Role of Interleukin-28B Polymorphism as a Predictor of Sustained Virological Response in Patients with Chronic Hepatitis C Treated with Triple Therapy: A Systematic Review and Meta-Analysis

Background and Objective Chronic hepatitis C represents an important health problem. The aim of our meta-analysis was to establish the role of reference single nucleotide (rs) 12979860 allele of interleukin-28B ( IL28B ) CC versus CT+TT genotype (the most researched allele of IL28B ) as a predictor of sustained virological response (SVR) in patients with chronic hepatitis C treated with triple therapy. Methods The PubMed, MEDLINE, Lilacs, Scopus, Ovid, EMBASE, Cochrane and Medscape databases as well as abstract books from important gastroenterology and hepatology meetings were searched for all studies published until 15 July 2012 that analysed the relationship between the polymorphism of IL28B and SVR in patients with chronic hepatitis C, genotype 1, treated with pegylated interferon + ribavirin + direct antiviral agents (telaprevir or boceprevir). The following keywords were used: IL28B polymorphism, chronic hepatitis C, sustained virological response, SVR, triple therapy, telaprevir, boceprevir. Results Odds ratios (ORs) with 95 % confidence intervals were pooled from five study populations (1,641 cases) using a random–effects model. The SVR rate was significantly higher in patients with the CC genotype of IL28B than in those with non-CC genotypes (CT and TT): OR = 3.91 (95 % CI 2.11–7.28), p < 0.0001. Higher SVR rates were obtained in chronic hepatitis C patients with the CC genotype of IL28B , regardless of their therapeutic status (naïve patients: OR = 3.99 [95 % CI 1.67–9.51], p < 0.0001; and previously treated ones: OR = 2.15 [95 % CI 1.35–3.43], p = 0.001). Conclusion IL28B polymorphism seems to influence the SVR rate in patients with chronic hepatitis C treated with triple therapy, but further studies are needed to clarify the mechanism and the influence of other factors on the SVR rates.