Methods for direct and indirect antisperm antibody testing

Antisperm antibodies (ASA) are one well-known cause of refractory infertility in both males and females. In females, a sperm immobilization test, which detects sperm-immobilizing antibodies indirectly in the patient's serum, requires complement for the reaction and thus seems to be a more specific immunological reaction. In males, an immunobead test or a mixed antiglobulin reaction test, which detects ASA directly on the sperm surface, is a screening test because of the nonspecific reaction.

[Local sperm antibodies and general levels of immunoglobulins in ovulatory cervical mucus]

OBJECTIVE

The aim of our preliminary study was to compare the levels of total local sIgA and IgG with activity of detected sperm antibodies in ovulatory cervical mucus (OCM).

SETTING

Department of Gyneacology and Obstetrics, Medical School and Faculty Hospital, Charles University, Plzen.

METHODS

We screened samples of OCM from 12 pacients aged 26-31 (29,6 years on average) by radial immunodifusion (RID) to determine s IgA and IgG. Indirect MAR test was used for detection of spermagglutinationg antibodies.

RESULTS

We found out by RID the average concentration of sIgA in OCM 567,84 mg/l (0 -1250,47) and the average concentration of IgG in OCM 23,57 mg/l (8,74-47,99). Antibody activity against sperm cells dominates in IgA with 6 pacients, in IgA with 1 patient, in IgA and IgG together with 1 infertile woman and in IgA and IgM isotypes together with 1 patient. No local sperm antibodies were determined with 3 patients.

CONCLUSION

We proved the hypothesis, that the levels of spermagglutinating antibodies do not correlate with findings of total sIgA and IgG in OCM with our patients.

[Isolation and immunology identification of spermagglutinating antibodies from human serum]

OBJECTIVE

Isolation of spermagglutinating antibodies and their assesment.

DESIGN

Retrospective study.

SETTING

Special consulting for reptoduction immunology, Department of Obstetrics and Gynecology, Charles University and Faculty Hospital, Plzen.

METHODS

Fractionation of serum samples by liquid exclusion chromatography, examination of full sera and their chromatographic fractions by Friberg teste (Tray Agglutination Test--TAT), indirect antiimmunoglobulin reaction test (i-MAR test) and by supplementar radial immunodiffusiona (RID).

RESULTS

Isolation of spermagglutinating fractions of antisperm antibodies positive sera preserved spermagglutinating aktivity and confirmed great spermagglutinating potential of IgM.

CONCLUSION

According to assesment of the presence of IgG and IgG we reported possible states of immunisation: actual immunisation with IgM activity, perpetual stimulation (IgG and IgM) and, finaly, anamnestic titres in IgG. These findings can help us to choose an optimal way of treatment. Excluding gel chromatography is suitable method for serum proteins fractionation, but not their identification--presence of antisperm antibodies does not affect the chromatographic spectrum, nor the RID patterns.

Experimental immunological infertility effect of anti-GAPDH-2 antibodies on the fertility of female mice

OBJECTIVE

To examine the relationship between an antibody against GAPDH-2, a sperm-specific protein, and infertility of female mice.

DESIGN

Basic research.

SETTING

National Research Institute for Family Planning Beijing, World Health Organization Collaboration Center of Human Reproduction.

ANIMAL(S)

New Zealand rabbit, NIH and ICR mice.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Enzyme-linked immunoabsorbent assay, Western blot and indirect immunostaining assays, standard fertility assay, and sperm agglutination assay.

RESULT(S)

Antibodies against the full-length GAPDH-2 were raised. Its specificity was assessed by immunoblotting and indirect immunostaining assays. The antibody immunoreacted with human sperm GAPDH-2 and the mouse homolog GAPDS but did not cross-react with GAPDH. Treatment of female mice with IP injection of anti-GAPDH-2 serum significantly reduced their fertility. Anti-GAPDH-2 serum caused the agglutination of normal mice sperm in vitro. The anti-GAPDH-2 antibody was detectable in the sera and uterine fluid of the mice immunized with GAPDH-2.

