Antisperm antibodies and conception

Anti-sperm Antibodies as an Increasing Threat to Male Fertility: Immunological Insights, Diagnostic and Therapeutic Strategies

It is a fact that sperm possess antigenic properties. Substantial scientific research suggests that specific antibodies that attach to sperm antigens can induce infertility in both humans and other species. Antisperm antibodies (ASA) represent a significant etiology of infertility in humans, leading to immunoinfertility. The association between ASA and infertility is multifaceted. The observation of sperm agglutination, although not conclusive for the diagnosis of immunological infertility, may suggest the presence of ASA. Nevertheless, ASA may also manifest in the lack of any sperm agglutination. Managing ASA from an andrological perspective depends on the underlying cause and the specific approaches healthcare professionals adopt. The precise etiology of male infertility resulting from ASA remains unclear. Current research has examined the impact of ASA and its prevalence among infertile males to understand the relationship between ASA and changes in semen parameters. However, the findings have been inconclusive. Numerous techniques have been documented for the management of immunoinfertility. This review examines the importance of ASA in the context of infertility, encompassing the postulated mechanisms underlying the development of ASA, the various assays employed for detecting them, and the available treatments.

Advances in Male Contraception: When Will the Novel Male Contraception be Available?

Many contraceptive methods have been developed over the years due to high demand. However, female contraceptive pills and devices do not work for all females due to health conditions and side effects. Also, the number of males who want to actively participate in family planning is gradually increasing. However, the only contraceptive options currently available to males are condoms and vasectomy. Therefore, many male contraceptive methods, including medication (hormonal and non-hormonal therapy) and mechanical methods, are under development. Reversibility, safety, persistence, degree of invasion, promptness, and the suppression of anti-sperm antibody formation are essential factors in the development of male contraceptive methods. In this paper, male contraceptive methods under development are reviewed according to those essential factors. Furthermore, the timeline for the availability of a new male contraception is discussed.

Differential metabolites screening in yak (Bos grunniens) seminal plasma after cryopreservation and the evaluation of the effect of galactose on post-thaw sperm motility

Sperm survival and activity depend on the provision of energy and nutrients from seminal plasma (SP). This study aimed to investigate the variations of metabolites within SP before and after freezing and subsequently explore the potential regulatory mechanisms affecting yak sperm cryodamage due to changes in metabolites in the SP. Untargeted metabolomics analysis was performed to screen for differential metabolites, followed by KEGG analysis to identify enriched signaling pathways. The combinatorial analysis of metabolomics and sperm proteomics revealed the influence of key SP metabolites on sperm proteins. Subsequently, the relevant differentially expressed proteins were verified by Western blot analysis. Finally, the mechanism underlying the positive effect of galactose on sperm motility was determined by assessing the change in ATP content in sperm before and after freezing and thawing. The data showed that a total of 425 and 269 metabolites were identified in the positive and negative ion modes, respectively. Freezing and thawing resulted in the up-regulation of 70 metabolites and the down-regulation of 29 metabolites in SP. The primary impact of freezing and thawing was observed in carbohydrate metabolism, including pyruvate metabolism, pentose phosphate pathway, galactose metabolism, the TCA cycle, and butanoate metabolism. In the combined analysis and Western blot results, a significant positive correlation was observed between galactose and Aldo-keto reductase family 1 member B1 (AKR1B1) (P < 0.05), which has the ability to convert galactose into galactol. Furthermore, the addition of galactose to thawed semen improved sperm motility by increasing AKR1B1 protein in sperm and was associated with the content of ATP. These data identify differential metabolites between fresh and frozen-thawed SP and suggest that galactose is a valuable additive for cryopreserved sperm, providing a theoretical basis for further exploration of the refrigerant formula for yak sperm cryopreservation.

From Diagnosis to Treatment: Comprehensive Care by Reproductive Urologists in Assisted Reproductive Technology

Infertility is a global health concern, with male factors playing an especially large role. Unfortunately, however, the contributions made by reproductive urologists in managing male infertility under assisted reproductive technology (ART) often go undervalued. This narrative review highlights the important role played by reproductive urologists in diagnosing and treating male infertility as well as any barriers they face when providing services. This manuscript presents a comprehensive review of reproductive urologists' role in managing male infertility, outlining their expertise in diagnosing and managing male infertility as well as reversible causes and performing surgical techniques such as sperm retrieval. This manuscript investigates the barriers limiting urologist involvement such as limited availability, awareness among healthcare professionals, and financial constraints. This study highlights a decrease in male fertility due to lifestyle factors like sedentary behavior, obesity, and substance abuse. It stresses the significance of conducting an evaluation process involving both male and female partners to identify any underlying factors contributing to infertility and to identify patients who do not require any interventions beyond ART. We conclude that engaging urologists more effectively in infertility management is key to optimizing fertility outcomes among couples undergoing assisted reproductive technology treatments and requires greater education among healthcare providers regarding the role urologists and lifestyle factors that could have an effect on male fertility.

Characterization of a spontaneously occurring self-reactive antibody against sperm in mice

We previously established a spontaneously occurring monoclonal antibody, namely Ts3, that was reactive to sperm from an aged male mouse. The present study investigated the characteristic properties and reproductive functions of Ts3. Immunofluorescent staining revealed that Ts3 reacted to epididymal sperm, and the corresponding antigen was located in the midpiece and principal piece. Immunohistochemistry revealed positive reactions in the germ cells and Sertoli cells in the testis, the epithelial cells in the epididymis and vas deferens. Through western blotting with two-dimensional electrophoresis, we demonstrated that Ts3 reacted with four spots, which were around Mr ∼25,000-60,000 and pI 5-6. MALDI-TOF/TOF mass spectrometry identified outer dense fiber 2 (ODF2) as a candidate for Ts3. ODF2 is a cytoskeletal structural component located in the midpiece and principal piece of the flagella of mammalian sperm. This was validated with the result of immunofluorescent staining, suggesting that ODF2 was the main target antigen for Ts3. Sperm immobilization test showed that Ts3 possessed sperm immobilizing activity. Furthermore, Ts3 impaired early embryo development but not in vitro fertilization. These results suggest that ODF2 plays an important role in both sperm function and early embryonic development.

