The sperm-cervical mucus contact test: a preliminary report

Engineering sperm-binding IgG antibodies for the development of an effective nonhormonal female contraception

Many women risk unintended pregnancy because of medical contraindications or dissatisfaction with contraceptive methods, including real and perceived side effects associated with the use of exogenous hormones. We pursued direct vaginal delivery of sperm-binding monoclonal antibodies (mAbs) that can limit progressive sperm motility in the female reproductive tract as a strategy for effective nonhormonal contraception. Here, motivated by the greater agglutination potencies of polyvalent immunoglobulins but the bioprocessing ease and stability of immunoglobulin G (IgG), we engineered a panel of sperm-binding IgGs with 6 to 10 antigen-binding fragments (Fabs), isolated from a healthy immune-infertile woman against a unique surface antigen universally present on human sperm. These highly multivalent IgGs (HM-IgGs) were at least 10- to 16-fold more potent and faster at agglutinating sperm than the parent IgG while preserving the crystallizable fragment (Fc) of IgG that mediates trapping of individual spermatozoa in mucus. The increased potencies translated into effective (>99.9%) reduction of progressively motile sperm in the sheep vagina using as little as 33 μg of the 10-Fab HM-IgG. HM-IgGs were produced at comparable yields and had identical thermal stability to the parent IgG, with greater homogeneity. HM-IgGs represent not only promising biologics for nonhormonal contraception but also a promising platform for engineering potent multivalent mAbs for other biomedical applications.

Microenvironment of the male and female reproductive tracts regulate sperm fertility: Impact of viscosity, pH, and osmolality

BACKGROUND

Terminally differentiated mammalian sperm are exposed to gradients of viscosity, pH, and osmolality both in the male and female reproductive tract during their perilous journey to quest the ovum. The complex physicochemical factors play an integral role in preparing sperm for the fertilization process.

OBJECTIVES

To elucidate the influence of the reproductive tract microenvironment especially viscosity, pH, and osmolality in regulating sperm functional and fertilization competence.

MATERIALS AND METHODS

The data used in this review were collected from the research papers and online databases focusing on the influence of viscosity, pH, and osmolality on sperm function.

DISCUSSION

The gradients of viscosity, pH, and osmolality exist across various segments of the male and female reproductive tract. The changes in the viscosity create a physical barrier, pH aid in capacitation and hyperactivation, and the osmotic stress selects a progressive sperm subpopulation for accomplishing fertilization. The sperm function tests are developed based on the concept that the male genotype is the major contributor to the reproductive outcome. However, recent studies demonstrate the significance of sperm genotype-environment interactions that are essentially contributing to reproductive success. Hence, it is imperative to assess the impact of physicochemical stresses and the adaptive ability of the terminally differentiated sperm, which in turn would improve the outcome of the assisted reproductive technologies and male fertility assessment.

CONCLUSION

Elucidating the influence of the reproductive tract microenvironment on sperm function provides newer insights into the procedures that need to be adopted for selecting fertile males for breeding, and ejaculates for the assisted reproductive technologies.

The biophysical principles underpinning muco-trapping functions of antibodies

In addition to the classical immunological functions such as neutralization, antibody-dependent cellular cytotoxicity, and complement activation, IgG antibodies possess a little-recognized and under-utilized effector function at mucosal surfaces: trapping pathogens in mucus. IgG can potently immobilize pathogens that otherwise readily diffuse or actively swim through mucus by forming multiple low-affinity bonds between the array of pathogen-bound antibodies and the mucin mesh. Trapping in mucus can exclude pathogens from contacting target cells, and facilitate their rapid elimination by natural mucus clearance mechanisms. Despite the fact that most infections are transmitted at mucosal surfaces, this muco-trapping effector function has only been revealed within the past decade, with the evidence to date suggesting that it is a universal effector function of IgG-Fc capable of immobilizing both viral and highly motile bacterial pathogens in all major mucosal secretions. This review provides an overview of the current evidence for Fc-mucin crosslinking as an effector function for antibodies in mucus, the mechanism by which the accumulation of weak Fc-mucin bonds by IgG bound to the surface of a pathogen can result in immobilization of antibody-pathogen complexes, and how trapping in mucus can contribute to protection against foreign pathogens.

Engineering tetravalent IgGs with enhanced agglutination potencies for trapping vigorously motile sperm in mucin matrix

Multivalent antibodies such as sIgA can crosslink motile entities such as sperm and bacteria, creating agglomerates that are too large to permeate the dense mucin matrix in mucus, a process commonly referred to as immune exclusion. Unfortunately, sIgA remains challenging to produce in large quantities, and easily aggregates, which prevented their use in clinical applications. To develop sIgA-like tetravalent antibodies that are stable and can be easily produced in large quantities, we designed two IgGs possessing 4 identical Fab domains, with the Fabs arranged either in serial or in the diametrically opposite orientation. As a proof-of-concept, we engineered these tetravalent IgG constructs to bind a ubiquitous sperm antigen using a Fab previously isolated from an immune infertile woman. Both constructs possess at least 4-fold greater agglutination potency and induced much more rapid sperm agglutination than the parent IgG, while exhibiting comparable production yields and identical thermostability as the parent IgG. These tetravalent IgGs offer promise for non-hormonal contraception and underscores the multimerization of IgG as a promising strategy to enhance antibody effector functions based on immune exclusion.