CONCLUSION(S)

These results show that GAPDH-2 should be further evaluated as a promising candidate in the development of an antifertility immunogen. Detecting anti-GAPDH-2 antibodies in the bodily fluid of subjects afflicted with indeterminate infertility may be a new diagnostic index.

Expression of a recombinant human sperm-agglutinating mini-antibody in tobacco (Nicotiana tabacum L.)

The murine monoclonal antibody (mAB) S19 recognizes an N-linked carbohydrate antigen designated sperm agglutination antigen-1 (SAGA1) located on the membrane protein CD52. This antigen is added to the sperm surface during epididymal maturation. Binding of the S19 mAB to SAGA-1 causes the rapid agglutination of sperm and blocks pre-fertilization events. Previous studies indicated that the S19 mAB may be a potential specific spermicidal agent (termed a spermistatic) capable of replacing current spermicidal products that contain harsh detergents with harmful side effects. The nucleotide sequences encoding the heavy (H) and light (L) chains of the S19 antibody were cloned. A chimeric gene was constructed using the nucleotide sequences encoding the variable regions of both the H and L chains, and this gene (scFv1 9) was expressed in transgenic tobacco (Nicotiana tabacum L.) to produce a recombinant anti-sperm antibody (RASA). Highest levels of RASA expression were observed in BY-2 plant cell suspension cultures and regenerated N. tabacum cv. Xanthi plants transformant in which the RASA coding sequences were expressed under the control of the Cauliflower Mosaic Virus 35S promoter containing a double-enhancer sequence (2X CaMV 35S). Subsequent modifications of the transgene including the addition of a 5'-untranslated sequence from the tobacco etch virus (TEV leader sequence), N-terminal fusion of the coding region with an endoplasmic reticulum targeting signal of patatin (pat) and C-terminal fusion with the endoplasmic reticulum retention signal peptide KDEL showed further enhancement of RASA expression. The plant-expressed RASA formed intrachain disulfide bonds and was primarily soluble in the cytoplasmic fraction of the cells. Introduction of a poly-histidine (6xHIS) tag in the recombinant RASA protein allowed for rapid purification of the recombinant protein using Ni-NTA chromatography. Optimization of scale-up production and purification of this plant-derived recombinant protein should provide large quantities of an inexpensive spermistatic plantibody.

[Inhibin B and intraacrosomal proteins in men from the couples with fertility disorders]

THE AIM

To monitor the basic andrologic and immunologic sperm factors and the levels of inhibin B in serum and in seminal plasma in men from the couples with infertility disorders.

SETTING

Department of Gynecology and Obstetrics, Medical School, Charles University and University Hospital, Plzen, Institute of Molecular Genetics, AV CR, Prague, Institute of Clinical Immunology and Allergology, LF UK a FN, Plzen.

METHODS

We used conventional methods for estimation of sperm quality according to WHO and we detected the intra-acrosomal proteins by monoclonal antibodies (Hs8 and Hs14, immunofluorescent method), spermantibodies by direct mixed antiimunoglobulin reaction (MAR) test, and we examined inhibin B in serum (< or =400 pg/ml= A) and in seminal plasma (< or = 600 pg/ml= N) by ELISA in 355 men aged 21-52 years (ø 34 years) with normal levels of FSH, LH and testosterone. The control group was created by 56 health sperm donors.

RESULTS

We found 65% normospermatics in the group of 355 patients, 34.9% men with various kind of pathologies. Predominance of spermagglutinating antibodies was found in 15.77% in IgG, in 19.44% in IgA, in 8.44% in IgA and IgG together. Normal intraacrosomal proteins were reached in 74.65% for Hs8, in 20.85% pathologic, in 86.2% normal findings for Hs14, in 4.23% pathologic. The immunological results in control group were completaly negative. Pathological levels of inhibin B in seminal plasma was found in 37.2% (152 men), in 25% in serum, and in 5.6% in serum and in seminal plasma together. In 54.7% of patients we found physiological levels of inhibin B in both biological fluids. We also compared physiological 109/152 (71.71%), and pathological spermiogrammes 43/152 (28.29%) with abnormal levels of inhibin B in seminal plasma, with intraacrosomal proteins to levels of inhibin B in serum. Our detailed study shows high interidividual results, which must be studied in complex with diagnosis of decreased fertility in man.

