The complete title: The effect of interleukin-28B rs12979860 polymorphism on the therapeutic response of Moroccan patients with chronic hepatitis C.

There is increasing evidence for the effect of rs12979860 IL28B polymorphism in response to the standard treatment PEG-IFN/RBV (i.e. combination of pegylated interferon and ribavirin) in chronic hepatitis C virus (HCV) infection. The present study aimed to determine the impact of IL28B associations in interferon responsiveness in 187 Moroccan patients with chronic HCV infection. HCV RNA levels were measured with a real-time RT-PCR assay and treatment efficacy was assessed by sustained virological response (SVR) and patients were classified as responders or non-responders. IL28B rs12979860 polymorphism genotyping was achieved by PCR-HRM technique. The results demonstrated that SVR was achieved in 102 patients (55%); while 69 were non-responders (37%) and 16 relapsed (8%). Genotype 1 was the predominant HCV genotype detected in 112 patients followed by genotype 2 in 56 patients. The genotype CC was observed in 42 cases (25%); CT in 69 (41%) and TT in 57 (34%) demonstrating a C allele frequency of 46%. The SVR was observed in 32 patients with genotype CC accounting for 76%. The frequencies of rs12979860 CC type in infected individuals with HCV genotype 1 were 47% and 12% respectively in SVR and non-SVR groups. A highly statistically significant association between this SNP and SVR was found (p<0.001). Using multivariate logistic regression analysis, CC genotype was an independent factor for SVR. In the group of patients infected with genotype 2, SVR rate was 79%. The frequency of rs12979860 CC type in SVR group (n=4) was 9% and rs12979860 non-CC genotype was highly associated with SVR (p=0.001). This finding adds evidence that genotyping for the IL-28B rs12979860 SNP can be a good parameter for the prediction of treatment success in patients with chronic hepatitis C before initiation of antiviral therapy in Morocco.