A comparison of the usefulness of SpermMar and immunobead tests for the detection of antisperm antibodies

Seminal biomarkers for the evaluation of male infertility

For men struggling to conceive with their partners, diagnostic tools are limited and often consist of only a standard semen analysis. This baseline test serves as a crude estimation of male fertility, leaving patients and clinicians in need of additional diagnostic biomarkers. Seminal fluid contains the highest concentration of molecules from the male reproductive glands, therefore, this review focuses on current and novel seminal biomarkers in certain male infertility scenarios, including natural fertility, differentiating azoospermia etiologies, and predicting assisted reproductive technique success. Currently available tests include antisperm antibody assays, DNA fragmentation index, sperm fluorescence in situ hybridization, and other historical sperm functional tests. The poor diagnostic ability of current assays has led to continued efforts to find more predictive biomarkers. Emerging research in the fields of genomics, epigenetics, proteomics, transcriptomics, and metabolomics holds promise for the development of novel male infertility biomarkers. Seminal protein-based assays of TEX101, ECM1, and ACRV1 are already available or under final development for clinical use. Additional panels of DNA, RNA, proteins, or metabolites are being explored as we attempt to understand the pathophysiologic processes of male infertility. Future ventures will need to continue data integration and validation for the development of clinically useful infertility biomarkers to aid in male infertility diagnosis, treatment, and counseling.

Seminal fluid antisperm antibodies measured by direct flow cytometry do not correlate with those measured by indirect flow cytometry, the indirect immunobead test, and the indirect mixed antiglobulin reaction

OBJECTIVE

To compare the direct flow cytometric (FCM) measurement of sperm-bound antibodies with the indirect FCM measurement of unbound antisperm antibodies in seminal plasma of the same ejaculates. To compare the FCM measurements with the indirect mixed antiglobulin reaction (MAR) and the indirect immunobead test (IBT) performed on the same seminal plasmas.

SETTING

University hospital-based infertility service.

PATIENTS

Eleven infertile men with a positive immunoglobulin (Ig) G direct MAR test and antibody positivity on the direct FCM measurements. Four control patients with a negative IgG-direct MAR test.

MAIN OUTCOME MEASURES

The proportion of spermatozoa positive for IgG and IgA antibodies as measured by various tests.

RESULTS

The direct and indirect FCM measurements for sperm-bound antibodies from seminal plasma did not correlate with each other. In general, IgG antibodies were not detectable by indirect FCM whereas IgA were detected in lower proportions than by direct FCM measurements. Weak correlation was observed between the indirect FCM, indirect MAR, and indirect IBT measurements.

CONCLUSION

Nearly all of the IgG and some of the IgA antisperm antibodies in seminal fluid bind to spermatozoa. Thus, indirect tests to measure antisperm antibodies from seminal plasma are likely to miss the presence of antisperm IgG antibodies while detecting some cases of IgA antibodies.

Infertility due to antisperm antibodies

Immunoinfertility is an important problem, involving a significant number of infertile couples. Although the presence of antibodies on sperm has better prognostic value than those in serum or seminal plasma, it may not be the sole authentic evidence of immunoinfertility. Infertility from antisperm antibodies is likely only when they bind to a relevant sperm antigen involved in a specific fertility function. The variance in functional deficits seen in immunologic infertility is most likely related to antibodies directed at different sperm antigens or different class, subclass, or isotypes. Antibodies to FA-1 seem to be of significant importance in human immunoinfertility. In approaching couples with infertility, a high index of suspicion for antibodies is necessary to avoid misdiagnosis. In the optimal situation, all semen analyses should be screened for sperm-bound antibodies, but if this is impractical, testing should be performed on high-risk individuals (Table I). In couples in which the man has sperm-bound antibodies, and in whom there is no identifiable female factor, treatment should be instituted. Most treatments for immunoinfertility have been disappointing because of poor results, adverse effects, or high cost. Corticosteroid therapy has shown some promise in published reports (mostly poorly designed studies), but increase in pregnancy rate is modest and adverse effects may be significant. In our opinion, informed consent should be documented prior to institution of corticosteroid therapy, and subjects should be closely monitored. Advanced reproductive technologies offer a higher safety profile, and, with increasing technology, higher pregnancy rates. We recommend progressing from "low-tech" procedures, such as IUI and reserving the higher level procedures, such as IVF and ICSI, for those couples in whom pregnancy does not occur. The highest level reproductive technologies give the best current prospects for pregnancy in patients with this difficult problem but also are invasive and costly. It is hoped that further work in the laboratory will give rise to newer, safer, and less expensive effective treatments in the very near future.

