Elevated Seminal Plasma TLR-2 Levels are Associated with Leukocytospermia

Introduction: Leukocytospermia is associated with male infertility, but its underlying mechanisms are not fully understood. This study aimed to investigate the association between seminal plasma toll-like receptor 2 (TLR-2) and prostaglandin E2 (PGE2) levels and leukocytospermia in infertile Iraqi men, and to evaluate their potential as differential biomarkers. Methods: Eighty infertile men attending an infertility clinic in Iraq were enrolled. Semen analysis was performed according to WHO 2010 criteria. TLR-2 and PGE2 levels in seminal plasma were quantified using ELISA. Participants were categorized based on leukocytospermia status, varicocele presence, and smoking habits. Statistical analyses included correlation tests and receiver operating characteristic (ROC) curve analysis. Results: Seminal plasma TLR-2 levels were significantly higher in leukocytospermic patients compared to non-leukocytospermic men (15.14 ± 1.06 vs. 9.27 ± 1.42 ng/mL, p < 0.05). TLR-2 levels showed strong negative correlations with sperm concentration (r = -0.675), total sperm count (r = -0.673), progressive motility (r = -0.669), and normal morphology (r = -0.616) (all p < 0.001). Positive correlations were observed between TLR-2 and round cell concentration (r = 0.684) and white blood cell count (r = 0.668) (both p < 0.001). Smoking and varicocele did not significantly influence TLR-2 levels. ROC analysis revealed high diagnostic accuracy for TLR-2 in identifying leukocytospermia (AUC = 0.993, p < 0.05). In contrast, PGE2 levels showed no significant differences or correlations with semen parameters. Discussion: The elevated TLR-2 levels in leukocytospermic samples and strong correlations with semen parameters suggest a potential role for TLR-2 in inflammationrelated male infertility. The persistence of this association regardless of smoking status or varicocele presence further supports TLR-2’s specificity as a biomarker for leukocytospermia. Conclusion: Elevated seminal plasma TLR-2 levels are associated with leukocytospermia and poor semen parameters in infertile Iraqi men. TLR-2 shows promise as a differential biomarker for male infertility, particularly in cases of leukocytospermia.