The immunoglobulin class of antispermatozoal antibodies in serum

The Role of the Immune Response in Chlamydia trachomatis Infection of the Male Genital Tract: A Double-Edged Sword

Chlamydia trachomatis (CT) is the most prevalent bacterial sexually transmitted infection in the world, with more than 100 million cases reported annually. While there have been extensive studies into the adverse effects that CT infection has on the female genital tract, and on the subsequent ability of these women to conceive, studies into the consequences on male fertility have been limited and controversial. This is in part due to the asymptomatic nature of the infection, where it is estimated that 50% of men with Chlamydia fail to show any symptoms. It is accepted, however, that acute and/or persistent CT infection is the causative agent for conditions such as urethritis, epididymitis, epididymo-orchitis, and potentially prostatitis. As with most infections, the immune system plays a fundamental role in the body’s attempts to eradicate the infection. The first and most important immune response to Chlamydia infection is a local one, whereby immune cells such as leukocytes are recruited to the site of infections, and subsequently secrete pro-inflammatory cytokines and chemokines such as interferon gamma. Immune cells also work to initiate and potentiate chronic inflammation through the production of reactive oxygen species (ROS), and the release of molecules with degradative properties including defensins, elastase, collagenase, cathespins, and lysozyme. This long-term inflammation can lead to cell proliferation (a possible precursor to cancer), tissue remodeling, and scarring, as well as being linked to the onset of autoimmune responses in genetically disposed individuals. This review will focus on the ability of the immune system to recognize and clear acute and persistent chlamydial infections in the male genital tract, and on the paradoxical damage that chronic inflammation resulting from the infection can cause on the reproductive health of the individual.

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.

The testis in immune privilege

The production, differentiation, and presence of male gametes represent inimitable challenges to the immune system, as they are unique to the body and appear long after the maturation of the immune system and formation of systemic self-tolerance. Known to protect germ cells and foreign tissue grafts from autoimmune attack, the 'immune privilege' of the testis was originally, and somewhat simplistically, attributed to the existence of the blood-testis barrier. Recent research has shown a previously unknown level of complexity with a multitude of factors, both physical and immunological, necessary for the establishment and maintenance of the immunotolerance in the testis. Besides the blood-testis barrier and a diminished capability of the large testicular resident macrophage population to mount an inflammatory response, it is the constitutive expression of anti-inflammatory cytokines in the testis by immune and particularly somatic cells, that represents an essential element for local immunosuppression. The role of androgens in testicular immune regulation has long been underestimated; yet, accumulating evidence now shows that they orchestrate the inhibition of proinflammatory cytokine expression and shift cytokine balance toward a tolerogenic environment. Furthermore, the role of the testicular dendritic cells in suppressing antigen-specific immunity and T-lymphocyte activation is discussed. Finally, the active role mast cells play in the induction and amplification of immune responses, both in infertile humans and in experimental models, highlights the importance of preventing mast cell activation to maintain the immune-privileged status of the testis.

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.

Study of antisperm antibodies bound to the sperm cell surface and their relationship to circulating ASA

PROBLEM

Direct and indirect tests for antisperm antibody (ASA) detection are commonly used in laboratories for the diagnosis of male immunological infertility. Even though the two kinds of tests study the same immunological phenomena, frequently no perfect correlation is found even on large series of patients and with precise statistical models. The aim of the present investigation was to try to establish whether biological models can explain the antibody test results and if a predictive threshold can be established for expected positivity/negativity.

METHOD

The data relate to 667 patients, who were screened using the Direct Immunobead test (d-IBT) for ASA bound to the sperm surface and with the gelatin and tray agglutination test (GAT and TAT) in sera for circulating ASA. Correlation were studied and cases of no correlation were further analyzed.

RESULTS

The number of patients with a clinically significant positivity to d-IBT (binding percentage > or = 20%) was 134 (20.1% of total patients). The analysis of the results of direct and indirect tests shows that the discordances are due to differences in the Ig class of immunization or to the site of epitopes involved. In fact, as far the Ig class is concerned, if d-IBT shows a prevalent or exclusive IgG or IgA positivity, this results in a poor correlation between binding percentage to d-IBT and GAT-TAT titers. If both the Ig classes are involved, the level of positivity of the two kinds of test are strictly related. As far as the site of Ag-Ab reaction on the sperm surface is concerned, the wide immunization involving all the surface sperm antigens (mixed), shown by d-IBT, is related to higher indirect test titers.

CONCLUSION

Local and systemic antisperm immunizations are strictly related and a predictive threshold of expectation can be established to explain even apparently discordant direct and indirect results.

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.