Emerging arguments for reproductive technologies in wildlife and their implications for assisted reproduction and conservation of threatened marsupials

Assisted reproductive technologies (ARTs) have significant potential to make a meaningful contribution to the conservation of threatened wildlife. This is true of Australia's iconic, and endangered koala (Phascolarctos cinereus). If developed, ARTs could offer a solution to manage genetic diversity and costs in breeding programs and may provide frozen repositories for either insurance or the practical production of genetically resilient koalas for release and on-ground recovery. Holding back the wider use of ARTs for koalas and other wildlife is a lack of funding to close the remaining knowledge gaps in the marsupial reproductive sciences and develop the reproductive tools needed. This lack of funding is arguably driven by a poor understanding of the potential contribution ARTs could make to threatened species management. We present a review of our cross-disciplinary and accessible strategy to draw much needed public attention and funding for the development of ARTs in wildlife, using emerging cost and genetic modelling arguments and the koala as a case study.

The impact of male factors and their correct and early diagnosis in the infertile couple's pathway: 2021 perspectives

PURPOSE

The current clinical practice in reproductive medicine should pose the couple at the centre of the diagnostic-therapeutic management of infertility and requires intense collaboration between the andrologist, the gynaecologist and the embryologist. The andrologist, in particular, to adequately support the infertile couple, must undertake important biological, psychological, economical and ethical task. Thus, this paper aims to provide a comprehensive overview of the multifaceted role of the andrologist in the study of male factor infertility.

METHODS

A comprehensive Medline, Embase and Cochrane search was performed including publications between 1969 and 2021.

RESULTS

Available evidence indicates that a careful medical history and physical examination, followed by semen analysis, always represent the basic starting points of the diagnostic work up in male partner of an infertile couple. Regarding treatment, gonadotropins are an effective treatment in case of hypogonadotropic hypogonadism and FSH may be used in men with idiopathic infertility, while evidence supporting other hormonal and nonhormonal treatments is either limited or conflicting. In the future, pharmacogenomics of FSHR and FSHB as well as innovative compounds may be considered to develop new therapeutic strategies in the management of infertility.

CONCLUSION

To provide a high-level of care, the andrologist must face several critical diagnostical and therapeutical steps. Even though ART may be the final and decisive stage of this decisional network, neglecting to treat the male partner may ultimately increase the risks of negative outcome, as well as costs and psychological burden for the couple itself.

Male factor infertility: A contemporary overview of investigation, diagnosis and management

Infertility, defined as the failure to achieve a clinical pregnancy after 1 year of regular, unprotected sexual intercourse, is a public health issue of global concern. It affects up to 12% of couples worldwide. While traditionally, research and treatment have focused on female causes of infertility, male factors contribute to up to 70% of cases and therefore deserve appropriate recognition. The purpose of this comprehensive review is to detail the diagnostic work-up, investigations and management of male factor infertility. We discuss much-debated pathologies, such as varicocele, and novel investigations, including sperm DNA fragmentation and reactive oxygen species.

Level of evidence: Not applicable

Pathogenesis of Autoimmune Male Infertility: Juxtacrine, Paracrine, and Endocrine Dysregulation

According to global data, there is a male reproductive potential decrease. Pathogenesis of male infertility is often associated with autoimmunity towards sperm antigens essential for fertilization. Antisperm autoantibodies (ASAs) have immobilizing and cytotoxic properties, impairing spermatogenesis, causing sperm agglutination, altering spermatozoa motility and acrosomal reaction, and thus preventing ovum fertilization. Infertility diagnosis requires a mandatory check for the ASAs. The concept of the blood-testis barrier is currently re-formulated, with an emphasis on informational paracrine and juxtacrine effects, rather than simple anatomical separation. The etiology of male infertility includes both autoimmune and non-autoimmune diseases but equally develops through autoimmune links of pathogenesis. Varicocele commonly leads to infertility due to testicular ischemic damage, venous stasis, local hyperthermia, and hypoandrogenism. However, varicocelectomy can alter the blood-testis barrier, facilitating ASAs production as well. There are contradictory data on the role of ASAs in the pathogenesis of varicocele-related infertility. Infection and inflammation both promote ASAs production due to "danger concept" mechanisms and because of antigen mimicry. Systemic pro-autoimmune influences like hyperprolactinemia, hypoandrogenism, and hypothyroidism also facilitate ASAs production. The diagnostic value of various ASAs has not yet been clearly attributed, and their cut-levels have not been determined in sera nor in ejaculate. The assessment of the autoimmunity role in the pathogenesis of male infertility is ambiguous, so the purpose of this review is to show the effects of ASAs on the pathogenesis of male infertility.

Sperm Parameters, ASAs and Apoptosis After Processing by the Double Tube and Swim up Methods

The aim of this study was to improve the quality of semen samples by using a novel double-tube (DT) method. The DT method was developed to select sperm and compared with traditional swim-up (SU) technique for 31 semen samples. Sperm DNA integrity were tested with TUNEL and SCSA. Content of antisperm antibodies (ASA) in the semen was measured by ELISA and MAR. Levels of the caspase-3 in the sperm were assessed by western blotting. After SU and DT, 15 couples and 16 couples were underwent IVF-ET. The number of RCDs, the percentage of SDF and DFI, ASA and the level of caspase-3 were significantly decreased after DT and SU (p = .001 and p< .001). When the DT and SU compared, there were significant changes in the number of RCD, the percentage of SDF and DFI, ASA and the level of caspase-3 (p< 0.05-0.001). There was a higher cleavage rate (p = .017) and a lower abortion rate (p< .05) in DT-IVF group than in SU-IVF group. DT selection yielded spermatozoa with low RCDs, DFI, ASA, and caspase-3 which would be benefit for ART.

