Increased IL-18 levels in seminal plasma of infertile men with genital tract infections

Am J Reprod Immunol. 2006 Jun;55(6):428-33. doi: 10.1111/j.1600-0897.2006.00380.x.

Abstract

Problem: Interleukin (IL)-18 is a novel cytokine, previously known as interferon (IFN)-gamma inducing factor. We evaluated the levels of IL-18 and IFN-gamma in seminal plasma (SP) of fertile and infertile men.

Method of study: Semen samples were obtained by masturbation from 80 men, and were examined for the levels of IL-18 and IFN-gamma by enzyme-linked immunosorbent assay. Seven groups were included: (i) fertile men (n = 18), (i) infertile men with genital tract infections (n = 17), (iii) with varicocele (n = 15), (iv) with Klinefelter syndrome (n = 6), (v) with cryptorchidism (n = 7), (vi) with mumps orchitis (n = 7), and (vii) with idiopathic testicular lesions (n = 10).

Results: Mean levels of IL-18 were higher in SP from infertile men with genital tract infections compared with SP from other groups except Klinefelter syndrome (P < 0.05). However, no significant differences could be detected for IFN-gamma. A significant positive correlations was found between IL-18 and IFN-gamma in total patient population (P < 0.001). Moreover, a negative correlation was observed between IL-18 and sperm concentrations, and motility (P < 0.01 and < 0.03, respectively). Furthermore, there was a positive and statistically significant association between IL-18 and IFN-gamma levels in SP of infertile men with genital tract infections (P < 0.0001). However, there was no relationship between IL-18 and IFN-gamma, and semen parameters in the same group.

Conclusion: SP IL-18 levels were increased in men with urogenital infections. Thus, the elevated expression of IL-18 in SP may be used as a diagnostic marker in the male genital tract infections.

MeSH terms

  • Adolescent
  • Adult
  • Cryptorchidism / complications
  • Cryptorchidism / immunology
  • Genital Diseases, Male / complications*
  • Genital Diseases, Male / diagnosis
  • Genital Diseases, Male / immunology*
  • Humans
  • Infections / complications*
  • Infections / diagnosis
  • Infections / immunology*
  • Infertility, Male / complications*
  • Infertility, Male / etiology
  • Infertility, Male / immunology*
  • Interferon-gamma / metabolism
  • Interleukin-18 / metabolism*
  • Klinefelter Syndrome / complications
  • Klinefelter Syndrome / immunology
  • Male
  • Middle Aged
  • Mumps / complications
  • Mumps / immunology
  • Orchitis / complications
  • Orchitis / immunology
  • Semen / immunology*
  • Varicocele / complications
  • Varicocele / immunology

Substances

  • Interleukin-18
  • Interferon-gamma