Obstructive azoospermia of unknown origin: sites of obstruction and surgical outcomes

Although the majority of patients with obstructive azoospermia have medical histories or signs related to seminal tract obstruction, the pathogenesis of the obstruction is unknown in some patients. Of 38 patients with obstructive azoospermia treated at our hospital preoperative data did not indicate causes or sites of obstruction in 6. Operative and pathological findings showed obstruction at the proximal convoluted vas deferens or between the most distal portion of the cauda epididymis and the vas deferens in 8 of 11 blocked seminal tracts. Microsurgical epididymovasostomy resulted in a patent anastomosis in all 6 patients and pregnancy in 2. In patients with obstructive azoospermia of obscure preoperative causes, it is highly probable that the obstruction sites are in the convoluted vas deferens or the transitional region between the cauda epididymis and vas deferens, and that fertility may be restored by microsurgical epididymovasostomy.

Relationship between antisperm antibodies and testicular histologic changes in humans after vasectomy

OBJECTIVE

To determine whether or not there is an association between testicular histologic changes and antisperm antibodies in vasectomized men.

METHODS

Morphometry was performed on testicular biopsy specimens obtained from 19 vasectomized men and 21 fertile control subjects. Antisperm antibody status was determined on the serum of each patient and control subject using the indirect immunobead assay.

RESULTS

Significant increases in seminiferous tubule wall thickness (p < 0.001), focal interstitial fibrosis (p < 0.001), and percent composition of interstitium (p < 0.01) were observed in vasectomized men as compared with control subjects. Serum antisperm activity was present in 74 percent of the vasectomized men but none in the control subjects (p < 0.001). There was no association between testicular histologic changes and immune status.

CONCLUSIONS

Vasectomized men exhibit significant testicular histologic changes and increased autoimmune activity as compared with fertile control subjects. These histologic changes are not directly associated with antisperm antibody status, suggesting that some other pathophysiologic process must be responsible.

Risk factors for antisperm antibodies in infertile men

PROBLEM

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

METHOD

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

CONCLUSIONS

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

The detection of antisperm antibodies in serum: a comparison of the tray agglutination test, indirect immunobead test and indirect SpermCheck assay

Testing for antisperm antibodies (ASAs) is an important part of the work-up of the sub-fertile couple, yet there is little consensus regarding the most appropriate methods. The SpermCheck assay (GSC; Bio-Rad Laboratories Inc., Diagnostics Division, Hercules, CA, U.S.A.) is supplied with wash buffer, controls and bead reagent which detects all three major classes of ASAs (IgA, IgG and IgM) in a single test. This study compared results on a bank of samples using the tray agglutination test (TAT), immunobead test (IBT), GSC and a modified SpermCheck assay to detect a single isotype in each test (SISC). The IBT and SISC showed excellent correlation, with 127/141 (90.1%) tests agreeing. There was an apparent lack of sensitivity to IgM with GSC as 8/15 (53.3%) samples testing positive with IBT and 7/15 (46.7%) testing positive with SISC were negative with GSC. Of the 24 IBT-negatives, seven (29.2%) were positive for TAT, indicating a high incidence of non-immunological agglutination, though this decreased as the TAT titre increased. The proportion of samples testing positive for IBT increased with TAT titre: 3/20 (15.0%) for TAT-negative samples, 6/10 (60.0%) for low titres and 21/24 (87.5%) for high titres. This was also observed when comparing the GSC with TAT. The TAT therefore appears useful as a first-line screen, whilst the inability of the GSC to adequately detect IgM limits its use as an indirect test. Both the IBT and SISC can be used to further investigate the type and class of ASA present.

Serum antisperm antibodies in men with vas deferens obstruction caused by childhood inguinal herniorrhaphy

OBJECTIVE

To study the incidence of serum antisperm antibodies in patients with vas deferens obstruction caused by childhood inguinal herniorrhaphy.

DESIGN

Retrospective.

SETTING

Kansai Medical University and Kyoto University Hospital.

PATIENTS

Thirteen patients with vas deferens obstruction caused by childhood inguinal herniorrhaphy.

MAIN OUTCOME MEASURES

Indirect immunobead test for serum antisperm antibodies.

RESULTS

Of 13 patients, 7 (54%) and 2 (15%) tested positive for immunoglobulin (Ig)G and IgA class antisperm antibodies, respectively; all patients tested negative for IgM class antibodies. The incidence of antisperm antibodies was not different between the patients with possible epididymal obstruction and those without epididymal obstruction.

CONCLUSIONS

A significant percentage of patients with vasal obstruction caused by infant inguinal herniorrhaphy have serum antisperm antibodies despite the absence of sperm granulomas.

Detection of antisperm antibodies on the surface of living spermatozoa using flow cytometry: preliminary study

OBJECTIVE

To assess the use of flow cytometry (FCM) analysis of living spermatozoa subjected to indirect immunofluorescence staining with the mouse anti-human immunoglobulin (Ig)G monoclonal antibodies (FCM test) as an objective method for the detection of antisperm antibodies in semen and serum.

DESIGN

The comparative studies were conducted with the direct and indirect mixed antiglobulin reaction (MAR) and FCM test performed by FCM analyzer FACSCAN (Becton Dickinson Immunocytometry Systems, Mountain View, CA).

