IL-28B polymorphisms and the response to antiviral therapy in HCV genotype 2 and 3 varies by ethnicity: a meta-analysis.

Studies of IL-28B genotype in patients with hepatitis C virus (HCV) genotype 2/3 infection have yielded conflicting results. The aim of this meta-analysis was to obtain a pooled odds ratio (OR) of the impact of IL-28B genotype on achieving sustained virologic response (SVR) in patients with HCV genotype 2/3 infection treated with pegIFN and ribavirin. A meta-analysis with a random effects model was performed, and study heterogeneity and publication bias were assessed. Forty-three percent of the Caucasians (11 studies) and 86% of Asians (five studies) had the favourable IL-28B genotype. In Caucasians, the pooled OR of SVR with the favourable IL-28B genotype was 1.36 (95%CI: 0.98-1.88, P = 0.07) in all patients and 1.55 (95%CI: 1.10-2.18, P = 0.01) in patients treated with pegIFN and ribavirin for ≥24 weeks. In Asians, the pooled OR of SVR in patients with the favourable IL-28B genotype was 1.99 (95%CI: 0.94-4.25, P = 0.07). The favourable IL-28B genotype was also significantly associated with rapid virologic response (RVR) in both groups (Caucasians: OR: 1.82, 95%CI: 1.12-2.96, P = 0.02; Asians: 2.39, 95%CI: 1.39-4.11, P = 0.002), as well as the likelihood of an SVR in a subgroup of 350 Caucasian patients without an RVR (OR: 3.29, 95%CI: 1.67-6.51, P = 0.001). The favourable IL-28B genotype is a statistically significant predictor of SVR and RVR in Caucasian patients treated with pegIFN and ribavirin for 24 weeks. In contrast, the favourable IL-28B genotype is associated with RVR, but not SVR in Asian HCV genotype 2 patients.