Sperm Immobilizing Antibodies Interfere With Sperm Migration From the Uterine Cavity through the Fallopian Tubes

PROBLEM : It is well known that sperm migration in cervical mucus is impaired by sperm immobilizing antibodies secreted in the mucus. However, it is not clear yet whether sperm migration from the uterine cavity through the fallopian tubes to the peritoneal cavity is impaired by sperm immobilizing antibodies. To test the possible impairment of sperm migration in the tubes, laparoscopic examinations were carried out and the presence of motile sperm in the peritoneal fluid after intra-uterine insemination was investigated. METHOD : Peritoneal sperm recovery tests were performed in 28 infertile women with sperm immobilizing antibodies in their sera, and the results were compared with those in 322 infertile women without the antibodies. Both the sperm immobilizing antibody titers (SI₅₀) and complement activities (C'H₅₀) in peritoneal fluid were compared with those in patients' sera. In some experiments, the supernatant of the peritoneal fluid was used as a source of complement for the sperm immobilization tests instead of guinea pig serum. RESULTS : Among couples with normal semen characteristics by the criteria of WHO, sperm recovery in the peritoneal fluid was observed in only 3 (11.1%) of 27 patients with sperm immobilizing antibodies, compared with 72 (34.0%) of 212 patients without the antibodies (P<0.025). The antibody titers of the patients with the sperm recovery were very low by the quantitative sperm immobilization test. In most patients, a similar amount of sperm immobilizing antibodies was present in the peritoneal fluid and the sera. Though the complement activities in the peritoneal fluid were less than those in sera, the former were still found to be sufficient to immobilize sperm in vivo. CONCLUSIONS : These results suggest that the complement-dependent sperm immobilizing antibodies could interfere with sperm migration in the female genital tract at the level of the fallopian tubes.     

Effects of sera from infertile women with sperm immobilizing antibodies on fertilization and embryo development in vitro in mice

PROBLEM: This study was performed to investigate if patients' sera with anti-human sperm antibodies show inhibitory effects on in vitro fertilization (IVF) and embryo development in mice. METHOD OF STUDY: Patients' sera were collected from eight infertile women having sperm immobilizing antibodies and 17 infertile women without the antibodies. Male ICR mice and female F1 mice (BALB/c X C57BL/6J) were used. In mouse IVF, pre-incubated sperm were cultured in the medium containing patient's serum with or without sperm immobilizing antibodies, or bovine serum albumin (BSA) as a control. The fertilization rates and the incidences of blastocyst formation were compared. RESULTS: A mouse sperm immobilization test was established. Five (62.5%) of eight serum samples with sperm immobilizing antibodies and nine (52.9%) of 17 serum samples without the antibodies showed sperm immobilizing activities in mice. There was no significant difference between the two groups. Five sera with sperm immobilizing activities in human and mice, and five sera without sperm immobilizing activities in human or mice were used for the further experiments. The fertilization rates in BSA, patient's serum with sperm immobilizing antibodies, and that without the antibodies were 82.5% (746/904), 43.6% (508/1165), and 64.5% (669/1037), respectively. There were significant differences between the groups. The incidences of blastocyst formation were 59.9% (447/746), 31.7% (161/508), and 47.7% (319/669), respectively. There were also significant differences between the groups. CONCLUSIONS: Some of the patient's serum with and without sperm immobilizing antibodies could immobilize sperm with complement. However, as compared with control, sera with sperm immobilizing activities against human and mouse sperm significantly blocked IVF and inhibited embryo development in mice. Further studies are required to investigate the mechanisms of the blocking effects of antisperm antibodies on fertilization and embryo development using the mouse model.     