SETTING

Clinical infertile service.

PATIENTS

Seventy-six semen and 20 sera samples of infertile patients were analyzed.

RESULTS

For IgG in semen there was a highly significant correlation between the direct MAR and FCM test. Six of 12 IgG-positive samples revealed also IgA, and just one sample, which showed negative MAR, was positive for IgM in FCM test. Flow cytometry test and indirect MAR showed also a highly significant correlation of the results of IgG detection in sera.

CONCLUSIONS

Flow cytometry test may be used to verify that IgG antisperm antibodies are on the surface of living spermatozoa either retrieved directly from an ejaculate or after exposure to serum and to determine proportion of antisperm antibodies-positive spermatozoa, titer, and quantity of antibodies bound to the cell surface.

Unilateral obstruction of the vas deferens caused by childhood inguinal herniorrhaphy in male infertility patients

OBJECTIVE

To study the incidence, diagnosis, and treatment of unilateral obstruction of the vas deferens caused by inguinal herniorrhaphy (IH) during childhood.

DESIGN

Retrospective.

SETTING

Kyoto University Hospital.

PATIENTS

Unilateral obstruction of the vas deferens after IH was diagnosed and treated in 10 of 724 subfertile patients.

INTERVENTIONS

Reanastomosis of the vas deferens using a microsurgical two-layer technique.

MAIN OUTCOME MEASURES

Follow-up seminal analysis of the patients and the occurrence of pregnancy in their wives.

RESULTS

The incidence of unilateral vas deferens obstruction caused by IH was 26.7% for subfertile patients with a history of IH during childhood. Unilateral vas deferens obstruction was detected through palpation of the scrotal vas deferens in 7 of the 10 patients. After vasovasostomy, the semen quality improved in 5 patients, and pregnancy was achieved by 2 patients.

CONCLUSIONS

The incidence of vas deferens obstruction was unexpectedly high in subfertile patients with a history of IH during childhood. Careful palpation of the scrotal content was a useful and noninvasive method to diagnose unilateral vas deferens obstruction, and microsurgical vasovasostomy was treatment of choice.

Evaluation of immunological infertility

To evaluate the frequency with which immunological factors are associated with infertility, 92 couples with unexplained infertility were studied by using assays to detect anti-sperm antibodies (ASA), human leukocyte antigen tissue types (HLA), lymphocytotoxic antibodies (LCA), and inhibitors of mixed lymphocyte culture (MLC) and mouse blastocyst assay (MBA). Seventy-three of the women had blood assayed for antiphospholipid antibodies (APA). The frequencies of APA, ASA, LCA, inhibitors of MLC and MBA, as well as HLA associations previously reported to be related to infertility (B locus blanks, single DQ locus in offspring, greater than 1 DR sharing between mates) among 92 infertile couples were compared with those observed among 41 fertile control couples. No significant differences in the frequencies of APA, ASA, MBA, and HLA associations between fertile and infertile couples were observed. Fertile couples demonstrated the presence of wife anti-husband LCA and MLC inhibitors more frequently than did infertile couples (51% vs. 8%, P = 0.0001 and 29% vs. 4%, P = 0.002, respectively). While APA, ASA, HLA tissue typing, LCA, and MLC and MBA have been previously reported as being markers of autoimmune and alloimmune responses relating to reproductive outcome, the current data suggest that more specific markers are necessary to diagnose immunological components of infertility.

The predominance of IgG1 and IgG3 subclass antisperm antibodies in infertile patients with serum antisperm antibodies

Mouse monoclonal antibodies (MAb) specific for each of the four human IgG subclasses and immunofluorescence flow cytometry were used to evaluate the subclass of the IgG antibody response to sperm in serum samples from 13 men and 6 women with a high titer (greater than 1:15,625) of IgG antisperm antibodies (ASA] determined by an indirect immunobead test. Five sera without ASA were also studied as a control. All 19 (100%) of the ASA-positive sera contained immunoglobulin (Ig)G ASA of the IgG1 and IgG3 subclasses. A 1:1 correlation was observed between the presence of IgG1 and IgG3 ASA. IgG2 was essentially undetectable, while IgG4 reactivity, although less intense than IgG1 and IgG3, was more prominent in the sera from the five vasectomized men. The ability of the IgG1 and IgG3 ASA-positive sera to deposit complement (C) on sperm was demonstrated by the concomitant binding to antibody-laden sperm of polyclonal antibodies to the membrane attack complex (C5b-9) of C. Both C-fixing and non-C-fixing ASA-positive sera were found to possess IgG1 and IgG3 antisperm antibodies. The predominance of IgG1 and IgG3 subclasses suggested a T-cell dependent immune response to sperm antigens.