Potential mechanisms of SARS-CoV-2 action on male gonadal function and fertility: Current status and future prospects

The novel coronavirus was recognised in December 2019 and caught humanity off guard. The virus employs the angiotensin‐converting enzyme 2 (ACE2) receptor for entry into human cells. ACE2 is expressed on different organs, which is raising concern as to whether these organs can be infected by the virus or not. The testis appears to be an organ enriched with levels of ACE2, while the possible mechanisms of involvement of the male reproductive system by SARS‐CoV‐2 are not fully elucidated. The major focus of the present studies is on the short‐term complications of the coronavirus and gains importance on studying the long‐term effects, including the possible effects of the virus on the male reproductive system. The aim of this review was to provide new insights into different possible mechanisms of involvement of male gonads with SARS‐CoV‐2 including investigating the ACE2 axis in testis, hormonal alterations in patients with COVID‐19, possible formation of anti‐sperm antibodies (ASA) and subsequently immunological infertility as a complication of SARS‐CoV‐2 infection. Finally, we suggest measuring the sperm DNA fragmentation index (DFI) as a determiner of male fertility impairment in patients with COVID‐19 along with other options such as sex‐related hormones and semen analysis. Invasion of SARS‐CoV‐2 to the spermatogonia, Leydig cells and Sertoli cells can lead to sex hormonal alteration and impaired gonadal function. Once infected, changes in ACE2 signalling pathways followed by oxidative stress and inflammation could cause spermatogenesis failure, abnormal sperm motility, DNA fragmentation and male infertility.

Latheef S, Sharun K, Khurana SK, K. A, Tiwari R, Bhatt P, K. V, Chaicumpa W. Role of Antisperm Antibodies in Infertility, Pregnancy, and Potential forContraceptive and Antifertility Vaccine Designs: Research Progress and Pioneering Vision

Sperm of humans, non-human primates, and other mammalian subjects is considered to be antigenic. The effect of changes in autoimmunity on reproductive cells such as spermatozoa and oocytes play a critical but indistinct role in fertility. Antisperm antibodies (ASAs) are invariably present in both females and males. However, the degree of ASA occurrence may vary according to individual and gender. Although the extent of infertility due to ASAs alone is yet to be determined, it has been found in almost 9-12% of patients who are infertile due to different causes. Postcoital presence of spermatozoa in the reproductive tract of women is not a contributory factor in ASA generation. However, ASA generation may be induced by trauma to the vaginal mucosa, or by anal or oral sex resulting in the deposition of sperm inside the digestive tract. It is strongly believed that, in humans and other species, at least some antibodies may bind to sperm antigens, causing infertility. This form of infertility is termed as immunological infertility, which may be accompanied by impairment of fertility, even in individuals with normozoospermia. Researchers target ASAs for two major reasons: (i) to elucidate the association between ASAs and infertility, the reason ASAs causes infertility, and the mechanism underlying ASA-mediated infertility; and (ii) to assess the potential of ASAs as a contraceptive in humans in case ASAs influences infertility. Therefore, this review explores the potential application of ASAs in the development of anti-spermatozoa vaccines for contraceptive purposes. The usefulness of ASAs for diagnosing obstructive azoospermia, salpingitis, and oligoasthenoteratozoospermia has been reviewed extensively. Important patents pertaining to potential candidates for spermatozoa-derived vaccines that may be utilized as contraceptives are discussed in depth. Antifertility vaccines, as well as treatments for ASA-related infertility, are also highlighted. This review will address many unresolved issues regarding mechanisms involving ASAs in the diagnosis, as well as prognoses, of male infertility. More documented scientific reports are cited to support the mechanisms underlying the potential role of ASA in infertility. The usefulness of sperm antigens or ASAs (recombinant) in human and wild or captive animal contraceptive vaccines has been revealed through research but is yet to be validated via clinical testing.

Intracytoplasmic sperm injection for male infertility and consequences for offspring

Intracytoplasmic sperm injection (ICSI) has become the most commonly used method of fertilization in assisted reproductive technology. The primary reasons for its popularity stem from its effectiveness, the standardization of the procedure, which means that it can easily be incorporated into the routine practice of fertility centres worldwide, and the fact that it can be used to treat virtually all forms of infertility. ICSI is the clear method of choice for overcoming untreatable severe male factor infertility, but its (over)use in other male and non-male factor infertility scenarios is not evidence-based. Despite all efforts to increase ICSI efficacy and safety through the application of advanced sperm retrieval and cryopreservation techniques, as well as methods for selecting sperm with better chromatin integrity, the overall pregnancy rates from infertile men remain suboptimal. Treating the underlying male infertility factor before ICSI seems to be a promising way to improve ICSI outcomes, but data remain limited. Information regarding the health of ICSI offspring has accumulated over the past 25 years, and there are reasons for concern as risks of congenital malformations, epigenetic disorders, chromosomal abnormalities, subfertility, cancer, delayed psychological and neurological development, and impaired cardiometabolic profile have been observed to be greater in infants born as a result of ICSI than in naturally conceived children. However, as subfertility probably influences the risk estimates, it remains to be determined to what extent the observed adverse outcomes are related to parental factors or associated with ICSI.

Human spermatozoa anti-proprotein convertase subtilisin/kexin type 4 synthesis using New Zealand rabbit for novel immunocontraception in males

Purpose

Proprotein convertase subtilisin/kexin type 4 (PCSK4, a 54-kDa protease) is expressed in the plasma membrane of the acrosome in human spermatozoa. It plays a critical role in penetrating the zona pellucida. Synthesis of human anti-PCSK4 might be important for novel male immunocontraception.