Study of sperm antibodies in the sera of vasectomized males

Agglutination and immobilization tests were performed to detect the presence of sperm antibodies in the sera of 100 vasectomized men. Overall, 52% of subjects had sperm antibodies. 50% showed agglutinating antibodies, while immobilizing antibodies were present in 40%. Of the 52 positive cases, 23 showed agglutinating antibody alone in their sera. 73 had both agglutinating and immobilizing antibodies, and 3.8% had sperm immobilizing activity alone. The age incidence of the presence of sperm antibodies was as follows: under 35 years, 66%; 36-40 years, 50%; 41-45 years, 50%; and 46 years and above, 33.3%. The highest percentage of presence of sperm antibodies was recorded in men who had been vasectomized less than 1 year previously (75%). Significantly high titers of sperm agglutinating activity were found in 20% of the positive cases, while high titers of sperm immobilizing activity were noted in 40% of positive cases. It has been suggested that the development of sperm antibodies after vasectomy may prevent subsequent successful restoration of fertility by reanastomosis.     

Effects of Sperm Immobilizing Antibodies on Pregnancy Outcome in Infertile Women Treated With IVF-ET

PROBLEM: Since it was found that anti-sperm antibodies could impair in vitro development of fertilized eggs in the presence of complement in rats, the effects of sperm immobilizing antibodies on human pregnancy were examined in infertile women treated with IVF-ET. METHOD: The pregnancy outcomes of 143 ET cycles in 58 infertile women with sperm immobilizing antibodies and 363 ET cycles in patients with tubal infertility as control were compared. Diagnosis of chemical pregnancy was done when the urinary hCG level had risen over 50 IU/L but a gestational sac could not be demonstrated later. Antibody titers of sperm immobilizing antibodies (SI₅₀ units) were measured by a quantitative sperm immobilization test. RESULTS: 33 (23.1%) of 143 cycles in the patients with sperm immobilizing antibodies and 56 (15.4%) of 363 cycles in the control patients were diagnosed as pregnancy. The pregnancy rates were significantly higher in the former than in the latter (P<0.05). In the patients with sperm immobilizing antibodies, 12 (36.4%) were chemical pregnancies, 5 (15.2%) were clinical abortions, and 16 (48.5%) had deliveries. In the control group, 18 (32.1%) were chemical pregnancies, 10 (17.9%) were clinical abortions including ectopic pregnancies and 28 (50.0%) had deliveries. There was no significant differences in each category. When the SI₅₀ titers at the time of conception were considered, chemical pregnancy rates were 22.2% (4/18) in patients with SI₅₀ titers below 10 units, but those in patients with SI₅₀ titers above 10 were 50.0% (5/10) and above 100 were 60.0% (3/5), respectively, (P > 0.05). In four of five patients who had both chemical and clinical pregnancies, the SI₅₀ titers at the time of conception were higher in the chemical pregnancy cycles than in the clinical pregnancy cycles. CONCLUSIONS: Though the pregnancy rates were significantly higher in the patients with sperm immobilizing antibodies as compared to those with tubal infertility, chemical pregnancy rates were also higher in the patients with higher sperm immobilizing antibody titers. These results suggest that sperm immobilizing antibodies may cause the damage of early development of human embryos in vivo in the small number of patients with a high titer of the antibodies.     

Females' isoimmunity to sperm is associated with sperm autoimmunity in their husbands

One hundred twenty-five fertile couples and 334 infertile couples were tested for the presence of cytotoxic and hemagglutinating antibodies to sperm. Elevated titers of sperm antibodies were absent in both partners of fertile couples. Of 79 infertile males with levels of sperm antibodies in the previously established negative range, 97% had wives who also had low titers of sperm antibodies. Of 255 infertile males positive for serum hemagglutinating antibodies, 56% had wives whose serum contained significant circulating hemagglutinating antibodies, while 93 of 202 (46%) males with significant cytotoxic antibody titers had wives whose serum contained elevated cytotoxic antibody titers. The females developed elevated titers of sperm antibodies in the serum and cervical mucus if their husbands had significant titers of hemagglutinating and cytotoxic sperm antibodies in the serum and seminal plasma samples. Females' isoimmunity to sperm was significantly associated with their husbands' autoimmunity to sperm and infertility.     

