To examine levels of interleukin-6 (IL-6) in fertile semen donors and patients with varicocele and examine its association with semen characteristics and levels of reactive oxygen species (ROS). We conducted a prospective study consisting of 15 fertile donors (controls) and 35 infertile patients with varicocele. Semen analysis was performed according to the World Health Organization guidelines. IL-6 levels were measured using the enzyme-linked immunosorbent assay. ROS (×10 4 counted photons per minute per 20 × 10 6 sperm) and total antioxidant capacity (molar trolox equivalents) were measured using a chemiluminescence assay. The sperm concentration and motility were significantly greater in the donors compared with the infertile patients with varicocele (P <0.0001 and P = 0.01, respectively). The IL-6 (log 10 [IL-6 + 1]) and ROS (log 10 [ROS + 1]) levels were significantly greater in infertile patients with varicocele than in the donors (IL-6: 2.1 [1.7, 2.4] versus 0.7 [0, 1.9], P = 0.003; ROS: 1.8 [1.2, 2.6] versus 1.0 [0.7, 1.6], P = 0.04). The total antioxidant capacity levels were significantly lower in the varicocele patients (1166.7 ± 366.2) than in the donors (1556.4 ± 468.1; P = 0.003). The IL-6 levels correlated significantly with the ROS levels in the infertile patients with varicocele (r = -0.39; P = 0.01). Infertile patients with varicocele exhibited elevated levels of IL-6 and ROS and decreased levels of total antioxidant capacity. Pro-inflammatory cytokine IL-6 and oxidative stress may play a role in the pathophysiology of infertility in these patients. © 2004 Elsevier Inc.
Nallella, K. P., Allamaneni, S. S. R., Pasqualotto, F. F., Sharma, R. K., Thomas, A. J., & Agarwal, A. (2004). Relationship of interleukin-6 with semen characteristics and oxidative stress in patients with varicocele. Urology, 64(5), 1010–1013. https://doi.org/10.1016/j.urology.2004.05.045