Materials and Methods

We used semen from adult males as the source of antigen (acrosomal PCSK4). Isolation and antigen characterization were done by immunohistochemistry followed by electrophoresis. Purification of PCSK4 was done by the electroelution method, followed by immunization with an animal model (Oryctolagus cuniculus). Antibody was collected, purified, and tested by using Western blot and dot blot. Antibody in vitro potential testing was performed on human spermatozoa by laser scanning microscopy with rhodamine stain under a light microscope and on rat spermatozoa.

Results

Human anti-PCSK4 bound with PCSK4 on the head of human spermatozoa and could interfere with rat spermatozoa activity to penetrate the oocyte.

Conclusions

The result of this study can be used as a basis to develop new immunocontraceptives targeted towards males. This study shows that antibodies from induction of PCSK4 from spermatozoa may hinder fertilization.

An observational multicentre study on the efficacy and safety of assisted reproductive technologies in women with rheumatic diseases

Objectives

The aim was to determine whether assisted reproductive technologies (ARTs) confer additional risk in rheumatic patients (in terms of disease flare and fetal–maternal complications) and whether, if performed, their efficacy is affected by maternal disease.

Methods

Sixty infertile rheumatic women undergoing 111 ART cycles were included. Clinical pregnancy rate, live birth rate, maternal disease flares and maternal–fetal complications were recorded.

Results

One hundred and eleven ART cycles in 60 women were analysed. We reported 46 pregnancies (41.4%), 3 (3.1%) cases of ovarian hyperstimulation syndrome and no cases of thrombosis during stimulation, pregnancy and puerperium. One or more maternal complication was reported in 13 (30.2%) pregnancies, and fetal complications occurred in 11 fetuses (21.1%). The live birth rate was 98%, but we reported three (6%) perinatal deaths in the first days of life. During puerperium, we recorded one (2.5%) post-partum haemorrhage and one (2.5%) articular flare.

Conclusion

The safety and efficacy of the ARTs, demonstrated in the general population, seems to be confirmed also in rheumatic patients. No evidence was found to advise against their application, and the choice of therapy should be made depending on the patient’s risk profile, irrespective of whether the pregnancy is natural or artificial induced.

Recombinant Human PH20: Baseline Analysis of the Reactive Antibody Prevalence in the General Population Using Healthy Subjects

Background

Recombinant human PH20 (rHuPH20) is used to depolymerize hyaluronan in the subcutaneous space, increasing the dispersion and absorption of co-administered drugs. While ~ 5 to 10% of rHuPH20 treatment-naïve healthy volunteers have demonstrated rHuPH20-reactive antibodies, associations with age, sex, fertility, and immune disorders remain unknown.

Objectives

Using demographically diverse healthy volunteers, we assessed the prevalence of rHuPH20-reactive antibodies in the general population and potential associations with fertility and autoimmunity diseases.

Methods

In total, 896 subjects aged ≥ 12 years (767 adults; 129 children) without prior exposure to rHuPH20 were enrolled. A demographic and limited medical history review was performed, and K3-EDTA-anticoagulated plasma was analyzed for rHuPH20-reactive antibodies using a bridging immunoassay.

Results

Adult and pediatric positivity rates for rHuPH20-reactive antibodies were 5.2% (40/767) and 1.6% (2/129), respectively. Titers ranged from 5 to 2560 (median 30). In five antibody-positive subjects from whom repeated samples were available, antibody titers remained unchanged or decreased fourfold over periods up to 590 days. The prevalence of rHuPH20-reactive antibodies significantly increased with age (p = 0.0006) and was significantly higher in males than in females (p = 0.0010). Men who had fathered children had a significantly increased prevalence of rHuPH20-reactive antibodies than men who had not (p = 0.0036), whereas the rate of childbearing was not significantly different between rHuPH20 antibody-positive and -negative women. The prevalence between racial/ethnic groups was not significantly different, nor was the presence/absence of an autoimmune disorder.

Conclusions

Approximately 1/20 of the adult population had rHuPH20-reactive antibodies. The reason remains unknown; however, no evidence for a negative effect on fertility or association with autoimmune disease was demonstrated.

Electronic supplementary material

The online version of this article (10.1007/s40259-018-0260-y) contains supplementary material, which is available to authorized users.

Infectious, inflammatory and 'autoimmune' male factor infertility: how do rodent models inform clinical practice?

BACKGROUND

Infection and inflammation of the reproductive tract are significant causes of male factor infertility. Ascending infections caused by sexually transmitted bacteria or urinary tract pathogens represent the most frequent aetiology of epididymo-orchitis, but viral, haematogenous dissemination is also a contributory factor. Limitations in adequate diagnosis and therapy reflect an obvious need for further understanding of human epididymal and testicular immunopathologies and their contribution to infertility. A major obstacle for advancing our knowledge is the limited access to suitable tissue samples. Similarly, the key events in the inflammatory or autoimmune pathologies affecting human male fertility are poorly amenable to close examination. Moreover, the disease processes generally have occurred long before the patient attends the clinic for fertility assessment. In this regard, data obtained from experimental animal models and respective comparative analyses have shown promise to overcome these restrictions in humans.

OBJECTIVE AND RATIONALE

This narrative review will focus on male fertility disturbances caused by infection and inflammation, and the usefulness of the most frequently applied animal models to study these conditions.

SEARCH METHODS

An extensive search in Medline database was performed without restrictions until January 2018 using the following search terms: 'infection' and/or 'inflammation' and 'testis' and/or 'epididymis', 'infection' and/or 'inflammation' and 'male genital tract', 'male infertility', 'orchitis', 'epididymitis', 'experimental autoimmune' and 'orchitis' or 'epididymitis' or 'epididymo-orchitis', antisperm antibodies', 'vasectomy'. In addition to that, reference lists of primary and review articles were reviewed for additional publications independently by each author. Selected articles were verified by each two separate authors and discrepancies discussed within the team.