Studies on Sperm Survival and Motility in the Presence of Cytotoxic Sperm Antibodies

ABSTRACT: The effect of cytotoxic sperm antibodies and native complement in the serum and secretions from 40 fertile and 93 infertile couples on in vitro sperm survival and motion characteristics was studied. Sperm survival in vitro was unaffected by sera from fertile and infertile subjects without cytotoxic sperm antibodies and from infertile men with antibodies to control but not to autologous sperm. Sperm survival was reduced (P < .001) by sera from infertile men with antibodies to autologous sperm or to antologous and control sperm and from women with cytotoxic antibodies to sperm from both. Sera from fertile couples without sperm antibodies enhanced sperm swimming speed and motility index (P < .0001). Sera from infertile women with or without cytotoxic sperm antibodies did not affect sperm motility. Sperm survival and motility were reduced by seminal plasma from infertile men with cytotoxic antibodies to autologous and/or control sperm. Seminal plasma from fertile men enhanced sperm survival. Cervical mucus from infertile women with antibodies to autoimmune husbands' sperm or to husbands' and control sperm inhibited sperm motion, whereas cervical mucus from infertile women without sperm antibodies and women with antibodies to control sperm failed to have any effect. It is concluded that cytotoxic sperm antibodies developed through exposure to sperm antigens in autoimmune infertile men decrease in vitro sperm survival and/or motility.     

Sperm immobilizing antibodies in the sera of infertile women cause low fertilization rates and poor embryo quality in vitro

PROBLEM: The effects of sperm immobilizing antibodies in the sera of infertile women on fertilization and embryo quality in vitro were investigated. METHOD OF STUDY: Before the introduction of sperm immobilization test (SIT) as a routine test for female infertility, 85 oocytes were collected in nine in vitro fertilization (IVF) cycles from four infertile women who were afterward found having had sperm immobilizing antibodies in their sera and the oocytes were inseminated with swim-up sperm in a medium containing the patient's serum. Fifty oocytes were collected in five IVF cycles from five infertile women possessing the antibodies in their sera and the oocytes were inseminated with swim-up sperm in a medium supplemented with human serum albumin (HSA). RESULTS: In the former group, 41 of 85 oocytes were fertilized, giving a fertilization rate of 48.2%. In the latter group, 43 of 50 oocytes were fertilized, giving a fertilization rate of 86.0%. There was a significant difference of the fertilization rate between the groups (P < 0.0001). Embryo quality was assessed by the Veeck's classification. The grade 1 and grade 2 embryos were considered good quality. Using this classification, 16 (39.0%) of 41 embryos incubated in the medium containing the patient's serum were good quality, while 34 (79.1%) of 43 embryos incubated in the medium supplemented with HSA were good quality. There was also a significant difference between the groups (P = 0.0003). CONCLUSIONS: These findings might indicate that sperm immobilizing antibodies in the sera of infertile women cause low fertilization rates and poor embryo quality in vitro. It is suggested that SIT in the sera of infertile women should be performed at least before proceeding IVF. The manipulation of gametes and embryos from patients having sperm immobilizing antibodies should be carefully carried out especially to avoid contaminating patient's serum and follicular fluid in the culture medium in order to have a better IVF result.     

A digital method of sperm immobilization test: comparison to the conventional method

Antisperm antibodies have been found in infertile patients and those causing immobilization of sperm are considered to be closely related to unexplained infertility. These antibodies are usually identified by a sperm immobilization test which involves counting motile sperm under microscope. This test is subjective as it relies on the judgement of the examiner with respect to sperm motility. In this study, we analyzed motile sperm by a digital method using Sperm Quality Analyzer. The results were compared with those obtained by the conventional method. We found that the two methods yielded identical results, with 14 of 66 samples tested being positive and 52 negative for sperm immobilizing antibodies. These results show that the digital method is objective and of value in the measurement of motile sperm in determination of sperm immobilizing antibodies.     