A comparison of the direct immunobead test and other tests for sperm antibodies detection

The authors report the results of a correlation study between the direct Immunobead Test (d-IBT) and other techniques for antisperm antibodies detection. The Gelatin Agglutination Test (GAT) and Tray Agglutination Test (TAT) were used to detect antibodies in blood serum and seminal plasma ("indirect methods"). The Direct IgG Mixed Antiglobulin Reaction Test (d-MAR test) was used to detect sperm antibodies bound to the sperm surface ("direct method"). A good concordance between the methods, measured by phi and K tests, was found and satisfactory mathematical models were established by regression analyses.

Comparison of the indirect immunobead, radiolabeled, and immunofluorescence assays for immunoglobulin G serum antibodies to human sperm

The relative sensitivities of the indirect immunobead test, the indirect flo cytometric immunofluorescence assay, and an indirect radiolabeled antiglobulin assay were compared. Eighteen immunobead test positive sera and 18 negative sera were used as the standard for the other two assays. Of the 18 positive sera, 14 (77%) and 5 (27%) were positive in the immunofluorescence assay and the radiolabeled antiglobulin assay, respectively. Four (22%) of the low titer immunobead test positive sera were negative by both the immunofluorescence assay and the radiolabeled antiglobulin assay. However, there was a significant positive correlation between the results of the immunofluorescence assay and the radiolabeled antiglobulin assay (r = 0.73) and between the results of the radiolabeled antiglobulin assay and the titer of the immunobead test (r = 0.82). The use of an unselected sperm population in the radiolabeled antiglobulin assay and the classical indirect immunofluorescence method using methanol-fixed sperm gave false-positive results in the radiolabeled antiglobulin assay and the immunofluorescence assay. These results suggested that immunoglobulin G antisperm antibody positive sera may be reactive both to sperm surface and internalized sperm antigens.

Radio-immuno binding test for anti-sperm antibody detection: analysis and critical revision of various methodological steps

The authors report the results of a methodological study to optimize a radioimmunoassay to detect anti-sperm antibodies. They describe here the definitive methodology with all the data relating to the laboratory trials conducted at each step of the technique. Results seem to demonstrate that this radioimmunological method is sufficiently simple, specific, sensitive and reliable for use in a highly specialized laboratory of reproductive immunology. Furthermore, this type of analytical approach, whilst indicating once more the difficulty of the technical study of anti-sperm autoimmunity, confirms (with concrete data) the necessity of being extremely "prudent" in evaluating the results of this kind of anti-sperm antibody test.

Binding of sperm-reactive antibodies in human sera to surface-associated antigens on human sperm compared by indirect immunobead, immunofluorescence, and immunogold assays

Human sera were identified as positive or negative for sperm-reactive antibodies in a solid-phase enzyme-linked immunosorbent assay (ELISA). Of these, 28 positive and 22 negative sera were blind-coded and used as first antibody to compare three immunoassays, a modified liquid-phase indirect immunobead assay (IBA); a liquid-phase indirect immunofluorescence assay (IFA); and a solid-phase indirect immunogold assay (IGA). These three immunoassays perform both as sperm-reactive antibody detection assays and as sperm-associated antigen localization assays. As antibody detection assays, the IBA, IFA, and IGA gave 37, 27, and 28 positives and 13, 23, and 22 negatives, respectively. The usefulness of the IBA as an antigen localization assay was limited by the size of the marker, while the smaller IFA and IGA markers enabled increased resolution of binding patterns of sperm-reactive antibodies to surface-associated sperm antigens. Although the antigen-antibody binding patterns were almost identical for IFA and IGA, suggesting the same sperm-associated antigens were detected by both assays, the IGA reaction product was stable, higher in resolution, and visible by light microscopy.

Changes in sperm antibody test results when spermatozoa are subjected to capacitating conditions

Cytotoxic and immunobead-binding antibody assays were used to document possible changes in antigenicity after the spermatozoa were subjected in vitro to capacitating conditions. Serum and seminal plasma immunobead-binding immunoglobulin (Ig)A, sperm surface IgG, and IgA, and seminal plasma cytotoxic antibody titers in 26 autoimmune infertile men were decreased against autologous spermatozoa under capacitating conditions. Cytotoxic antibodies and immunobead-binding IgG, IgA, and IgM against husbands' sperm undergoing capacitation, in the cervical mucus of these women, were less than those against uncapacitated sperm. Conversely, sperm antibody levels were increased against the capacitated husbands' sperm in the husbands' serum and wives' cervical mucus, originally testing negative for cytotoxic antibodies against uncapacitated sperm. Antibody levels were unaltered against donors' sperm undergoing capacitation, except for a reduction in titers in the serum of isoimmune wives. The differences in sperm antibody assay results, depending on whether or not spermatozoa are incubated under conditions favoring capacitation, are specific to the husbands' and not to the donors' spermatozoal antigens.

