Detection of sperm antibodies in semen using the immunobead test: a survey of 813 consecutive patients

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.

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.

Anti-sperm antibodies detection by a modified MAR test: Towards a better definition of its indications

RESEARCH QUESTION

Anti-sperm antibodies (ASA) have been shown to reduce male fertility but consensus about the precise situations in which tests should be carried out are lacking. In infertility investigations, should the mixed antiglobulin reaction (MAR) test be a first-line test? Should it be carried out systematically before assisted reproductive technology (ART)? What are the risk factors for ASA?

DESIGN

All infertile patients (n = 1364) were tested with SpermMar (modified MAR test) between July 2013 and June 2017. Intra-patient variability of the MAR test was also assesed by comparing two tests within the same year in selected patients (n = 101).

RESULTS

The main factor that influenced the percentage of ASA was the presence or absence of sperm agglutination. In the presence of agglutinations, 27 out of 72 (37.5%) patients were positive for ASA compared with 33 out of 1292 (2.6%) in the absence of agglutinations (P < 0.0001). When one risk factor was present (spontaneous sperm agglutination, history of scrotal trauma or inguinal surgery), 33 out of 179 (18.44%) tests were positive for ASA (≥50% coated spermatozoa), whereas only 27 out of 1242 (2.2%) were positive when no risk factor was present (P < 0.0001).

CONCLUSIONS

ASA detection should not be systematically recommended in investigations of fertility status and before ART but reserved for when sperm agglutination is found during conventional sperm examination, or if the patient has a history of scrotal trauma or has undergone inguinal surgery.

Application of computer-aided sperm analysis (CASA) for detecting sperm-immobilizing antibody

PROBLEM

Since the 1970s, anti-sperm antibodies have been studied as a pathogenic factor contributing to infertility. The complement-dependent sperm-immobilization test (SIT) and quantitative SIT have been used as effective tools for detecting anti-sperm antibodies in clinical settings. These tests have been carried out traditionally by manually counting the number of motile sperm through eye estimation.

METHOD OF STUDY

In this study, we developed a novel method using computer-aided sperm analysis. The results were compared with those obtained by the traditional method.

RESULTS

The results were identical and 25 of 78 samples tested were positive and 53 samples were negative for sperm-immobilizing (SI) antibodies based on both methods. For SI-positive samples, the values of SI₅₀ obtained using the two methods correlated closely with high co-efficiency.

CONCLUSION

Using the novel method, manually counting the number of motile spermatozoa becomes unnecessary. The novel method presented here will increase the objectivity and convenience of using the SIT as a clinical indicator.

Incidence of Sperm Surface Autoantibodies and Relationship with Routine Semen Parameters and Sperm Kinematics

PROBLEM

Antisperm antibodies (ASA) are associated with male subfertility. However, results on sperm surface autoantibodies are controversial, the relationship between ASA and semen parameters (WHO, 2010) is unknown, and data on ASA and sperm kinematics are scarce.

METHOD OF STUDY

A retrospective study carried out in men undergoing routine semen analysis (WHO 2010), ASA evaluation (direct SpermMAR(™) (IgG) test), and computer-assisted sperm analysis (CASA).

RESULTS

A 2.6% and a 5.9% incidence of ASA-positive cases were found (cut-off 50% and 10%, respectively; n = 7492). ASA-positive samples had lower (P < 0.0001) sperm concentration, count, motility, and hypo-osmotic swelling (HOS) test score. HOS results did not correlate with sperm vitality in normozoospermic samples with high ASA levels. In unselected samples, ASA-positive samples (cut-off 50%) showed decreased sperm kinematics (VSL, VAP, LIN, ALH, STR, BCF, WOB), but in normozoospermic samples, ASA-positive and ASA-negative subgroups had similar CASA results.

CONCLUSIONS

ASA evaluation is highly relevant in full semen assessment.

The Epidemiology of Anti-Sperm Antibodies Among Couples with Unexplained Infertility in North West Bank, Palestine

INTRODUCTION

Anti sperm antibodies (ASA) can present in serum and semen and they may lead to impair the sperms function leading to infertility. The precise mechanism of generation of these antibodies is yet to be discovered.

AIM

This study was performed to determine the prevalence of anti-sperm antibodies (ASA) in patients with unexplained infertility. The study was initiated also to explore the possible factors that may associate with ASA formation and how ASA status is associated with pregnancy rates after going with in vitro fertilization - intracytoplasmic sperm injection (IVF-ICSI).

