Antisperm antibodies to sperm surface antigens in women with genital tract infection

Screening for Chlamydia trachomatis in Egyptian women with unexplained infertility, comparing real-time PCR techniques to standard serology tests: case control study

BACKGROUND

To study the prevalence of Chlamydia infection in women with primary and secondary unexplained infertility using ELISA technique for antibody detection and real time, fully automated PCR for antigen detection and to explore its association with circulating antisperm antibodies (ASA).

METHODS

A total of 50 women with unexplained infertility enrolled in this case control study and a control group of 44 infertile women with a known cause of infertility. Endocervical specimens were collected for Chlamydia antigen detection using PCR and serum samples for antibodies detection. Circulating anti-sperm antibodies were detected using sperm antibody Latex Agglutination tests.

RESULTS

The overall prevalence of Chlamydial infection in unexplained infertility cases as detected by both ELISA and PCR was 40 % (20/50). The prevalence of current Chlamydial genital infection as detected by real-time PCR was only 6.0 % (3/50); two of which were also IgM positive. Prevalence of ASA was 6.0 % (3/50); all were sero-negative for anti-C.trachomatis IgM and were PCR negative.

CONCLUSION

The incidence of Chlamydial infection in Egyptian patients with unexplained infertility is relatively high. In the setting of fertility investigations; screening for anti. C.trachomatis antibodies using ELISA, and treatment of positive cases should be considered. The presence of circulating ASA does not correlate with the presence of old or current Chlamydia infection in women with unexplained infertility.

Female sex hormones regulate the Th17 immune response to sperm and Candida albicans

STUDY QUESTION

What role do female sex hormones play in the antisperm immune response?

SUMMARY ANSWER

We found that sperm induce a Th17 immune response and that estradiol down-regulates the antisperm Th17 response by dendritic cells.

WHAT IS KNOWN ALREADY

Estradiol down-regulates the immune response to several pathogens and impairs the triggering of dendritic cell maturation by microbial products.

STUDY DESIGN, SIZE, DURATION

Ex vivo and in vivo murine models of vaginal infection with sperm and Candida albicans were used to study the induction of Th17 and its hormonal regulation.

PARTICIPANTS/MATERIALS, SETTING, METHODS

We analyzed the induction of Th17 cytokines and T cells in splenocytes obtained from BALB/c mice challenged with sperm and C. albicans. For the in vivo vaginal infection models, we used ovariectomized mice treated with vehicle, estradiol or progesterone, and we assessed the effect of these hormones on the immune response in the lymph nodes.

MAIN RESULTS AND THE ROLE OF CHANCE

Th17 cytokines and T cells were induced by sperm antigens in both ex vivo and in vivo experiments. Estrus levels of estradiol down-regulated the Th17 response to sperm and C. albicans in vivo.

LIMITATIONS, REASONS FOR CAUTION

This study was conducted using murine models; whether or not the results are applicable to humans is not known.

WIDER IMPLICATIONS OF THE FINDINGS

Our results describe an adaptive mechanism that reconciles immunity and reproduction and further explains why unregulated Th17 could be linked to infertility and recurrent infections.

STUDY FUNDING/COMPETING INTEREST(S)

This work was supported by research grants from the Instituto de Salud Carlos III (ISCIII) (PI10/00897) and Fundación Mutua Madrileña to M.R. M.R. holds a Miguel Servet contract from the ISCIII (CP08/00228). M.A.M.-F. was supported by (ISCIII) INTRASALUD PI09/02029. We have no conflicts of interest to declare.

TRIAL REGISTRATION NUMBER

Not required.

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

PROBLEM

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

METHOD OF STUDY

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

RESULTS

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

CONCLUSION

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

Heterosexual spread of HIV infection

Sexual transmission is the most common route of spread of human immunodeficiency virus (HIV), with heterosexual transmission of HIV infection accounting for 90% of those infected in 1992 and over 75% of the 10–12 million of those infected to date worldwide. Yet, heterosexual transmission is poorly understood. Since HIV can be transmitted from HIV-infected people who are asymptomatic as well as from those who have the acquired immunodeficiency syndrome (AIDS), we must better define the potential for transmission of HIV from HIV-infected individuals as well as the factors which influence the susceptibility of HIV-uninfected individuals.