A comparison of sperm antibody assays

Cytotoxicity and Immunobead-binding immunoglobulin G assays agreed in 81% of sera from infertile men (n = 173), 74% of sera from their wives, 75% of seminal plasma, and 82% of cervical mucous samples (p less than 0.001; chi 2 analysis of positive and negative results) when tested against sperm from the same donors. Cytotoxic and immunofluorescent IgG antibody results agreed in 79% of sera from men and women, 76% of seminal plasma, and 76% of cervical mucus (p less than 0.001; chi 2 analysis of positive and negative results). Titers or percent binding of sperm by cytotoxicity, hemagglutination, and IgG Immunobead-binding or immunofluorescence assays in serum and secretions of husbands and wives correlated (p less than 0.001). A significantly increased number of positive results was observed in cytotoxic and Immunobead-binding IgG assays when the husbands' and donors' sperm were used rather than donors' sperm alone. On the basis of this study we conclude: (1) that cytotoxicity, Immunobead-binding IgG, and immunofluorescent IgG sperm antibody assays correlate when sperm from the same source are used, (2) that women's isoimmunity to husbands' sperm is associated with their husbands' autoimmunity to sperm irrespective of the assay, and (3) that it is desirable to use sperm from the husbands and nonautoimmune fertile men in these assays.

Effect of different procedures of semen preparation on antibody-coated spermatozoa and immunological infertility

To assess whether procedures of semen preparation can reduce the proportion of antibody-coated spermatozoa, semen samples with positive direct mixed antiglobulin reaction (MAR) were washed in media supplemented with 10% or 50% fetal cord serum (FCS). Washing reduced the MAR to a negative level, but the MAR was identical to that in the native semen when spermatozoa were resuspended in serum-free medium. Donor spermatozoa, recovered after swim-up in media supplemented with 10% or 50% FCS or after passage through a column with 7.5% human serum albumin (HSA), were incubated in serum samples with both agglutinating and cytotoxic antisperm antibodies. Cytotoxic activity was significantly reduced against sperm filtered over the albumin column.

Immunological status of patients before and after vasovasostomy as determined by the immunobead antisperm antibody test

With the immunobead antisperm antibody test a prospective study was conducted to evaluate the immune status of 55 men before and after vasectomy reversal. A third of the vasectomy patients (19 of 55) had significant serum-sperm antibodies (20 per cent binding or more) detected by the indirect immunobead antisperm antibody test. Of 31 vasovasostomy patients 12 (38 per cent) had significant sperm-surface antibodies (20 per cent binding or more) by the direct immunobead antisperm antibody test. Preoperative serum assays correctly classified the antibody status of 69 per cent of the vasectomy patients. The immunological impact of spermatic granuloma formation, duration of vasal obstruction, patient age and presence of sperm in the vasal fluid at operation also were assessed. An inverse relationship between the proportion of antibody-bound sperm and the percentage of motile sperm in the ejaculate of vas reversal patients was found with videomicrographic semen analysis. The percentage motility was significantly lower among patients with greater quantities of sperm-surface antibodies. No other parameter of semen analysis showed this difference when compared for positive or negative immunobead antisperm antibody test results.

An evaluation of the accuracy of screening antisperm antibodies using the combined GAM immunobead

A simplified method of screening for antisperm antibodies has been previously described using rabbit antihuman immunoglobulin immunobeads (GAM beads). These reports have indicated a high correlation between the GAM bead and maximal individual isotype binding. However, preliminary data in our laboratory (using a 14% cut-off criterion) indicated a high frequency of samples with positive GAM bead, but negative individual isotype results. This study was conducted to evaluate more critically the use of the GAM bead for initial antisperm antibody screening. Immunobead binding tests were performed on 98 undiluted sera. The maximal binding of the individual isotype beads (IgG, IgA, or IgM) and the GAM beads were significantly correlated (r = 0.94, P = 0.0001). However, when results were categorized as positive or negative, there was a significantly lower frequency (P less than 0.05) of positive samples using the individual isotype (46.9%) than using the GAM approach (58.2%). These data support the hypothesis that, based on continuous percent binding, the GAM bead method produces results similar to individual isotype testing. However, when data are interpreted categorically, the results may differ significantly.

Determination of adenosine triphosphate in human semen to estimate the fertilizing potential and to quantify sperm antibodies

The measurement of the ATP content of fresh semen is as accurate as the estimation of sperm motility by conventional methods in discriminating between semen of fertile versus subfertile men. The ATP content of frozen thawed donor semen is correlated with the probability of conception per cycle of insemination. Exact quantification of cytotoxic sperm antibodies in serum is possible with the adenosine-triphosphate-release-cytotoxicity test, since measurement is free of the bias of microscopic examination. The procedure has been simplified by testing only one serum dilution and calculating the 'sperm toxicity index'.