MATERIALS AND METHODS

A cross-sectional study was conducted on 42 normal infertile couples consulting Razan Medical Center for Infertility & I.V.F. in Nablus, Palestine, from December 2012 - March 2013. Serum levels of immunoglobulins G (IgG) ASA were measured in participants (males and females) using enzyme-linked immunosorbent assay (ELISA). In addition, participants also filled a questionnaire about the presence of previous varicocele repair, inguinal hernia repair, orchitis, testicular trauma and vasectomy reversal among males and severe coitus bleeding and coitus during menses or puerperium among females. Couples were also asked about previous IVF-ICSI procedures and the outcome of the procedure in terms of either they got pregnant or not. Data was analysed using SPSS software.

RESULTS

The prevalence of ASA was 14.3% (6/42) among all couples, 9.5% (4/42) among males and 4.8% (2/42) among females. There was no significant relationship between previous varicocele repair, previous inguinal hernia repair, or orchitis and formation of ASA (p value =0.64, 0.56, and 0.26 respectively). Previous trauma, vasovasostomy, severe coitus bleeding and coitus during menses or puerperium were not observed in any of the study sample. ASA did not seem to affect the outcome of IVF-ICSI (p-value =0.54).

CONCLUSION

Prevalence of ASA in infertile couples in the north part of Palestine is similar to that obtained worldwide. ASA formation does not relate to any of the studied risk factors and does not seem to associate with pregnancy rate after IVF-ICSI. We recommend further studies using a larger sample size and including all parts of Palestine in order to generalize the obtained results.

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.

Prostasomes are mediators of intercellular communication: from basic research to clinical implications

Prostasomes are nanosized microvesicles secreted by acinar epithelial cells of the prostate gland. Furthermore, they are intracellular microvesicles inside another larger vesicle, a so-called storage vesicle, equivalent to multivesicular bodies of late endosomal origin. Prostasomes are thought to play an important role in intercellular communication by direct interaction primarily between the immobile acinar cells of the prostate gland and the mobile spermatozoa. Prostasomes transfer not only membrane components but also genetic material to spermatozoa. They are rich in various transferable bioactive molecules (e.g., receptors and enzymes) that promote the fertilizing ability of spermatozoa. In this review, the pleiotropic biological effects of prostasomes that are relevant for successful fertilization will be discussed. The ability to synthesize and export prostasomes to the extracellular space is observed not only in normal prostate epithelial cells but also in malignant prostate cells. Release of prostasomes by prostate cancer cells suggests a role in malignant cell growth and proliferation. These findings may provide new therapeutic and diagnostic strategies.

Anticorps antispermatozoïdes : indications, étiologies et applications en 2011, de l’exploration de l’infertilité au concept d’immunocontraception masculine

La présente revue de la littérature a pour but de préciser en 2011 les techniques utilisées pour le dépistage des anticorps antispermatozoïdes (ACAS) et l’intérêt de ce dépistage dans diverses situations physiopathologiques mais aussi dans le choix du traitement des infertilités par les techniques d’assistance médicale à la procréation (AMP). De plus, l’étude des cibles et du rôle des ACAS dans l’infertilité a permis la mise au point d’un vaccin contraceptif masculin efficace dans certains modèles animaux et potentiellement utilisable chez l’homme.

Antisperm antibodies and conception

Sperm have been known to be antigenic for more than a century. There is a strong body of evidence that in humans and in other species at least some antibodies that bind to sperm antigens can cause infertility. Therefore, these antibodies are of interest today for two practical reasons. Firstly, the association of the antibodies with infertility means that they must be detected and then the couples treated appropriately. Secondly, because these antibodies can induce infertility they have the potential to be developed for contraceptive purposes in humans and also for the control of feral animal populations.

Association between sperm autoantibodies and enhanced embryo implantation rates during in vitro fertilization

Previous investigations have demonstrated the propensity of strong IgA-class sperm autoantibodies to impede fertilization. However, because there has not been a general consensus on this issue, the aim of this retrospective analysis was to focus on the effects of different levels of IgA-class antibodies on each stage of the IVF procedure. This study has confirmed that high level IgA class antibodies significantly reduce fertilization rates but, unexpectedly, also has shown a very significant improvement in embryo implantation rates in patients with weak to moderate antibody levels. Interlaboratory prospective collaborative studies are being planned to test this preliminary observation more stringently.

Are antisperm antibodies indeed sperm-specific?

Antisperm antibodies (ASA) are present in a high percentage of infertile patients. The development of ASA in the male depends on the sequestration of antigens on germ cells, the testis being an immune privileged region. In this study, we investigated the specificity of ASA binding to sperm antigens by exposing a number of organ preparations to ASA. In none of the organ homogenates was a significant difference between the results of the Western blot with ASA-containing fluids, neither serum nor seminal plasma, and those without ASA observed. We conclude from our results that the ASA tested in our study obviously are sperm-specific. ASA as an autoimmune are thus restricted to spermatozoa. The antigens are suitable for trials in immune therapy, they may also serve for the development of antigen-specific diagnosis and treatment in infertility. They also indicate cognate antigens of possible immune contraceptive agents.

