The presence of Interleukin 35 in seminal plasma: is it a ‎significant ‎issue in male infertility? ‎

Approximately half of infertility in couples can be attributed to male factors, which may occur in a wide range of causes. Examining seminal plasma parameters is the initial and simplest approach in male infertility evaluation and provides valuable information about fertility status. In this study, the presence and relationship between the concentration of interleukin 35 (IL-35) in seminal plasma and standard parameters of sperm in infertile men were investigated. Semen analysis was performed on semen samples of men referred to the Infertility Center of Shiraz University of Medical Sciences. Semen samples were analyzed in accordance with the laboratory guidelines of the World Health Organization and were divided into three groups including 21 normozoospermic, 21 asthenoteratozoospermic, and 15 azoospermic samples. The seminal concentration level of IL-35 was analyzed using the enzyme-linked immunosorbent assay (ELISA) method. Results showed that IL-35 was detectable with different levels in the seminal plasma of studied groups, however, its concentration did not show a statistically significant difference (p>0.05). The correlation analysis between IL-35 concentration and sperm standard parameters showed that there is a significant negative correlation between IL-35 concentration and the normal sperm morphology percentage (r=0.317, p=0.04), while no significant correlation was observed with sperm count (r=-0.27, p=0.08) and sperm motility (r=-0.27, p=0.08). Despite the presence of IL-35 in semen, even in normozoospermic male patients, its role and functional significance have not been determined. The existence of a negative relationship between the IL-35 concentration and the normal sperm morphology percentage can indicate its importance in male infertility status.