OUTCOMES

There is clear evidence that models mimicking testicular and/or epididymal inflammation and infection have been instructive in a better understanding of the mechanisms of disease initiation and progression. In this regard, rodent models of acute bacterial epididymitis best reflect the clinical situation in terms of mimicking the infection pathway, pathogens selected and the damage, such as fibrotic transformation, observed. Similarly, animal models of acute testicular and epididymal inflammation using lipopolysaccharides show impairment of reproduction, endocrine function and histological tissue architecture, also seen in men. Autoimmune responses can be studied in models of experimental autoimmune orchitis (EAO) and vasectomy. In particular, the early stages of EAO development showing inflammatory responses in the form of peritubular lymphocytic infiltrates, thickening of the lamina propria of affected tubules, production of autoantibodies against testicular antigens or secretion of pro-inflammatory mediators, replicate observations in testicular sperm extraction samples of patients with 'mixed atrophy' of spermatogenesis. Vasectomy, in the form of sperm antibodies and chronic inflammation, can also be studied in animal models, providing valuable insights into the human response.

WIDER IMPLICATIONS

This is the first comprehensive review of rodent models of both infectious and autoimmune disease of testis/epididymis, and their clinical implications, i.e. their importance in understanding male infertility related to infectious and non-infectious/autoimmune disease of the reproductive organs.

Prevalence of naturally occurring antisperm antibodies (ASA) in blood serum and seminal plasma, and their relationship with cryopreserved semen quality and fertility of buffalo bulls

The present study was undertaken to determine the levels of antisperm antibodies (ASA), sperm-bound immunoglobulins A and G (IgA and IgG) in blood serum and seminal plasma of breeding buffalo bulls, and establish their relationship with quality and fertility of cryopreserved semen. Frozen semen (50 straws/bull) was procured from thirty Murrah buffalo bulls. Additionally, fresh semen of same ejaculate of each bull was also separated for seminal plasma for ASA analysis. Blood samples of all bulls were collected in non-heparinized vials and serum was harvested from them. The ASA, IgA- and IgG-bound spermatozoa were analyzed in blood serum and seminal plasma by immuno-peroxidase assay (IPA) and immunobead-binding assay (IBA). On the basis of per cent ASA, IgA- and IgG-type, all bulls were divided into 2 groups viz. group 1 (< 40% ASA, IgA and IgG in serum; < 20% ASA, IgA and IgG in seminal plasma) and group 2 (> 40% ASA, IgA and IgG in serum; > 20% ASA, IgA and IgG in seminal plasma) for further comparisons. The frozen-thawed semen was also evaluated for percent motility (total and progressive), concentration, viability, abnormality, HOST, acrosome integrity, acrosome reaction, CMPT and first FSCR. The percentage of ASA (37.1±3.8 vs 22.3±1.5), IgA- (44.2±3.1 vs 21.6±2.7) and IgG-bound spermatozoa (35.5±3.0 vs 19.7±4.6) were significantly higher in serum than in seminal plasma. In blood serum, sperm motility, acrosome reaction, CMPT and FSCR were significantly higher in bulls with < 40% ASA as compared to their counterparts. In seminal plasma, bulls with < 20% ASA exhibited significantly higher sperm concentration as compared to their contemporary mates. Sperm concentration (982.2±50.4 vs 874.9±36.3%) in blood serum and acrosome reaction (56.6±2.7 vs 49.9±2.3%) in seminal plasma were the only parameters that were significantly higher in bulls with < 40% and < 20% IgA, respectively than in their counterparts. For IgG-type, sperm concentration and acrosome reaction were significantly higher in bulls with < 40% than in those with > 40% IgG in blood serum. In seminal plasma, acrosome reaction and FSCR were significantly higher in bulls with < 20% IgG than in their contemporary mates. In conclusion, detection of surface-bound ASA was associated with changes in quality and fertility of buffalo bull semen.

Urogenital Infection as a Risk Factor for Male Infertility

BACKGROUND

Infections of the genital tract are considered common causes of male fertility disorders, with a prevalence of 6-10%. Most of the affected men are asymptomatic. The diagnostic evaluation is based mainly on laboratory testing. Inconsistent diagnostic criteria have been applied to date, and this may explain the controversial debate about the role of infection and inflammation in the genital tract as a cause of infertility. The risk of an irreversible fertility disorder should not be underestimated.

METHODS

This review is based on pertinent publications retrieved by a selective literature search in PubMed, including guidelines from Germany and abroad and systematic review articles.

RESULTS

The main causes of inflammatory disease of the male genital tract are ascending sexually transmitted infections (STIs) and uropathogens. Chronic prostatitis has no more than a limited influence on ejaculate variables. By contrast, approximately 10% of men who have had acute epididymitis develop persistent azoospermia thereafter, and 30% have oligozoospermia. Obstruction of the excurrent ducts can ensue, as can post-infectious disturbances of spermatogenesis. The differential diagnostic evaluation includes the determination of testicular volumes, hormone concentrations, and ejaculate variables. Epidemiological data are lacking with regard to infertility after primary orchitis of infectious origin; however, up to 25% of testicular biopsies obtained from infertile men reveal focal inflammatory reactions. Multiple studies have suggested a deleterious effect of leukocytes and inflammatory mediators on sperm para - meters. On the other hand, the clinical significance of bacteriospermia remains unclear.

CONCLUSION

Any suspicion of an infectious or inflammatory disease in the male genital tract should prompt a systematic diagnostic evaluation and appropriate treatment. For patients with obstructive azoospermia, the etiology and site of the obstruction determine the surgical approach to be taken. In the near future, the elucidation of underlying pathophysiological mechanisms and the identification of suitable biomarkers may enable new strategies for conservative treatment.