CONCLUSION

Andrologic and immunologic analysis in the group of 355 men showed normal parameters of spermiogrammes in 231 patients (65%), in the rest of men the immunologic profil was in various parts pathologic. Only 105 men have got excellent spermiogrammes. Inhibin B as hormon regulates in back the secretion of FSH, and serves as good indicator in male reproductive failures.

Isolation of a sperm-agglutinating factor from Staphylococcus aureus isolated from a woman with unexplained infertility

Spermatozoal agglutinating factor (SAF) that agglutinates human spermatozoa has been isolated from Staphylococcus aureus. By scanning electron microscopy, Staphylococcus aureus adherence was observed on sperm tails.

[Ovulatory mucus and its pH, arborization and spermagglutination antibodies in women with fertility disorders]

OBJECTIVE

We studied pH of ovulatory mucus, sperm penetration through capillary filled with ovulatory mucus in one hour and presence of local spermagglutinating antibodies.

METHODS

We measured pH, arborization and Kremer test in ovulatory mucus in 127 women with fertility disorder. Indirect mixed antiimunoglobulin reaction test (i-MAR-test for IgG, IgA, IgM and IgE) was used for detection of spermagglutinating antibodies.

RESULTS

pH 7.4-9.6 (physiological limit) was found in 94/127 women (74%), pH < 7.4 in 33 women (26%). 60% of 94 patients with physiological pH had Kremer's test above 2cm/hour (normal sperm penetration in ovulatory mucus), in 40% of them reduction of sperm penetration (< 2cm/hour, swelling, shaking, cytotoxicity) was seen. Sperm antibodies in ovulatory mucus in 24% patients with pH < 7.4 and 22% patients with physiological pH were studied. In 111 patients with regular menstrual cycle a classical arborization was found in 81%, in 14% was not proved. In 16 patients with irregular menstrual cycle classical arborization was observed in 11 of them. Local sperm antibodies were detected only in 13% of the total count of patients, it means in 17 patients. Their ovulatory mucus showed classical arborization. 30 healthy fertile women created the control group, only one secretion had pathological findings in all studied parameters owing to latent mycotic infection.

SUMMARY

Pathological pH of ovulatory mucus, hormonal dysbalance, and presence of local spermagglutinating antibodies evidently influence penetration of sperm cells through cervix uteri. Otherwise pathological microbial vaginal environment can start a cross reaction with the surface microbes and sperm epitopes. One sign of ovulation, arborization of cervical ovulatory mucus, is not connected directly with the presence of local sperm antibodies, but insufficient estrogen influence is a sign of the reduced immunosuppression in cervix area.

[The incidence of agglutination and its influence on sperm quality and fertility of boar semen]

The aim of this study was to examine the incidence of sperm agglutinations and their relationships with sperm quality and fertility. Semen samples of 40 boars of an AI-station were investigated. Nineteen of the 40 investigated boars showed a constantly low (< 10% agglutinated sperm), 3 an intermediate (10-20%) and 6 boars a high level (> 20%) of agglutination in raw semen. The degree of agglutination in sperm samples of 12 boars varied distinctly during the investigation period. During summer more (P < 0.05) agglutinated sperm were observed (11.0 +/- 11.6%) than during winter (6.2 +/- 7.3%). There was no association between bacterial contamination and incidence of agglutinations (P > 0.05). After dilution in extender the percentage of agglutinated sperm decreased from 6.2 +/- 7.3% to 1.1 +/- 1.4% (P < 0.0001). Twenty-four hours after dilution the percentage of progressively motile sperm was 7.4% lower (P < 0.05) in ejaculates with an initially high degree of agglutination (> 20% agglutinated sperm) compared to samples with an initially low degree of agglutinated sperm (< 10%). Plasma membrane integrity, mitochondrial membrane potential, acrosome reaction and chromatin structure were independent (P > 0.05) from the level of agglutination. Fertility data did not differ (P > 0.05) between boars with low and high numbers of agglutinated sperm in raw semen. The results show that there are individual, ejaculatory and seasonal variations in the incidence and degree of agglutination. Agglutinations have a negative effect on motility of sperm and disappear to a large extent after dilution in sperm extender. They have no negative consequences on fertility.

