Interferon alpha receptor 2 expression by peripheral blood monocytes in patients with a high viral load of hepatitis C virus genotype 1 showing substitution of amino Acid 70 in the core region.

ABSTRACT

BACKGROUND/AIM: When patients with chronic hepatitis C (CHC) are treated with interferon (IFN)-based therapy, achieving serum HCV-RNA negativity by week 12 (early viral response, EVR) is an important predictor of a sustained virologic response. The aim of this study was to clarify whether changes in IFN-alpha receptor 2 (IFNAR-2) expression by peripheral blood monocytes (Mo) and the EVR rate differed between patients with genotype 1b and a high viral load showing substitution of amino acid 70 in the core region of HCV (mutant, n = 20) and patients without this substitution (wild, n = 23). PATIENTS AND METHODS: Forty-three CHC patients were studied, and received pegylated IFN plus ribavirin. IFNAR-2 expression by Mo was determined using flow cytometry to measure the mean fluorescence intensity (MFI) before and up to 28 days after starting therapy. RESULTS: The EVR rate of the mutant group was significantly lower than that of the wild group (35 vs.70%). The MFI of Mo was significantly higher in the wild group than in the mutant group before and also 3, 7, and 28 days after starting therapy. CONCLUSIONS: Mutation of HCV was related to lower IFNAR-2 expression by Mo before and after starting therapy.