Antisperm antibodies: detection assays for antisperm antibodies: what do they test?

Influence of inguinal hernia repair on sperm autoimmunity: The largest single center experience

BACKGROUND

Studies on immunological infertility after inguinal hernia correction are few and not very representative. Anti-sperm antibodies have been shown to reduce male fertility. Although the extent of infertility due to anti-sperm antibodies alone is not very clear, data indicates that about 8%-10% of infertile patients have immunological infertility DESIGN: This retrospective study includes all infertile male patients (n = 2258) who underwent mixed antiglobulin reaction tests and urologic examination from 2000 to 2020. Sperm quality (assessed by the number of spermatozoa, their motility, vitality, and normal form) was also evaluated. Among these patients, 191 had previously undergone unilateral or bilateral inguinal hernia surgery repair. The aim of the study is to evaluate if there is a higher incidence of positive mixed antiglobulin reaction test among patients undergoing inguinal hernioplasty compared to the unselected infertile population.

RESULTS

Anti-sperm antibodies would seem to increase in both patients who performed general andrological surgery and groin hernia correction, respectively 3.48 (95% Confidence Interval: 1.70-7.10; p < 0.001) and 2.45 (95% Confidence Interval: 1.01-5.99; p < 0.05) times more than the unselected infertile population.

CONCLUSIONS

Mixed antiglobulin reaction test could be useful in patients undergone previous scrotal surgery or hernia correction men, to avoid false unexplained infertility diagnoses and to direct the couple to assisted reproductive technology procedures. Basal evaluation of spermatozoa does not actually consider andrological surgery as an indication to autoimmunity investigation.

A novel tissue engineering-based assay for immunological infertility

Antisperm antibodies (ASA) are present in 9-36% of infertile couples, a condition called immunological infertility. The variability of ASA in terms of antigenic specificity and biological effects has made it difficult to design a test able to distinguish reliably between ASA that contribute to infertility and those that do not. To develop a reliable and reproducible method able to detect sperm antibodies, we took advantage of recent progress made in tissue engineering techniques. We used collagen gel as a bio-scaffold for the production of engineered sperm analogues. The advantages of using collagen gels include biocompatibility, ease of fabrication and low cost. We found that this tissue engineering-based assay is more specific and more sensitive than a conventional test routinely used for ASA detection. In addition, it exhibited low intra- and inter-variations. We envision the use of this novel approach for the detection of a variety of autoantibodies in autoimmune diseases. In addition to diagnostic purposes, tissue-engineering based tests could be useful in monitoring treatments with bio-drugs.

Antisperm antibodies in infertile men and their correlation with seminal parameters

Aim:  Antisperm antibodies (ASA) in males cause the autoimmune disease 'immune infertility'. The present study intended to detect the presence of ASA and their incidence in men with unexplained infertility, as well as to evaluate the correlation between the presence of ASA and semen parameter alterations. Methods:  Blood and sperm assessment were collected to carry out a direct and indirect mixed antiglobulin reaction (MAR) test and semen analysis in infertile and fertile men from the University Hospital of the Faculty of Medicine, Sao Paulo State University, Sao Paulo. Results:  In the MAR test, 18.18% of infertile men were positive for ASA. In fertile men, no positivity was found. A significant correlation between the presence of ASA with an increased white blood cell count plus a decreased hypoosmotic swelling test result was observed. Conclusions:  The results indicate that ASA are involved in reduced fertility. It is not ASA detection per se that provides conclusive information about the occurrence of damage to fertility. The correlation between infertility and altered seminal parameters reinforce the ASA participation in this pathology. (Reprod Med Biol 2007; 6: 33-38).

Search for peptide sequences involved in human antisperm antibody-mediated male immunoinfertility by using phage display technology

The aim of the present study was to delineate peptide sequences against which antisperm antibodies (ASA) are raised in immunoinfertile men. Using the phage display technology, seven unique and novel dodecamer amino acid sequences were identified that reacted with the sera of immunoinfertile men. The peptides were synthesized based upon these amino acid sequences and examined for their immunoreactivity with sera from ASA-positive immunofertile men (n = 15) and ASA-negative fertile men (n = 18) for IgM, IgG, and IgA class of antibody in the enzyme-linked immunosorbent assay (ELISA). All the seven synthetic peptides showed a significantly (P < 0.001) higher mean absorbance values for IgG and/or IgA class of antibody with the immunoinfertile sera compared to fertile control sera. Three of the seven peptides demonstrated a stronger reaction (>2 SD units) with 27%-40% of immunoinfertile sera compared to fertile controls. These peptide sequences may find applications in the specific diagnosis and treatment of immunoinfertility and in contraceptive vaccine development. The phage display technique provides an exciting and novel technology to delineate sperm epitopes involved in immunoinfertility.

Clinical associations and mechanisms of action of antisperm antibodies

OBJECTIVE

To review and critique the current English literature describing the effects of antisperm antibodies (ASA) on mammalian fertility.

DESIGN

A comprehensive English language literature was searched using Medline and by hand-searching. Emphasis was placed on clinically relevant articles.

RESULT(S)

Results from the studies were extrapolated and the effects of ASA on fertility described.

CONCLUSION(S)

Antisperm antibodies may interfere with fertility. Not all ASA cause infertility. Current tests cannot differentiate the infertility-related ASA from those that do not interfere with infertility, because the antigenic specificities of these ASA are not known. The antigens which the infertility-related ASA must be characterized to allow an accurate detection and proper treatment for couples with ASA.

Validity of a rapid assay for antisperm antibodies in semen

OBJECTIVE

To determine the validity of a rapid assay for antisperm antibodies in semen.