IgG in cervicovaginal mucus traps HSV and prevents vaginal herpes infections

IgG is the predominant immunoglobulin in cervicovaginal mucus (CVM), yet how immunoglobulin G (IgG) in mucus can protect against infections is not fully understood. IgG diffuses rapidly through cervical mucus, slowed only slightly by transient adhesive interactions with mucins. We hypothesize that this almost unhindered diffusion allows IgG to accumulate rapidly on pathogen surfaces, and the resulting IgG array forms multiple weak adhesive crosslinks to mucus gel that effectively trap (immobilize) pathogens, preventing them from initiating infections. Here, we report that herpes simplex virus serotype 1 (HSV-1) readily penetrated fresh, pH-neutralized ex vivo samples of CVM with low or no detectable levels of anti-HSV-1 IgG but was trapped in samples with even modest levels of anti-HSV-1 IgG. In samples with little or no endogenous anti-HSV-1 IgG, addition of exogenous anti-HSV-1 IgG, affinity-purified from intravenous immunoglobulin, trapped virions at concentrations below those needed for neutralization and with similar potency as endogenous IgG. Deglycosylating purified anti-HSV-1 IgG, or removing its Fc component, markedly reduced trapping potency. Finally, a non-neutralizing IgG against HSV-gG significantly protected mice against vaginal infection, and removing vaginal mucus by gentle lavage abolished protection. These observations suggest that IgG-Fc has a glycan-dependent "muco-trapping" effector function that may provide exceptionally potent protection at mucosal surfaces.

Sperm surface antigens and the prospects for contraceptive vaccine development

It has been estimated that 500 million couples world-wide have no access to contraception and that approximately 20% of births between 1995 and 2000 will be unwanted. Such statistics have important implications for the rate of world population growth and the possibility of maintaining a sustainable population. Although political change and the empowerment of women across the world will help address these issues, it will also be important to increase the availability of contraceptives; not only the modalities that are in current use, but also novel methods that will satisfy needs that are presently unfulfilled. One such alternative could be a vaccine targeting the human spermatozoon.

Micro- and macrorheology of mucus

Mucus is a complex biological material that lubricates and protects the human lungs, gastrointestinal (GI) tract, vagina, eyes, and other moist mucosal surfaces. Mucus serves as a physical barrier against foreign particles, including toxins, pathogens, and environmental ultrafine particles, while allowing rapid passage of selected gases, ions, nutrients, and many proteins. Its selective barrier properties are precisely regulated at the biochemical level across vastly different length scales. At the macroscale, mucus behaves as a non-Newtonian gel, distinguished from classical solids and liquids by its response to shear rate and shear stress, while, at the nanoscale, it behaves as a low viscosity fluid. Advances in the rheological characterization of mucus from the macroscopic to nanoscopic levels have contributed critical understanding to mucus physiology, disease pathology, and the development of drug delivery systems designed for use at mucosal surfaces. This article reviews the biochemistry that governs mucus rheology, the macro- and microrheology of human and laboratory animal mucus, rheological techniques applied to mucus, and the importance of an improved understanding of the physical properties of mucus to advancing the field of drug and gene delivery.

Relationship between level of serum sperm immobilizing antibody and its inhibitory effect on sperm migration through cervical mucus in immunologically infertile women

PROBLEM

Sperm immobilizing antibodies often interfere with the penetration of sperm through the cervical mucus. However, the relationship between sperm immobilizing antibody titer and the result of the post-coital test (PCT) has not yet been clarified. The aim of this study was to investigate whether the 50% sperm immobilization unit (SI50) titer, a quantitative measure of sperm immobilizing antibody, in patients' sera was correlated with the result of PCT.

METHOD OF STUDY

The sperm immobilization test (SIT) was performed for 2834 infertile women in two university hospitals. The SI50 titers were evaluated by quantitative SIT. In some cases with sperm immobilizing antibody, PCT was carried out before ovulation and assessed according to the criteria of World Health Organization (1992). Infertile couples with abnormal semen characteristics were excluded.

RESULTS

Seventy-four of 2834 women had sperm immobilizing antibodies in their sera, giving a positive rate of 2.6%. Twenty-four (77.4%) of 31 women with sperm immobilizing antibodies and 28 (20.4%) of 137 women without the antibody had abnormal PCT results. There was a significant difference between the two groups (P<0.0001). When patients with sperm immobilizing antibodies were divided into two groups according to the SI50 titers, the abnormal result of PCT was obtained in all 10 patients with high (>10) SI50 titers, while that was 14 (66.7%) in 21 patients with low (10) SI50 titers. There was a significant difference between the two groups (P=0.04).

