Is peginterferon and ribavirin therapy effective in Korean patients with chronic hepatitis C?

Chronic hepatitis C (CHC) affects approximately 170 million people worldwide, and over 3 million individuals are newly infected each year. Kim et al reported that the adjusted prevalence rate of hepatitis C virus (HCV) infection in the general Korean population is approximately 0.78%, and the prevalence has been increasing. HCV is an important cause of liver diseases, such as liver cirrhosis and hepatocellular carcinoma (HCC). When it is not treated properly, patients diagnosed with CHC may progress to liver cirrhosis within 20 years and the 5-year risk of non-cirrhotics developing HCC was 4.8%. The standard treatment for CHC is a combination of pegylated interferon and ribavirin (PEG-IFN/ RBV). The purpose of this antiviral therapy is to achieve sustained virologic response (SVR), which is defined as negativity for HCV RNA by real time PCR at 24 weeks after completing treatment. Previous reports have shown that HCV genotype, serum HCV RNA level before treatment, age, gender, body mass index, fibrosis, and ethnicity affect the outcome of antiviral therapy, and more recently, genome wide association studies (GWAS) showed that polymorphisms near the interleukin 28B (IL28B) gene might have a profound effect on treatment outcome. According to surveys conducted in the West, the SVR rate for HCV genotype 1 is 40-50% and for HCV genotype non-1 is 7080%. In Korean patients, the SVR rate of HCV genotype 1 is about 70% and for HCV genotype non-1 is 80-90%. Although it is not conclusive yet, it seems that ethnicity may have strong influence on treatment response. Our review of the literature showed that Asians CHC patients have better treatment responses than patients in the West. In special consideration of the Korean studies, Park et al by pooled analysis, found that Korean HCV genotype 1 patients had a better SVR rate than corresponding Western patients (62.7% vs. 42.4%) (Table 1). A recent GWAS showed that single nucleotide polymorphisms (SNPs) near IL28B are associated with virologic response in patients with genotype 1, and also prevalence of good response SNPs was high in Asian CHC patients. Lyoo et al and Jeong et al reported, CHC patients with the rs12979860 CC and rs8099917 TT genotypes showed significantly higher SVR than patients with the CT and TG/GG genotype (70.2% and 68.6% vs. 25% and 33.3%, respectively), provided convincing evidence supporting that ethnicity importantly determines treatment response in CHC patients. According to Heo et al, the clinical trial group had a significantly higher SVR rate than the cohort group for patients with Is peginterferon and ribavirin therapy effective in Korean patients with chronic hepatitis C?