Sperm granuloma and sperm agglutination in a dog with asthenozoospermia

A mongrel dog, aged 2 years, was found to have only a small number of sperm, immobilization of all sperm, and many sperm agglutinations in its ejaculates, and scrotal palpation revealed a small nodule in the left cauda epididymis. Addition of the dog's seminal plasma or serum to the semen of 2 normal dogs caused immobilization and agglutination of their sperm. Histological examination showed that the nodule was a sperm granuloma. Many lymphocytes were seen in the stroma around the sperm granuloma. Anti-sperm antibodies are presumed to be present in the semen and serum of the asthenozoospermic dog.

Changes in epididymal protein anti-agglutinin on ejaculated boar spermatozoa during capacitation in vitro

This study is a detailed investigation of changes in epididymal protein anti-agglutinin on ejaculated boar spermatozoa during an incubation designed to promote capacitation in vitro. Ejaculated spermatozoa were collected from six mature boars, washed, and incubated to promote capacitation. Sperm samples were subjected to Western blotting-densitometric analyses, flow cytometry after immunostaining and immunocytochemical observation by indirect immunofluorescence. An antiserum to anti-agglutinin was raised in a rabbit by subcutaneous injection of a purified antigen, as described previously (Harayama et al. 1999). Western blotting-densitometric analyses revealed an approximate halving of the amount of sperm-bound anti-agglutinin during the first 45-min incubation, followed by a gradual decrease thereafter. Comparison between immunostained sperm samples by flow cytometry before and after incubation confirmed this decrease in sperm-bound anti-agglutinin during the incubation. Microscopic characterization established that this decrease occurred mainly on the acrosome. Supplementation with seminal plasma (5% or 10%, v/v) attenuated the decrease. These findings are consistent with the conclusion that a large portion of the anti-agglutinin bound to sperm acrosomes is released at an early stage of the capacitation process in vitro.

Effect of immunization with synthetic peptide corresponding to region 1-17 of human seminal plasma inhibin on fertility of male rats

Immunization of adult male rats with a synthetic peptide corresponding to the region 1-17 of human seminal plasma inhibin (hSPI) resulted in agglutination of epididymal sperm, severely affecting the fertility of the animals (75% reduction in fertility as compared to control). This effect was found to be dependent on the antibody titer to hSPI. There was a significant rise in circulating follicle-stimulating hormone levels, with luteinizing hormone and testosterone levels remaining unaffected. The histology of the testes and other reproductive organs revealed that these organs remained unaltered. The N-terminal 1-17 amino acid peptide of hSPI may hold promise as an immunogen for male immunocontraception.

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

OBJECTIVE

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

DESIGN

In vitro laboratory experiments.

SETTING

University research laboratory.

PATIENT(S)

Fertile semen donors.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

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

RESULT(S)

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

CONCLUSION(S)

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

Biochemical characterization of sperm agglutination antigen-1, a human sperm surface antigen implicated in gamete interactions

The anti-sperm monoclonal antibody (mAb) S19 was previously demonstrated to agglutinate human spermatozoa, inhibit sperm penetration of cervical mucus, and inhibit sperm-zona pellucida binding. These results implicated the cognate S19 antigen, designated sperm agglutination antigen-1 (SAGA-1), in gamete interactions and identified SAGA-1 as an attractive candidate for immunocontraceptive development. In the present study, evaluation of sperm agglutination with video microscopy showed that the S19 mAb rapidly and completely agglutinated human spermatozoa in a "tangled" pattern of agglutination. One- and two-dimensional immunoblot analyses identified SAGA-1 as a highly acidic, polymorphic sperm protein with an apparent molecular mass of 15-25 kDa and an isoelectric point of 2.5-3.0. Periodate treatment abolished this immunoreactivity, demonstrating that the S19 mAb reacted with a carbohydrate epitope and indicating that SAGA-1 is a glycoprotein. Absence of S19 immunoreactivity in postvasectomy seminal fluid implicated the testis, epididymis, and/or proximal vas deferens in the expression of SAGA-1. In solubility and phase partitioning assays, SAGA-1 was extracted from spermatozoa in Triton X-114 and exhibited the hydrophobic characteristics of integral and glycosylphosphatidyl inositol-anchored membrane proteins. These results identify SAGA-1 as a hydrophobic, highly acidic sperm glycoprotein that is localized on the entire sperm surface and has potential significance as a target for antibodies that inhibit sperm function and gamete interactions.

