The effects of lymphokines and monokines on human sperm fertilizing ability in the zona-free hamster egg penetration test

Antisperm cell-mediated immunity has been associated with infertility in men and women. The purpose of this study was to determine whether the products of activated lymphocytes and macrophages (lymphokines and monokines) affect the fertilizing ability of human spermatozoa in the zona-free hamster egg penetration test. Of a panel of six different purified cytokines tested, the lymphokine gamma-interferon and the monokine tumor necrosis factor significantly affected the ability of human sperm to penetrate hamster eggs. An inhibitory effect was observed when motile sperm were harvested for use in the assay by a swim-up technique after overnight incubation in low amounts of these cytokines and also when the factors were added to the cultures at the time sperm were introduced to the eggs. These data contribute further evidence that soluble factors produced by activated lymphocytes and macrophages in reproductive tissues could be significant mediators of immunologic infertility.

Evaluation of antisperm antibodies in infertile couples with immunobead test: prevalence and prognostic value

We know that antisperm antibodies can cause infertility. We studied the prevalence of the immune response against spermatozoa in infertile couples using immunobead test. 16.2% of the men were autoimmune and 7.3% of the women isoimmune. Both partners were immune in 1.6% of the couples. We also studied the degree of impairment of sperm penetration into cervical mucus in couples in which one of the partners exhibited immunity and we found that generally it correlates with the proportion of sperm exhibiting surface-bound immunoglobulins. In some cases the sperm penetration into cervical mucus was normal in spite of immunization. So other mechanisms of interference should be explored. We found a significant difference (p less than 0.02) in the conception rate between immune and non immune couples (19.3% vs 42%). The pregnancy outcome of immune couples was favorable only in 50% of the cases.

Detection of antisperm antibodies on the surface of motile spermatozoa. Comparison of the immunobead binding technique (IBT) and the mixed antiglobulin reaction (MAR)

Investigators testing for antisperm antibodies have recently focused on tests that detect the Ig classes of the sperm-bound antibodies. The aim of this study was to compare the sensitivity of two of these tests, viz. the immunobead binding technique (IBT) and the mixed antiglobulin reaction (MAR). Twenty-one male or female sera were tested for IgG and IgA antisperm antibodies with the IBT and the MAR. The sera were selected on the basis of the IBT results, and the MAR was carried out without knowledge of these results. For IgG antisperm antibodies, there was a highly significant correlation between the two tests (P = 0.0043), whereas, for IgA antisperm antibodies, the correlation was poor (P = 0.2951), because the IBT revealed a positive reaction for IgA in sera in which no such antibodies could be detected by the MAR.

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.

Detection and titration of class-specific antisperm antibodies in serum using an enzyme-linked immunosorbent assay

An antisperm antibody enzyme-linked immunosorbent assay (ELISA) that uses whole unfixed sperm and detects immunoglobulin G (IgG) and IgA antibodies in serum was developed. Donor sperm were washed and plated on poly-L-lysine-treated microtiter plates. The patient's sera were diluted to concentrations of 1:4 to 1:256 and incubated with sperm. Positive and negative sera had been previously tested for IgG antisperm antibody activity with a radiolabeled antiglobulin assay. Samples were considered positive when the mean absorbance of triplicate wells was greater than 2 SD above the pooled negative mean. Intra-assay variation was 7.9 and 9.6% for pooled negative and positive controls, respectively. Identical titers of control positive serum were consistently detected. A correlation of 0.83 was observed between ELISA IgG serum titers and radiolabeled antiglobulin results (N = 12). All negative samples tested negative in both assays (N = 21). Some serum samples showed IgA antisperm antibodies. Determination and titration of class-specific antibodies in serum should facilitate initial screening and follow-up of patients at risk for antisperm antibodies.

[Reproductive immunology]

In this article, immunology of fetoplacental survival in pregnancy and immunologic mechanisms in infertility, abortions and preeclampsia are discussed. Rh incompatibility, pregnancy in renal transplant patients, autoimmune diseases and cancer in pregnancy are also reviewed.

