Impact of inflammation on male reproductive tract

Abstract

Fertility in the male is dependent on the proper production of sperm cells. This process, called spermatogenesis is very complex and involves the synchronization of numerous factors. The presence of pro-inflammatory cytokines, tumor necrosis factor-alpha (TNF-α), interleukin-1 alpha (IL-1 α) and interleukin 1 beta (IL-1 β) cytokines in the male reproductive tract (testis, epididymis and sperm) may have certain physiological functions. However, when the levels of these cytokines are higher than normal, as seen in conditions of inflammation, they become very harmful to sperm production. Moreover, inflammation is also associated with oxidative stress and the latter is well known to impair sperm function. Epidemiological studies regarding male infertility have revealed that more and more infertile men suffer from acute or chronic inflammation of the genitourinary tract, which often occurs without any symptoms. The inflammatory reactions within the male genital tract are inevitably connected with oxidative stress. Oxidative stress, especially in sperm, is harmful because it damages sperm DNA and causes apoptosis in sperm. This article reviewed the suggested mechanisms and contribution of inflammation to male infertility. In addition, the review was further strengthened by discussing how inflammation affects both fertility and assisted reproductive technologies (ART).