Early viral kinetics during hepatitis C virus genotype 6 treatment according to IL28B polymorphisms

To investigate the early viral kinetics and interleukin-28B (IL28B) polymorphisms of hepatitis C genotype 6 during pegylated interferon and ribavirin therapy.

Sixty-five patients with chronic hepatitis C virus (HCV) infection treated with pegylated interferon and ribavirin (PEG-IFN/RBV) were included, of whom 15 (23.1%), 16 (24.6%) and 34 (52.3%) patients were infected with hepatitis C genotype 1 (HCV-1), genotype 3 (HCV-3) and genotype 6 (HCV-6), respectively. Serum HCV-RNA levels were measured frequently during the first 4-wk of therapy. DNA extracted from samples was analyzed for the IL28B single nucleotide polymorphism (SNP) rs12979860 by polymerase chain reaction and direct sequencing.

During the first 4-wk of therapy, the mean viral decline for patients with HCV-6 (5.55 ± 1.82 log₁₀IU/mL) was comparable to that of patients with HCV-3 (5.55 ± 1.82 log₁₀IU/mL vs 5.86 ± 1.02 log₁₀IU/mL, P = 0.44) and was significantly higher than patients with HCV-1 (5.55 ± 1.82 log₁₀IU/mL vs 4.23 ± 1.99 log₁₀IU/mL, P = 0.04). In the HCV-6 group, the first phase (days 0-2) viral decline was significantly higher in patients with the favorable rs12979860 CC than non-CC genotypes (2.46 ± 1.01 log₁₀IU/mL/wk vs 1.70 ± 0.67 log₁₀IU/mL, respectively, P = 0.045). A statistically insignificant decrease in the second-phase (days 7-28) decline was also found in patients with the CC genotype than those with the non-CC genotype, though not significantly different (1.24 ± 0.64 log₁₀IU/mL/wk vs 0.80 ± 0.65 log₁₀IU/mL/wk, respectively, P = 0.172). At baseline, the SNP genotype was an independent predictor of rapid virological response but not of sustained virological response.

The IL28B genotype was linked to an impact on early viral kinetics in response to PEG-IFN/RBV therapy in HCV-6 infected patients.