CONCLUSION

The SI50 titer in the serum can predict inhibitory effects on sperm migration through cervical mucus in immunologically infertile women. Evaluation of the SI50 titers in patients' sera seems to be useful for decision-making in infertile women with sperm immobilizing antibodies regarding whether they have the possibility of conceiving by timed intercourse.

Immune testing in fertility practice: truth or deception?

PURPOSE OF REVIEW

Much attention has been paid to the role of immunology in reproductive success or failure. Every step in the establishment of normal pregnancy has been implicated as a possible site of immune-mediated reproductive failure. The widespread testing of antiphospholipid, antinuclear, antithyroid, and antisperm antibodies, as well as generalized immune testing, have thus been employed to diagnose patients with otherwise unexplained infertility or recurrent pregnancy loss. Controversial data surrounding the widespread and variable use of immune testing in current fertility practice is reviewed to determine which tests are warranted based on sound scientific evidence. Because it is postulated that early miscarriage, when occult, could represent a failure of embryo implantation indistinguishable from unexplained infertility, this analysis of immune testing includes a discussion of patients with recurrent pregnancy loss.

RECENT FINDINGS

Despite the increased prevalence of abnormal immune testing associated with early reproductive failure, the most rigorous studies have not proven a cause and effect between these phenomena. There is wide variation and inconsistency regarding this association, depending upon which test(s) are employed, the study methodology used, and the patient population under study. The significance of selected immunological test abnormalities associated with early reproductive failure is uncertain.

SUMMARY

Great variability exists in identifying candidates for immune testing, determining which tests to order, interpreting the test results, and offering immunologic treatments. This review argues that the use of widespread immune testing in clinical practice can not be supported by existing data. The resulting therapies are similarly of unconfirmed benefit and may cause harm.

Diffusion of macromolecules and virus-like particles in human cervical mucus

To determine whether or not large macromolecules and viruses can diffuse through mucus, we observed the motion of proteins, microspheres, and viruses in fresh samples of human cervical mucus using fluorescent recovery after photobleaching and multiple image photography. Two capsid virus-like particles, human papilloma virus (55 nm, approximately 20,000 kDa) and Norwalk virus (38 nm, approximately 10,000 kDa), as well as most of the globular proteins tested (15-650 kDa) diffused as rapidly in mucus as in saline. Electron microscopy of cervical mucus confirmed that the mesh spacing between mucin fibers is large enough (20-200 nm) for small viruses to diffuse essentially unhindered through mucus. In contrast, herpes simplex virus (180 nm) colocalized with strands of thick mucus, suggesting that herpes simplex virus, unlike the capsid virus particles, makes low-affinity bonds with mucins. Polystyrene microspheres (59-1000 nm) bound more tightly to mucins, bundling them into thick cables. Although immunoglobulins are too small to be slowed by the mesh spacing between mucins, diffusion by IgM was slowed by mucus. Diffusion by IgM-Fc(5 mu), the Fc pentamer core of an IgM with all 10 Fab moieties removed, was comparably slowed by mucus. This suggests that the Fc moieties of antibodies make low-affinity bonds with mucins.

Sexual function in spinal cord lesioned men

STUDY DESIGN

Review of literature.

OBJECTIVE

To review the physical aspects related to penile erection, ejaculatory dysfunction, semen characteristics, and techniques for enhancement of fertility in spinal cord lesioned (SCL) men.

SETTING

Worldwide: individuals with traumatic as well as non-traumatic SCL.

RESULTS

Recommendations for management of erectile dysfunction in SCL men: If it is possible to obtain a satisfactory erection but of insufficient duration, then try to use a venous constrictor band to find out if this is sufficient to maintain the erection. Otherwise we recommend Sildenafil. If Sildenafil is not satisfactory then use intracavernous injection with prostaglandin E(1) (some SCL men may prefer cutaneous or intraurethral application). We discourage the implantation of penile prosthesis for the sole purpose of erection. Recommendations for management of ejaculatory dysfunction in SCL men: Penile vibratory stimulation (PVS) to induce ejaculation is recommended as first treatment choice. If PVS fails, SCL men should be referred for electroejaculation (EEJ). Semen characteristics: Impaired semen profiles with low motility rates are seen in the majority of SCL men. Recently reported data gives evidence of a decline in spermatogenesis and motility of ejaculated spermatozoa shortly after (few weeks) an acute SCL. It is suggested that some factors in the seminal plasma and/or disordered storage of spermatozoa in the seminal vesicles are mainly responsible for the impaired semen profiles in men with chronic SCL. Fertility: Home insemination with semen obtained by PVS and introduced intravaginally in order to achieve successful pregnancies may be an option for some SCL men and their partners. The majority of SCL men will further enhance their fertility potential when using either PVS or EEJ combined with assisted reproduction techniques such as intrauterine insemination or in vitro fertilization with or without intracytoplasmic sperm injection.

