Background/Objectives: Interleukin-6 (IL-6), a pleiotropic cytokine involved in immune regulation, is consistently detected in human semen, even in the absence of overt infection. Its contribution to sperm dysfunction, oxidative stress, and inflammation remains incompletely understood. This study evaluated the associations between seminal IL-6 concentrations and markers of semen quality, oxidative stress, nuclear integrity, and genital tract inflammation in infertile men. Methods: A cohort of 204 infertile men was assessed. Seminal IL-6 was quantified by electrochemiluminescence immunoassay. Semen parameters, malondialdehyde (MDA), catalase (CAT) activity, sperm DNA fragmentation index (DFI), sperm chromatin decondensation index (SDI), leukocytospermia, and bacteriospermia were measured. Analyses included correlation testing, IL-6 threshold stratification (<30, 30–60, 60–100, ≥100 pg/mL), and multivariate regression. Results: IL-6 was detectable in all samples (median: 31.52 pg/mL; range: 1.5–5000 pg/mL). Higher IL-6 levels were significantly associated with reduced sperm concentration, progressive motility, and vitality, and with increased DFI, SDI, MDA, leukocyte counts, and bacteriospermia (p < 0.001). In multivariate models, IL-6 independently predicted reduced progressive motility (β = −0.005; p = 0.032) and elevated leukocyte count (β = 0.0018; p < 0.0001). Logistic regression further showed that IL-6 increased the odds of DFI ≥ 30%, SDI ≥ 30%, and bacteriospermia (p < 0.05). Conclusions: Seminal IL-6 emerges as a sensitive biomarker of immuno-oxidative stress and sperm dysfunction in infertile men. Its integration into clinical evaluation may improve the assessment of inflammatory and oxidative contributors to male infertility.

Objective: The objectives of this study were to characterize the clinical, hormonal, and extended biomarker profile of infertile men in a Moroccan context, based on a retrospective single-center study, and to assess the relevance of selected markers for initial andrological assessment. Methods: This descriptive, retrospective, single-center study included 1399 men consulting for infertility between January and December 2024 in a specialized center. Collected data encompassed lifestyle habits, medical history, semen parameters (WHO 2021 criteria), sperm DNA fragmentation (TUNEL assay), nuclear decondensation, and hormonal assays (FSH, testosterone, and inhibin B) available in a subset of 156, 56, and 26 patients (for FSH, testosterone, and inhibin B, respectively). Associations with oligozoospermia were explored using univariate logistic regression analysis. Results: The mean age was 39.0 ± 8.0 years; 57% presented with primary infertility, and 82.8% were active smokers. A sperm concentration <16 M/mL was observed in 31.6% of patients. Among the 156 patients analyzed, high FSH levels were observed in 24% of cases. As for inhibin B, among the 26 patients evaluated, a decrease in levels was observed in 38% of cases. Pathological DNA fragmentation was found in 9.6%. In univariate analysis, oligozoospermia was significantly associated with elevated FSH (OR = 7.25; 95% CI: 3.15–16.70), varicocele (OR = 1.81), and smoking (OR = 0.66). Conclusion: This is the first large-scale Moroccan study integrating advanced biomarkers into the assessment of male infertility. The observed associations between elevated FSH, sperm DNA fragmentation, and varicocele support the development of a simplified andrological triage strategy, particularly relevant in resource-limited settings.