Effects of the CCR5-Δ32 mutation on antiviral treatment in chronic hepatitis C

Background/Aims: The CC-chemokine receptor (CCR) 5-Δ32 mutation may predispose to chronic liver disease and high level viremia in hepatitis C. However, it is unclear whether CCR5-Δ32 also affects the response to antiviral treatment. Methods: We determined CCR5 genotypes in patients with hepatitis C treated with either interferon-α (N=78) or interferon and ribavirin (N=78). In each group, rates of end of treatment responses (ETRs) and sustained virological responses (SVRs) were compared between CCR5-Δ32 carriers and homozygous CCR5 wildtype patients. Results: ETR and SVR were achieved in 25 and 12 patients with interferon-α and in 52 and 45 patients with interferon/ribavirin treatment, respectively. CCR5-Δ32 carriers had significantly lower ETR rates than homozygous CCR5 wildtype patients (10.5 vs. 39.0%; P=0.02), whereas SVR rates only showed a non-significant trend (5.3 vs. 18.6%). Multivariate analysis confirmed CCR5-Δ32 carriage as an independent negative predictor for ETR in interferon-α monotherapy (odds ratio: 0.16; 95% confidence limits: 0.032–0.82; P=0.03). In interferon/ribavirin treated patients CCR-Δ32 carriers and CCR5 wildtype patients had similar ETR rates [19.2% vs. 23.1%] and SVR rates [20.0% vs. 21.2%]. Conclusions: Response rates to interferon-α monotherapy are reduced in hepatitis C virus (HCV)-infected patients carrying the CCR5-Δ32 mutation. However, interferon/ribavirin combination treatment may overcome this negative effect of CCR5-Δ32.