Correlation of the bovine cervical mucus penetration test with human sperm characterisitics in 1,406 ejaculates

The bovine cervical mucus penetration test (BCMPT) was performed to determine its usefulness in screening the ability of sperm to successfully penetrate mucus in vitro. Ejaculates were obtained by masturbation from patients attending an infertility clinic. Routine semen analysis was performed using a microcomputerized multiple-exposure photography system. The BCMPT was performed. Overall, the average penetration of the mucus was 38 +/- 0.46 mm. Of the 1,406 ejaculates analyzed, 244 (17%) displayed a negative result (0-20 mm), 291 (21%) a questionable result (21-30 mm), and 871 (62%) a positive result (>30 mm). A highly significant (p < .001) correlation between mucus penetration distance and sperm MD (r = 0.541), MI (r = 0.484), count (r = 0.475), motility (r = 0.448), velocity (r = 0.400) and morphology (r = 0.369) was observed. Overall, the finding of an abnormal semen parameter resulted in a 34 +/- 5% accurate prediction of a negative or questionable BCMPT (<30 mm), while a normal semen parameter resulted in a 90 +/- 4% accurate prediction of a positive BCMPT (>30 mm). Sperm MD showed the strongest positive predictive value (98%), while morphology showed the greatest negative predictive value (50%). Of the 1,406 samples, 25 +/- 2% of the samples with normal semen parameters displayed a negative BCMPT. Conversely, 6 +/- 2% of samples with abnormal parameters showed a positive BCMPT. The BCMPT successfully identifies a significant subpopulation of patients as having an inadequate penetration of mucus with otherwise normal semen characteristics.

Evidence for a unique N-linked glycan associated with human infertility on sperm CD52: a candidate contraceptive vaccinogen

A major objective in developing a sperm antigen-based contraceptive vaccine for humans is the discovery of sperm surface immunogens that are functionally relevant and sperm specific. The latter criterion is deemed essential to avoid the possibility of inducing autoimmune disease upon vaccination. This review presents evidence that a unique carbohydrate epitope is synthesized in the human epididymis, is attached to the core peptide of CD52, a lymphocyte differentiation marker, and is subsequently inserted into the sperm membrane via a glycosylphosphatidylinositol anchor. This unique CD52 glycoform is localized to the entire sperm surface, functions as a potent target for agglutinating and cytotoxic antibodies, and is one of the few well-defined sperm surface glycoproteins indicated in human antibody-mediated infertility.

Do autoantibodies to sperm reduce fecundity? A mini-review in historical perspective

PROBLEM

The paradox that early studies of antisperm antibodies in men showed a strong correlation between titers of circulating antibodies (essentially immunoglobulin [Ig] G) and reduction in conception rates, whereas more recent studies have indicated that the antifertility effect is mainly (or exclusively?) associated with IgA antibodies, impairing sperm migration through cervical mucus, was studied.

METHOD OF STUDY

Relevant literature focusing on antibodies on ejaculated sperm was analyzed.

RESULTS

Direct mixed antiglobulin reaction (MAR) and immunobead-binding tests are excellent and sensitive techniques for demonstrating antibodies of the IgG and IgA classes on sperm, and they have revealed that IgA antibodies are, with very rare exceptions, found only when IgG antibodies are also present. However, these tests tell little about the amounts of antibodies present, and attempts to measure quantitatively the amounts of Ig on sperm have indicated higher levels of IgA than IgG (despite the strongest MAR reactivities for IgG).

CONCLUSIONS

The patients with high levels of IgA to their sperm are mainly men with strong immune responses and, therefore, also high antibody titers in serum. Apparently, the locally produced IgA antibodies reach the sperm and occupy the binding sites before the main bulk of IgG reaches the seminal compartment with the prostatic fluid.

Clinical value of tests for assessing male infertility

The laboratory assessment of the male partner of an infertile couple is an important aspect of the overall investigation of that couple. The laboratory tests are designed essentially to determine whether (a) the semen samples contain adequate numbers of normal motile sperm, and the sperm are able (b) to migrate to the site of fertilization and (c) to fertilize oocytes. Within this framework, tests can be viewed as being either descriptive, in terms of describing the ejaculate and sperm, or assessing functional qualities of the sperm. Irrespective of the nature of the test, it must satisfy simple criteria, namely being reproducible and able to discriminate between the fertile and infertile populations reliably. External quality assurance programmes now exist for semen analysis and allied techniques to help laboratories to standardize their reporting and to identify the source of possible errors.