A Mouse Model for Dietary Xenosialitis: ANTIBODIES TO XENOGLYCAN CAN REDUCE FERTILITY

Humans can incorporate the xenoglycan N-glycolylneuraminic acid (Neu5Gc) from the diet into reproductive tissues and secretions. Most humans also have circulating antibodies specific for this dietary xenoglycan. The potential for inflammation induced by incorporated Neu5Gc and circulating anti-Neu5Gc antibodies, termed xenosialitis, has been discussed as a factor influencing several human diseases. Potential effects of xenosialitis on human fertility remain unknown. Here, we investigate possible adverse effects of the presence of Neu5Gc on sperm or endometrium combined with anti-Neu5Gc antibodies in semen or uterine secretions in a mouse model. We use Cmah(-/-) mice, humanized for Neu5Gc deficiency. We find that the viability, migration, and capacitation of sperm with incorporated Neu5Gc are negatively affected when these are exposed to anti-Neu5Gc antibodies. In addition, we find that after copulation, activated uterine neutrophils and macrophages show increased phagocytosis of sperm in the presence of anti-Neu5Gc antibodies via the complement receptor 3 (C3R) and Fcγ I/II/III (Fc receptor). Furthermore, Neu5Gc in endometrial cells combined with the presence of anti-Neu5Gc antibodies alters the receptivity and decidualization of endometrial explants. These studies provide mechanistic insights on how Neu5Gc on sperm and/or endometrium combined with anti-Neu5Gc antibodies in semen and uterine fluid might contribute to unexplained human infertility.

Assessment of antisperm antibodies in a sample of Egyptian patients with hepatitis C virus infection

Association of hepatitis C virus (HCV) with autoimmune phenomena and impaired semen parameters has been previously reported. The aim of this study was to investigate the influence of HCV infection on the development of antisperm antibodies (ASAs) in HCV-positive males. The study was conducted on 30 HCV-infected individuals and 30 healthy control subjects. In both patients and control groups, liver enzymes and reproductive hormones were measured; computer-assisted semen analysis (CASA) was performed; HCV-RNA in serum was measured and IgG and IgA ASAs in semen were determined. Free testosterone, sperm concentration, progressive and total motility were significantly lower in HCV patients than in the control group, whereas ASAs of the IgG and IgA classes were significantly higher in HCV patients. However, correlations between viral load and the examined semen parameters and ASAs were nonsignificant. In conclusion, HCV may be responsible for the increased ASAs detected in HCV patients in the present study, possibly providing another plausible explanation for the decreased sperm motility reported in HCV patients. These findings could be of value in fertility management of HCV patients.

Antisperm protein targets in azoospermia men

BACKGROUND:

The number of couples that meet the definition of infertility at reproductive ages is increasing worldwide. One of the most known conditions of infertility in males is azoospermia, defined as complete absence of spermatozoa in the semen. Azoospermia manifests in two forms, namely obstructive and non-obstructive azoospermia. Although the presence of antisperm antibody (ASA) has been reported in 88% of the patients with obstructive azoospermia (OA), interestingly, there is no data regarding ASA targets in OA individuals.

AIM:

The present study aimed to identify sperm antibody targets in a group of OA men.

SETTINGS AND DESIGN:

The present study was carried out on 27 OA infertile men and 27 healthy fertile age-matched males as cases and controls, respectively.

SUBJECTS AND METHODS:

The sperm proteome was separated using two-dimensional gel electrophoresis technique, transferred onto the polyvinylidene fluoride membrane, and blotted with the sera of a group of OA men. Then, it was compared with the membranes blotted with the sera of a group of healthy fertile men. Matrix-assisted laser desorption/ionization time-of-flight/time-of-flight (MALDI TOF/TOF) mass spectrometry was used to identify the different blotted spots and finally the results of the mass analysis were confirmed using reverse transcriptase polymerase chain reaction method.

RESULTS:

The results indicated that OA patients might produce antibody against two sperm proteins, Tektin-2 and triose phosphate isomerase. Moreover, the expressions of the two targeted proteins were confirmed at RNA level.

CONCLUSIONS:

The findings of the present study revealed two functionally important sperm proteins as antibody targets in azoospermic men.

Immune Aspects of Female Infertility

Immune infertility, in terms of reproductive failure, has become a serious health issue involving approximately 1 out of 5 couples at reproductive age. Semen that is defined as a complex fluid containing sperm, cellular vesicles and other cells and components, could sensitize the female genital tract. The immune rejection of male semen in the female reproductive tract is explained as the failure of natural tolerance leading to local and/or systemic immune response. Present active immune mechanism may induce high levels of anti-seminal/sperm antibodies. It has already been proven that iso-immunization is associated with infertility. Comprehensive studies with regards to the identification of antibody-targets and the determination of specific antibody class contribute to the development of effective immuno-therapy and, on the other hand, potential immuno-contraception, and then of course to complex patient diagnosis. This review summarizes the aspects of female immune infertility.

Are sperm capacitation and apoptosis the opposite ends of a continuum driven by oxidative stress?

This chapter explores the possibility that capacitation and apoptosis are linked processes joined by their common dependence on the continued generation of reactive oxygen species (ROS). According to this model capacitation is initiated in spematozoa following their release into the female reproductive tract as a consequence of intracellular ROS generation, which stimulates intracellular cAMP generation, inhibits tyrosine phosphatase activity and enhances the formation of oxysterols prior to their removal from the sperm surface by albumin. The continued generation of ROS by capacitating populations of spermatozoa eventually overwhelms the limited capacity of these cells to protect themselves from oxidative stress. As a result the over-capacitation of spermatozoa leads to a state of senescence and the activation of a truncated intrinsic apoptotic cascade characterized by enhanced mitochondrial ROS generation, lipid peroxidation, motility loss, caspase activation and phosphatidylserine externalization. The latter may be particularly important in instructing phagocytic leukocytes that the removal of senescent, moribund spermatozoa should be a silent process unaccompanied by the generation of proinflammatory cytokines. These observations reveal the central role played by redox chemistry in defining the life and death of spermatozoa. A knowledge of these mechanisms may help us to engineer novel solutions to both support and preserve the functionality of these highly specialized cells.