Incidence of infertility of immune origin in a group of marriages with unexplained infertility

This study was designed to estimate the incidence of infertility of immune origin in a group of 102 married couples with unexplained infertility, out of a total of 1346 couples being treated for infertility. The tests included microagglutination of spermatozoa, microzone sera immunoelectrophoresis and sera immunodiffusion methods. In this group the sera of 23 (22.55%) women and 21 (20.58%) men contained antibodies, and these seemed to be the only cause of infertility. In relation to the total number of 1346 couples, infertility of immune origin was found in 1.70% of female and 1.56% of male partners. Conjugal immune-origin infertility was present in 0.56% of marriages. Out of 1346 treated infertile marriages, an immunologic factor was evidently the only cause of infertility in 2.57%.

Immunology of spermatozoa and cervical mucus

Auto-immunization of the male and iso-immunization of the female with spermatozoal or testicular material can lead to a significant impairment of fertility. Interference of sperm antibodies with reproductive processes may occur by impairment of sperm migration through cervix, uterus and tubes and by blocking adherence of spermatozoa to the surface of the zona pellucida of the oocyte. A very important point to consider in this context is the immunological situation in the female genital tract which is a target organ for sex hormones. Observations in human and subhuman primates as well as in other mammalian species have shown that the levels of immunoglobulins and specific antibodies in secretions of the different compartments of the female reproductive tract are low compared to the serum in general and show typical cyclic changes under the influence of oestrogens and progesterone. Antibody levels appear to be especially low during the preovulatory period in cervical mucus and--according to observations in primates--in tubal fluid. Complement is present in borderline concentrations or not detectable. Data on levels of immunoglobulins or specific antibodies in endometrial fluid are scarce. However, their presence has been demonstrated. There are indications that a secretory immune system may be operational mainly in the cervical compartment of the female genital tract. Serum antibody levels do not reflect properly the immunological situation in secretions of the genital tract in most instances. This may be different in the male. Demonstrations of sperm antibodies in serum or even in genital secretions are not necessarily indicative of permanent sterility; the chances of conception may, however, be reduced. Antibody specificity, immunoglobulin class and quantitative relationships between spermatozoa and antibodies and hormonal influences have to be taken into consideration. Immunity to spermatozoa does not seem to be an all-or-nothing phenomenon and should be considered a relative rather than absolute cause of infertility.

Autoantibodies and common idiotypes in men and women with sperm antibodies

Antisperm antibodies have been implicated as a causative factor of infertility and pregnancy wastage. Since concomitant autoimmune phenomena were reported in men with antisperm antibodies, we investigated known antisperm antibody-positive sera from 25 women, 27 men, and the respective seminal plasma samples. The investigated autoimmune panel included a search for antinuclear antibodies, autoantibodies (in IgG, IgM and IgA isotypes) to seven phospholipids (cardiolipin, phosphatidylserine, phosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, phosphatidylinositol, and phosphatidic acid), to four histone subfractions (H1, H2A, H3, H4), and to four polynucleotides [ssDNA, dsDNA, poly(I), and poly(dT)], total immunoglobulin levels, and sperm antibody titers. The sera were also evaluated for the presence of a common anti-deoxyribonucleic acid antibody, and anticardiolipin antibody idiotypes. Levels of sperm antibody titers were significantly lower in women than in men. Both men and women with antisperm antibodies demonstrated elevated total IgG levels compared with those of normal control subjects. Only women showed elevated levels of total IgM. Sera from 24% of women and 11% of men with antisperm antibodies demonstrated antinuclear antibody titers greater than 1:40. The most striking autoantibody abnormalities were found among antiphospholipid antibodies. Sera from women with antisperm antibodies demonstrated higher autoantibody production than was found in their male counterparts. A significant correlation was found between antisperm antibodies and IgM anticardiolipin and IgA anti-phosphatidylinositol in women and between sperm antibodies and IgA phosphatidylserine antibodies in men. The presence of anticardiolipin and anti-deoxyribonucleic acid antibody idiotypes was significantly more frequent in women than in men. By means of discriminant analysis and variables selected by this mathematical model, the identification of 24 of 25 women and 26 of 27 men with antisperm antibodies was correctly predicted. These results suggest that women and men respond differently to sperm antigens. The apparent cross-reactivity between sperm antibodies and other autoantibodies, usually associated with autoimmune disease, suggests that a polyclonal B cell activation, similar to that seen in autoimmune diseases, occurs in patients with sperm antibodies.