The influence of sperm morphology and the number of motile sperm inseminated on the outcome of intrauterine insemination combined with mild ovarian stimulation

OBJECTIVE

To determine the influence of sperm morphology and the number of motile sperm inseminated on the outcome of IUI in hMG-stimulated cycles and to establish lower limits for these variables below which the expectation of pregnancy is limited.

DESIGN

Retrospective study of data from 1990 to 1992.

SETTING

Tertiary referral Reproductive Medicine Unit.

PATIENTS

Couples with bilaterally patent fallopian tubes, and > or = 200,000 motile sperm recovered in a trial preparation before treatment. No other semen criteria were used to exclude couples. Women were stimulated with hMG irrespective of whether they were ovulatory or anovulatory. The study comprised 163 couples who underwent 330 cycles.

MAIN OUTCOME MEASURES

Pregnancy rate (PR) per cycle was related to the percentage normal sperm morphology in the fresh semen sample and the number of motile sperm inseminated after sperm preparation by swim-up or Percoll gradients.

RESULTS

The overall PR was 16.1% per cycle. The PR was highest in the first cycle of treatment (21.4%) and declined in the second and third cycles. The miscarriage rate was 10.4% and the incidence of multiple pregnancies was 13.9%. Two groups of patients were defined on the basis of sperm morphology: a "poor outcome" group ( < or = 10% normal) and a "good outcome" group ( > 10% normal). The PRs in these two groups were 4.3% and 18.2%, respectively, and the cumulative PRs after three cycles were 8.3% and 40.1%, respectively. The number of motile sperm inseminated did not significantly affect the PR.

CONCLUSIONS

The degree of teratozoospermia affected the PR in hMG-stimulated IUI cycles and a normal morphology value of 10% in the fresh semen distinguished couples with good and poor outcomes. In contrast, the number of motile sperm inseminated did not significantly influence IUI outcome.

A comparison of intrauterine insemination in superovulated cycles to intercourse in couples where the male is receiving steroids for the treatment of autoimmune infertility

OBJECTIVE

To compare IUI with timed intercourse in men receiving oral steroid therapy for the treatment of infertility associated with antisperm antibodies.

DESIGN

A prospective, randomized, cross-over trial.

SETTING

All patients were managed and treated at the Andrology Unit, Churchill Hospital, Oxford, United Kingdom.

PATIENTS AND PARTICIPANTS

Thirty males who were found to have antisperm levels of > or = 50% [using the indirect immunobead test with isotypes immunoglobulin (Ig) G, IgA, and IgM (GAM) beads] in either seminal plasma or serum on routine testing were recruited with their partners into the study.

MAIN OUTCOME MEASURES

Antisperm antibody levels in seminal plasma and serum, sperm parameters, conception rates, and pregnancy outcome.

RESULTS

There was a statistically significant reduction in seminal plasma antisperm antibody levels associated with steroid therapy. There was a significant improvement in certain spermatozoan parameters during steroid therapy. The cumulative pregnancy rate over four cycles of IUI was 39.4%. The cumulative pregnancy rate over four cycles of natural intercourse was 4.8%. There was a significantly higher chance of achieving a pregnancy with IUI.

CONCLUSION

Intrauterine insemination significantly improves the chance of achieving a conception when used as an adjuvant therapy to cyclical intermediate dose steroid therapy. Antisperm antibody levels in seminal plasma are significantly reduced during treatment with cyclical intermediate dose steroid therapy, although levels in serum appear to be unaffected. Cyclical intermediate dose steroid therapy significantly improves certain sperm parameters but, when used in isolation, is associated with a low pregnancy rate.

Methods to evaluate reproductive health of the human male

The proportion of men suffering from subfertility has increased and sperm quality of the general population has decreased rather dramatically during the last decades. Conventional methods to measure sperm concentration, motility, and morphology give a rough estimate of the fertilizing capacity of semen. Objective assessment of motility characteristics and morphometric image analysis may give more precise information, but technology still needs to be refined. Some aspects of the functional capacity of spermatozoa may be impaired before measurable changes occur in their number or morphology. A battery of tests is described to evaluate sperm migration and capacitation, acrosome reaction and acrosin activity, zona adhesion and binding, sperm oolemma fusion, sperm head decondensation, and chromatin make-up. Also methods are described to localize the possible site of impairment of the genital tract. Implementation of these methods may enhance our capability to detect minor effects of environmental hazards on male reproductive health.

