Background: Antioxidant imbalance is major trigger for chronic
hepatitis C (CHC) occurrence and progression. Aim: To determine the
erythrocyte antioxidative enzymes activities, superoxide dismutase
(SOD), glutathione peroxidase (GPx) and catalase (CAT), before and
after therapy with pegylated interferon alpha-2a and ribavirin and to
evaluate their clinical significance as potential diagnostic markers of
sustained virological response (SVR). Methods: SOD, GPx, CAT,
liver function parameters and high sensitivity C reactive protein
(hsCRP) levels were measured in 53 CHC patients both before and
after treatment and in 56 healthy controls. Results: Baseline SOD,
GPx and CAT activities were significantly lower in CHC patients
compared to the controls (p<0.001), and they were significantly
higher after the treatment (p<0.001). A significant positive correlation
existed between SOD, GPx, CAT, before and after treatment
(p<0.001) and with aminotransferases prior to treatment (p<0.001).
After treatment, only GPx showed significant negative correlation
with aminotransferases (p<0.001). Receiver operating characteristic
curve analysis results for SOD, GPx and CAT are following: area
under the curve of 0.975, 0.988, 0.817; sensitivity of 93.5%, 71.7%,
100% and specificity of 100% for all, respectively. 46 SVR achievers
have significant increase of SOD, GPx and CAT activities (p<0.001
for all), unlike 7 SVR non-achievers (p=0.31, p=0.717, p =0.85
respectively). SOD, CAT, GPx levels are statistically higher
(p<0.001 for all) in patients with: hepatitis C virus genotypes 1 and 4
compared to genotypes 2 and 3, higher levels of fibrosis compared to
lower, SVR achievers compared to SVR non-achievers. HsCRP
levels are significantly raised in CHC patients with decreased
antioxidant enzymes activities (p<0.05). Conclusion: Antioxidant
imbalance is the initiator of onset and progression of CHC. The
combined antiviral therapy leads to the restoration of antioxidant
balance. GPx, SOD and CAT may be diagnostic markers of treatment
outcome