Effect of sperm antibodies on pregnancy outcome in a subfertile population

The relationship between sperm antibodies, conception, and miscarriage was examined in 109 infertile couples. Antibodies present on the surface of husbands' ejaculated sperm and antibodies in husbands' or wives' sera that reacted with a purified population of the husbands' motile spermatozoa were detected by an enzyme-linked immunosorbent assay. During an 18-month period, conception occurred in 33 (30.3%) of the couples; 16 (14.7%) women subsequently suffered a spontaneous miscarriage during the first trimester, whereas 17 (15.6%) women maintained their pregnancies past this time period. Antisperm antibodies were present in sera from only two of 17 (11.8%) women with successful pregnancies, whereas seven of 16 (43.8%) women who miscarried and 29 of 76 (38.2%) who did not conceive had these antibodies in their sera. IgG (22.4%) and IgM (21.1%) antisperm antibodies predominated in sera of women who did not conceive, whereas IgA (37.5%) and IgG (37.5%) antibodies were most prevalent in sera of women with miscarriages. In men, the presence of antisperm antibodies in sera was unrelated to fertility. However, there was a correlation between sperm surface antibodies and an inability to conceive. IgG was identified on ejaculated spermatozoa from eight of 76 (10.5%) men whose wives failed to conceive and in none of 33 men whose wives conceived. Similarly, IgA was present on spermatozoa from 16 (21.1%) infertile and two (6.1%) fertile men. Thus antisperm antibodies in female sera and on ejaculated spermatozoa were associated with a failure to conceive and first-trimester miscarriage.

Anti-sperm antibodies and immune subfertility

A brief description of immune subfertility, caused by antibodies directed against sperm-specific glycoproteins in the sperm membrane, is given. Observations during the last few years have indicated that this immune disease is primarily caused by anti-sperm antibodies of the IgA class, and recent results from vasovasostomized men lend further support to this theory. Detection of anti-sperm antibodies should therefore include characterization of the immunoglobulin class of antibodies. In male patients this can be achieved by direct mixed anti-globulin reaction test or immunobead-binding test on the patients' spermatozoa, and in female patients cervical mucus can be tested by indirect versions of the same tests.

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.

Clinical evaluation of the new sperm antibody slide-test for detection of antibodies to spermatozoa in cervical mucus and seminal plasma

A new commercially available Sperm Antibody Slide-Test kit for the detection of antibodies to sperm (Biotec Diagnostica International GmbH, Hannover, FRG) was evaluated with respect to its diagnostic value in immunological infertility. The new test correlates better with clinical findings than the sperm-agglutination and sperm-immobilization assays. Compared with the other two tests, it shows a higher percentage of positive reactions with infertile patients. None of the 100 fertile subjects was positive in the Sperm Antibody Slide-Test, as opposed to approx. 13% false positives by the conventional methods. In addition, the new test is easier to perform and requires no vital spermatozoa. Since the kit is stable for over 12 months at 4-8 degrees C, requires no spermatozoal preparations, and has a relatively quick reaction time of 2-5 minutes, it is well suited for the routine diagnosis of patients with immunological infertility problems.

Sperm-cervical mucus interaction, in particular in the presence of antispermatozoal antibodies

Disturbances of the interaction between spermatozoa and cervical mucus can cause subfertility or infertility. The diagnosis of such a disturbed interaction is possible with simple laboratory tests. Oligomucorrhoea and dysmucorrhoea are the most frequent causes of a disturbed sperm--cervical mucus interaction. Antispermatozoal IgA plays a quantitatively limited, but qualitatively important role. Sophisticated time-consuming laboratory investigations have mostly only additional value for the diagnosis.