Acrobeads test as a predictor of fertilization in vitro

PROBLEM

To determine whether the results of the Acrobeads test, which measures the expression of the complement regulator molecule CD46 on the inner acrosomal membrane following the acrosome reaction, accurately identifies semen specimens that will exhibit reduced or failed fertilization following conventional IVF insemination.

METHOD

The Acrobeads test was performed on semen specimens from 97 consecutive patients preparing to undergo an IVF cycle utilizing a standardized insemination protocol. Motile sperm populations were examined at 6 h and 24 h post-isolation for sperm-bead agglutination. Results of the Acrobeads test were compared to that of TRITC-PSA staining in matched specimens to directly measure the spontaneous loss of acrosome content. The percentages of TRITC-PSA-negative sperm were determined in freshly isolated motile populations and in duplicate aliquots incubated 18 to 20 h under sperm capacitating conditions. The relationship between the results of both analyses estimating spontaneous acrosome reactions and the rate of fertilization of metaphase II oocytes was examined.

RESULTS

The Acrobeads score did not correlate significantly with the rate of fertilization by insemination at 6 h or at 24 h. The negative predictive value of this test was 21.4%. There was no correlation between the Acrobeads score and the percentage of sperm undergoing a spontaneous acrosome reaction as detected by TRITC-PSA labeling. In contrast, the increment increase in the percentage of spontaneous acrosome reactions as quantified by TRITC-PSA staining was correlated with the fertilization rate.

CONCLUSIONS

Contrary to previous reports, our prospective, double-blinded study failed to demonstrate that the Acrobeads test can accurately predict fertilization outcome in IVF. Therefore, the routine use of this test to screen patients prior to an IVF cycle in order to select appropriate treatment (i.e., ICSI) cannot be recommended.

Effect of sperm-agglutinating antibodies on sperm capacitation and acrosome reaction

OBJECTIVE

To study the effect of polyclonal/monospecific antisera on sperm agglutination versus capacitation as well as acrosome reaction.

MATERIALS AND METHODS

Swim-up spermatozoa from cauda epididymides of fertile male hamsters were incubated under liquid paraffin with polyclonal/monospecific antisera obtained from immunized BALB/C mice, as well as with normal serum from control BALB/C mice, at various dilutions.

RESULTS

The anti-sperm antibodies caused a significant (P < .05) sperm agglutination of various types of dilutions below 1:1000. Both capacitation and true acrosome reaction were inhibited significantly in the spermatozoa incubated with polyclonal/monospecific antisera. Capacitation in the spermatozoa with normal serum started earlier, i.e., at 2 hours of incubation compared to 3 hours of incubation in controls.

CONCLUSION

The data differentiate the sperm agglutinating activity from anticapacitation and antiacrosome reaction activity of antisperm antisera at 1:1000 dilution.

Mixed antiglobulin reaction and tray agglutination test for detection of sperm antibodies

OBJECTIVE

To compare levels of sperm-agglutinating antibodies in male and female sera, cervical ovulatory mucus, and seminal plasma by two different tests.

PATIENTS AND METHODS

408 women and 404 men with long-lasting unexplained infertility and recurrent IVF failure were immunologically examined. Tray agglutination and mixed antiglobulin reaction tests were used for the comparison of sperm-agglutinating antibodies in sera, in ovulatory cervical mucus, and in seminal plasma.

RESULTS

High secretory IgA positivity predominated in seminal plasma in 16 (3.9%) of infertile men and in cervical ovulatory mucus in 114 (27.9%) of infertile women. Positivity in two sperm antibodies together, in IgG and IgA, and IgM and IgE was also observed. Immunological anti-sperm antibodies in sera indicate high levels of sperm antibodies in IgG and IgM.