Variation in Antisperm Antibody Results Using Different Assays

PROBLEM: The detection of various types of antisperm antibodies (ASA) in the serum varies among different assays. This variation may influence the diagnosis and management of infertile couples who are tested for such immunologic factors. This prospective study was conducted to determine the variation in the results of ASA as measured by the sperm immobilization (SI), sperm agglutination (SA), and the indirect immunobead (IB) assays. METHOD: The sera of 79 patients that tested positive for ASA by at least one of the assays listed above were concurrently tested with all three assays. RESULTS: Using an individual ASA assay, 66 (84%), 26 (33%) or 36 (46%) of sera tested positive by the SA, SI, or IB assays, respectively. However, using a combination of assays, 67 (85%), 78 (99%) or 40 (51%) of sera tested positive using either the SA+SI, SA+IB or SI+IB assays, respectively. CONCLUSION: These findings suggest that the utilization of different assays to detect ASA may detect sera that are positive for ASA with more reliability than single assay testing.     

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

PROBLEM: The presence of antisperm antibodies (ASA) in males can reduce fecundity, however, relationship between the two is disputed. This study was performed to investigate if there is diversity of ASA bound to sperm surface using immunobead test (IBT) combined with complement dependent sperm immobilization test (SIT). METHODS: The ASA bound to sperm surface were detected using the direct IBT (D-IBT) in 275 semen samples. In some cases with ASA detected by D-IBT, sperm immobilizing antibodies bound to sperm surface were also evaluated using direct SIT (D-SIT). RESULTS: The incidence of the immunoglobulin G (IgG), IgA, and IgM classes of ASA detected by D-IBT were 2.5, 1.8, and 0.4%, respectively. Totally, nine (3.3%) infertile men had ASA on the sperm surface. D-SIT was tested positive in four (66.7%) of six cases with ASA assessed by D-IBT. CONCLUSIONS: Some of the sperm-bound antibodies are associated with complement dependent sperm immobilizing antibodies, indicating that there exists a heterogeneity of sperm-bound antibodies. This result might be one of the reasons for the controversy about the relationship between ASA and immunological infertility in men.     

Diversity of the inhibitory effects on fertilization by anti-sperm antibodies bound to the surface of ejaculated human sperm

BACKGROUND: The presence of anti-sperm antibodies (ASA) in males can reduce fecundity. However, it has been shown that there is a diversity of ASA bound to the sperm surface. This study was performed to investigate the inhibitory effects on fertilization by ASA in males. METHODS: ASA were detected using the direct-immunobead test (D-IBT) in 509 semen samples. In some cases, the direct-sperm immobilization test (D-SIT) was carried out. The fertilizing ability of infertile males with ASA was determined as follows; (i) an IVF fertilization rate of >/=50%, (ii) a hemizona index (HZI) of >/=50%, and (iii) pregnancy established without the use of ART. RESULTS: In total, 18 (3.54%) infertile males had ASA on the sperm surface. Except for one male with an absolute indication for ICSI because of severe asthenozoospermia and two males who dropped out of this study, fertilizing ability in 15 males could be determined. Four (26.7%) men did not satisfy the criteria. The existence of sperm immobilizing antibodies on the surface of ejaculated sperm had no impact on fertilization. In four (57.1%) of seven patients who had IB-bound sperm of >/=80%, fertilizing ability was inhibited, while none of the eight patients who had <80% IB-bound sperm had an inhibitory effect on fertilization. There was a significant difference between the two groups (P = 0.01). CONCLUSIONS: Some sperm-bound antibodies are related to the inhibitory effects on fertilization, indicating that a diversity of sperm-bound antibodies exists in males. This result might be one of the reasons for the controversy of the relationship between ASA and male immunological infertility. Based on the present study, a sperm-zona pellucida binding assay should be performed for appropriate decision making in infertile males with ASA.     

The Immunoglobulin Class of anti-spermatozoal antibodies in Serum

ABSTRACT: 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.     