DESIGN

Prospective comparison of the results of standard and rapid antisperm antibody assays performed simultaneously.

SETTING

Tertiary care infertility center.

PATIENT(S)

Couples who presented for infertility evaluation.

INTERVENTION(S)

Semen analysis and measurement of antisperm antibodies in semen using a standard and a rapid immunobead binding test (IBT).

MAIN OUTCOME MEASURE(S)

[1] Comparison of sperm parameters between semen-containing antisperm antibodies and semen free of antisperm antibodies. [2] Validation of the rapid test by calculation of sensitivity, specificity, positive and negative predictive values of the rapid assay using the standard assay as a gold standard. [3] Cost comparison of the standard and rapid test.

RESULT(S)

[1] Nine semen specimens with antisperm antibodies had a significantly lower sperm concentration, motility, and total motile fraction compared to 44 specimens without antisperm antibodies. Also, specimens with antisperm antibodies had a significantly higher percentage of vibratory sperm and percent of bound antisperm antibodies. The strict morphology, liquefaction time, semen volume, and white blood cell concentration were no different between the two groups. [2] Using a threshold of > or =12% of bound antisperm antibodies in the rapid assay, the sensitivity, specificity, positive and negative predictive values of the test are 100% when correlated with a threshold of > or =20% in the standard assay. Increasing the threshold in the standard assay decreases the specificity and positive predictive value of the rapid assay but not the sensitivity and the negative predictive value. [3] The cost of the rapid assay was 16% that of the standard test and its performance took 20% of the time it took to set and perform the standard test.

CONCLUSION(S)

A rapid test for antisperm antibodies is valid, reliable, and more cost and labor effective than a standard IBT.

Basis, diagnosis and treatment of immunological infertility in men

Sperm-reactive antibodies (SpAb) are found attached to sperm, or present in serum or seminal fluid, in approximately 6% of men presenting with infertility. Data supports their pathophysiological role in some cases by the interference with sperm motility and/or sperm-egg interaction. The occurrence of SpAbs may follow disruption of either the cellular barrier separating sperm antigens from the immune system (e.g. testis trauma or obstruction to sperm outflow), or to dysregulation of normal immunosuppressive activities within the male reproductive tract. The epididymis is likely to be the key site of antibody generation, especially in the setting of obstruction. Detection methods are all based on the detection of Ig isotypes rather than specific antibody-antigen interactions, which limits their usefulness. Treatment options in the past (immunosuppression, intrauterine insemination, conventional in vitro fertilization) have been superceded by intracytoplasmic sperm injection (ICSI) which appears to circumvent all adverse effects of male SpAbs.

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.

Value of flow cytometric assay for the detection of antisperm antibodies in women with a history of recurrent abortion

PROBLEM

To verify the proposed relationship between recurrent spontaneous abortions and the presence of maternal antisperm antibodies (ASA) in women as detected by a sensitive and reliable method.

METHOD OF STUDY

The presence of maternal antipaternal immunoglobulin G (IgG) and immunoglobulin M (IgM) antibodies were determined against three different paternal antigens comprising T, B lymphocytes and semen cells by a sensitive flow cytometric crossmatch method to examine their possible correlation with pregnancy outcome. Group 1 consisted of sera obtained from 24 women with a history of abortion, and lymphocytes and semen samples collected from their husbands at the same time of visiting the in vitro fertilization (IVF) Clinic at King Faisal Specialist Hospital and Research Center. Sera, lymphocytes and semen samples were also collected from six couples with no history of abortion who served as controls (Group 2).

RESULTS

Using a sensitive flow cytometric assay to analyse the samples, without knowledge of clinical status, elevated levels of both IgG and IgM were detected in Group 1. However, no significant association was found when compared with normal females who had healthy pregnancies.

CONCLUSION

Flow cytometry is a highly sensitive and specific tool for the detection of alloantibodies in human sera from patients with rejected transplanted organs. Our findings suggest that maternal antipaternal antibodies with respect to IgG and IgM classes do not play a major role in women with a history of recurrent abortions, despite the presence of increased levels of antibodies against three different sources of paternal antigens.

Antisperm antibodies detection by flow cytometry is affected by aggregation of antigen-antibody complexes on the surface of spermatozoa

Flow cytometry (FCM) analysis of live antibody-coated spermatozoa subjected to immunofluorescence staining (FCM test) is considered an objective method for the quantitative detection of antisperm antibodies (ASA). But the cross-linking of cell surface antigen (Ag) with bivalent antibodies and/or antigen-antibody (Ag-Ab) complexes with second antibodies may induce the reorganization of surface components (patching and capping) and result in their shedding from the sperm surface. The present study estimates the relationship between aggregation of Ag-Ab complexes on the sperm surface and the results of indirect FCM test. Swim-up spermatozoa of normozoospermic men were incubated with ASA-positive sera from infertile patients and with second antibodies fluorescein isothiocyanate (FITC)-labelled goat anti-human IgG polyclonal antiserum under different conditions and then analysed by FCM and fluorescence microscopy. It was shown that low temperature, cytochalasin B, excess or lack of the primary and/or secondary antibodies and sperm fixation by paraformaldehyde may inhibit aggregation and shedding of Ag-Ab complexes and dramatically increase ASA quantity determined on the sperm surface. However, inhibition of aggregation on the live sperm surface was observed only in a minority of ASA-positive samples and was poorly reproducible using semen of different donors. A high probability of Ag-Ab complex shedding from the sperm surface during experimental manipulation limits the use of indirect FCM test for quantitative ASA determination.