Immunologic infertility

In general, the management of antibody-mediated infertility has been plagued by misdiagnosis due to the choice of assay system, therapies that may be associated with major side effects, and a failure to learn from the models of other antibody-mediated diseases. An important consideration in diagnosing antibody-mediated infertility is to use an immunoglobulin-specific technique that employs intact or living spermatozoa. Once this is done, a search should be made for what functional deficits in reproduction are associated with the presence of the antisperm antibodies. This would include postcoital testing, tests for ovum penetration (human sperm/hamster egg penetration assay), and tests for the ability of the sperm in the presence of antibody to undergo the acrosome reaction. Once the extent of the reproductive deficit is known, appropriate therapy can then be suggested. I believe that a "case" must be built to prove that antibody-mediated fertility actually exists in a particular couple, even in the presence of a positive test that is known to be highly specific. Sperm antibodies can attach to the sperm's surface without detrimentally affecting reproductive function. In a similar vein, low levels of sperm antibodies could give a positive test result, but the level may be insufficient to be a major detriment to fertility. It is hoped that in the near future isolation of specific sperm antigens will be used to identify antibodies against antigens critical to reproductive function. It may be possible to determine the minimal amount of antisperm antibody that is necessary to disturb each individual step in reproductive function. If a patient is found to have sperm antibodies whose quantity exceeds this amount, then the patient can be appropriately labeled as having antibody-mediated infertility. The array of therapies available for the couple's unique fertility problem(s) can then be described to the patient, and an appropriate therapeutic choice made.

Reproductive immunology

The maternal immune system is challenged with paternal antigens through exposure to trophoblast tissue and fetal cells crossing the placenta into the maternal circulation. The dose of antigen, the manner of presentation (cellular, subcellular, or soluble), and the nature of the antigen all determine the type of response that will be elicited. It is also clear that complex maternal immunologic responses, including antibodies to red blood cell antigens, HLA-A, HLA-B, HLA-C, and HLA-D antigens, and cell-mediated responses such as proliferation, lymphokines, cytotoxicity, and suppressor cells, are generated to a variety of paternal antigenic determinants. The fact that some of these reactions are detected in vitro in the absence of maternal serum, but not in its presence, suggests that the local milieu is important in influencing their expression in vivo. For example, such factors as hormones (cortisol, progesterone, and estrogen), pregnancy-associated glycoproteins (alpha 2-macroglobulin and beta 1-glycoprotein) and AFP, which have immunosuppressive properties, may all serve nonspecifically to inhibit and decrease the general tone of maternal immunologic responses, particularly at the placental interface, where many of these factors are present in high concentrations. However, these nonspecific factors may not be sufficient to prevent presensitized effector lymphocytes from continuing an ongoing rejection process, as is often the case in the chronic rejection of an allograft. For this purpose, specific enhancing antibodies would play an important role by blocking maternal responses or protecting the fetus. There may be a subtle balance created on the trophoblast cell surface between specific antibodies and trophoblast or embryonic alloantigens, resulting in limited expression of antigens capable of inducing rejection reactions. This could favor the production of blocking antibodies and/or T-suppressor cells, as opposed to cytotoxic antibody and killer cells. In fact, low levels of antigen density on the cell surface favor a blocking effect by IgG rather than cytotoxicity. Blocking or enhancing antibodies can exert their effect on maternal immunologic responses in several ways. They could block the afferent limb by combining with antigen and preventing sensitization or increasing the level of sensitivity. An example of the latter would be the coating of fetal cells that enter the maternal circulation. Enhancing antibodies could work directly on the effector cells to suppress their function. The antibody itself, or more likely antigen-antibody complexes, may be important in this regard.(ABSTRACT TRUNCATED AT 400 WORDS)

Involvement of fertilization antigen (FA-1) in involuntary immunoinfertility in humans

Sera from immunoinfertile patients (n = 32) and fertile controls (n = 20) were analyzed for cross-reaction with a purified and characterized sperm-specific glycoprotein, the fertilization antigen (FA-1), employing an enzyme-linked immunosorbent assay. The immunoinfertile sera demonstrated a strong reaction with FA-1 when compared with fertile control sera. There was no correlation between the reaction of sera with FA-1 and the titers obtained through the sperm agglutination technique and the sperm immobilization technique. Immunoinfertile sera showed binding with the protein bands in the regions corresponding to FA-1 on Western blots involving sodium deoxycholate-solubilized human sperm. Antigens isolated with immunoaffinity chromatography involving immunoinfertile sera also demonstrated antigen bands corresponding to FA-1 in sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Of the seven immunoinfertile couples, three that had antibodies to FA-1 in the male as well as female partners demonstrated a block of fertilization (IVF) due to antibodies bound on the sperm surface. The anti-FA-1 antibody activity was detected in serum as well as in follicular fluid and seminal plasma. Immunoinfertile sera that showed an inhibition of human sperm penetration of zona-free hamster ova showed a significant (P less than 0.001) increase in penetration rates after absorption with FA-1. These results indicate that sera from immunoinfertile patients had antibodies reacting with FA-1, and these antibodies are involved in the fertilization process.

