Differences in the factors associated with serum viral load between genotypes 1 and 2 in patients with chronic hepatitis C

Purpose The serum hepatitis C virus (HCV) load is persistently stable in patients with untreated chronic hepatitis C, but its differences between individuals vary widely (above 4 logU/mL). Because serum viral load is an important factor for predicting clinical outcome of interferon-based antiviral therapy, this study was performed to clarify the factors associated with serum viral load in chronic hepatitis C patients. Methods We retrospectively analyzed data from 669 chronic hepatitis C patients with HCV genotype 1 or 2 infection. Stepwise regression analysis was used to estimate the relationship between demographic, viral, or biochemical variables and serum viral load. Results In univariate analysis, serum lipid profiles, such as total cholesterol, low-density lipoprotein (LDL) and triglyceride levels, and hemoglobin A1c (HbA1c) were correlated with the serum HCV viral load. In multivariate analysis, HCV genotype 1 infection and higher total cholesterol levels were associated with higher viral load. After stratification by HCV genotype, the serum viral load was associated with triglyceride and HbA1c in genotype 1 and with platelet counts and LDL in genotype 2. Histological data (413 patients) showed correlation between severe liver fibrosis and decreased serum viral load in patients with HCV genotype 2 but not genotype 1 infection. Conclusions These results suggest that viral kinetics is affected by different host factors for genotypes 1 and 2.