Human sperm protein encyclopedia and alloantigen index: mining novel allo-antigens using sera from ASA-positive infertile patients and vasectomized men

Anti-sperm antibodies (ASA) are an important cause of immunological infertility. The objective of this study was to identify immunodominant sperm antigens recognized by anti-sperm antibodies (ASA) in serum samples of infertile men, women and vasectomized men. High-resolution two-dimensional gel electrophoresis was employed to separate human sperm proteins using isoelectric focusing (IEF) or nonequilibrium pH gradient electrophoresis (NEPHGE), followed by PAGE and Western blotting. Serum samples from five infertile male and five infertile female subjects that contained ASA as assayed by the immunobead binding test (IBT), were analyzed by Western blotting using NEPHGE gels followed by enhanced chemiluminescence (ECL) to identify the basic sperm antigens reactive to the sera. Serum samples from five fertile male and five fertile female subjects that were ASA-negative by IBT were used as controls. Serum samples from six vasectomized men collected before vasectomy and at different time intervals until 6 months after vasectomy were analyzed by Western blotting using IEF gels. The ECL blots were analyzed to compare immunoreactivity between serum samples from fertile and infertile subjects and identify antigens unique to sera of the infertile subjects. Similarly, immunoreactivity between serum samples from pre- and post-vasectomy was compared to identify antigens unique to sera collected following vasectomy. Five allo-antigenic basic protein spots were recognized by sera from infertile males but not from fertile subjects. Five sperm iso-antigenic basic spots were recognized by infertile female subjects. Two among six of the vasectomized men's sera showed a difference in the Western blot profile 6 months after vasectomy, recognizing at least one new protein spot in each case when compared to pre-vasectomy sera. The acrosomal protein SP-10 was identified as an alloantigen recognized by a post-vasectomy serum. Molecular identities of the known allo- and iso-antigens identified in this study and in previous studies from this laboratory are reviewed and discussed.

Antichlamydial and Antisperm Antibodies in Patients with Chlamydial Infections

PROBLEM

Establishing the correlation between antichlamydial antibodies (AchAbs) and antisperm antibodies (ASA) in patients with chlamydial infections.

METHOD OF STUDY

ASA were studied in sera from patients (142 with genital, 57 with ocular chlamydial infections) and control group (n = 100) by gelatin and tray agglutination test (TAT), sperm immobilization test (SIT) and ELISA. AchAbs were revealed by ELISA.

RESULTS

A significantly higher (P < 0.05) ASA incidence was noted in patients with genital infections as compared with controls and patients with ophthalmologic infection (P < 0.0001), but not between patients with ophthalmologic infection and controls (P > 0.05). A significant correlation was established between AchAbs and ASA for TAT (r = 0.8214, P = 0.0341), SIT (r = 0.797, P = 0.032) and ELISA (r = 0.8519, P = 0.0313) in patients with genital infections only.

CONCLUSIONS

The genital Chlamydia infection may play a role in the induction of ASA. This is probably a result of the inflammatory process, but not of cross-reactivity between sperm and Chlamydia trachomatis antigens.

