Immune mechanisms and the role of oxidative stress in intrahepatic cholestasis of pregnancy

INTRODUCTION: The purpose of this study was to investigate levels of inflammatory cytokines such as interleukin 6 (IL-6), tumor necrosis factor α (TNF-α) and neopterin and oxidative stress status in patients with intrahepatic cholestasis of pregnancy (ICP) as well as their potential role in the pathophysiology. MATERIAL AND METHODS: Thirty patients with ICP (Group 1) and 30 healthy pregnant women (Group 2) were included in this prospective case-control study. Levels of IL-6, TNF-α and neopterin were determined in both of the groups. Total anti-oxidant status (TAS) and total oxidative stress (TOS) levels were determined by means of a fully automated Erel method. Oxidative stress index (OSI) was calculated as the ratio of TOS to TAS. RESULTS: There was no significant difference between the groups in IL-6 and TNF-α levels (p = 0.105 and p = 0.722, respectively). The mean neopterin level was significantly higher in Group 1 compared to Group 2 (2.34 ±0.77 and 1.57 ±0.38, respectively, p = 0.001). In addition, TAS, TOS and OSI levels were significantly higher in Group 1 (p = 0.004, p = 0.001 and p = 0.001, respectively) compared to Group 2. DISCUSSION: Intrahepatic cholestasis of pregnancy is an inflammatory disorder in which maternal immune reaction may play a role. Interleukin 6 and TNF-α, which are some of the markers of humoral reaction, act as an indicator of abnormal reaction rather than acute-phase reaction in ICP. Further clinical trials and supportive placental findings are needed on the role of cytokines in cellular and humoral immune reactions during the symptomatic period and delivery to better understand the role of immune mechanisms in the aetiology of ICP.