Analysis of 508 infertile male patients in south-western Finland in 1980-2000: hormonal status and factors predisposing to immunological infertility

OBJECTIVE

To analyse the factors predisposing to male immunological infertility from the hospital records of 508 patients that had been treated for infertility in the Turku University Central Hospital from 1980 to 2000. In addition, the hormonal status was investigated at the beginning of treatment.

RESULTS

Patients with a history of mumps, or either a fresh varicocele or a history of varicocele had statistically significant lower levels of MAR antisperm antibodies (ASAs) than patients with no such conditions. Repair of varicocele (either surgical or embolisation), showed a statistically significant enhancement of the total sperm cell counts in ejaculates, but it appeared not to have any influence on other parameters of the semen analysis (mobility and morphology). Of all male infertility patients, 66.3% had normal hormonal status at the beginning of treatment, 12.6% of patients had hypotestosteronemia and 22.1% had subclinical hypogonadism. Patients with subclinical hypogonadism had lower total sperm cell count in ejaculates than patients with normal hormonal status although they had statistically significant more offspring. In addition, it appeared that mumps orchitis as well as smoking and alcohol abuse are risk factors for subclinical hypogonadism.

CONCLUSION

No clear predisposing factor for male immunological infertility could be found. However, patients with subclinical hypogonadism differed from other male infertility patients and thus may form a special group among the male infertility patients.

Male factor infertility: evaluation and management

There is a male factor involved in up to half of all infertile couples. Potential etiologies in male factor infertility are many and require thorough evaluation for their accurate identification. A complete medical history in conjunction with a focused examination can allow for an appropriate choice of laboratory and imaging studies. The semen analysis is a crucial first step, but by no means is it sufficient to determine a specific etiology or dictate therapy. A systematic approach is necessary to help guide the work-up and rule out less likely causes. The etiologies discussed within this article are tremendously broad, and the prognosis for any given couple depends, in large part, on the etiology. Without a firm understanding of the genetics, anatomy, physiology, and complex interplay of the male reproductive system, the evaluation becomes an inefficient exercise that often fails to define the precise etiology. Couples with male factor infertility need a systematic approach with the efficiency of ultimate treatment determined largely by the physician's ability to identify the specific cause of the man's reproductive failure.

Sperm preparation for ART

The onset of clinical assisted reproduction, a quarter of a century ago, required the isolation of motile spermatozoa. As the indication of assisted reproduction shifted from mere gynaecological indications to andrological indications during the years, this urged andrological research to understand the physiology of male germ cell better and develop more sophisticated techniques to separate functional spermatozoa from those that are immotile, have poor morphology or are not capable to fertilize oocytes. Initially, starting from simple washing of spermatozoa, separation techniques, based on different principles like migration, filtration or density gradient centrifugation evolved. The most simple and cheapest is the conventional swim-up procedure. A more sophisticated and most gentle migration method is migration-sedimentation. However, its yield is relatively small and the technique is therefore normally only limited to ejaculates with a high number of motile spermatozoa. Recently, however, the method was also successfully used to isolate spermatozoa for intracytoplasmic sperm injection (ICSI). Sperm separation methods that yield a higher number of motile spermatozoa are glass wool filtration or density gradient centrifugation with different media. Since Percoll as a density medium was removed from the market in 1996 for clinical use in the human because of its risk of contamination with endotoxins, other media like IxaPrep, Nycodenz, SilSelect, PureSperm or Isolate were developed in order to replace Percoll. Today, an array of different methods is available and the selection depends on the quality of the ejaculates, which also includes production of reactive oxygen species (ROS) by spermatozoa and leukocytes. Ejaculates with ROS production should not be separated by means of conventional swim-up, as this can severely damage the spermatozoa. In order to protect the male germ cells from the influence of ROS and to stimulate their motility to increase the yield, a number of substances can be added to the ejaculate or the separation medium. Caffeine, pentoxifylline and 2-deoxyadenosine are substances that were used to stimulate motility. Recent approaches to stimulate spermatozoa include bicarbonate, metal chelators or platelet-activating factor (PAF). While the use of PAF already resulted in pregnancies in intrauterine insemination, the suitability of the other substances for the clinical use still needs to be tested. Finally, the isolation of functional spermatozoa from highly viscous ejaculates is a special challenge and can be performed enzymatically to liquefy the ejaculate. The older method, by which the ejaculate is forcefully aspirated through a narrow-gauge needle, should be abandoned as it can severely damage spermatozoa, thus resulting in immotile sperm.