Cytotoxic sperm antibodies and in vitro fertilization of mature oocytes: a preliminary report

The fertilization rates of mature oocytes during in vitro fertilization and embryo transfer (IVF-ET) using fetal cord serum-supplemented insemination media were greater than or equal to 57% for five infertile couples without sperm antibodies (group 1). But they were less than or equal to 50% for four of nine infertile couples (group 2) with cytotoxic sperm antibodies in both partners (n = 6) or the husband alone (n = 3). Two women in group 1 were successful in achieving normal, full-term pregnancies with the delivery of normal infants (chi2 = 4.2, P less than 0.05, by chi-square analysis). One of them consistently tested negative for sperm antibodies, while her husband was previously treated with antibiotics for infection and transient sperm antibodies in the seminal plasma. Subsequently, antibody titers in the husband were in the normal range when the successful IVF-ET was performed. One woman in group 2, with antibodies to her autoimmune husband's sperm but not control sperm and with a long-standing poor postcoital test sperm motility, conceived through artificial insemination with donor sperm (AID) after failing to conceive with her husband through IVF-ET. These data suggest that the presence of cytotoxic sperm antibodies in the serum and/or secretions of both partners reduces the rates of fertilization of mature oocytes in spite of using fetal cord serum in the IVF media. Pregnancy achievement is impaired in this group.

The effect of an IgA1 protease on immunoglobulins bound to the sperm surface and sperm cervical mucus penetrating ability

A major site of impaired fertility in men with autoimmunity to sperm rests at the level of restricted sperm entry and motion within cervical mucus. We studied the effects of a protease derived from Neisseria gonorrhoeae, whose substrate specificity is limited to human IgA1, on the ability of antibody-bound sperm to penetrate human cervical mucus in vitro. IgA on the sperm surface, but not IgG, was degraded by IgA1 protease. A correlation was seen between the levels of IgA bound relative to IgG and the improvement in sperm cervical mucus penetrating ability after IgA1 protease exposure. These results provide evidence that antisperm autoantibodies of both IgA and IgG classes impair the ability of spermatozoa to populate the female reproductive tract. They implicate the Fc region of the immunoglobulin molecule in mediating this effect and offer the potential to restore male fertility by treating antibody-bound sperm in vitro with immunoglobulin-directed bacterial proteases, before insemination.

Association between major histocompatibility antigen and reproductive performance

Many studies have both supported and refuted an association between HLA antigens and reproductive performance. To clarify these discrepant results, HLA antigens from 59 couples experiencing recurrent spontaneous abortions and 79 couples with unexplained infertility were compared with 51 fertile couples. Patients with recurrent spontaneous abortions were classified as either primary (no children) or secondary (abortions after having children or stillbirths) aborters, and patients with unexplained infertility were classified as primary (never pregnant) or secondary (previously pregnant) infertiles. The amount of antigenic disparity, homozygosity, and the probability of producing a heterozygotic offspring were analyzed for each group. Significantly more disparities at combined HLA loci and at DR loci were observed when childbearing controls were compared with primary aborters. Significant disparity between controls and secondary aborters was at the DQ locus. Total homozygosity as well as homozygosity at DR and DQ loci were significantly increased among primary aborters, but not secondary aborters, and at the B locus among secondary, but not primary infertile couples. Significant association in probability of heterozygote production was seen at the DQ locus in patients with primary infertility. These results indicate that controversy involving association of HLA and reproductive performance can be explained by properly classifying recurrent spontaneous aborters and unexplained infertiles.