CONCLUSION

Sperm immunoglobulin specification is important for therapeutic influence upon immunocompetent cells.

A solid-phase assay for the detection of anti-sperm antibodies

PROBLEM

ELISA is an ideal assay method for a large-scale screening of anti-sperm antibodies among a large number of infertile males. However, conventional ELISA with whole spermatozoa needs time-consuming steps of centrifugation.

METHOD

A solid-phase assay used for detecting anti-sperm antibodies was established. This assay is suitable not only for detecting circulating anti-sperm antibodies of IgG, IgM, and IgA subclass simultaneously but also for screening hybridomas secreting anti-sperm monoclonal antibodies (mAbs). The microtiter plates, on which solubilized sperm antigens are fixed, can be stored at -80 degrees C for up to six months without losing reactivity with anti-sperm antibodies.

RESULTS

Using this assay, 53 sera (13 were proven positive and 40 were proven negative for sperm agglutination antibody) were tested. Although the false-negative rate was 0%, the false-positive rate was 32%. One thousand one hundred sixty-five supernatants from hybridomas constructed with splenocytes of mice who were hyperimmunized with human sperm and nonsecreting myeloma cells were tested by this solid-phase assay and two anti-sperm mAb secreting clones were selected and established.

CONCLUSIONS

It is recommended that for research work this assay could be used for the first screening of the hybridoma secreting anti-sperm mAb, and for clinical use this assay might be suitable for the first screening of sera of infertile patients. However, conventional bioassays should follow to confirm the biological meaning of the positivity.

Purification and characterization of a boar sperm protein interacting with immunoglobulins from an infertile woman

Immunoglobulin G (IgG) fraction was prepared from a serum obtained from an infertile woman (IS) that induced sperm agglutination of human and boar sperm. The antisperm antibodies interacted with a 50-kD boar sperm protein, determined by immunoblot. The 50-kD protein was extracted with deoxycholate (DOC) and purified by affinity chromatography on concanavalin A column, ion exchange chromatography on CM52 column, affinity chromatography on IS IgG-protein G-agarose, and by preparative electrophoresis with electroelution. The purified 50-kD protein migrated as a single homogeneous band when analyzed by sodium dodecyl sulfate polyacrylamide gel electrophoresis and by Western blot. The production of antibodies against specific sperm proteins may be a cause of immunological infertility.

[Immunological causes of male infertility]

Sperm (spermatozoa and the various secretions of the accessory glands) with its very complex antigenic system is only produced from puberty and thus at a time when the body has already had a for a long time the facility to respond to an antigenic stimulation with an immune reaction. Because of this, the spermatozoa, in contrast to other cells of the organism, are considered as strangers and may behave as auto-antigens. However, the existence of a haemato-testicular barrier, that prevents all contact between the sperm and the immune system must be recognized in man, its rupture has the consequence of formation of anti-spermatozoa antibodies. It is estimated that 5% of cases of sterility are of immunological origin and linked to the presence in man and/or woman of anti-sperm antibodies. The production is greater in man than in women because of the roles, in the first of macrophages and in the second of polynuclear neutrophils in the destruction of the spermatozoa. Anti spermatozoal antibodies play a part in sterility by: Spontaneous agglutination in ejaculation, thus preventing their progression in the female genital tract. Free spermatozoa, charged with antibody are retained at the level of the cervical secretion = SHAKING phenomenon. The anti-spermatozoal antibodies mask some antigens, so preventing penetration of the spermatozoa into the ovule. Contact of spermatozoa with antibody fixed to the uterine tissue is followed by secretion of histamine and this encourages the expulsion of an implanted egg. This is before the existence of: Spontaneous agglutination in ejaculation, Oligospermatosis, Indeterminate cause sterility, Immobilisation of the spermatozoa in the cervical secretion, Failure of repetition.

Identification of the sperm antigen interacting with antibodies in serum from an infertile woman

Serum (IS) obtained from an infertile woman induced head-to-head agglutination of human sperm. The immunoglobulin G (IgG) fraction of the IS was prepared by ammonium sulfate fractionation and DEAE cellulose chromatography. The IgG localized to the post-acrosomal region of the sperm, determined by indirect immunofluorescence and interacted with a human sperm protein with an estimated Mr of 80 kDa, determined by immunoblotting. The identity of the interacting sperm antigen was verified by isolating the 80 kDa sperm protein by affinity chromatography. The present results suggest that the anti-80 kDa antibodies may be responsible for the infertility.