Office based screening of sperm autoimmunity

Sperm autoimmunity has been reported as a contributory cause of male factor infertility in up to 10% of subfertile men. The standard laboratory technique for the determination of sperm bound antisperm antibodies is the direct immunobead test. However, because of its complex methodology this test does not readily lend itself as a screening tool for this diagnosis. We describe a simple office based procedure, the sperm mixed antiglobulin reaction, for the detection of antisperm antibodies and compare its diagnostic accuracy with the standard direct immunobead test. Both assays were simultaneously performed on each of 102 semen specimens from men with male factor infertility. The rate of detection of sperm autoantibodies was 16.6% and 19.6% by the direct immunobead test and sperm mixed antiglobulin reaction, respectively. Compared to the direct immunobead test, sperm mixed antiglobulin reaction demonstrated a sensitivity and specificity of 100% and 96%, respectively. The positive predictive value was 85% and the negative predictive value was 100%, emphasizing its particularly useful role as a screening tool for office based detection of sperm autoantibodies in men who present for evaluation of fertility potential.

Prevalence of antisperm antibodies by SpermMARtest in subjects undergoing a routine sperm analysis for infertility

To evaluate the prevalence of antisperm antibodies (ASA) attached to the sperm plasma membrane in male partners of infertile couples, the binding of latex particles to spermatozoa was investigated using SpermMARtest, included routinely in semen analysis. A total of 860 men were examined, who were referred consecutively for semen analysis. Of these, 750 men were referred because of infertility (0.6-10 years in duration) whereas 110 were volunteers with a history of previous fertility. Samples were assessed by the SpermMARtest kit using latex particles sensitized with human IgG. Sperm-latex binding was read after 3 min and samples scored as negative, positive or highly positive when < 10, > 10-40, or > 40% binding occurred, respectively. Of the samples 132 (17.3%) were excluded because of azoo- or severe oligo-asthenozoospermia. IgG attached to spermatozoa were detected in nearly 13% of semen samples from the infertile population and in one of 110 fertile men (0.9%). From the infertile group, 6.2% of samples showed > 40% binding, and 6.7% intermediate binding, with an overall ASA prevalence of 12.9% in subjects undergoing semen analysis for infertility.

Comparison of mixed antiglobulin reaction and direct immunobead test for detection of sperm-bound antibodies in subfertile males

OBJECTIVE

To compare two methods of detection of surface bound antibodies on spermatozoa from subfertile males.

DESIGN

Prospective comparison of direct mixed antiglobulin reaction (MAR) for immunoglobulin (Ig)G with direct immunobead test (IgG and IgA) applied to spermatozoa from male partners of infertile couples. Circulating unbound antibody measured by tray agglutination test in serum and seminal plasma in a representative proportion.

SETTING

Seminology laboratory.

PATIENTS

One hundred nine male partners of infertile couples.

RESULTS

Highly significant correlation between direct MAR (IgG) and direct immunobed test (IgG) and between both of these tests and serum unbound antibody measured by tray agglutination test. Highly significant correlation between direct immunobead test (IgA) and seminal plasma unbound antibody measured by tray agglutination test, but no correlation with MAR (IgG).

CONCLUSIONS

Mixed antiglobulin reaction (IgG) is a cheap, quick, and sensitive screening test, but immunobead test (IgA) provides useful additional information on class of antibody on spermatozoa that may be clinically more important.

Screening assays for immunologic infertility: a comparison study

Because the immunobead antisperm antibody test (IBT) is difficult to learn and results are heavily operator-dependent, we compared findings on IBT with those of SpermMAR and SpermCheck in 58 patients to determine whether the latter two tests could demonstrate improved screening ability. Assays performed on both sperm and serum (i.e., direct and indirect) yielded 100% positive predictive values when IBT was used as the standard. Both SpermCheck and SpermMAR are easier to perform, and, as the former has a slightly greater sensitivity, we recommend SpermCheck for the detection of immunologic infertility.

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

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