Interleukin 28B Polymorphism as a Predictive Factor to Treatment Response in Chronic Hepatitis C Genotype 4 Egyptian Patients

Iman H Shehata¹, Rasha A Nasr^1*, Mohamed S Badr², Runia F El-Folly³, Ayman R Abdelkader⁴

¹Medical Microbiology and Immunology, Faculty of Medicine Ain Shams University,

²Molecular Biology, Medical Research Center, Ain Shams University,

³Tropical Medicine, Ain Shams University,

⁴ Internal Medicine, Ahmed Maher Teaching Hospital. Cairo, Egypt

*Corresponding author’s E-mail: Rnasr2@hotmail.com;

Tel: (+2) 01116545915 

Accepted 03 December, 2012

Abstract

Single nucleotide polymorphisms (SNPs) in the IL-28B gene are considered one of the most important baseline predictors of sustained virological response (SVR) to peg-interferon (PegIFN) and ribavirin (Rbv) in patients with hepatitis C virus (HCV) genotype 1 infection, and much less so in HCV-2 and -3. Whether this holds true for HCV-4 patients too is unknown.The purpose of this study was to determine the relevance of SNP in the IL28B gene region rs12979860 to treatment response in a well characterized cohort of Egyptian patients with genotype 4 HCV infection. This study included 43 patients with chronic genotype 4 HCV infection previously treated with standard doses of PegIFN-α/Rbv. IL28B SNP genotyping at rs12979860 was detected using the LightMix® Kit. Each of CC and CT genotype were present in 34.8% of patients, while 30% had the TT genotype. Seventeen (39.5%) of patients achieved a SVR, while 26 (60.5%) did not. Of the 17 responders, 13 had genotype CC, 4 had genotype CT, while none with genotype TT responded. Patients having CC genotype achieved significantly higher SVR rates (86.6%) compared with CT/TT patients (14%). By univariate analysis, fibrosis stage F0-2 (OR 10, 95%CI 1.78-56.15, P=0) and IL-28B genotype CC (OR 17.87, 95%CI 2.73-116.87, P=0.003) were significantly associated with SVR. In conclusion, IL-28B polymorphism is significantly associated with response to PegIFN and Rbv in Egyptian patients with chronic genotype 4 HCV infection. The advance knowledge of patient’s genotype could be in the future an important component of the clinical decision of initiating treatment.

Keywords: Hepatitis C virus, IL28B, Single nucleotide polymorphism, Sustained virological response.