Detection of sperm antibodies on unwashed spermatozoa with the immunobead test: a comparison of results with the routine method and seminal plasma TAT titers and SCMC test

This study investigated whether the immunobead test (IBT) could, for the purposes of simplicity and saving time, be applied directly on an unwashed semen sample instead of washed spermatozoa. These two methods were performed simultaneously on the semen samples of 15 men with a positive MAR test and 10 men with a negative MAR test. A possible association was found between the unwashed samples, showing positive IB binding (greater than 20%) on the tail and/or head and the seminal plasma TAT titers (P less than .00001, Fisher's exact test). In all cases with IB binding of greater than or equal to 20% on unwashed spermatozoa, positive seminal plasma TAT titers (greater than or equal to 32) and SCMC tests (greater than or equal to 50%) were found. In all cases where the binding of the beads was mainly located on the tailtips of the washed or unwashed spermatozoa, negative seminal plasma TAT titers and SCMC tests were found. Coating of the head and/or upper tail regions in both methods was always associated with high TAT titers and a strong-positive SCMC test. It is concluded that the IBT for IgA, but not for IgG, can be performed directly on unwashed semen and that the position of IB binding on the spermatozoa is of prognostic importance with regard to the expected outcome of the SCMC test and seminal plasma TAT titers.

The significance of the zona-free hamster oocyte test for the evaluation of male fertility

Results of the zona-free hamster oocyte test were compared with pregnancy rates after coitus and after artificial insemination with donor semen (AID) in 322 primary infertile couples. Artificial donor insemination was offered if in the test the percentage of hamster oocytes with at least one decondensed sperm head (oocyte-sperm interaction rate) was less than 20. If the rate was less than 5, the pregnancy rate after coitus was significantly lower than in the group with a rate of greater than or equal to 5 to less than 20. In the former group, the pregnancy rate by AID was significantly higher than the pregnancy rate by coitus. We conclude that the zona-free hamster oocyte test is useful to predict the chance to achieve pregnancy in couples with unexplained infertility and to determine whether AID can increase this chance.

Chlamydial infection--a female and/or male infertility factor?

After screening a large series (n = 491) of asymptomatic males of infertile partnerships for chlamydial immunoglobulin (Ig) G antibodies (Chlam AB), no significant influence of past chlamydial infection was found with regard to semen analysis, postcoital testing, in vitro sperm-cervical mucus penetration tests with hormonally standardized cervical mucus, circulating antisperm antibodies (detected with three different methods), local IgG and IgA antibodies (detected by means of the mixed antiglobulin reaction test) on the sperm surface, the sperm-cervical mucus contact test, and a microbial screening of semen samples for mycoplasmas and other potentially pathogenic micro-organisms. However, when the findings were correlated with infertility factors of patients' female partners and the subsequent pregnancy rate in a prospective study, a significant positive correlation of male Chlam AB with a tubal factor in their wives as cause of the couple's infertility was found. The results suggest that the main influence of Chlamydia trachomatis on male fertility is based on sexual transmission and negative influence on tubal function of female partners, but not on reduced sperm functional capacity.

Evaluation of the accuracy of the home ovulation detection kit, Clearplan, at predicting ovulation

A home ovulation testing kit, Clearplan, that detects the urinary luteinizing hormone (LH) surge was compared with basal body temperature (BBT) charts and cervical scoring as a method of ovulation prediction in 54 consecutive patients. The accuracy of all these methods was evaluated using daily serum LH measurements. Clearplan was shown to be significantly more accurate at timing ovulation than were BBT charts (P less than 0.0001) and cervical scoring (P less than 0.025). In 82%-88% of cases the kit predicted ovulation within one day and in 89%-96% of cases within two days of the serum LH surge. The kits were found to be easy to use and their potential place in clinical practice is discussed; home ovulation testing may ultimately replace serum LH assays as the method of choice in timing ovulation.

Treatment of male sperm autoimmunity by using the gamete intrafallopian transfer procedure with washed spermatozoa

Sixteen couples were diagnosed as having immunological infertility. To detect sperm-bound immunoglobulin (Ig), i.e., IgA, IgG, and IgM antibodies, the direct immunobead test (IBT) was used. In each individual patient, the direct IBT was greater than or equal to 70% positive for either IgA or IgG or both. The indirect IBT was positive for IgA and IgG antibodies in the serum of all the patients. Semen was collected in 15 mL medium (Ham's F10 [Gibco, Grand Island, NY] + 10% whole blood serum) and prepared with the wash and swim-up method. Patients in the study group were treated for their immunological infertility problem by performing the gamete intrafallopian transfer (GIFT) procedure. An ongoing pregnancy was achieved in 7 of the 16 (43%) couples treated with the GIFT procedure with an ongoing pregnancy rate of 24.1% (7 of 29) per cycle. The GIFT procedure appears to be an effective and safe way of treating male immunological infertility.

Is serology of any use when searching for correlations between Chlamydia trachomatis infection and male infertility?

Evidence on Chlamydia trachomatis causing male infertility is conflicting. We therefore collected data on epidemiological and clinical correlates of chlamydial infection and male fertility in 184 males visiting our Fertility Unit. Antibodies against Chlamydia trachomatis in serum and semen were also determined. Significant correlations were demonstrated between current chlamydial urethral infection and semen immunoglobulin (Ig) A, serum IgA and serum IgG. These parameters, however, were neither related to a history of sexually transmitted disease nor to lifetime number of sexual partners. Why, in the male, serology does not correlate with chlamydial infection in a more remote past is explained. Our data support, on epidemiological as well as serological grounds, the conclusion that chlamydial infection probably does not contribute significantly to male infertility.

