Inflammation and Oxidative Stress in Seminal Plasma: Search for Biomarkers in Diagnostic Approach to Male Infertility

Oxidative and inflammatory damage underlie several conditions related to male infertility, including varicocele. Free light chains of immunoglobulins (FLCs) are considered markers of low-grade inflammation in numerous diseases. Coenzyme Q10 (CoQ10), a lipidic antioxidant and anti-inflammatory compound, is involved in spermatozoa energy metabolism and motility. We aimed to evaluate FLCs' seminal levels in patients with varicocele in comparison to control subjects and to correlate them with CoQ10 and Total Antioxidant Capacity (TAC) in human semen. Sixty-five patients were enrolled. Semen analysis was performed; patients were divided into three groups: controls, 12 normozoospermic patients, aged 34 (33-41) years; varicocele (VAR), 29 patients, aged 33 (26-37) years; and idiopathic, 24 oligo-, astheno- and oligoasthenozoospermic patients aged 37 (33.5-40.5) years. FLCs (kappa and lambda) were assayed by turbidimetric method; CoQ10 by HPLC; TAC by spectrophotometric method. lambda FLCs showed a trend toward higher levels in VAR vs. controls and the idiopathic group. VAR showed a trend toward lower kappa FLCs levels vs. the other two groups. When comparing kappa/lambda ratio, VAR showed significantly lower levels vs. controls and idiopathic. Moreover, CoQ10 seminal levels showed higher levels in VAR and idiopathic compared to controls. Data reported here confirm lower levels of kappa/lambda ratio in VAR and suggest a possible application in personalized medicine as clinical biomarkers for male infertility.