Distribution of IL28B Polymorphism in a Cohort of Italians and Immigrants with HCV Infection: Association with Viraemia, Stage of Fibrosis and Response to Treatment

Interleukin 28B Polymorphism as a Predictor of Sustained Virological Response to Sofosbuvir-Based Therapy for Hepatitis C Virus Patients

In various genome-wide correlation studies, interleukin (IL)28B gene polymorphism has been strongly correlated with both the therapeutic and spontaneous mediated clearance of hepatitis C virus (HCV). Therefore, this study aimed to evaluate the genotype and allele frequency distributions of IL28B (rs12979860) in patients with chronic hepatitis C and assess the IL28B polymorphisms as predictors of sustained virological response to SOF-based therapy for HCV in Egyptian patients. This retrospective case-control study was conducted on 54 chronic HCV patients who completed treatment with SOF/DCV ± RBV for 12 weeks and responded to treatment with SVR12 (the responder group) as a control group, and 54 chronic HCV patients who completed treatment with SOF/DCV ± RBV for 12 weeks and did not respond to treatment and failed to achieve SVR12 (the non-responder group) as a case group. The CC genotype frequency of IL-28B (rs12979860) was greater in the responder group (51.9%). In contrast, the TT genotype frequency was higher in the non-responder group (48.1%) (p < 0.001), and the T allele significantly increased the risk of non-responses by 3.13 fold. Therefore IL-28B (rs12979860) SNP could be used as a genetic predictor of sustained virological response to SOF+DCV ± RBV-based HCV treatment in Egyptian patients.

Possible relationship between IL28B rs12979860 and TLR2 -196 to -174 del/ins polymorphisms and the liver fibrosis stage in hepatitis C patients

It has been shown that host factors play an important role in the progression of hepatitis C virus (HCV) infection. Toll-like receptor 2 (TLR2) del and interleukin 28B (IL28B) T alleles can mediate liver inflammation and pathogenesis of hepatocellular carcinoma. In the present study, the possible relationship between the IL28B rs12979860 C/T and TLR2 -196 to -174 del/ins gene variants and different fibrosis stages and host factors in hepatitis C patients was investigated. IL28B and TLR2 polymorphisms in the blood of 50 hepatitis C patients at different stages of fibrosis (24 mild/moderate, 26 advanced) and 24 healthy controls were examined by RT-qPCR. The highest frequency of the TLR2 del (26.9%) and IL28B T (46.2%) alleles was found in hepatitis C patients with the most advanced fibrosis, and the lowest frequency was found in healthy controls. There was a statistically significant difference between hepatitis C patients with advanced fibrosis and healthy controls in terms of the TLR2 del (p = 0.0062) and IL28B T (p = 0.0017) allele frequencies. However, no statistically significant difference was found between the mild/moderate fibrosis and severe fibrosis patient groups in terms of genotype or IL28B and TLR2 polymorphisms (p > 0.05). In addition, there was a significant difference between patients with mild/moderate or advanced fibrosis who carried the TLR2 del allele together with the IL28B CT genotype and healthy controls. The present study emphasizes that the TLR2 and IL28B gene variants cannot be single biomarkers for the determination of fibrosis stage in hepatitis C infection but together can play an important role in predicting severe disease.