Two-dimensional electrophoretic analysis of sperm antigens recognized by sperm immobilizing antibodies detected in infertile women

In this study, high resolution two-dimensional (2-D) gel electrophoresis was used to identify human sperm antigens recognized by the sera from infertile women having sperm immobilizing (SI) antibodies. Two-D gel electrophoresis was employed to separate Percoll purified human sperm proteins using isoelectric focusing (IEF), followed by polyacrylamide gel electrophoresis (PAGE). Sperm proteins were transferred to the nitrocellulose membranes and immunoblotted with seven sera from infertile women with high titers of SI antibodies and 6 sera from those without SI antibodies. The blots were compared to the 2-D composite image of human sperm proteins [Sperm Protein Encyclopedia] and sperm surface index and the sperm surface proteins recognized by infertile sera were identified. Fifty-two human sperm surface proteins reacted with sera containing SI antibodies, while 35 of these were reactive with the SI-negative control sera. The average numbers of protein spots reacted with test and control sera were 24.6 and 15.0 respectively. A subset of sperm surface proteins which were unique to the SI antibodies were identified by the following criteria; the sperm protein spots which were highly reactive with the infertile sera containing SI antibodies but not reactive with any of the SI-negative infertile sera. The coordinates of 4 prominent immunoreactive sperm proteins were considered as possibly relevant to antibody mediated female infertility.

Human sperm proteome: immunodominant sperm surface antigens identified with sera from infertile men and women

The objective of this study was to identify those immunodominant sperm antigens recognized by antisperm antibodies (ASA) in the serum samples of infertile men and women. High-resolution two-dimensional gel electrophoresis was employed to separate human sperm proteins using isoelectric focusing or nonequilibrium pH gradient electrophoresis, followed by PAGE. Serum samples from 15 infertile male subjects and 6 infertile female subjects that contained ASA as assayed by the immunobead binding test (IBT) were analyzed by Western blotting followed by enhanced chemiluminescence (ECL). Serum samples from 10 fertile subjects (5 males and 5 females) that were ASA negative by IBT were used as controls. The ECL blots were analyzed by computer scanning to compare the immunoreactivity between serum samples from fertile and infertile subjects and to identify the antigens unique to the sera of the infertile subjects; 98 sperm auto- and iso-antigenic protein spots were recognized by sera from infertile males and females but not from fertile subjects. Based on vectorial labeling with 125I at the sperm surface, a subset of 6 auto- and iso-antigens was identified as possibly relevant to antibody-mediated infertility.

The potential use of sperm antigens as targets for immunocontraception; past, present and future

Immunocontraception, and in particular the targeting of antibodies to gamete-specific antigens implicated in sperm egg binding and fertilisation, offers an attractive approach to the growing global problem of overpopulation. Such an idea is not new; indeed several immunocontraception trials, using animal model systems, have been reported in recent years and a number are reviewed here. However, the results of these studies have been largely disappointing. We believe that two fundamental flaws attribute to the poor success of most of these preliminary immunocontraceptive trials. Firstly, loss of fertility has invariably been used as the assay. This presupposes that immuno-neutralisation of a single, gamete-specific antigen will be sufficient to cause a significant reduction in fertility; however, recent data suggests that such a premise may not be well-founded for a number of reasons. Secondly, and arguably the most important flaw, is the almost universal, but largely inappropriate, use of systemic immunisation as the sole route of antigen delivery. Whilst systemic immunisation regimes may lead to high serum IgG levels, these levels do not correlate with specific antibody levels in the reproductive tract or with contraceptive efficacy. Hence, an alternative antigen delivery approach is required which will induce an effective local immune response in the reproductive tract. Here we discuss the ways in which this might be achieved.

Characterization of a potent sperm-agglutinating monoclonal antibody and its cognate antigens

OBJECTIVE

To identify sperm antigens that are capable of eliciting infertility-related sperm-agglutinating antibodies.

DESIGN

In vitro laboratory experiments.

SETTING

University research laboratory.

PATIENT(S)

Fertile semen donors.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Sperm agglutination, immunofluorescence localization, and flow cytometric analysis of surface expression of A36 antigens. Antigen analysis by Western immunoblotting.

RESULT(S)

Monoclonal antibody A36 induced intensive head-to-head, tail-to-tail, and head-to-tail agglutination of motile human spermatozoa. Antigens recognized by A36 were localized on the acrosomal cap and in the principal tail regions of motile, noncapacitated human sperm. Changes in subcellular levels and localization of the A36-recognized epitope occurred after capacitation and acrosomal loss. A36 reacted with a polymorphic series of proteins in Western blots of sperm extracts from humans and various other animal species, including mouse testis extracts. A common 53-kd antigen was recognized by the antibody in the different antigenic preparations.

