Flow cytometric determination of spermatozoa binding monoclonal antibodies does not improve the prediction of fertility potential

In a previous publication the determination of binding of several monoclonal antibodies to human spermatozoa by flow cytometry was described in 223 patients. In normozoospermic samples the percentage of spermatozoa binding antibodies was higher than in samples with oligozoospermia. However, only weak correlations were found between the percentage of antibody binding spermatozoa and sperm count, motility and morphology. Thus the antibody binding may represent a property different from the classical parameters and might improve the prediction of fertility in the patients. A questionnaire was sent to all the patients inquiring about a conception in their female partners. One hundred and twenty one out of the 223 patients replied, 103 of whom we were able to evaluate. Forty five of them had induced a pregnancy in their partners. The mean values of sperm count, motility and morphological normal cells, as well as the percentages of cells that bound antibodies, were significantly higher in the group of men whose partners became pregnant, than in those who had not achieved conception. The differences, however, were only marginal. We conclude from our results that the determination of the percentage of spermatozoa binding the monoclonal antibodies used in our study is not likely to improve the prediction of conception probability.

Flow cytometric determination of binding of monoclonal antibodies to human spermatozoa

Although several monoclonal antibodies to sperm antigens are available, only few systematical reports on the appearance of distinct antibody binding structures in spermatozoa of infertile patients are available. We studied the binding frequency of six monoclonal antibodies (TUS-1, -2, -10, -17, -19, -20) by means of a flow cytometer in different semen samples and their possible relationship to other sperm parameters, in particular to the motility parameters as determined by computer-assisted semen analysis. The percentage of vital spermatozoa binding the different antibodies was 21.5% (TUS-2) to 52.1% (TUS-20). The percentage binding was higher in samples with normozoospermia than in those with oligo-asthenoteratozoospermia. A significant correlation occurred between sperm concentration and the percentage of spermatozoa stained by TUS-2 and TUS-17; between motile spermatozoa and those binding TUS-17 and TUS-20; the velocity average path and those binding TUS-17; an inverse correlation occurred between the morphologically-abnormal spermatozoa and those binding TUS-20; an inverse correlation between TUS-17 and acrosin. We conclude from our results that although the antigens of the antibodies concerned are not yet characterized, the determination of antibody binding will give additional information on the functional status during capacitation and acrosome reaction of spermatozoa.