Sperm Immunity in Infertile Couples: Antibody Titers Are Higher Against the Husbands' Sperm Than to Sperm From Controls*

ABSTRACT: Titers of hemagglutination and cytotoxic antibodies to sperm were determined in the sera, seminal plasma, cervical mucus, and vaginal secretions from 69 infertile couples, using sperm from the husbands and from normal control subjects. Titers of hemagglutination and cytotoxic antibodies were significantly higher (p = 0.002 and p < 0.001, respectively) against autologous sperm as contrasted with sperm from control subjects in sera from 55 autoimmune males. Hemagglutination and cytotoxic antibody titers were also significantly higher (p = 0.044 and p < 0.001, respectively) against their husbands' sperm as contrasted with control sperm in sera from 46 females with isoimmunity to sperm. Ninety percent of males and females with sperm immunity were positive for histocompatibility antigens HLA-B7, HLA-B8, and/or HLA-BW35. In males, the presence of increased serum cytotoxic antibody titers against autologous versus control sperm was significantly associated with the presence of HLA-B7 allele (p = 0.0017) and with HLA-B7, HLA-B8, and/or HLA-BW35 in general (p < 0.05). In the females, increased serum antibody titers to their own husbands' versus control sperm were not preferentially associated with HLA-B7, HLA-B8, or HLA-BW35 antigens.     

Immunology: Diversity of the blocking effects of antisperm antibodies on fertilization in human and mouse

The blocking effects of complement-dependent sperm immobilizingantibodies in the sera of infertile women and monoclonal antispermantibodies against humans and mice on fertilization were investigated.The hemizona assay (HZA) and sperm penetration assay (SPA) wereused to study the inhibitory effects of sera from 22 infertilepatients positive for sperm immobilizing antibodies. Use ofthese tests allowed us to differentiate whether the antibodyblocked sperm—zona pellucida tight binding and/or spermpenetration into the ooplasm. The zona pellucida penetrationassay (ZPA) was also used to study the effects of four monoclonalantibodies (mAbs) on human sperm penetration into the zona pellucida.Seven mAbs against murine spermatozoa were tested for theirinhibitory effects on in-vitro fertilization (IVF) and HZA inmice. Of 22 patient sera with sperm immobilizing antibodies,21 (95.5%) inhibited HZA attachment and penetration, whereasthis did not occur in any of 13 patient sera without these antibodies.However, 19 of 22 (86.4%) patient sera with sperm immobilizingantibodies and eight of 13 (61.5%) patient sera without theseantibodies inhibited the SPA. Two (2C6, 1G12) of four mAbs againsthuman spermatozoa showed strong inhibitory effects in all theassays (HZA, ZPA and SPA). One mAb (3B10) did not inhibit HZAbut blocked ZPA and SPA. Another mAb (H6-3C4) seemed to haveno inhibitory effects on fertilization. Two (Vx 5 and Vx 8)of seven mAbs against murine spermatozoa inhibited IVF in micebut did not block mouse HZA. These findings suggest that antispermantibodies block fertilization at specific stages. Some of themmay inhibit sperm capacitation and thus prevent all processesof fertilization that follow. Some other antibodies may notaffect capacitation and sperm binding to zona pellucida butinhibit the acrosome reaction, followed by the blocking of spermpenetration through zona pellucida and ooplasm.     

Quantitation of Sperm Bindable IgA and IgG in Seminal Fluid

ABSTRACT: Seminal fluid and serum from 95 infertile males were assayed for sperm bindable immunoglobulins using an indirect ELISA with whole target sperm. The ELISA method was compared to seminal fluid and serum immobilization and agglutination assays (functional assays). In this infertile group, the ELISA assay was positive in 22% of seminal fluids (>1.2 fg IgA/ sperm and >0.3 fg IgG/sperm). The seminal fluid antibodies were IgA and had an accompanying elevated IgG component in 78% of patients. There was a 96% correlation between negative seminal fluid functional assays and negative ELISA, and a 95% correlation between positive seminal fluid functional assays and positive ELISA. Positive serum sperm antibody tests were found in 71% of the infertile males with positive seminal fluid sperm antibodies, but 29% of the infertile males with strongly positive IgA seminal fluid sperm antibodies showed normal levels of serum sperm antibodies by either ELISA or functional assays. The ELISA method gives reproducible quantitation of sperm antibodies in seminal fluid and correlates well with accepted functional assays. Comparisons with serum sperm antibody assays suggests that seminal fluid sperm antibody analysis complements the serum analysis of sperm antibodies.     

