[Association of interleukin 28B polymorphisms with response to pegylatedinterferon plus ribavirin therapy for chronic hepatitis C].

OBJECTIVE: To investigate the characteristics of gene polymorphisms at rs12979860 of interleukin 28B (IL28B) and explore the relationships between the genetic polymorphisms and the antiviral therapy efficiency for chronic hepatitis C patients in the Sichuan region of China.

METHODS: Data from 56 patients treated for 48 weeks with PEG-IFN alpha-2a plus weight-based Ribavirin (RBV), which were followed for 24 weeks after the end of treatment, were analyzed. And the IL28B rs12979860 genotype was detected by polymerase chain reaction-restriction techniques (PCR) and sequencing analysis.

RESULTS: Two genotypes, CC (76.8%) and CT (23.2%), were identified in the study. There are no significant correlation in sex, age, body weight, routes of infection, baseline ALT value, baseline viral load and hepatitis C viral (HCV) genotype between the patients with CC genotype and CT genotype (P>0.05). PEG-IFN alpha-2a plus RBV showed a conspicuous therapeutic effect in patients of the Sichuan region of China, and the rate of sustained virological response (SVR) was 82.1% (46/56). The higher rates of SVR were observed in patients with IL28B genotype CC than genotype CT (90.7% versus 53.8%, P=0.009). Statistically higher proportion of SVR wasn't observed in patients with lower baseline viral load (< or =6 x 10(5) IU/mL) [88.2% versus 79.5% in patients with higher baseline viral load (> or = 6 x 10(5) IU/mL), P=0.684] and statistically lower proportion of SVR wasn't observed in patients infected with HCV genotype 1 (76.9% versus 92.9% in patients infected with HCV genotype non-1, P = 0.363). The higher rates of SVR were observed in patients with IL28B genotype CC than patients with genotype CT in the group of higher baseline viral load (> or = 6 x 10(5) IU/mL) (87.5% versus 42.9%, P=0.033) and in HCV genotype 1 infected patients (89.7% versus 50.0%, P=0.025).

CONCLUSION: CC genotype was accounted for the majority at rs12979860 in patients of the Sichuan region of China. The higher rates of SVR were observed in IL28B genotype CC than genotype CT. Compared to HCV viral genotype and baseline viral load, IL28B genotype may predict the treatment effect of greater value.