Discovery of human posterior head 20 (hPH20) and homo sapiens sperm acrosome associated 1 (hSPACA1) immunocontraceptive epitopes and their effects on fertility in male and female mice

The key goals of immunocontraception research are to obtain full contraceptive effects using vaccines administered to both males and females. Current research concerning human anti-sperm contraceptive vaccines is focused on delineating infertility-related epitopes to avoid autoimmune disease. We constructed phage-display peptide libraries to select epitope peptides derived from human posterior head 20 (hPH20) and homo sapiens sperm acrosome associated 1 (hSPACA1) using sera collected from infertile women harbouring anti-sperm antibodies. Following five rounds of selection, positive colonies were reconfirmed for reactivity with the immunoinfertile sera. We biopanned and analysed the chemical properties of four epitope peptides, named P82, Sa6, Sa37 and Sa76. Synthetic peptides were made and coupled to either bovine serum albumin (BSA) or ovalbumin. We used the BSA-conjugated peptides to immunise BALB/c mice and examined the effects on fertility in female and male mice. The synthetic peptides generated a sperm-specific antibody response in female and male mice that caused a contraceptive state. The immunocontraceptive effect was reversible and, with the disappearance of peptide-specific antibodies, there was complete restoration of fertility. Vaccinations using P82, Sa6 and Sa76 peptides resulted in no apparent side effects. Thus, it is efficient and practical to identify epitope peptide candidates by phage display. These peptides may find clinical application in the specific diagnosis and treatment of male and female infertility and contraceptive vaccine development.

Prostasomes: Their Characterisation: Implications for Human Reproduction: Prostasomes and Human Reproduction

The prostate is a principal accessory genital gland that is vital for normal fertility. Epithelial cells lining the prostate acini release in a defined fashion (exocytosis) organellar nanosized structures named prostasomes. They are involved in the protection of sperm cells against immune response in the female reproductive tract by modulating the complement system and by inhibiting monocyte and neutrophil phagocytosis and lymphocyte proliferation. The immunomodulatory function most probably involves small non-coding RNAs present in prostasomes. Prostasomes have also been proposed to regulate the timing of sperm cell capacitation and induction of the acrosome reaction, since they are rich in various transferable bioactive molecules (e.g. receptors and enzymes) that promote the fertilising ability of sperm cells. Antigenicity of sperm cells has been well documented and implicated in involuntary immunological infertility of human couples, and antisperm antibodies (ASA) occur in several body fluids. The propensity of sperm cells to carry attached prostasomes suggests that they are a new category of sperm antigens. Circulating human ASA recognise prostasomes, and among 12 identified prostasomal antigens, prolactin- inducible protein (95 %) and clusterin (85 %) were immunodominant at the expense of the other 10 that were sporadically occurring.

The role of SPRASA in female fertility

Fertility is a complex process and infertility can have many causes. Sperm protein reactive with antisperm antibody (SPRASA)/sperm lysozyme-like protein 1 is a protein discovered as the target of autoantibodies in infertile men and previously thought to be expressed only in sperm. Using a bovine in vitro fertilization model, we have shown that SPRASA antiserum reduced sperm binding to zona-free oocytes and the development of embryos to morulae but did not affect the postfertilization cleavage rate to 2 cells or sperm motility. We demonstrated that SPRASA was expressed in ovarian follicles, corpora lutea, and oocytes by a combination of reverse transcription-polymerase chain reaction and immunohistochemistry. Female mice immunized with SPRASA had profound infertility following timed matings and those mice that did become pregnant had reduced fetal viability. The levels of antibodies reactive with SPRASA in 204 fertile and 202 infertile couples were elevated in 3 infertile but no fertile women. Together, these results indicate that SPRASA has a role in female fertility.

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.

Antisperm antibodies and fertility association

OBJECTIVE

To evaluate the relation between antisperm antibodies (ASA) and human fertility by reviewing the scientific literature of the last 45 years.

METHODS

We carried out a review of scientific literature about antisperm antibodies and infertility published in spanish or english in databases as Pubmed, Medline, Scielo, some books and another gray literature include information related to this review and that is published in the last 45 years.

SUMMARY OF EVIDENCE

Infertile couples suffer infertility by immunological mechanisms mainly by the presence of antisperm antibodies ASA in blood, semen or cervicovaginal secretions; the formation of ASA in men and women may be associated with disturbance in immunomodulatory mechanisms that result in functional impairment of sperm and thus its inability to fertilize the oocyte.

CONCLUSION

Immunological infertility caused by ASA is the result of interference of these antibodies in various stages of fertilization process, inhibiting the ability of interaction between sperm and oocyte.

Infectious, inflammatory, and immunologic conditions resulting in male infertility

This article provides an overview of infectious and inflammatory conditions associated with male infertility. These conditions may affect several components of the male reproductive tract and therefore have the ability to potentially alter sperm function. The effect of these conditions on male fertility is poorly understood and often underestimated.

Immunodominant semen proteins I: New patterns of sperm proteins related to female immune infertility

Infertility affects approximately 10% of couples at reproductive age. Semen constituents may be potential immunogenic structures for women. The aim of our work is to detect and identify sperm proteins interacting with serum IgG antibodies from women with fertility disorders. The biochemical characterization of sperm antigens was performed using one and two dimensional gel electrophoresis, both of which were followed by immunoblotting. The IgG-binding proteins of interest were identified using mass spectrometry. From the serum pool of 30 infertile women, we detected sperm antigens within a relative molecular mass range between 30–80 kDa with an isoelectric point of 4–7. No antigens were detected using the serum pool from 10 fertile women (control group). Heat shock proteins (HSP 70) were identified as major sperm antigens associated with female immune infertility. Additionally, we report for the first time that alpha-enolase is a significant sperm antigen from the serum pool of infertile women. We suggest that the IgG-binding proteins identified in our study are related to immune infertility in the case of certain women with abnormally high levels of IgG antibodies linked to sperm proteins. Our results might be useful in the diagnoses of female immune infertility and may provide potential targets for further therapeutic treatment.