ACP best practice no 170. Investigation of infertility with the emphasis on laboratory testing and with reference to radiological imaging

This review will discuss the investigation of infertility, with emphasis on laboratory testing and reference to the value of other investigations, including clinical and radiological. The role of laboratory investigations is viewed within an appropriate clinically directed pathway that includes medical, surgical, and social history together with environmental factors. Because embryology and assisted reproduction techniques are developing rapidly and produce continuous changes in everyday practice, this article gives a critical review of the plethora of tests that are currently used.

Male infertility

Infertility affects 13-18% of couples and growing evidence from clinical and epidemiological studies suggests an increasing incidence of male reproductive problems. The pathogenesis of male infertility can be reflected by defective spermatogenesis due to pituitary disorders, testicular cancer, germ cell aplasia, varicocele and environmental factors or to defective sperm transport due to congenital abnormalities or immunological and neurogenic factors. Recent studies suggest an increased incidence of genetic disorders related to male infertility which may affect different levels, interfering with germ cell generation and maturation or leading to the production of non-functional spermatozoa. The identification of genetic causes of male infertility raises the issue of the transmission of defects to the offspring, a situation that is becoming more important given the increasing use of intracytoplasmic sperm injection (ICSI), a procedure in which the natural selection of the spermatozoa is by-passed. Fertilization can occur in vitro using ejaculated, epididymal or testicular spermatozoa, either fresh or frozen-thawed, providing opportunities hitherto not possible for men to be genetic fathers.

Male antisperm antibodies: association with a modified sperm stress test and lipid peroxidation

We previously reported a modified sperm stress test (MOST), low scores (< 0.39) in which were associated with sperm-related abnormal in vitro fertilization. Preliminary observations suggested that the presence of male sperm antibodies (ASA) could give low MOST scores. It was therefore decided to undertake a study to verify this possible association and also to ascertain if such a relationship was causal in nature. Six hundred and fifty semen samples from patients consulting for infertility were assessed for basic seminal characteristics, motion parameters (CASA), ASA and MOST. Thirty-nine samples (6%) were ASA-positive. Samples with and without ASA showed similar characteristics, except for percentage of normal forms and MOST scores (0.35 +/- 0.03 vs. 0.67 +/- 0.01, P < 0.001, for ASA-positive and -negative, respectively). There was a strong statistical association between presence of ASA and low MOST scores (P < 0.0001). One-hundred per cent of ASA-positive samples displayed low MOST scores. To verify the nature of this relationship, we incubated ASA-free spermatozoa with ASA-positive and -negative (control) sera. Despite an increase in the percentage of ASA-bearing spermatozoa in those aliquots incubated with ASA-positive serum, their original (pre-incubation) MOST scores remained unchanged. Furthermore, the rate of lipid peroxidation, indirectly reflected in MOST scores, was not different in the aliquots incubated with ASA. In conclusion, there seems to be a strong association between presence of ASA and low MOST values in semen samples of infertile patients; however, the relationship does not appear to be causal.

Diversity of antisperm antibodies bound to sperm surface in male immunological infertility

PROBLEM

The presence of antisperm antibodies (ASA) in males can reduce fecundity, however, relationship between the two is disputed. This study was performed to investigate if there is diversity of ASA bound to sperm surface using immunobead test (IBT) combined with complement dependent sperm immobilization test (SIT).

METHODS

The ASA bound to sperm surface were detected using the direct IBT (D-IBT) in 275 semen samples. In some cases with ASA detected by D-IBT, sperm immobilizing antibodies bound to sperm surface were also evaluated using direct SIT (D-SIT).

RESULTS

The incidence of the immunoglobulin G (IgG), IgA, and IgM classes of ASA detected by D-IBT were 2.5, 1.8, and 0.4%, respectively. Totally, nine (3.3%) infertile men had ASA on the sperm surface. D-SIT was tested positive in four (66.7%) of six cases with ASA assessed by D-IBT.

CONCLUSIONS

Some of the sperm-bound antibodies are associated with complement dependent sperm immobilizing antibodies, indicating that there exists a heterogeneity of sperm-bound antibodies. This result might be one of the reasons for the controversy about the relationship between ASA and immunological infertility in men.