CONCLUSION(S)

A mouse antibody to human sperm, monoclonal antibody A36, caused intensive agglutination of noncapacitated human spermatozoa and reacted with antigens on the acrosomal cap and in the principal tail regions. Of the multiple polypeptides that were reactive with the monoclonal antibody in sperm extracts from humans and other animal species, a common 53-kd antigen was recognized.

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.

Expression of the human antigen SPAG2 in the testis and localization to the outer dense fibers in spermatozoa

ABSTRACT Antisperm antibodies (ASAs) have been implicated in some instances of infertility. To characterize sperm antigens relevant to immunologic and immunocontraceptive development, SPAG2 (sperm-associated antigen 2) was identified by screening a human testis cDNA library with human sera positive for ASAs. Subsequently, two isoforms, SPAG2-1 and SPAG2-2, were identified in testis and placenta libraries, respectively. In the current study, Southern analysis of human genomic DNA with a probe common to the two SPAG2 isoforms indicated a single SPAG2 gene; therefore, alternative splicing is a likely mechanism for production of variant mRNAs. In situ hybridization of human testis sections demonstrated the expression of SPAG2 in primary spermatocytes, with decreased or arrested expression in postmeiotic cells. Immunofluorescence of Triton X-100-extracted spermatozoa with an anti-SPAG2 peptide antiserum indicate that SPAG2 is an intracellular component of the sperm flagellum. Electron microscopy refined this localization to the outer dense fibers (ODFs), structural filaments associated with the mammalian sperm axoneme. The ODFs have been reported to be composed of keratin-like intermediate filament proteins. However, SPAG2 does not exhibit the molecular characteristics of such proteins, nor does SPAG2 demonstrate sequence homology with previously characterized ODF proteins. Therefore, SPAG2 represents a novel protein of human sperm ODFs. Characterization of SPAG2 will further our understanding of ODF function in normal sperm motility and of flagellar abnormalities that lead to male infertility.

Characterization of human sperm antigens reacting with antisperm antibodies from autologous sera and seminal plasma: comparison among infertile subpopulations

Immunoblotting techniques were used to characterize the reactivity of human sperm antigens with sperm antibodies from different groups of infertile subjects. Sperm antigens of each subject were tested with autologous sperm antibodies present in serum and seminal plasma in order to assess whether there were qualitative differences in the antigenic structure of spermatozoa among the various infertile groups. Sixty-one infertile males, divided into six groups according to changes in the two main semen parameters (sperm concentration and motility), entered the study. Immunoreactivity to several antigens, in both serum and seminal plasma, was usually demonstrated in infertile subjects. Using a complex statistical package no significant difference was found in the distribution of antigens between groups; this included previously termed "fertility-related antigens' (28, 35, 57 and 62kDa proteins). This suggests that the most relevant sperm antigens involved in reproduction have no particular relationship to sperm concentration and motility.

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.

Characterization of human sperm antigens reacting with antisperm antibodies from autologous sera and seminal plasma in a fertile population

Immunoblotting techniques were used to characterize the reactivity of human sperm antigens with antisperm antibodies from a population of fertile individuals. In particular, sperm antigens of each subject were tested with the same subject's antisperm antibodies present in blood serum and seminal plasma in an attempt to construct a preliminary map of the antigen domains of the normal spermatozoon. Fifty-five fertile males, comprising 22 subjects with a pregnant partner and 33 subjects attending assisted reproductive technology sessions for proven partner's infertility and with normal semen quality entered the study. A high proportion of sera (82%) and seminal plasma (62%) showed antisperm antibodies reacting with one or more sperm antigens. Specific immunoreactivity was often demonstrated to 45-kDa, 50-kDa, 55-kDa, 69-kDa, 72-kDa and 85-kDa proteins in serum and to 59-kDa and 72-kDa proteins in seminal plasma. These proteins are the most frequently involved sperm antigens in the immune responses in fertile subjects. Further studies in an infertile population are necessary to distinguish between these antigens of minor relevance in sperm function from others significantly involved in immunological infertility.