The incidence and influence upon fertility of antisperm antibodies in seminal fluid following vasectomy reversal

Seminal plasma samples from men undergoing vasovasostomy were analysed for antisperm antibodies using the indirect immunobead test. A pre-operative assessment showed antisperm antibodies of either IgA or IgG class to be present in 9/27 (33.3%) men. A significant increase (P less than 0.05) in the post-operative incidence of the antibodies was seen in the men who achieved patency (27/45, 60%) but not in those men for whom no sperm were seen in the ejaculate (4/10, 40%). After follow-up for a minimum of 1 year, conception rates for couples in which the male partner had achieved patency were similar in the groups with no antibodies detected post-operatively (12/18, 66.7%) or with IgA alone (2/3, 66.7%), but was reduced significantly in the presence of IgG (1/9, 11.1%; P less than 0.05) or IgA + IgG (3/15, 20.0%; P less than 0.01).

Simple radioimmunobinding assay for quantitation of sperm antibodies of IgG immunoglobulin class

The immunobead test (IBT) is an excellent test for initial sperm antibody screening and evaluation but is impractical when used to quantitate antibody levels using a twofold dilution series. The aim of this study, therefore, was to develop a relatively simple radioimmunobinding assay that would allow quantitation of sperm antibodies of IgG immunoglobulin class, which predominate in male sera. [125I]-Protein G was chosen as the radioligand because it binds to all IgG subclasses, but not to IgA or IgM. The results of the investigation indicate that the [125I]-protein G assay (PGA) allows efficient quantitation of sperm antibodies, as evidenced by a highly significant (P less than .0001) correlation (Spearman's, Rs = 0.94) between the PGA results and IgG-IBT titres.

Evaluation of a simplified adenosine triphosphate release cytotoxicity test for the detection of sperm antibodies in human serum

The adenosine triphosphate release cytotoxicity test (ARCT) is an objective method for the detection of cytotoxic sperm antibodies in serum providing measurements without the bias of microscopic estimation. The procedure has been simplified by testing only one serum dilution and calculating the "sperm toxicity index". The latter is closely correlated with the sperm cytotoxic titer. Immunoglobulin class determination of 32 sera with sperm cytotoxic activity was performed by means of the indirect mixed antiglobulin reaction (MAR test) and the indirect immunobead (IB) test, and revealed that all sera were positive for IgG, 17% for IgM and 20% for IgA. Of 32 sera without sperm cytotoxic activity, 19% contained sperm specific IgG, 6% had IgM class antibodies belong mainly to the IgG class since the results of the ARCT and the indirect MAR test for IgG are closely correlated. The ARCT appears to be useful as a simple and objective method for the detection and quantitation of cytotoxic antisperm antibodies.

Sperm antibodies and human in vitro fertilization

In order to directly evaluate the effects of sperm antibodies in human in vitro fertilization (IVF), the authors preincubated donor sperm in female sera containing sperm antibodies and then inseminated supernumerary human oocytes from a gamete intrafallopian transfer (GIFT) program. The sperm were incubated for 30 minutes in medium containing 20% serum with antisperm activity (Test); or no antisperm activity (Control) as assessed by the immunobead test (IBT). Each oocyte was inseminated with 1 to 2 X 10(5)/ml of the preincubated motile sperm with Control or Test treatments allocated on a random basis. Six positive sera were tested in 17 experiments, resulting in a fertilization rate of 41% (25/61) versus 84% (36/43) for controls (P less than 0.001). When considered individually, three of six positive sera caused significant inhibition. The only serum that gave complete inhibition had the highest titer for IgG (10,000) and lower IgA (100). Absorption with protein A reduced the IgG titer to less than 10 and removed the fertilization inhibitory activity. These results confirm that sperm antibodies from female sera can inhibit human IVF.

Sperm antibodies and human fertilization

Previous investigations using zona-free hamster oocytes and salt-stored human zonae pellucidae, and retrospective analysis of routine human in vitro fertilization (IVF) results have suggested that sperm antibodies can impair the fertilizing capacity of human spermatozoa. The results of our investigations using viable human oocytes confirm that human antispermatozoal antibodies can inhibit fertilization by human spermatozoa. In the future we plan to examine the mechanism of fertilization inhibition, including characterization of the sperm antigens involved. These studies may facilitate the development of immunocontraceptive vaccines and of new treatments for immunological infertility.

The indirect mixed antiglobulin reaction test using a commercially available kit for the detection of antisperm antibodies in serum

A simple procedure is described for the detection of antisperm antibodies of the IgG class in human serum using the indirect mixed antiglobulin reaction (MAR) test. The test uses only one dilution of serum (1/16) and no washing procedures. The test was performed in 361 sera. Comparative studies were conducted with the tray agglutination test (TAT) in 164 sera and with the direct MAR test on semen in 110 cases. In 24 sera with borderline test results, and in 13 sera with discordant findings, evidence of antisperm antibody activity was investigated by means of additional testing, namely, the adenosine triphosphate release cytotoxicity test (ARCT) and the indirect immunobead tests (IB) for IgA and IgM. Using the value of 40% reaction between motile spermatozoa and coated latex particles as the lower limit of significant activity, the indirect SpermMAR test has a sensitivity of 96% and specificity of 87%. The two false-negative indirect MAR results occurred in cases with IgM, the clinical significance of which is doubtful. Hence, the indirect MAR test appears to be an ideal screening procedure for sperm antibodies in serum since it is easy to perform and sensitive. Considering the false-positive rate of 13%, additional tests should, however, be performed on sera with a reaction of 40% or more in order to assess the relevance of the antibodies as a cause of infertility.