Antisperm antibodies detection by flow cytometry is affected by aggregation of antigen-antibody complexes on the surface of spermatozoa

Flow cytometry (FCM) analysis of live antibody-coated spermatozoa subjected to immunofluorescence staining (FCM test) is considered an objective method for the quantitative detection of antisperm antibodies (ASA). But the cross-linking of cell surface antigen (Ag) with bivalent antibodies and/or antigen-antibody (Ag-Ab) complexes with second antibodies may induce the reorganization of surface components (patching and capping) and result in their shedding from the sperm surface. The present study estimates the relationship between aggregation of Ag-Ab complexes on the sperm surface and the results of indirect FCM test. Swim-up spermatozoa of normozoospermic men were incubated with ASA-positive sera from infertile patients and with second antibodies fluorescein isothiocyanate (FITC)-labelled goat anti-human IgG polyclonal antiserum under different conditions and then analysed by FCM and fluorescence microscopy. It was shown that low temperature, cytochalasin B, excess or lack of the primary and/or secondary antibodies and sperm fixation by paraformaldehyde may inhibit aggregation and shedding of Ag-Ab complexes and dramatically increase ASA quantity determined on the sperm surface. However, inhibition of aggregation on the live sperm surface was observed only in a minority of ASA-positive samples and was poorly reproducible using semen of different donors. A high probability of Ag-Ab complex shedding from the sperm surface during experimental manipulation limits the use of indirect FCM test for quantitative ASA determination.

Comparison of human cervical mucus and artificial sperm penetration media

The cervical mucus penetration tests aid research and determine the clinical importance of positive sperm antibody tests. Limited availability and variability of human cervical mucus have instigated the search for mucus substitutes for these tests. This study compares sperm migration in cervical mucus with that in artificial media including hyaluronate solution, egg white and albumin Tyrode solution. Results were quantified by measuring the migration distance (the maximum distance of capillary migration from a semen reservoir by spermatozoa after 1 h) and the sperm concentration at half the migration distance. The mean of both measures for cervical mucus and hyaluronate solution were equivalent [4.4 +/- 1.1 (SD) versus 4.3 +/- 1.0 cm and 118 +/- 51 versus 111 +/- 44x10(3)/ml], and higher than in egg white and albumin Tyrode solution. Antisperm antibodies impaired sperm penetration in cervical mucus and hyaluronate solution in a similar manner (r = 0.92). These results suggest that hyaluronate solution sufficiently resembles human cervical mucus in terms of penetrability that it may be used as a substitute for mucus in capillary tube tests of sperm function. The higher penetrability of cervical mucus and hyaluronate solution is probably related to a channelling effect due to their polymeric structure.

The characterization of human spermatozoa membrane proteins--surface antigens and immunological infertility

The aim of this study was to isolate and characterize highly enriched membrane proteins by two-dimensional (2-D) electrophoresis and to identify surface antigens binding sperm autoantibodies (SpAb). The presence of SpAb may reduce fertility by affecting sperm motility and acrosome reaction. The presence of the SpAb was shown to prevent sperm penetration of cervical mucus, to inhibit sperm-zona pellucida interaction, and to interfere with the sperm-egg fusion. The swim-up method was used to separate mature and motile sperm. Sperm membranes were obtained by hypoosmotic swelling, homogenization and sonication. Membranes were further isolated by differential centrifugation steps. The highly purified human sperm membrane proteins were separated by two-dimensional gel electrophoresis and electrotransferred to polyvinylidene difluoride (PVDF) membrane. The antigens were identified by bound SpAb, the sources of which were seminal plasma samples of infertile patients or of patients following vasectomy. Fourteen surface antigens were detected. Their identification may be (i) important for understanding the mechanism by which SpAb impair sperm fertilization capacity, (ii) suitable as a basis of new methods of fertility regulation, and (iii) helpful in developing reproducible and reliable methods for determinations of SpAb.

Effect of seminal oxidative stress on fertility after vasectomy reversal

OBJECTIVE

To evaluate seminal oxidative stress in men after vasectomy reversal and to determine whether seminal oxidative stress could predict fertility after vasectomy reversal.

DESIGN

Measurement of seminal reactive oxygen species (ROS) and total antioxidant capacity (TAC) in normal donors, men who were fertile after vasectomy reversal, and men who were infertile after vasectomy reversal.

SETTING

A male infertility clinic of a tertiary care center.

PATIENT(S)

Thirty men who underwent vasectomy reversal and 17 normal donors.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Semen characteristics, seminal ROS, and TAC were measured with chemiluminescence assays in samples from donors and reversal patients.

RESULT(S)

Mean adjusted seminal ROS (log [ROS+1]) was higher in infertile reversal patients (2.38+/-0.25) than in normal donors (1.30+/-0.14). Seminal ROS was also higher in all (fertile and infertile reversal combined) reversal patients than in donors. Total antioxidant capacity did not differ between groups. The ROS-TAC score, a composite index of seminal oxidative stress, was a significant predictor of fertility. A ROS-TAC score of 45 or greater had a positive predictive value of 73% in predicting fertility.

CONCLUSION(S)

Seminal oxidative stress is associated with vasectomy reversal. The ROS-TAC score is a possible predictor of infertility after vasectomy reversal.

