Evaluation of serum proinflammatory cytokines, oxidative stress, and other biochemical markers in chronic viral hepatitis B and C infections

INTRODUCTION: Infection with the hepatitis B virus (HBV) or the hepatitis C virus (HCV) results in inflammatory responses, which can subsequently lead to severe progressive hepatic disease. Oxidative stress resulting from changes in the activity of antioxidant enzymes and cytokines and causing an excessive accumulation of reactive oxygen species has been identified as a key factor in the pathogenesis and progression of chronic liver inflammation and disease. Minerals such as zinc (Zn) and copper (Cu), which are part of the biochemical structure of some antioxidant enzymes, also play a part in the complicated pathogenesis of HBV and HBC infections. The aim of this study was to investigate the effects of chronic viral HBV and HCV infection on the status of some serum cytokines, antioxidant enzymes, lipid peroxidation, and serum Zn and Cu levels, and to determine if there was any relationship between them.
METHODS: A total of 78 patients with positive clinical and serological markers of HBV or HCV infection were included: 40 chronic HBV-positive patients, 30 inactive HBV carriers, and 8 chronic HCV-positive patients. Thirty healthy subjects were also included in the study as a control group. The level of serum cytokines tumor necrosis factor-α (TNF-α), interleukin-1β, (IL-1 β), interleukin-2R (IL-2R), interleukin-6 (IL-6), and interleukin-8 (IL-8) was analyzed with a chemiluminescent enzyme immunometric test, the activity of antioxidant enzymes superoxide dismutase (SOD), phospholipid hydroperoxide glutathione peroxidase (GSH-Px), and catalase (CAT) was measured in erythrocytes, and the malondialdehyde (MDA) level was measured in plasma using a fluorescence spectrophotometric method. The serum Zn and Cu concentration was measured with a flame atomic absorption spectrophotometer.
RESULTS: Serum cytokine (TNF-α, IL-2R, IL-6, and IL-8) levels were significantly higher in both the HBV- and HCV-positive patient groups when compared with the control group (p<0.05). No statistically significant difference was found in IL-1β values between chronic HBV patients and inactive HBV carriers (p>0.05). Erythrocyte SOD, GSH-Px, and CAT activity, and the serum Zn level were low in both HBV and HCV patients (p<0.05), whereas the plasma MDA and serum Cu levels were found to be significantly elevated (p<0.05).
DISCUSSION AND CONCLUSION: An impaired oxidative stress reaction and increased proinflammatory cytokines were observed in patients infected with chronic HBV or HCV. Chronic viral hepatitis infection was also observed to affect the homeostasis of Zn and Cu, leading to an increase in the serum Cu level and a decrease in Zn as a result of metabolic interactions. The lipid peroxidation marker MDA may be a useful tool for observing and following up pathogenic mechanisms and the course of chronic HBV and HCV.