with sperm antibodies

Autoantibodies to thyroid microsomes were more frequent in 102 infertile men with complement-dependent sperm-immobilizing activity (sperm immobilization test [SIT] ) in serum (11.8%) than in a control group of 277 men of comparable ages and semen quality without sperm antibodies (4.3%, P less than 0.05). Frequencies of organ-specific antibodies (antigastric parietal cell, antithyroglobulin, and antithyroid microsome) in 57 men with genital tract obstructions and positive SIT were similar to those for control subjects, and there were no significant differences in the frequencies of non-organ-specific autoantibodies (antinuclear antibody, rheumatoid factor, antimitochondrial, and anti-smooth muscle) in the three groups. Because in men without genital tract obstruction antithyroid microsomal autoantibodies were more common with sperm antibodies than without, the possibility of a genetic factor in the causation of sperm autoimmunity should be considered.