Antisperm antibodies: origin, regulation, and sperm reactivity in human infertility

OBJECTIVE

To follow-up and expand discussion on the action mechanisms of antisperm antibodies in human infertility, the etiology and control of antisperm antibody induction, sperm antigens involved in immunoinfertility, and strategies for therapy.

DESIGN

A review of the recent literature with an emphasis on female immunoinfertility.

RESULTS

The role of antisperm antibodies in clinical infertility continues to be defined. Through assisted reproductive technologies, antisperm antibodies were shown to exert detrimental effects on different prefertilization and possibly postfertilization events. The female reproductive tract is part of the common mucosal immune system and is able to mount effective immune responses against infectious agents, foreign antigens, and, occasionally, sperm cells. Sperm membranes and constituents contain numerous antigenic components foreign to the human body, and yet antisperm antibodies become problematic in few women exposed to semen. Semen and sperm cells contain immunosuppressive factors capable of inhibiting different immune cells. Fertile women apparently produce antisperm antibodies but also possess neutralizing serum anti-idiotypic antibodies that are lacking in virgin and immunoinfertile women.

CONCLUSIONS

Antisperm antibodies can affect adversely human fertility but normally may be controlled by anti-idiotypic antibodies, which along with immunosuppressor factors in semen prevent their induction to a significant degree. This balance between detrimental and "beneficial" immune response to sperm may be shifted toward an antisperm antibody response by stimulatory factors such as infection. Therapies may be devised to stimulate the anti-idiotypic antibody system, to induce immune tolerance to sperm antigens, and to use antigens to adsorb antisperm antibodies from spermatozoa.

The role of antisperm antibodies in infertility

OBJECTIVE

To discuss the role of antisperm antibodies (Ab) in infertility, including proposed mechanisms of antisperm Ab formation, assays for their detection, and treatments for immune-mediated infertility.

DESIGN

Major studies in the published literature and data from The University of Texas Southwestern Medical Center, Division of Reproductive Endocrinology. Reports were reviewed that investigated the development and impact of alloimmunity and autoimmunity to spermatozoa in men and alloimmunity in women and the current methods of treatment for resultant subfertility.

RESULTS

The exposure of spermatozoal antigens to the mucosal and systemic immune systems results in development of immunity to a multiplicity of spermatozoal epitopes. The evaluation of studies that examine the role of antisperm Ab in infertility is complicated by the lack of standardization of antisperm Ab assays and the difficulty in identifying those epitopes for antisperm Ab binding that are responsible for subfertility. Sperm-associated antisperm Ab and antisperm Ab in cervical mucus (CM) reduce sperm mobility and may also impair sperm-ovum interaction. The clinical significance of serum antisperm Ab in both men and women, however, is controversial. Current therapy for antisperm Ab associated infertility is empiric and largely unproven.

CONCLUSIONS

Antisperm Ab on the sperm surface and in CM are implicated in the pathogenesis of a subset of patients with infertility. Further studies that determine the clinically relevant sites of antisperm Ab interaction will aid in directing the treatment of subfertility mediated by antisperm Ab.

Detection of Chlamydia trachomatis in semen by the polymerase chain reaction in male members of infertile couples

OBJECTIVE

Our objective was to evaluate the presence of asymptomatic Chlamydia trachomatis infection by means of the polymerase chain reaction in male members of couples with previously undiagnosed infertility.

STUDY DESIGN

Twenty-eight infertile-couples who had negative cultures or negative results when tested by deoxyribonucleic acid probe for Chlamydia trachomatis in semen and cervical samples were studied. Semen samples were tested for Chlamydia trachomatis by means of the polymerase chain reaction. Sera from both partners were diluted 1:128 and tested for immunoglobulin M antibodies to Chlamydia. Sera and ejaculated sperm were evaluated for the presence of antisperm antibodies. Semen analyses were also performed.