Special antigens on sperm from autoimmune infertile men

Sera from three fertile men and four infertile men without sperm antibodies, 17 infertile men with sperm antibodies in serum and seminal plasma (S.P.), and 25 infertile men with sperm antibodies in S.P. were tested by Western Blot analysis against sperm membrane extracts and S.P. from fertile nonautoimmune men and infertile autoimmune men. Sera from fertile men reacted against common antigens with molecular weights (MW) of 28, 38, 48, 60, and 68 kD present on sperm from autoimmune and nonautoimmune men and special antigen of MW 76 kD on the sperm of fertile men. Sera from 15 of 17 (88%) autoimmune infertile men with sperm antibodies in serum and S.P. detected special antigens with MW of 58 kD (sera reactivity in 47% of these men), 43kD (in 29%), 30 kD (in 24%), 35 kD (in 18%), 52 kD (in 12%), 41 kD (in 6%), and 71 kD (in 6%) on the sperm of autoimmune men in addition to the common antigens. Sera from 15 of 25 (60%) men with sperm antibodies in their S.P. showed reactivity to special antigens with MW 52 kD (in 20%), 35 kD (in 16%), 41 kD (in 16%), 58 kD (in 8%), 70/71 kD (in 8%), 30 kD (in 8%), and 56 kD (in 4%). Sera from 18 of 42 (43%) infertile men with sperm antibodies also detected special antigens of MW 26, 46, and 76 kD present only in fertile men's sperm. Sera from only 15 of 42 (36%) autoimmune infertile men reacted against special antigens with MW 17, 20, 23, 30, 43, and 58 kD in the seminal plasma of autoimmune infertile men.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of antispermatozoal antibodies in seminal plasma upon spermatozoal function

The indirect immunobead test for antispermatozoal antibodies of the class IgA, IgG and IgM was applied to the seminal plasma of male partners of infertile couples. The presence of both IgA and IgG was associated with a decreased incidence of good post-coital test results and a reduced rate of fertilization of human oocytes. No significant differences were found for men with IgA or IgG alone when compared to men with no detectable antispermatozoal antibodies.

A computerized postcoital test sperm motility: comparison with clinical postcoital test and correlations with sperm antibodies

Sixty-five infertile women had a conventional postcoital test (PCT), a computerized postcoital test (cPCT), and sperm antibody testing. Twenty-four women had good cervical mucus and good PCT sperm motility (group 1), 23 had poor cervical mucus and poor PCT sperm motility (group 2), and 18 had good cervical mucus but poor PCT sperm motility (group 3). The percentage of motile sperm, mean linearity, and the motility index of sperm by cPCT also were decreased in groups 2 and 3 (p less than 0.001) in contrast to group 1. A reduced PCT sperm count was significantly associated with positive titers of antibodies to autologous sperm in the husbands' serum, whereas a reduced PCT motility correlated with high titers of cytotoxic antibodies to husbands' sperm in the wives' serum and cervical mucus. An increased percentage of vibratory sperm at PCT correlated with elevated titers of cytotoxic antibodies to husbands' sperm in the wives' serum and cervical mucus, and hemagglutinating (r = 0.44; p less than 0.001) and immunofluorescent IgA antibodies to husbands' sperm (r = 0.47; p less than 0.001) in the cervical mucus. Mean swimming speed of sperm by cPCT correlated inversely with cytotoxic and hemagglutinating antibody titers to husbands' sperm, and immunobead-binding IgM and immunofluorescent IgG, IgA, and IgM (r = 0.52; p less than 0.001) antibodies to sperm in the seminal plasma. Motility indices correlated inversely with cytotoxic antibody titers to husbands' sperm in the wives' serum, and hemagglutinating antibody titers to husbands' sperm in cervical mucus. The predictive values of PCT and cPCT for the presence of cytotoxic and immunofluorescent IgA antibodies to autoimmune husbands' sperm were 76% and 71%, respectively, in the serum and 85% and 75%, respectively, in the cervical mucus of the wives. The predictive value of PCT and cPCT for immunobead-binding and immunofluorescent IgM antibodies to sperm in the wives' serum was 71%. Computerized PCT measures more sperm characteristics than PCT, although it is in general agreement with PCT.

