Prevalence Of HCV Resistant Association Substitutions To Direct-Acting Antiviral Agents In Treatment-Na?ve HCV Genotype 1b Infected Patients In Western China

Background:Direct-acting antiviral agents(DAAs)against hepatitis C virus(HCV)are potent and highly efficacious.However,resistance-associated substitutions(RASs)to DAAs can impair the treatment effectiveness even at baseline.Moreover,the prevalence of baseline RASs in HCV genotype 1b-infected patients in Western China is still unclear.Methods:Direct sequencing of the HCV NS3,NS5 A and NS5 B regions was performed in baseline serum samples of 70 DAAs treatment-na?ve HCV 1b-infected patients in Western China.The sequences were analyzed with MEGA version v5.05 software.Evolutionary patterns of RASs and amino acid covariance patterns in the NS3,NS5 A and NS5 B genes were analyzed by MEGA and Cytoscape(version 3.2.1),respectively.Results:The presence of at least one RASs in the NS3 region(C16S,T54 S,Q80R/L,A87 T,R117H,S122 G,V132I,V170I)was observed in 85.48%(53/62)of patients,RASs in the NS5 A region(L28M,R30 Q,Q54H,P58S/T,Q62H/R,Y93H)were observed in 42.42%(28/66)of patients,and RASs in the NS5 B region(N142S,A300 T,C316N,A338 V,S365A,L392 I,M414L,I424 V,A442T,V499 A,S556G)were observed in 100%(44/44)of patients.Evolutionary patterns of RASs and amino acid covariance patterns in NS3,NS5 A and NS5 B genes were reported.Conclusions:The prevalence of RASs relevant to DAA detected in the NS3,NS5 A and NS5 B regions of HCV 1b from DAA treatment-na?ve patients is high.Therefore,more attention should be paid to RASs associated with DAAs in the upcoming DAAs-treatment era in China.