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 (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.