First study investigating the determination of protamine in seminal plasma from azoospermic donors: Suggestion of new methods to diagnose obstructive azoospermia, and to capture childbearing sperm for testicular sperm extraction (TESE) and insemination sperm injection (ICSI).

Abstract We analysed seminal plasma of 88 normozoospermic, 40 oligozoospermic and 32 azoospermic donors. During this study, we were the first to record the protamine concentration in the seminal plasma of azoospermic donors. The seminal protamine concentrations were found to be 19.6 - 62.8 IU/ml in normozoospermic donors; 25.4 - 100.8 in oligozoospermic donors; and, most notably, 23.7 - 219.4 IU/ml in azoospermic donors. These results indicate that, based on seminal plasma protamine concentrations, even azoospermic donors were able to produce as much sperm as normo- and/or oligozoospermic donors. Using statistical analyses, significant differences were found between azoospermic and normozoospermic donors (p = 0.0018). Protamine content was found to be a direct marker for the presence of sperm. The data from this study provided evidence for a new therapeutic approach for testicular varicose veins, which are found in obstructive or non-obstructive azoospermia. High seminal protamine concentrations indicated the future possibility of acquiring childbearing sperm for insemination sperm injection (ICSI) and testicular sperm extraction (TESE), even with azoospermic donors. Given these results, we also suggest a new cut-off value for acquisition of childbearing sperm in selection for ICSI.