Soluble FAS and FAS ligand levels in seminal plasma: association with basic parameters of semen analysis.

Background/aim: Binding of FAS ligand (FASL) to its physiological receptor FAS, induces the activation of caspase-8, which triggers cell death. The FAS-FASL system regulates germ cell death. In this study, the role of the FAS-FASL system in male infertility was examined.

Patients And Methods: 72 samples were used (age=38.76 ± 9.06 years). Basic semen analysis was performed according to the WHO Laboratory Manual. Soluble (s) forms of FAS and FASL were measured in seminal plasma using commercially available immunoassay kits.

Results: Among the examined samples, 24 were normal and 48 abnormal, as evaluated by basic semen analysis. sFAS and sFASL levels in abnormal samples were slightly higher than in the normal ones. In all samples, sFAS correlated negatively with pH. In normal samples, sFAS was positively correlated with sperm concentration. In abnormal samples, sFAS strongly correlated with sFASL.

Conclusion: Both factors of the FAS system were detected in seminal plasma. Further studies are necessary to shed light into the possible role of FAS-FASL system in male infertility.