ABO blood group incompatibility and infertility in Nigerian couples

ABO blood group substances were determined in either the seminal plasma (male patients) or saliva of 100 infertile couples and 100 control subjects. Comprehensive infertility evaluation was performed in all patients. Results were analysed in groups of couples with respect to their ABO blood group and compared with fertile control subjects. Over 70% of fertile marriages were compatible. Comparison of infertile and fertile couples for either ABO compatibility or incompatibility did not reveal any statistically significant difference (P greater than 0.05). This suggests some measure of low zone tolerance to ABO antigens on spermatozoa, for only a small minority of sperm introduced during coitus gains access to the oviduct and ultimately to the peritoneal cavity.

[Immunologic aspects of sterility and infertility]

In the complex field of reproductive immunology, related disciplines overlap. Beyond the normal projects of family planning and sterility diagnosis and treatment, new possibilities of population control and early detection of chromosomal and genetic anomalies are pointed out. After a short introduction to the topic of sterility and infertility, the immunoregulatory mechanisms during physiological and pathological pregnancies are discussed. The antigenicity in the female and male reproductive tract and of the gametes themselves are described in detail. Various methods for sperm-antibody detection are compared, especially, a radioimmunoassay developed by the authors.

Antibody binding specificity to donor sperm in sera from infertile patients

Indirect testing for elevated sera levels of antisperm antibody assumes that all relevant antigens are present on the target sperm utilized. In the present study, the heterogeneity of reactivity of positive sera with sperm from different donors was addressed. When 68 sera that previously tested positive by either sperm immobilization test (SIT) or ELISA or both were tested for antisperm antibody levels by a quantitative ELISA using nine different sperm donors, the frequency of positive reactions was 51% for men and 81% for women. A 50% correlation of SIT- and ELISA-positive results could be improved to 85% using the same sperm specimen. This would improve the overall correlation of functional and ELISA test results from 95% to 99% in the infertile population studied. The data suggest that individual sperm may vary in their antigenic expression and that comparison of methods between laboratories could be improved if equivalent target sperm were used.

Probabilistic assessment of the degree of antigen sharing in couples with impaired reproductive performance

Increased histocompatibility antigen sharing has been reported in couples experiencing recurrent infertility problems. Mathematical expressions describing the probability distribution of the number of antigens shared by randomly mating couples are derived for a single locus, two linked loci, and multiple independent systems. These theoretical frequencies are applied in concert with conventional statistical procedures to evaluate hypotheses concerning antigen distributions. Extensions for simultaneous consideration of other genetic systems are discussed.

Intrauterine inseminations with washed human spermatozoa

The success of intrauterine inseminations with washed human spermatozoa was evaluated in four groups of patients. The first two groups were couples in whom either the man or the woman had detectable circulating sperm-agglutinating antibodies. The third group included couples where the woman exhibited hostile or absent cervical mucus, whereas the fourth group represented couples with oligozoospermic males. The couples underwent 3.7 +/- 2.1 insemination cycles, with a 30% overall pregnancy rate for all four groups. Intrauterine inseminations of women with hostile cervical mucus yielded a 68% conception rate. Couples with either male or female serum sperm-agglutinating antibodies showed 25% and 40% pregnancy rates, respectively. However, none of the couples with oligozoospermic males achieved pregnancy. Intrauterine inseminations with washed human spermatozoa thus represent a satisfactory method of achieving pregnancy in women with hostile cervical mucus and in couples with circulating sperm agglutinating antibodies. Couples in whom oligozoospermia has been identified as the principal cause of infertility do not seem to benefit from this therapy.