RESULTS

Chlamydia trachomatis was identified in semen from 11 (39.3%) of the male partners. Its detection correlated with the presence in the ejaculate of motile sperm containing antisperm antibodies (p < 0.01). Either antisperm immunoglobulin G, immunoglobulin A, or both were located on sperm only from 5 (45.5%) of the 11 men whose results were positive when tested for Chlamydia trachomatis. Similarly, immunoglobulin G or immunoglobulin A antibodies to sperm were only detected in 5 (45.5%) of the spouses of men with Chlamydia in semen. Immunoglobulin M antibody to Chlamydia trachomatis was identified in only one of the men. However, antichlamydial immunoglobulin M antibodies were present in sera from 6 (54.5%) female partners of men with seminal Chlamydia trachomatis but in none of the other 17 women (p < 0.01).

CONCLUSION

Although undetected by culture of deoxyribonucleic acid probe of semen samples, Chlamydia trachomatis was nevertheless identified in semen of some symptom-free men by the polymerase chain reaction. This is probably a result of the increased sensitivity of the polymerase chain reaction to detect Chlamydia trachomatis. The increased prevalence of an autoimmune response to sperm in men with this organism in their semen suggests that a subclinical chlamydial infection may activate an immune response to sperm. A similar association between Chlamydia trachomatis in semen and circulating antisperm antibodies in female partners indicates that Chlamydia may also induce an immune response to sperm in women. Infertility in these couples may be the result of a direct inflammatory response in the cervix or endometrium to repeated Chlamydia exposure or of the ability of Chlamydia to evoke an immune response to spermatozoa.

A quantitative objective method for the evaluation of anti-sperm cell-mediated immunity in humans

Anti-sperm cell-mediated immunity (CMI) is considered as a crucial facet of infertility in patients of both sexes. A precise and objective method is designed, based on a one-step agarose leukocyte migration inhibition factor (LMIF) assay. The migration areas are evaluated by a computer-assisted image analysis system. Optimal concentrations of leukocytes and sperm, as well as technical conditions are described. The radial migration indexes (RMI) and area migration indexes (AMI) are computed and expressed as a migration index (MI) percentage for each patient or control. Preliminary clinical results indicate a highly significant association between migration inhibition and cases of 'immunopathological infertility'. The method described is considered a promising tool for a rapid and quantitative evaluation of a suspected anti-sperm CMI in infertile and recurrently aborting patients.

Identification of human sperm antigens reacting with antisperm antibodies from sera and genital tract secretions

OBJECTIVE

To identify sperm antigens reacting with antisperm antibodies relevant in human infertility.

DESIGN

The reactions of separated sperm antigens with antibodies present in sera and genital tract secretions from infertile and fertile females and males were examined by immunoblotting techniques.

SETTING

The patients were followed in an outpatient setting of a hospital clinic.

PATIENTS

One hundred consecutive infertile males and females, referred for determinations of antisperm antibodies, comprised the study group. Fifty hospital and faculty employees with proven fertility served as a control group.

RESULTS

A high proportion of sera from fertile and infertile humans contained antibodies reacting with at least one sperm antigen. However, two discrete bands of antigenic proteins with molecular weights of 44 and 72 kd reacted significantly more frequently with serum antibodies from infertile females than from fertile females. No apparent correlation could be demonstrated between any particular antigen and serum antibodies from infertile males. Nevertheless, antigenic proteins of 62 kd were identified as the major sperm antigens reacting with antibodies present in seminal plasmas from infertile males.

CONCLUSIONS

The major sperm antigens reacting with systemic antibodies differ from the antigens recognized by local antisperm antibodies. Sperm antigens exhibiting relative molecular weights of 62 kd are major antigens reactive with local antisperm antibodies from infertile humans.