Antisperm antibodies: etiology, pathogenesis, diagnosis, and treatment

OBJECTIVE

To critically review the English-language literature and describe the current diagnosis, prevalence, etiology, and treatment of antisperm antibodies (ASA).

DESIGN

A comprehensive literature search of the English-language literature published between 1966 and December 1997 was performed on MEDLINE. Articles were also located via bibliographies of published works.

RESULT(S)

Data were excerpted from articles identified by MEDLINE search. The diagnosis, prevalence, etiology, and treatment of ASA are described.

CONCLUSION(S)

There is sufficient evidence that ASA impair fertility in couples with unexplained infertility. A number of different methodologies are available, which may be used in their detection. However, in many cases, test interpretation is subjective. Although there is not enough evidence to support systemic treatment for ASA, application of a variety of assisted reproductive technologies improves outcome.

Clinical value of tests for assessing male infertility

The laboratory assessment of the male partner of an infertile couple is an important aspect of the overall investigation of that couple. The laboratory tests are designed essentially to determine whether (a) the semen samples contain adequate numbers of normal motile sperm, and the sperm are able (b) to migrate to the site of fertilization and (c) to fertilize oocytes. Within this framework, tests can be viewed as being either descriptive, in terms of describing the ejaculate and sperm, or assessing functional qualities of the sperm. Irrespective of the nature of the test, it must satisfy simple criteria, namely being reproducible and able to discriminate between the fertile and infertile populations reliably. External quality assurance programmes now exist for semen analysis and allied techniques to help laboratories to standardize their reporting and to identify the source of possible errors.

Male immunologic infertility: sperm performance on in vitro fertilization

OBJECTIVE

To analyze sperm performance in a group of patients with male immunologic infertility treated with IVF-ET.

DESIGN

Retrospective clinical study.

SETTING

Patients attending a private IVF clinic.

PATIENT(S)

The study group comprised seven men with significant levels of surface-bound antisperm antibodies treated in nine IVF cycles. The control group comprised nine couples with female tubal infertility and no indication of male factor infertility treated on the same cycle.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Fertilization rate, early embryonic development, implantation, and clinical pregnancy rate (PR).

RESULT(S)

Forty-six (44.2%) of 104 inseminated oocytes were fertilized in the study group compared with 65 (84.4%) of 77 in the control group, which was a significant difference. Surface-bound antisperm antibodies significantly inhibited early embryonic cleavage in the study group (13 [28.3%] of 46 embryos with at least 3 blastomeres) compared with the control group (41 [63.1%] of 65 embryos, with at least 3 blastomeres). The percentage of good-quality embryos (grades 1 and 2) was similar in the study and control groups (71.7% and 78.5%, respectively). The percentage of poor-quality embryos (grade 4 and two pronuclei) was higher in the study group compared with the control group (13.9% versus 9.2%, respectively); however, the difference was not significant. The implantation rate and clinical PR were lower in the study group (3% and 11%, respectively) compared with the control group (9.5% and 44%, respectively), but the difference was not statistically significant.

CONCLUSION(S)

The fertilization rate and early embryonic cleavage of human embryos was found to be reduced significantly in patients with high levels of surface-bound antisperm antibodies. Moreover, embryonic quality and the PR may be compromised by the presence of significant levels of surface-bound antisperm antibodies.

Assisted reproductive technologies and immune infertility

The fields of reproduction and immunology are now interfacing to enhance the ability of women to achieve their desired family size. Much work needs to be done to understand the role of immunologic processes in both fertilization, implantation, and maintenance of a healthy pregnancy.

Evaluation of the immunological cause of male infertility

The presence of antisperm antibodies was considered as one of the main causes of male infertility. This study was conducted on 776 semen samples of the male partners of infertile couples in order to evaluate the immunological factor. The detection of antisperm antibodies was performed by means of the direct Mixed Antiglobulin Reaction (MAR) test. A positive test was found in 35 samples. Hence, the prevalence of immunological infertility in this study is 4.5% among the male partners of infertile couples. Further explorations were performed on men with positive results, in order to detect the presence of antibodies in the sera by means of the indirect MAR tests, and sperm immobilization tests for quantitating the cytotoxic activity of the antibodies. The indirect MAR tests showed that 97% of the antibodies were present in sera, whereas 51% of the samples were cytotoxic. Routine semen analysis indicated that around 60% of the semen samples with antisperm antibodies were good. Semen culture showed that positive results were detected in 40% of samples. Clinical evaluations revealed that the presence of antisperm antibodies may have been the cause of long-standing infertility, on average 5 years, and were not all primary. Evaluations of all clinical and laboratory findings indicated that unilateral testis obstruction and male accessory gland infection were the main pathologies found.

