Prognostic capabilities of proteomic analysis of seminal plasma in males with azoospermia

Abstract

Introduction. According to research, seminal plasma is a rich source of biomarkers in male infertility including biomarkers of residual spermatogenesis in males with azoospermia. In many cases, extraction of seminal plasma does not require invasive procedures. Therefore, non-invasive test for identification of males with azoospermia and residual focal spermatogenesis can improve selection of patients for microdissection testicular sperm extraction (microTESE) and become a useful tool for patient consultation.The study objective is to evaluate capabilities of proteomic analysis of seminal plasma for identification of males with azoospermia and residual focal spermatogenesis in the testes who have higher chance for sperm extraction using the microTESE procedure.Materials and methods. Samples of seminal plasma of 36 males between 21 and 45 years of age (mean age 33.3 ± ± 3.9 years) were tested for proteomic composition. For proteomic analysis, proteins were hydrolyzed with trypsin. The obtained peptides were analyzed using chromatography-mass spectrometry complex composed of liquid chromatograph nano-HPLC Agilent 1100 and high-resolution mass spectrometer 7Т LTQ-FT Ultra. Proteomic analysis data were compared with results of the microTESE procedure.Results. In this study, proteomic composition of seminal plasma in azoospermia was assessed. Semi-quantitative analysis without markers using bottom-up approach identified 405 different proteins, and 174 of them were detected in all samples. The obtained quantitative parameters were sufficient to identify patients with focal spermatogenesis.Conclusion. Seminal plasma is a potential source of biological markers for prediction of sperm extraction success in patients with azoospermia. The presented results are preliminary, and further studies are needed to confirm the identified protein panel.

Keywords

• azoospermia
• ejaculate proteome
• male infertility
• seminal plasma