Antichlamydial and Antisperm Antibodies in Patients with Chlamydial Infections

Immune infertility in men

Male factors are implicated as the cause of roughly half of cases of infertility, and the presence of antisperm antibodies (ASA) may be responsible for some of these. Their presence is associated with a reduction in natural conception and live birth and impacts the success of assisted reproductive technologies. Interpretation of the data regarding ASAs and fertility is complicated by a lack of standardization in testing methodology and test thresholds and a lack of data on their prevalence in the healthy fertile population. Although their pathogenesis remains elusive, and many cases are idiopathic, a disruption in the immunologic blood-testis barrier (BTB) appears to contribute to the formation of ASA. As delineation of the specific antigen targets of ASA advances, it has been recognized that they may affect almost all aspects of sperm function, and ASA against different targets likely have specific mechanisms of impairing fertility. Intracytoplasmic sperm injection (ICSI) appears to be the most reliable method by which to overcome fertility impairment due to ASA, achieving similar outcomes to ASA-negative patients with regard to fertilization rates, embryonic development, clinical pregnancy rates, and live birth rates. The lack of consistency in testing for and reporting ASA remains a substantial barrier to achieving clarity in describing their role in infertility and the optimal management approach, and future research should use a unified approach to the detection and description of ASA. Determination of the specific antigens targeted by ASA, and their function and clinical relevance, would contribute to improving the understanding of ASA-mediated impacts on fertility and tailoring treatment appropriately to achieve the best outcomes for patients.

Effects of bacteria on male fertility: Spermatogenesis and sperm function

Bacterial infection can negatively affect different parts of the male genital tract and subsequently cause impaired spermatogenesis and male fertility. However, most of the previous studies have focused on the infected organs of the male genital tract and there are not many studies that investigated the direct effect of bacteria on sperm and their mechanism of action. Interestingly, bacteria can induce different damages on sperm cells such as DNA fragmentation, cell membrane peroxidation, and acrosome impairment. Such negative effects can be mediated by bacteria-secreted toxins and metabolites or by direct attachment of bacteria on the sperm cells and subsequent activation of signaling pathways related to oxidative stress, apoptosis, and inflammation. These bacteria-induced changes can impair semen parameters and subsequently cause infertility. Given the significant destructive effect of some bacteria on sperm function and male fertility, in this study, we reviewed the impact of male urogenital bacteria on spermatogenesis and sperm functions as well as the underlying mechanisms by which the bacteria can damage sperm.

Human Papillomavirus Prophylactic Vaccination improves reproductive outcome in infertile patients with HPV semen infection: a retrospective study

In this study we aimed to evaluate the effect on reproductive outcome of HPV vaccination in male subjects of infertile couples with HPV semen infection. In this single-center study, we retrospectively enrolled 151 infertile couples with detection of HPV in semen, attending our Hospital Unit of Andrology between January 2013 and June 2015, counseled to receive adjuvant HPV vaccination. Seventy-nine accepted vaccination (vaccine group) whilst 72 did not (control group). Our protocol of follow-up, aimed to evaluate HPV viral clearance, consisted in semen analysis, INNO-LiPA and FISH for HPV in semen cells after 6 and 12 months from basal evaluation. Spontaneous pregnancies, miscarriages and live births were recorded. Progressive sperm motility and anti-sperm antibodies were improved in the vaccine group at both time points (p < 0,05 vs control arm). Forty-one pregnancies, 11 in the control group and 30 in the vaccine group, were recorded (respectively 15% and 38,9%, p < 0,05) and resulted into 4 deliveries and 7 miscarriages (control group) and 29 deliveries and one miscarriage (vaccine group, p < 0,05 vs control group). HPV detection on sperms was predictive of negative pregnancy outcome. Adjuvant vaccination associated with enhanced HPV healing in semen cells and increased rate of natural pregnancies and live births.

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.

Incidence of sperm-immobilizing antibodies in infertile women with past Chlamydia trachomatis infection

PROBLEM

Among the risk factors for antisperm antibody production, inflammatory diseases of the genital tract are believed to play an important role. Chlamydia trachomatis infection is one of the most common sexually transmitted diseases. There are some reports suggesting that human sperm have antigens that cross-react immunologically with certain microbial antigens, such as C. trachomatis. However, this is still controversial. We performed a retrospective study to investigate the correlation between anti-chlamydial antibodies and sperm-immobilizing antibodies in infertile women.

METHOD OF STUDY

Between January 2007 and March 2009, the presence of sperm-immobilizing antibodies was examined by the sperm immobilization test using sera from 273 infertile women. Anti-chlamydial antibodies (IgG and IgA) were examined to prove past C. trachomatis infection by ELISA using the same sera from infertile women.

RESULTS

The overall incidence of sperm-immobilizing antibodies was 2.9% (8/273) in infertile women. The incidences of sperm-immobilizing antibodies were 6.4% (5/78) in cases with past C. trachomatis infection and 1.5% (3/195) in cases without past C. trachomatis infection. There was a significant difference between the two groups (P = 0.031).

CONCLUSION

A significantly higher incidence of sperm-immobilizing antibodies was noted in infertile women with past C. trachomatis infection compared with that of those without past C. trachomatis infection. This is the first demonstration that C. trachomatis infection could play a role in the production of sperm-immobilizing antibodies in infertile women.