Infertility due to antisperm antibodies

Immunoinfertility is an important problem, involving a significant number of infertile couples. Although the presence of antibodies on sperm has better prognostic value than those in serum or seminal plasma, it may not be the sole authentic evidence of immunoinfertility. Infertility from antisperm antibodies is likely only when they bind to a relevant sperm antigen involved in a specific fertility function. The variance in functional deficits seen in immunologic infertility is most likely related to antibodies directed at different sperm antigens or different class, subclass, or isotypes. Antibodies to FA-1 seem to be of significant importance in human immunoinfertility. In approaching couples with infertility, a high index of suspicion for antibodies is necessary to avoid misdiagnosis. In the optimal situation, all semen analyses should be screened for sperm-bound antibodies, but if this is impractical, testing should be performed on high-risk individuals (Table I). In couples in which the man has sperm-bound antibodies, and in whom there is no identifiable female factor, treatment should be instituted. Most treatments for immunoinfertility have been disappointing because of poor results, adverse effects, or high cost. Corticosteroid therapy has shown some promise in published reports (mostly poorly designed studies), but increase in pregnancy rate is modest and adverse effects may be significant. In our opinion, informed consent should be documented prior to institution of corticosteroid therapy, and subjects should be closely monitored. Advanced reproductive technologies offer a higher safety profile, and, with increasing technology, higher pregnancy rates. We recommend progressing from "low-tech" procedures, such as IUI and reserving the higher level procedures, such as IVF and ICSI, for those couples in whom pregnancy does not occur. The highest level reproductive technologies give the best current prospects for pregnancy in patients with this difficult problem but also are invasive and costly. It is hoped that further work in the laboratory will give rise to newer, safer, and less expensive effective treatments in the very near future.

Can the immunobead assay for detecting sperm antibodies in fresh samples be reproduced in cryopreserved/thawed human spermatozoa?

PROBLEM

To evaluate the reproducibility of the Immunobead Assay (IBA) on sperm samples before and after cryopreservation.

METHOD

Sperm samples (fresh and post-thaw) from known antibody negative donors (N = 20) were evaluated for percent immunobead binding by IBA following incubation with known antibody-positive serum.

RESULTS

In both fresh and thawed negative samples, the mean sperm head binding was 0.5% +/- 0.5, the mean sperm tail binding was 2.0% +/- 2.0 and the mean sperm head-tail binding was 3.0% +/- 2.0 for IgG, IgA and IgM type antibodies, respectively. The same samples exposed to positive sera showed 40.0% +/- 10.0 mean head binding, 7.0% +/- 8.0 mean tail binding and 47.0% +/- 11.0 mean head-tail binding.

CONCLUSIONS

IBA is highly reproducible for detecting sperm antibodies in both fresh and cryopreserved/thawed samples of human spermatozoa.

Interlaboratory interprotocol comparison of indirect immunobead assay for sperm-associated antibodies in serum

This investigation was designed to study the effect of two different protocols on the indirect sperm-associated antibody test on serum performed using Bio-Rad immunobead (IBT) at two andrology laboratories. Aliquots of 31 serum samples from infertile couples were analyzed by both protocols. The IBT was negative by both protocols (100% concordance) for 18 serum samples. Seven of the 13 remaining samples were positive by both protocols (> or = 10% bead attachment by protocol A and > or = 20% bead attachment by protocol B), for a concordance of 54%. The remaining six samples were positive by one of the two protocols. The overall concordance for positive and negative results was 81% (25 of 31 samples). Protocol A detected a higher percentage of bead attachments for IgG and IgA, while protocol B detected a higher percentage of bead attachments for IgM. The discordance in the results of IgA attachment obtained by the two protocols was statistically significant (p < .05). A standardized, uniform protocol for the indirect IBT is needed.

Fertilization efficiency of morphologically abnormal spermatozoa in assisted reproduction is further impaired by antisperm antibodies on the male partner's sperm

OBJECTIVE

To investigate the influence of antisperm antibodies on the sperm surface on the outcome of IVF and GIFT.

DESIGN

Matched controlled retrospective review of two large series.

SETTING

Reproductive endocrine divisions of two level-three academic centers.

PATIENTS

Twenty-nine male factor patients (38 IVF cycles) showing positive antisperm antibodies on the sperm by immunobead test treated by IVF at the Norfolk program and 56 similar patients (57 cycles) treated by GIFT at the Tygerberg program. Twenty-nine male factor patients (29 IVF cycles) with negative antisperm antibodies screening matched by wife's stimulation protocol and baseline semen analysis characteristics were used as controls in Norfolk; 56 GIFT patients (56 GIFT cycles) matched similarly were the Tygerberg controls. Study and control groups were divided according to sperm morphology pattern in normal, good, and poor prognosis subgroups for comparison.