Detection of anti-sperm antibodies in serum, seminal plasma and cervical mucus by the immunobead test

Anti-sperm antibodies in serum and seminal plasma were detected by means of an indirect immunobead test (IBT). Immunobeads with separate specificites for each immunoglobulin class (IBT-IgG, IBT-IgM, and IBT-IgA) were used. Semen parameters were controlled in all sperm donors and Biggers-Whitten-Whittingham (BWW) medium supplemented with human serum albumin (HSA) was used to increase sperm motility. This technique was tested with high titre anti-human sperm sera induced in rabbits. Sperm tails showed a good response by IBT. We included in this study 178 men and 35 women evaluated for infertility and the sera were also tested by the Tray Agglutination Test (TAT). Although the presence of semen markers such as agglutination or trembling of spermatozoa is meaningful even by itself, the percentage of anti-sperm antibodies was increased in the patients with markers, both using IBT (21.4%) and using TAT (35.7%). At high titres of specific immunoglobulins (rabbit antisera and vasectomized men), the correlation between IBT and TAT techniques was better than in sera with very low titres, in which more positive TAT's were detected.

Effect of antibodies to human seminal plasma inhibin on spermatogenesis and sperm agglutination in adult male rats

In vitro incubation of rat epididymal sperm with antiserum to human seminal plasma inhibin (As hSPI) caused agglutination of the sperm. In vivo administration of As hSPI to adult male rats resulted in a significant decrease in testicular as well as epididymal sperm counts. Furthermore, the majority (almost 90%) of the epididymal sperm were agglutinated. When these animals were mated with normal cycling females, significant reduction in fertility was observed.

[Plasmapheresis--a therapeutic method for immunity-related infertility?]

In a 30-year-old woman with primary idiopathic sterility the immunological cause of infertility was assessed (spermagglutination antibodies in serum and in the ovulation mucus of the uterine cervix). The patient was treated without success by condom therapy, general and local immunosuppression. Therefore treatment by means of membrane separation plasmapheresis was started during two preovulation periods. Serum spermagglutination antibodies class IgM declined from the original titre of 1:1024 to 1:16, immediately after homologous inseminations they rose, however, to the original titre and the patient did not become pregnant.

Techniques for sperm immobilization test

Several semiquantitative, quantitative, and microassay techniques had been developed to detect antibodies bound to human spermatozoa: sperm agglutination test (SAT), sperm immobilization test (SIT), immunofluorescence test, radioantiglobulin test, enzyme-linked immunosorbent assay (ELISA), mixed erythrocyte-spermatozoa antiglobulin reaction (MAR), "Panning" test, and immunobead test (IBT). Clinical application of these techniques include (a) detection of sperm immobilizing antibodies in sera of sterile women, (b) follow-up study of sperm immobilizing antibodies, and (c) detection of sperm immobilizing antibodies in cervical mucus and other secretions. The chemical structure of antigen epitope corresponding to Mab H6-3C4 may recognize the internally located repetitive unbranched N-acetyllactosamine structure, regardless of terminal substitution at Gal (i.e., sialyl-i as well as i structure). The majority of sperm-immobilization (SI) positive women's sera were absorbed with carbohydrate components on ejaculated sperm, but only one serum competed with Mab H6-3C4 on binding to sperm except a serum from whom lymphocytes were donated to make Mab H6-3C4. The SI agglutinating antibodies (Abs) in women's sera were raised to the carbohydrate epitopes of glycoprotein in HSP, but epitopes might have several different conformational structures. Studies are in progress to find whether or not SI-Abs could be generated to peptide epitope of human seminal plasma (HSP) or sperm.

Testicular biopsy: sperm antibodies

No circulating sperm-agglutinating or sperm-immobilizing antibodies were demonstrated in oligospermic or azoospermic men up to 14 days following bilateral testicular biopsies. Possible reasons for this lack of antigen-antibody response are discussed.