Association of IL28B gene variations with mathematical modeling of viral kinetics in chronic hepatitis C patients with IFN plus ribavirin therapy.

Asian patients with chronic hepatitis C (CHC) are known to have better virological responses to pegylated (Peg) IFN-based therapy than Western patients. Although IL28B gene polymorphisms may contribute to this difference, whether favorable hepatitis C virus (HCV) kinetics during treatment plays a role remains unclear. We enrolled 145 consecutive Taiwanese patients with CHC receiving Peg-IFN α-2a plus ribavirin for the study. Blood samples were taken more frequently at defined intervals in the first 3 d. Peg-IFN was administered at week 1. It was then administered weekly in combination with daily ribavirin for 24 or 48 wk. A mathematical model fitted to the observed HCV kinetics was constructed, which could interpret the transient HCV titer elevation after Peg-IFN treatment. The results demonstrated a comparable viral clearance rate (c = 3.45 ± 3.73) (day(-1), mean ± SD) but lower daily viral production rate (P = 10(6)-10(12)) in our patients than those reported previously in Western patients. Of 110 patients with a sustained virological response (SVR), 47 (43%) had a transient elevation of viral titer within 12 h (proportion of 12 h/3 d: 44% in non-SVR vs. 70% in SVR; P = 0.029). Among 91 patients with available rs8099917 data, patients with the TT genotype had an early surge of viral titer after therapy and a higher SVR and viral clearance rate than those with the GT genotype. In conclusion, Taiwanese patients with CHC receiving Peg-IFN plus ribavirin therapy have a lower daily viral production rate than Western patients, and the rs8099917 TT genotype may contribute to the increased viral clearance rate and better virological responses in these patients.

Association of IL28B genotypes with metabolic profiles and viral clearance rate in chronic hepatitis C patients.

PURPOSE: IL28B genotypes have a strong impact on treatment outcomes of chronic hepatitis C (CHC) and on-treatment viral kinetics. Since metabolic regulation and interferon response are highly integrated, metabolic profiles may play an important role in the link between IL28B genotypes and hepatitis C virus (HCV) infection. Thus, the association of IL28B rs8099917 genotypes with metabolic profiles and the impact of metabolic profiles on hepatitis C viral kinetic parameters were examined. METHODS: A case-control analysis including 278 CHC patients and 280 subjects without chronic HCV infection was performed. The associations of IL28B rs8099917 genotype with pretreatment metabolic profiles and early viral kinetic parameters were evaluated. RESULTS: Compared to HCV genotype 1 patients, the differences in metabolic profiles were more significant in genotype 2 patients. HCV genotype 2 patients with TT genotype had higher serum total cholesterol and high density lipoprotein (HDL) levels than those with GT genotype, and the differences remained significant when adjusted for age, sex, and body mass index (p = 0.005 for total cholesterol; p = 0.006 for HDL). In addition, patients with higher serum TG, higher fasting blood glucose, and lower HDL had a lower viral clearance rate. CONCLUSIONS: IL28B genotypes may affect lipid profiles of CHC patients, especially in HCV-genotype 2 patients. Patients with higher serum fasting blood glucose, triglyceride, and lower HDL have a lower viral clearance rate during pegylated interferon plus ribavirin therapy.