MAIN OUTCOME MEASURES

Fertilization rate of preovulatory oocytes used in IVF in Norfolk and of GIFT supernumerary preovulatory oocytes in Tygerberg; total and term pregnancy rates (PRs) and abortion rates.

RESULTS

Fertilization rate was significantly lower in the IVF (41.9% +/- 2.8%) as well as in the GIFT (26.8% +/- 3.8%) (mean +/- SE) study groups than in the respective control groups (73.1% +/- 3.9% and 61.8% +/- 3.9%). Total and term PRs in IVF per cycle (21.1% +/- 6.6%; 13.2% +/- 5.5%) and per transfer (23.5% +/- 7.4%; 14.7% +/- 6.1%), and in GIFT (25.0% +/- 5.8%; 19.6% +/- 5.3%) in the study groups were also lower when compared with their control counterparts (IVF per cycle: 62.1% +/- 6.2% and 41.4% +/- 6.0%; IVF per transfer: 41.9% +/- 2.0% and 27.9% +/- 1.9%; GIFT: 31.6% +/- 6.2% and 28.1% +/- 6.0%), but the difference did not reach statistical significance. Abortion rates were similar in the IVF study group (37.5% +/- 17.1%) and its control groups (39.9% +/- 11.5%). The abortion rate in the GIFT study group was 14.3% +/- 9.4%, and no abortions were recorded in the control group (not significant).

CONCLUSIONS

The presence of antisperm antibodies on the sperm surface per se impairs the outcome of assisted reproduction, mainly in terms of fertilization rate of preovulatory oocytes, and possibly in terms of total and term PRs. This holds true regardless of the impact of other semen parameters, particularly the morphology of the sperm within the semen sample.

A comparison of enzyme-linked immunosorbent assay (ELISA) with sperm immobilization test (SIT) in detection of antisperm antibodies in sera of infertile women

In the present study, an enzyme-linked immunosorbent assay (ELISA) for antisperm antibodies was compared with a traditional standard sperm immobilization test (SIT) in sera from 158 infertile women in order to evaluate their clinical usefulness for various causes of infertility. Ten pregnant and unmarried women were used as the control group. There was a higher incidence rate by ELISA (13.9%) compared with that by SIT (10.1%) after examination of overall samples, although the difference was not statistically significant. The unexplained infertility group exhibited the highest incidence among the various causes of infertility in both of these two methods. Fifteen (93.8%) of 16 patients with positive SIT showed positive reaction in ELISA method, indicating that a close correlation exists between the two methods. The positive predictive value (54.5%) of ELISA was significantly (p < 0.05) lower than that (87.5%) of SIT, as evaluated with the results of postcoital test (PCT) performed at periovulatory phase. This suggests that the ELISA method for antisperm antibodies is less specific than SIT in view of the PCT results. Nevertheless, no fresh sperms are not required for the ELISA examination. Thus, it seems that the ELISA method may provide a convenient and practical means for mass screening in detecting antisperm antibodies in clinical practice.

Prevalence of sperm bound antibodies in infertile men with varicocele: the effect of varicocele ligation on antibody levels and semen response

An increased level of antisperm antibodies has been demonstrated in infertile men with varicocele compared with normal fertile men, suggesting a possible cause and effect relationship. To evaluate the possible etiological role of antisperm antibodies in varicocele patients, we performed a prospective study of 32 infertile men undergoing varicocele ligation. Semen analyses and antisperm antibodies as measured by the immunobead test were performed preoperatively and postoperatively at 3 and 6 months. Of the infertile men with varicocele 28% had a positive immunobead test compared with 0% of normal fertile men. The average total motile sperm count was significantly different (p < 0.05, 2-tailed t test) for 9 varicocele patients with sperm-bound antibody (3.2 x 10(6)) compared with 23 without antibody (8.4 x 10(6)). Postoperatively, 68% of all patients exhibited improved semen parameters, with no change in antibody status in either group. Among the antibody positive group 71% showed an increase in motile sperm per ml. of 2.8 x 10(6) to 17.2 x 10(6) (525% increase, p < 0.05), while in the antibody negative group 67% showed an increase of 3.8 x 10(6) to 24.9 x 10(6) (553% increase, p < 0.05). Our study suggests that there is an increased incidence of sperm-bound immunoglobulin in infertile varicocele patients and an apparent adverse effect on semen parameters in these patients. However, the presence of sperm-bound immunoglobulin did not affect the percentage response to surgical correction, nor can we postulate an immunological mechanism as a major etiological factor in varicocele induced infertility.