Effect of IL-28B polymorphisms on the natural course of HBV infection

Abstract

The prediction of the consequences of disease is important to determine the therapy approaches and prevention of the chronical state in patients infected with hepatitis B virus (HBV). In recent years various studies are carried on to investigate the effect of IL-28B gene polymorphisms on the clinical course or therapy response in patients with chronic hepatitis B infection. The aim of the study was to evaluate the influence of IL-28B rs12979860 polymorphisms on the natural course of HBV infection. The study was designed prospectively, and the subjects were randomly selected among patients admitted to infectious disease outpatient clinics of Kocatepe University Medical School Hospital and Yunus Emre State Hospital located at provinces in Central Anatolia, Turkey. A total of 99 cases were included in the study and evaluated into three groups, namely, chronic hepatitis B patients (group 1, n= 43); inactive HBV carriers (group 2, n= 34) and subjects with acquired immunity after native infection (group 3, n= 22). There were no significant differences regarding the age and gender distribution between the groups (p> 0.05). All subjects were investigated for the IL-28B promoter single nucleotide polymorphism rs12979860 at position 3176 C/T, by real-time polymerase chain reaction (RT-PCR). Evaluation of the range of IL-28B rs12979860 C/T polymorphisms observed in the study groups showed that, the frequency of CC, CT and TT allels were as follows; 34.9%, 48.8% and 16.3 % in group 1; 47.1%, 35.3% and 17.6% in group 2; 63.6%, 27.7% and 13.6% in group 3, respectively. No significant differences were observed between the groups in terms of C/T allel distriubution (p> 0.05). However, in spite of statistical insignificance, the rate of CC allel in IL-28B rs12979860 gene was the highest in immune subjects (63.6%), while it was the lowest in chronic hepatitis B patients (34.9%). According to our data, IL-28B rs12979860 gene polymorphisms were not effective on the clinical course of HBV infection. In conclusion, further studies with large numbers of patients are needed to support these data.