Immunomagnetic method to select human sperm without sperm surface-bound autoantibodies in male autoimmune infertility

Using supermagnetic polymer microspheres coated with anti-immunoglobulins, spermatozoa without autoantibodies bound on their surface can be isolated from a sperm population showing a variable percentage of cells with autoantibodies bound on their surface. This simple technique seems to induce no modification of semen qualities; therefore, the concentration of sperm after immunomagnetic separation might be useful for in vivo or in vitro insemination in infertile couples with autoimmune male infertility.

A radiolabeled antiglobulin assay to identify human cervical mucus immunoglobulin (Ig) A and IgG antisperm antibodies

Antisperm immunoglobulin (Ig) A and IgG antibodies in human cervical mucus (CM) were identified by a radiolabeled antiglobulin assay. Cervical mucus samples from fertile and infertile women were exposed to a 1:3,200 dilution of 2-mercaptoethanol (2-ME), and 5 micrograms of the solubilized CM protein were assayed for the presence of IgA and IgG antisperm and anti-Candida activity by the radiolabeled antiglobulin assay. Purified human secretory IgA and IgG exposed to 2-ME retained the molecular integrity and functional activity of the untreated antibody molecules. CM aliquots collected after high-performance liquid chromatography (HPLC) fractionation were assessed for antisperm antibody activity; antisperm antibody activity was retained in the appropriate IgA or IgG CM fractions. The incidence of CM antisperm antibodies was minimally affected when the radiolabeled antiglobulin assay was performed with a motile sperm population. Approximately 70% of the CM IgA antisperm antibodies were of the IgA1 subclass; CM IgG was primarily of the IgG4 subclass. When Candida antigen was substituted for sperm in the radiolabeled antiglobulin assay, the CM antisperm antibodies were found to be exclusively sperm-specific. These data indicate that the radiolabeled antiglobulin assay using 2-ME to extract CM antibodies is a specific method for the assay of antisperm antibodies in CM.

Use of specific monoclonal antibodies to secretory IgA for the detection of spermatozoal antibodies in serum and seminal plasma by enzyme-linked immunosorbent assay

The role of anti-sperm secretory IgA has recently received attention since some workers feel it plays an important role in the prognosis of the immunologically infertile couple. Current methods used in our laboratory cannot separately detect anti-sperm secretory IgA. An enzyme-linked immunosorbent assay (ELISA) utilizing specific monoclonal antibodies to secretory IgA was used to detect anti-sperm secretory IgA as well as anti-sperm monomeric IgA and IgG in serum and seminal plasma of a sperm-antibody-positive (ASA+) and sperm-antibody-negative (ASA-) group of men. Results showed significantly raised serum levels in the ASA+ group when compared to the ASA- group for anti-sperm secretory IgA (P less than .001), anti-sperm monomeric IgA (P less than .001), and anti-sperm IgG (P less than .01). Seminal plasma levels were also raised in the ASA+ group, but only significantly so for monomeric IgA (P less than .02). The performed ELISA has definite potential in research, especially with the use of monoclonal antibodies for the detection of anti-sperm secretory IgA, but cannot as yet be used as a prognostic predictor of fertility in the individual antibody-positive patient. Infertility specific antigens will have to be identified and isolated and subsequently used in the ELISA.

Prognostic value of in vitro sperm penetration into hormonally standardized human cervical mucus

To analyze the prognostic value of the sperm cervical mucus penetration test (SCMPT), fresh semen samples of 99 male patients under infertility investigation were exposed to capillary tubes filled with freshly obtained cervical mucus (CM) of the patients' wives (WCM), fertile donors (DCM), and bovine CM (BCM). The quality of the human CM was standardized by oral administration of estrogens. The overall pregnancy rate after 6 months was 17.2% (17/99), and was significantly different in couples with poor and good SCMPT with WCM (1/44, 2.3% versus 16/55, 29%; P less than 0.001) in a prospective study. Human CM was superior to BCM as a penetration medium in providing more information about sperm function. The results suggest that in vitro sperm penetration testing with hormonally standardized CM of female partners adds an important dimension to sperm analysis with regard to fertility prognosis.

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.

Effect of rapid dilution of semen on sperm-bound autoantibodies

The effect of rapid dilution of autoantibody-positive semen on sperm-bound antibodies was studied in 12 male patients (0-100% IgA and 10-100% IgG). The direct immunobead test (IBT) and the sperm cervical mucus contact (SCMC) test were used to detect sperm-bound antibodies on spermatozoa before and after rapid dilution and swim up in HAM F-10 + 10% human blood serum. All patients tested had normal semen parameters. Sperm-bound antibodies detected after swim-up of semen samples ejaculated into 15 ml HAM F-10 + 10% serum (diluted) did not differ significantly from undiluted samples. Most values were lower (IBT and SCMC) but were not statistically significant. Sperm motility, forward progression, and morphology were statistically improved. Pregnancies resulting from washed semen (diluted) in combination with artificial insemination (AIH) or gamete intrafallopian tube transfer (GIFT) took place in spite of antibodies still present on the sperm membrane and can probably be attributed to improved semen quality, minimizing of ovum-sperm distance, and cervical mucus elimination.