Indirect mixed antiglobulin reaction (MAR) as a screening procedure for antisperm antibodies. II. Clinical studies

In this study the question was raised whether the indirect mixed antiglobulin reaction (MAR) using donor spermatozoa could substitute the direct MAR requiring motile spermatozoa in the patient's ejaculate in the screening for antisperm antibodies. Serum and seminal plasma from 48 men selected on the basis of the results in the direct MAR were tested by the indirect MAR. Both tests were carried out for IgG and IgA antisperm antibodies. A statistically significant correlation was found both between the sperm-bound IgG and the free IgG antisperm antibodies in serum as well as in seminal plasma and between sperm-bound IgA and the free IgA antisperm antibodies in seminal plasma whereas no correlation was found between the sperm-bound IgA and the free IgA antisperm antibodies in serum. This finding strongly supports the concept that the major part of the IgA antisperm antibodies in the ejaculate are locally produced.

Antisperm antibodies bind with different patterns to sperm of different men

Immunologic infertility is an important area of current clinical research. The immunobead test is a laboratory method that identifies the classes of antisperm antibodies and their binding sites on the sperm surface. In this study we have investigated the variability in the pattern of antibody binding to spermatozoa after passive transfer from blood serum. Serum from a single donor containing antisperm antibodies of the IgG class was used in all experiments. The spermatozoa from 27 semen donors were found to differ significantly in the degree and location of immunobead binding after exposure to this serum. There was substantial day-to-day variability in the results for individual semen donors and the overall variability in test results was significantly greater when a number of semen donors was used rather than a single donor. These data suggest that details of antisperm antibody binding after passive transfer from body fluids may depend on the sperm donor. The design of research studies involving antibody transfer must take this source of variability into account.

Prevalence of sperm surface antibodies in the male partners of infertile couples as determined by immunobead screening

A single simple laboratory test for the detection of sperm surface antibodies is described. Spermatozoa from 300 men who were investigated for infertility were tested for sperm surface antibodies using the Immunobead test (IBT). IBTs for IgG, IgA, and IgM were performed on each sample as well as an IBT using an Immunobead with activity against both light and heavy immunoglobulin chains and therefore capable of detecting any of the three isotypes ("GAM-IBT"). An excellent correspondence was found between GAM-IBT-positive samples and those positive by one or more of the isotype-specific Immunobeads. In 29 of 32 positive tests, the GAM bead binding was within 5% of the most positive isotype-specific bead's binding. There were no false-positive or false-negative tests comparing the GAM-IBT with the isotype-specific IBTs.

An improved immunobead test procedure for detecting sperm antibodies in serum

In order to improve the efficiency of IBT screening of sera for sperm antibodies, the use of immunobeads with attached rabbit antibodies directed against whole human immunoglobulin (IBT-GAM) was investigated and compared with the use of separate immunobeads specific for each of the main immunoglobulin classes (IBT-IgG, IBT-IgA, IBT-IgM). Sera found positive by the IBT-GAM procedure were then tested by IBT-IgG, -IgA, and -IgM procedures to determine the immunoglobulin class or classes of the sperm antibody. The new procedure is much more efficient for screening larger batches of sera and gives results identical with those from the old procedure when greater than or equal to 50% sperm coating is used as criterion of positivity. We now use the IBT-GAM procedure for initial screening of all sera, followed by further testing of positive sera on the same preparation to determine the immunoglobulin class or classes of the antibody.

The fertilization of human oocytes by spermatozoa from men with antispermatozoal antibodies in semen

Seventy-two couples, including 15 with antispermatozoal antibodies in the male partner's semen, were studied in a program of in vitro fertilization and embryo transfer. Cases were further subclassified as normospermic or oligospermic and antispermatozoal antibodies were assessed with categorization into the respective human immunoglobulin classes as determined using the indirect immunobead test. The study reveals that fertilization is significantly reduced (P less than 0.001) only if both IgA and IgG antibodies are present in semen but there is no reduction if either class is present alone. The fertilization rate of oocytes is significantly reduced (P less than 0.001) by sperm from oligospermic samples, and there is a further reduction in those cases with combined IgA/IgG antispermatozoal antibodies.

Effect of sperm antibodies in females on human in vitro fertilization

The effect of sperm antibodies derived from the female partner's serum on fertilization and embryo cleavage was evaluated by analyzing the Royal Women's Hospital in vitro fertilization (IVF) data. The results suggest that antispermatozoal isoantibodies detected by the immunobead test (IBT) can interfere with IVF. Thus, in a group of patients with IBT-IgG and IBT-IgA sperm antibody titers of greater than or equal to 10 in serum, a low fertilization rate (15%) was obtained when the wife's serum was used as serum supplement in the IVF culture medium. Where replacement (antibody-negative donor or cord) serum was used in the culture medium, a higher fertilization rate (69%) was obtained (P less than 0.01). These results underline the importance of using replacement serum in cases where the wife has significant sperm antibody levels in her serum. Six pregnancies were obtained in the antibody-positive group (n = 20), five of which occurred in patients with IBT-IgG and IBT-IgA-titers less than 10, for a pregnancy rate of 5/9 in this subgroup. Four of these patients delivered (4/9). Analysis of larger groups of antibody-positive patients is required for further evaluation of these results and ascertainment of the likelihood of occurrence of posttransfer effects of sperm antibodies on the embryo.