前列腺炎合并不育症患者的抗精子抗体评价

目的评价前列腺炎合并不育症患者的抗精子抗体关系.方法应用混合球蛋白试验(MAR试验)、浅盘精子凝集试验(TAT试验)和浅盘精子制动试验(SIT),对35例前列腺炎合并不育症患者(A组)的血清和精子表面抗精子抗体进行检测,随机选择35例男性不育门诊初诊者作对照(B组).结果 A组采用TAT检出血清抗精子抗体阳性5例,滴度水平在1:8～16,SIT未测出阳性,采用MAR试验检出精子表面抗体阳性8例.B组采用TAT检出血清抗体阳性4例,SIT阳性1例,采用MAR试验检出精子表面抗体阳性2例.经t检验,A组精子表面抗精子抗体阳性率显著高于B组(P＜0.01).结论前列腺炎合并不育症患者存在着精子免疫因素,且表现出精子表面抗体发生率升高,临床对这类不育患者治疗要重视前列腺炎的抗炎处理.     

Application of proteomic methods for identification of sperm immunogenic antigens

Although the immunogenic properties of sperm have been explored for a few decades, none of the antigens studied so far appears to be an effective target, to inhibit the fertilization process or shown the full spectrum of sperm antigenic potential. Antisperm antibodies (ASA) collected from infertile individuals and prepubertal boys with cryptorchidism together with two-dimensional (2D) electrophoresis have been employed. Immunoreactive antigens were cored from silver stained 2D gels and analyzed by mass spectrometry (MS). The obtained sequences were searched in the published protein databases. Altogether, 35 different sperm entities were identified in accessible protein databases, out of which 10 appeared to be sperm-specific. Additionally, 6 amino acid sequences indicated novel (hypothetical) proteins. Seventeen sperm entities were detected in sera samples from immune infertile males and 18 entities in ASA-positive seminal plasma (SP). Interestingly, we identified a few sperm structures, none of them sperm specific in sera samples from infertile females. Although, infertile males from whom the ASA-positive SP samples were obtained, did not have ASA in their circulation, the range of sperm antigens detected by systematic and local antibodies overlapped to a great extent (six identical entities). Sera samples from prepubertal boys allowed to show antigens, previously thought to be only present on mature sperm. Three out of four detected were sperm-specific. Using serum and SP of ASA-positive infertile adults and sera samples of prepubertal boys with testicular failure, we have extended the range of known, immunogenic sperm proteins as well as identified some novel antigens (n=6) of human sperm for further characterization.     

The Use of ELISA to Evaluate Human Antibody Binding to Epididymal Sperm From Different Species

PROBLEM: The impact of antibodies to epididymal sperm antigens in human infertility has been poorly understood. Cross-reactivity of human antibodies with animal epididymal sperm has been previously observed, however, only by means of qualitative methods. Moreover, it has been always compared to reactivity against human ejaculated rather than human epididymal sperm. METHOD: Following a screening study of 940 infertility patients, sperm agglutinating and immobilizing sera as well as sperm anbitody negative controls were used to standardize an ELISA employing human ejaculated sperm. Nine sera positive in ELISA were further tested against epididymal human, guinea pig, rat, and hamster sperm. Differences among groups were evaluated by factorial analysis of variance (ANOVA). RESULTS: The specificity and sensitivity of ELISA were shown to be 85.1% and 61.18%, respectively. Eight out of nine antisperm antibody-positive sera from infertile subjects reacted relatively stronger with epididymal than with ejaculated human sperm. All tested infertility sera showed strong although variable cross-reactivity with sperm from guinea pig, hamster, and rat. CONCLUSION: ELISA has definite potential in sperm antibody research, allowing quantitative assessment of the results and immotile sperm employment. The suggested predominant role of epididymal sperm antigens in immune responses related to fertility needs further investigation. Some of these antigens are obviously phylogenetically perserved, and possibly in a quantitative aspect present differently on epididymal spermatozoa from various mammalian species.     