Clinical characteristics of subfertile men with antisperm antibodies

This study investigated the clinical features which could serve as markers to identify subfertile men with antisperm antibodies including age, duration of infertility, history of abdominal or perineal surgery and previous genital trauma. Of the 162 men studied, 43 had a positive test for antisperm antibodies. A significantly greater number of these patients had a history of genital trauma and appendicectomy. Whereas the aetiological role of genital trauma in spermatozoal autoimmunity is readily explicable, that of appendicectomy is not. It can only be postulated that inflammation of the appendix may sometimes affect the vas deferens or that there is some inadvertent injury to the vas deferens during appendicectomy.

Effect of sperm washing and swim-up on antibodies bound to sperm membrane: use of immunobead/sperm cervical mucus contact tests

The direct immunobead test (IBT) and the sperm cervical mucus contact (SCMC) test were used to evaluate the effect of sperm washes and swim-up on antibodies bound to the sperm membrane in 11 patients with autosperm antibodies (30-100% IgA and 30-100% IgG) but otherwise normal semen measurements. The tests were performed on semen samples before and after a wash/swim-up procedure in Ham F10 + 10% human blood serum. Sperm-bound antibodies in washed spermatozoa that were able to swim into a layer of medium did not differ from those in unwashed samples. The IBT and the SCMC test on unwashed and washed spermatozoa were also not significantly different. However, all other washed semen parameters were improved. Correct washing of semen samples is important when performing the IBT to prevent false negative results. Eight of the 11 partners (73%) of the patients tested became pregnant after treatment with washed sperm. The ongoing pregnancy rate was 64%.

Antisperm antibody tests: traditional methods compared to ELISA

Enzyme-linked immunosorbent assays (ELISAs) to detect sperm antibodies can be a useful addition to other tests. ELISAs allow more quantitative and detailed information than some other tests, but results should be compared to those of other tests. This study was conducted to correlate results of an ELISA that used a sperm membrane extract as antigen with those of other tests. Semen, seminal plasma, and serum of 34 sperm-antibody-positive and 36 sperm-antibody-negative men were tested. There was poor correlation between the ELISA results and those of the other tests. Only the results of a direct immunobead test done on semen correlated fairly well with results from ELISAs done on serum. Further studies are needed on fertility-specific antigens that can be identified and isolated and then studied by means of ELISAs.

Sperm antibodies, semen quality, and male infertility

Twelve couples who underwent infertility investigations at the Universitas Hospital in Bloemfontein were examined using several tests: postcoital (PCT), sperm-cervical-mucus-contact (SCMC-T), indirect immunobead (IBT), tray-agglutination (TAT), and sperm-immobilization procedures (SIT). Two factors played a role during the immunologic evaluation of a couple: semen quality and the intensity of the antibody in the cervical mucus or seminal plasma.

Intrauterine insemination of washed husband's spermatozoa: a controlled study

We performed intrauterine insemination with washed husband's spermatozoa in 27 couples with clear evidence of impaired sperm mucus interaction due to cervical hostility or immunologic male subfertility and in 30 couples with subnormal semen, but optimal cervical mucus qualities. In each couple insemination cycles were alternated with cycles during which normal intercourse took place. Both types of cycles were monitored for LH. When a clear rise of LH levels could be detected, either IUI was scheduled or intercourse advised for the following day. In the male subfertility group no difference between the pregnancy rates of insemination and intercourse cycles was present. In the group with impairment of sperm-mucus interaction, the pregnancy rate of the insemination cycles was 16%, whereas no pregnancies occurred during intercourse cycles.

Immunoglobulin class and regional specificity of antispermatozoal autoantibodies blocking cervical mucus penetration by human spermatozoa

The immunoglobulin class and regional specificity of sperm antibodies was analyzed in relation to in vitro cervical mucus penetration using a capillary test. There was a highly significant (chi 2, P less than 0.001) association of strong (greater than or equal to 95% sperm coated) immunobead test (IBT) results for sperm-bound antibodies of IgA immunoglobulin class with poor (less than 3.0 cm/2 h) mucus penetration. There was also a significant (P less than 0.01) association between poor penetration and the presence of antibodies on the sperm tail mainpiece. In contrast, IgG class antibodies did not show any significant association with poor penetration. These results confirm and extend previous work and imply that development of a male antispermatozoal vaccine that inhibits mucus penetration must involve stimulation of local IgA response rather than systemic antibody levels.