Background: Despite the outstanding results of direct-acting antiviral therapies (DAAs) of Hepatitis C infection (HCV), non-responders had to be more defined. Aim: assess the outcome of DAAs in linkage with Interferon lambda 3 (IFNL3) in HCV patients. Methods: This case-control-study was conducted on 495 chronic-HCV (genotype-4a), previously treated Egyptians by either DAAs (responders 195, 120 relapsers) or interferon/ribavirin (IFN/RBV) (140 responders, 60 relapsers), and 98 healthy controls. IFNL3 distribution, clinical and laboratory data were assessed. Results: CT was the most predominant genotype in Egyptians (51%). All genotypes were sensitive to DAAs mainly CT genotype (60%), even TT genotype (resistant to IFN/RBV 40%) had 29.2% sensitivity. CT genotype was predominant in sofosbuvir/Daclatasvir responders (67.6%) (OR = 0.66), while non-CT prevailed in relapsers (56.7%). TT genotype may respond to SOF/Ledi better than other regimens (66.7%). In IFN/RBV relapsers; CT genotype was commoner (50%) than others, while CC genotype predominated in responders (54.3%). The c allele was the commonest in responders to IFN/RBV (71.4%), while the T allele was resistant to treatment (65% in relapsers). Addition of RBV to SOF/DCV reported higher resistance with CT genotype (42.2%-50%) and TT genotype (17.8%-27.8%). Conclusion: This study recommended IFNL3 genotyping to be a prerequisite before stratifying treatment for HCV-4a Egyptians.
Keywords: Direct acting antiviral drugs; HCV; IFNL3; single nucleotide polymorphism; therapy response.