Antibodies to prostate-specific antigen in immunoinfertile women and men

Immunoinfertility is caused by antisperm antibodies (ASA) present in the female or male partner of an infertile couple. PSA is a serine protease produced primarily by the prostate gland and is present in human semen. Although the modulation of PSA has been investigated in prostate abnormalities, its role and effect of its dysfunction on human fertility has not been examined. The present study was conducted to examine the presence and incidence of antibodies to PSA in sera of immunoinfertile women and men. The presence of iso- and autoantibodies in the sera of immunoinfertile patients was examined using the well-characterized purified human PSA and seminal plasma from normal fertile men in ELISA. Sera were collected from infertile women (n=25) and infertile men (n=19) who were positive for ASA. Sera from ASA-negative fertile women (n=24) and fertile men (n=19) served as controls. In women, sera from 40% of the immunoinfertile women showed positive reactivity with PSA, and 20% reacted positively with seminal plasma. None of the sera from fertile women reacted positively with PSA or seminal plasma. In men, sera from 16% of the immunoinfertile men showed positive reactivity with PSA, and none (0%) with seminal plasma. None of the sera from fertile men reacted positively with PSA or seminal plasma. This is the first study to examine the presence and incidence of PSA antibodies in immunoinfertile women and men. The findings may have clinical application in the specific diagnosis and treatment of immunoinfertility in humans.

Standardization of a method to detect bovine sperm-bound antisperm antibodies by flow cytometry

The objectives were to standardize some methodological and analytical aspects of a direct technique to detect sperm-bound antisperm antibodies (ASAs) in bovine semen using flow cytometry, including the effects of prefixation of sperm membranes with formalin buffer solution and inclusion of dead cells in the analysis. Fourteen Angus bulls, including ASA-positive (experimentally induced ASAs) and 10 reproductively normal ASA-negative bulls, were used. Fixation of sperm membranes had no significant effect on the percentage of IgG- or IgA-bound spermatozoa detected by flow cytometry. However, including dead cells in the analysis increased the percentage of IgG-bound spermatozoa in fixed (live and dead 18.6 ± 9.7% and live 1.3 ± 0.5%; median ± SEM) and nonfixed samples (live and dead 18.8 ± 9.2%, live 1.5 ± 0.6%; P = 0.0029), as well as IgA-bound spermatozoa in fixed (live and dead 16.3 ± 6.4%, live 0.3 ± 0.5%) and nonfixed samples (live and dead 21.4 ± 4.6%, live 1.0 ± 0.5%; P = 0.0041) in semen from ASA-negative bulls. Intrasample, intra-assay, and interassay coefficients of variation (CV) were 0.8%, 4.6%, and 5.3%, respectively, for determination of sperm-bound IgG, and were 2.8%, 8.4%, and 40.3% for determination of sperm-bound IgA. Despite the high interassay CV for IgA determination, all ASA-positive bulls consistently had high percentages of IgA-bound spermatozoa. Flow cytometry correctly identified ASA-positive bulls. Confocal laser microscopy confirmed binding of ASAs to sperm heads and cytoplasmic droplets, and less frequently to midpieces and principal piece. In conclusion, although fixation was not necessary, dead cells should be excluded from the analysis, because ejaculates with a large proportion of dead cells can yield false-positive results. Flow cytometry was accurate and reliable for detection of sperm-bound IgG and IgA and discrimination between ASA-positive and ASA-negative bulls.

The progressive simplification of the infertility evaluation

OBJECTIVE

With the advent of evidence-based medicine, much of the complex testing that infertile couples used to undergo is no longer recommended as part of the routine evaluation. Examples of tests no longer implemented include the postcoital test, Rubin test of tubal patency, endometrial biopsy, sperm antibody testing, and the zona-free hamster test. The role of routine diagnostic laparoscopy and hysteroscopy is also reviewed.

CONCLUSIONS

In 2010, the simplicity of the current evaluation of couples presenting with infertility is essential information for patients to know at the initial visit. Ideally, it can help alleviate anxiety and provide patients with a road-map during a visit that is often associated with stress and high emotions.

TARGET AUDIENCE

Obstetricians & Gynecologists, Family Physicians.

LEARNING OBJECTIVES

After completion of this educational activity, the obstetrician/gynecologist should be better able to assess the current recommendations for evaluating infertile couples; examine the various ways to assess ovarian reserve, the uterine cavity, and fallopian patency; and appraise the controversy surrounding diagnostic surgery.

High-affinity binding of seminal plasma PSP94 to human immunoglobulin is through the Fab domain

Prostate secretory protein of 94 amino acids (PSP94) is one of the major proteins present in human seminal plasma. We had earlier reported that PSP94 has the ability to bind to human IgG. The aims of the present study were to further delineate the PSP94-IgG interaction and to understand whether this could have any significance in sperm function. Direct binding of IgG fragments to PSP94 showed maximal binding with F(ab')(2) followed by Fab, while Fc displayed least binding in ELISA. Binding kinetics of PSP94-IgG interaction using surface plasmon resonance (SPR) revealed high-affinity binding of IgG to PSP94 with a dissociation constant (K(D)) of 8.8 x 10(-)(11)M. PSP94-IgG interaction was found to be through the Fab domains of IgG. Real-time interaction kinetics revealed association constants for binding of IgG, Fab, and F(ab')(2) towards PSP94 to be of the same order but with altered dissociation constants. IgG and its F(ab')(2) fragment once complexed to PSP94 demonstrated negligible dissociation, while dissociation rate of Fab fragment was 6.6 x 10(-)(4). In silico molecular modeling of PSP94-IgG complex identified N- and C-terminal beta-strands of PSP94 to be the most plausible region involved in IgG interaction. Immunofluorescence studies revealed that IgG bound to human spermatozoa predominantly in the tail region, which could be prevented when IgG was preincubated with PSP94. This study reports for the first time that IgG forms a high-affinity complex with PSP94 through its F(ab')(2) domain and reveals the ability of PSP94 to prevent binding of IgG to spermatozoa.