Variation in antisperm antibody results using different assays

Dominant Prostasome Immunogens for Sperm-Agglutinating Autoantibodies of Infertile Men

The presence of naturally occurring anti-sperm antibodies (ASA) is a well-known cause of infertility in men and women, but the antigens for these antibodies are poorly characterized. We have previously shown that prostasomes adhere to sperm cells and that prostasomes are major targets for ASA associated with infertility. These autoantigens have not been characterized. We used 2-dimensional electrophoresis, immunoblotting, and mass-spectrometry to identify the prostasome antigens for these autoantibodies. By these techniques, we revealed that prolactin-inducible protein (PIP) and clusterin were dominant prostasome immunogens for sperm-agglutinating autoantibodies of 20 patients with immunological infertility. PIP was identified by 19 of 20 (95%) patient sera and clusterin by 17 of 20 (85%). In addition, 10 sporadically occurring prostasomal antigens were identified in this context, viz alcohol dehydrogenase [NADP+], annexin I, annexin III, BRCA1-associated ring domain protein 1, heat shock 27-kd protein, isocitrate dehydrogenase, lactoylglutathione lyase, NG,NG-dimethylarginine dimethylaminohydrolase 1, peroxiredoxin 2, and syntenin 1.

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.

Prostasome antigens as targets for sperm agglutinating antibodies demonstrated by 1-D gel electrophoresis and immunoblottings

Many immunoinfertile men have sperm agglutinating antibodies that are directed against prostasome-derived antigens, but these antigens have not been defined so far. We selected serum samples with high ELISA titres against prostasomes from a group of immunoinfertile patients with sperm agglutinating antibodies and used the sera for immunoblottings on 1-D SDS-PAGE of prostasomes and sperm cells. The immunoblottings with individual antiprostasome antisera on 1-D SDS-PAGE of prostasomes, revealed three to 10 bands for each serum. Eighty-five per cent of the serum samples contained bands in the 70-75 kDa region and 80% of the samples contained bands in the 50-55 kDa region. Immunoblottings of extracted sperm cells, revealed one to six bands in the molecular weight range 25-82 kDa and two of the samples recognized two bands with molecular weights (50 and 43 kDa) similar to immunoblottings of prostasomes. The prostasomal antigens recognized by the high titre-antisera of immunoinfertile men were generally different from the sperm antigens recognized by the same sera. This suggests that prostasomes offer a new set of antigens available for research on male immunoinfertility and immunocontraception.

Comparison of sperm quantity and quality in antegrade V retrograde ejaculates obtained by vibratory penile stimulation in males with spinal cord injury

Reduced fertility in men with spinal cord injury results from the inability to ejaculate and poor semen quality. Vibratory penile stimulation can induce ejaculation in many men with spinal cord injuries, but few studies have reported the effects of repeated vibratory stimulation on quantitative semen analysis tests. Fourteen spinal cord-injured males were enrolled in a prospective study to develop a quantitative profile of antegrade and retrograde ejaculate specimens collected during repeated vibratory stimulation. Antegrade specimens were obtained in 51 (84%) and retrograde specimens were obtained in all of the 61 trials (100%). Sperm were present in 70% and 64% of the antegrade and retrograde samples, respectively. Of the patients who underwent repeated vibratory stimulation attempts, three showed marked improvement in sperm counts and characteristics with repeated vibration and five showed normal fluctuation or no change in semen quality. Overall, there was a trend toward higher sperm counts in the antegrade samples (mean, 74.1 million) than in the retrograde samples (mean, 40 million), but no statistical significance was found. Mean sperm motility, sperm progressive motility, and percent normal sperm morphology were not significantly different between antegrade and retrograde specimens. Fructose and zinc, semen markers that reflect the presence of a true ejaculate, were present in all antegrade and retrograde specimens. In conclusion, (1) both antegrade and retrograde ejaculation occur with vibratory penile stimulation, with antegrade samples containing greater numbers of sperm but retrograde samples also having significant sperm counts, (2) repeated vibration may increase sperm concentration or may result in only minimal changes reflective of normal fluctuations, and (3) vibratory stimulation results in true ejaculation, as evidenced by semen markers.