Characterization of the Interleukin-28B Gene rs12979860 C/T Polymorphism in Turkish Chronic Hepatitis C Patients and Healthy Individuals.

BACKGROUND Host genetic factors can affect the progress of hepatitis-C virus (HCV) infection. Interleukin-28B (IL28B) single nucleotide polymorphisms may play an important role in the clearance of HCV spontaneously or with treatment. AIMS The aim of our study was to evaluate the rate of IL28B genotypes in patients with Chronic Hepatitis-C (CHC) and healthy control subjects and to examine the characteristics of patients in each IL28B subgroup. STUDY DESIGN Case-control study. METHODS IL28B polymorphisms were genotyped by Polymerase Chain Reaction and Restriction Fragment Length Polymorphism (PCR-RFLP) in all subjects. RESULTS The mean age was 52.3±10.9 years (33% female) in the CHC patients and 52.5±11.5 years (39.1% female) in the healthy controls. The percentage of patients with a high baseline viral load (≥400,000 IU/mL) was higher in the CT group (69.8%) compared to the C/C (44.4%) and T/T (50%) groups (p=0.021). There was no significant difference in liver fibrosis and liver necroinflammation distribution among the CC, CT and TT genotypes with mild, moderate and severe groups (p=0.058 and p=0.791, respectively). Mean age, gender ratio, body mass index, viral load at baseline, rate of HCV genotypes, baseline ALT levels were not significantly different among the three IL28B subgroups (p>0.05). A significant increase was observed in the frequencies of IL28B rs12979860 TT genotypes in the CHC patients (20.6%) compared to the healthy control group (8.7%) (p=0.033). CONCLUSION In the patients with chronic HCV-genotype 1b and 4 infections, the IL28B rs12979860 (C>T) gene polymorphism frequency of the TT genotype and T allele was higher than in healthy control subjects. This result indicates that the TT genotype may be more effective in the progression of HCV infection than other genotypes.