title: Relationship of interleukin-6 with semen characteristics and oxidative stress in patients with varicocele.
abstract: OBJECTIVE
  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).
  
  
  METHODS
  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 (x10(4) counted photons per minute per 20 x 10(6) sperm) and total antioxidant capacity (molar trolox equivalents) were measured using a chemiluminescence assay.
  
  
  RESULTS
  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 (log10 [IL-6 +1]) and ROS (log10 [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).
  
  
  CONCLUSIONS
  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.
authors.affiliation: Center for Advanced Research in Human Reproduction, Infertility and Sexual Function, Glickman Urological Institute and Department of Obstetrics and Gynecology, Cleveland Clinic Foundation, Cleveland, Ohio 44195, USA.
authors.forename: Kiran P
authors.initials: KP
authors.lastname: Nallella
authors.forename: Shyam S R
authors.initials: SS
authors.lastname: Allamaneni
authors.forename: Fabio F
authors.initials: FF
authors.lastname: Pasqualotto
authors.forename: Rakesh K
authors.initials: RK
authors.lastname: Sharma
authors.forename: Anthony J
authors.initials: AJ
authors.lastname: Thomas
authors.forename: Ashok
authors.initials: A
authors.lastname: Agarwal
mesh_terms: D000328:Adult; D000975:Antioxidants / Q000032:analysis; D006801:Humans; D007248:Infertility, Male / Q000150:complications / Q000378:metabolism / Q000503:physiopathology*; D015850:Interleukin-6 / Q000032:analysis / Q000378:metabolism*; D008297:Male; D018384:Oxidative Stress; D017382:Reactive Oxygen Species / Q000032:analysis; D012661:Semen / Q000737:chemistry / Q000378:metabolism*; D013081:Sperm Motility; D014646:Varicocele / Q000150:complications / Q000378:metabolism*
chemical_list: D000975:Antioxidants; D015850:Interleukin-6; D017382:Reactive Oxygen Species