Cross-Reactivity of Sperm and T Lymphocyte Antigens*

ABSTRACT: Evidence is presented for cross-reactivity between antigens on human sperm and T lymphocytes. In 25 infertile couples in which both the males and females had significant antisperm immunity, antibody (Ab) titers to thymocytes (mean ± S.E.M. 159 ±4 and 72 ± 14, respectively, in males and females), T cell lines CCRF-CEM (69±5 and 48±8) and HSB-2 (56±15) and 41±8), suppressorenriched (T_G) cells (26±6 and 66±28) and helper-enriched (T_g—) cells (26±4 and 46±14) were significantly elevated, as compared wth Ab titers in 45 normal males and 45 normal females without antisperm immunity. Antibody titers to adult B cells, B cell line RAJI, and granulocytes were similar in the two groups. Antisperm Ab titers in sera, sperm extracts, and seminal plasma of the infertile subjects were significantly reduced after absorption with sperm, thymocytes, or T cell line CCRF-CEM but not with the B cell line RAJI. Antithymocyte Ab titers in the sera were significantly reduced (p < 0.001) after absorption with thymocytes, CCRF-CEM, or sperm, but not RAJI. Lymphocytes from the infertile patients, when stimulated with pokeweed mitogen in vitro, produced antisperm and anti-T-lymphocyte antibodies at significantly higher titers than normal controls.     

Anti-sperm antibodies from infertile patients and their cognate sperm antigens: a review. Identity between SAGA-1, the H6-3C4 antigen, and CD52

PROBLEM: The correlation of anti-sperm antibodies (ASA) with some instances of unexplained infertility implicates a role for these antibodies in blocking fertilization. Improved diagnosis and treatment of immunologic infertility, as well as a more complete understanding of the mechanism behind this phenomenon, are dependent on the identification and characterization of relevant sperm antigens. METHOD OF STUDY: In this article, we review literature on methods employed to identify sperm antigens using anti-sperm polyclonal and monoclonal antibodies from infertile patients and vasectomized men. Particular focus is given to approaches using human and mouse monoclonal antibodies to define the SAGA-1 human sperm antigen. RESULTS: ASA present in sera and genital tract secretions from infertile patients and vasectomized men have been employed in a variety of methods to identify sperm antigens. In an alternate approach, a monoclonal antibody (mAb), H6-3C4, was immortalized from the lymphocytes of an infertile woman who exhibited sperm-immobilizing titers. Subsequently, the sperm-agglutinating, murine S19 mAb was shown to react with the H6-3C4 cognate antigen. The H6-3C4 S19 cognate antigen, designated Sperm Agglutination Antigen-1 (SAGA-1), was characterized as a polymorphic, highly acidic, GPI-anchored glycoprotein on the surface of human spermatozoa. Purification with the S19 mAb followed by microsequencing demonstrated that the SAGA-1 core peptide is identical to CD52, a glycoprotein on the surface of human lymphocytes. Immunoblot analysis demonstrated that these two glycoproteins differed in carbohydrate composition. Thus, sperm SAGA-1 and lymphocyte CD52 represent glycoforms, glycoproteins with the same core peptide but with different carbohydrate structures. CONCLUSIONS: Autoimmunity to the SAGA-1 and/or CD52 glycoforms may lead to infertility. Structural and immunologic differences between these glycoproteins may be important factors in the etiology of immunologic infertility and other autoimmune disorders.