Cytotoxic sperm antibodies inhibit sperm penetration of zona-free hamster eggs

Zona-free hamster egg sperm penetration assay was used to study the effects of cytotoxic sperm antibodies on egg penetration by the sperm of fertile and infertile men. Twenty-nine fertile and 9 infertile men did not have significant cytotoxic sperm antibodies in their serum and seminal plasma; 7 infertile men were positive for these antibodies in serum and seminal plasma. Two others were positive in sera, and 14 were positive in seminal plasma. Sperm from 18 of 23 (78%) infertile men with sperm antibodies had poor egg penetration (less than or equal to 20%) compared with only 6 of 38 (16%) nonautoimmune men (P less than 0.0001). Sperm from nonautoimmune fertile men were coated with seminal plasma and serum of autoimmune men and serum of isoimmune women, resulting in a significant decrease in hamster egg penetration. Sixteen of 21 (76%) seminal plasma samples with cytotoxic sperm antibodies reduced the control sperm penetration of hamster eggs by greater than or equal to 50%. Coating of sperm from fertile men with serum and seminal plasma samples from non-sperm-immune fertile and infertile subjects did not alter their penetration of hamster eggs. Coating of sperm from autoimmune men with cytotoxic antibody-positive autologous seminal plasma samples resulted in a significant decrease of egg penetration. The inhibitory effect of antibody-positive seminal plasma samples on egg penetration by control sperm was abrogated when the samples were preabsorbed with sperm. It is concluded that cytotoxic sperm antibodies, especially those in seminal plasma, inhibit hamster egg penetration by autologous and control sperm. This may explain in part the incidence of infertility associated with sperm antibodies.

Sperm cervical mucus contact test and immunobead test for sperm antibodies

Twenty-five patients were studied for the presence of sperm antibodies in their cervical mucus and seminal plasma. The sperm cervical mucus contact test (SCMC) and the immunobead test (IBT) were used to evaluate sperm antibody activity. A close correlation was found between the results of the SCMC and IBT tests, and it was concluded that both techniques can be regarded as good indicators of sperm antibodies.

Sperm/cervical mucus contact test for sperm antibodies

Thirteen couples with a history of primary infertility for at least 3 years were selected according to the following criteria: a positive sperm/cervical mucus contact (SCMC) test, the presence of sperm-agglutinating antibodies in the cervical mucus, and/or seminal fluid of one of the partners. Nine of the males and 4 of the 13 females were accordingly treated with high dosages of corticosteroids for 6 months. Among 4 (44%) males and 2 (50%) females a pregnancy ensued. Four (80%) of the 6 patients in whom a pregnancy was reported showed not only a decline in their sperm antibody titer but also a decrease in the percent shaking spermatozoa during SCMC testing.

Antibodies to spermatozoa: XI. The use of immunobeads for the detection of sperm antibodies in serum

Two procedures were developed and evaluated that used either larger or smaller volumes for the detection of sperm antibodies in serum by means of an indirect immunobead test (IBT). The immunobeads, coated with rabbit antibody to each of the major human immunoglobulins (IgG, IgA, or IgM), were mixed with preparations of donor sperm, onto which antibody had been coated by passive transfer from various serum samples. The results of the IBT could be evaluated in various ways: (1) positive or negative; (2) if positive, whether binding is to the tail, the head, or the head and tail of the sperm cells; (3) if positive, whether binding is by IgG, IgA, or IgM. The diverse IBT results were obtained from a group of 50 serum samples; these sera were also tested by two sperm agglutination methods; the gelatin agglutination test (GAT) and the tube-slide agglutination test (TSAT). There was an excellent agreement between the IBT and the GAT; it was not as good between the IBT and the TSAT. However, considering both agglutination methods together, 90% of the IBT-positive sera were agglutination-positive. In terms of morphological sites, tail binding occurred in 27 of 31 sera, head binding in 12 of 31 sera, and head-tail binding in 15 of 31 sera. The number with tail binding was very close to the number that were GAT-positive (26). As for the immunoglobulins, the most frequent class was IgG. IgA was 83% as frequent and IgM was only 25% as frequent as IgG.(ABSTRACT TRUNCATED AT 250 WORDS)

A modified enzyme-linked immunosorbent assay (ELISA) for the detection of antisperm antibodies

To find optimal test conditions of an indirect enzyme-linked immunosorbent assay (ELISA) for the detection of antisperm antibodies (ASA), several variations (solid phases, antigen load, incubations etc.) have been performed. In contrast to the so far used polystyrene microtiter plates, which have to be coated with spermatozoa by the help of glutaraldehyde, we applied positively charged PVC microtiter plates being able to adsorb unfixed spermatozoa and thus avoiding alteration of spermatozoal antigens by glutaraldehyde. The ELISA proved to be more sensitive than conventional methods, e.g. the GAT, the SIT and the TAT, and also more effective since the technique allows screening of more than one hundred test samples for ASA within one day. First results are presented evaluating sera and seminal plasma of andrological and dermatological patients and ten known fertile men for ASA by the described ELISA technique.

Correlation between the direct IgG MAR test (mixed antiglobulin reaction test) and seminal analysis in men from infertile couples

The direct IgG mixed antiglobulin reaction (IgG MAR) test was carried out in 395 male subjects from infertile couples, selected on the basis of their seminal characteristics (sperm concentration greater than 10 X 10(6)/ml, sperm motility greater than 10%); attempts were made to correlate results with the seminologic aspects of the ejaculate. A significant correlation was observed between a positive MAR test and spontaneous sperm autogglutination. No correlation was observed, however, between test positivity and concentration, motility and sperm morphologic features, the macroscopic aspects studied (viscosity, fluidification), or increased concentration of leukocytes.

An enzyme immunoassay for the detection of antisperm antibodies

A simple and reliable enzyme-linked immunosorbent assay (ELISA) for the detection of antisperm antibodies has been developed in our laboratory. The antigen for the solid phase was produced by sperm sonication while antihuman globulin conjugated to alkaline phosphatase was used as the developing reagent. The conditions and reagents of the assay were chosen to give a mild treatment of the antigen, simple manipulation during washing steps, and nontoxic and readily available reagents. The results were compared to a conventional microscopical method routinely used in our laboratory that detects agglutinating antibodies to human spermatozoa. In 96% of all cases antibodies detected by the microscopical method were also detected by ELISA. Moreover there were some cases where no antisperm antibodies could be demonstrated by microscopy, but gave a positive reaction with ELISA. These were usually cases of unexplained oligospermia, agglutinates in the ejaculate, and bad motility or low viability of the sperms. These results, and also titration experiments of positive samples demonstrate the higher sensitivity of the ELISA by comparison with microscopical methods.

Detection of anti-sperm activities of monoclonal antibodies to human sperm

The anti-sperm activities of a series of monoclonal antibodies to human sperm have been compared using agglutination, immunofluorescence, ELISA and 'panning' assays. The antibodies fell into two categories, those that could be detected by agglutination but not immunofluorescence assays and those that could be detected by immunofluorescence but not agglutination. Antibodies positive in the agglutination assays were also positive in the 'panning' assay. None of the antibodies tested was positive in the ELISA assays. These results, and others, are discussed in relation to the problems associated with the detection of anti-sperm antibodies in sub-fertile human populations.

Histoincompatibility in couples with unexplained infertility

Class I human leukocyte antigens (HLA-A, -B) and class II (HLA-DR) antigens were determined in 18 carefully selected couples suffering from unexplained infertility and subsequently compared with 30 normal fertile couples with no history of secondary sterility and with a control group consisting of randomly matched women and men from our laboratory cell panel. No significant differences in the frequencies of HLA antigens were detected between infertile and control groups. The frequency of shared HLA-A, -B, and -DR antigens among members of the couples was similar in all the groups. Finally, the one-way mixed lymphocyte culture showed normal reactivity of both infertile parental pairs in all combinations tested.

The immunoglobulin class of antispermatozoal antibodies in serum

The aim of this study was to determine the immunoglobulin class of circulating antisperm antibody using a technique called the indirect immunobead test (IBT). In the IBT sperm bound antibodies are detected using polyacrylamide beads coated with rabbit antihuman immunoglobulin classes IgG, IgA, and IgM. Of the 20 infertile men with serum immobilizins, 100% were found to be positive for sperm-bound IgG, 50% positive for IgA, and 0% positive for IgM, using the IBT. Similarly, 20 infertile females with serum immobilizins showed 95% positivity for IgG, 60% for IgA, and 15% for IgM. Thus there was a good correspondence between the presence of serum immobilizins as determined by the sperm immobilization test (SIT) and the IBT. This study provides data that indicates that IgG and IgA are the two major immunoglobulin classes of sperm antibody in male and female immune sera as detected by a simple, sensitive immunological technique, the serum IBT.