慢性丙型肝炎患者对NS3/4A蛋白酶抑制剂预存耐药的研究

Study of NS3 / 4 protease inhibitor resistance in chronic hepatitis C patients

目的对我国南方184例无抗病毒治疗史的慢性丙型肝炎患者进行NS3/4A蛋白酶抑制剂相关耐药位点检测。方法 NS3/4A蛋白酶抑制剂相关的耐药位点分析采用自行设计型别特异性引物行巢式PCR,PCR产物经纯化后采用直接测序法鉴定。结果 184例样本中有162例扩增成功,其中125例(77.16%)患者共检出266个变异位点。HCV1b型A156S变异率为18.33%,V170I为16.67%;HCV2a型V36L、Q80G、V170I变异率为100%,A156S为64.29%;HCV6a型Q80K变异率为95.45%,V170I为98.86%。结论未使用抗病毒药的慢性丙型肝炎患者对NS3/4A蛋白酶抑制剂也存在预存耐药,变异率因HCV基因型而不同。1b型发生变异较少,HCV2a型及6a型普遍发生变异。

Objective To study the NS3/4 protease inhibitor resistance polymorphism in 184 hepatitis patients without any treatment history. Methods A nested PCR protocol that amplified regions of viral NS3/4A was used to detect the naturally occurred drug-resistant polymorphism. Direct PCR sequencing was performed to analyze the sequences. Results 162 cases were successfully amplified in 184 samples. A total of 266 amino acid substitutions were detected in 125 （77.16%） patients. For the HCV lb genotype, the mutation rates of A156S and V170I were 64.29% and 16.67%, respectively. For HCV 2a genotype, the mutation rates of V36L, Q80G, V170I and A156S were 100%, 100%, 100% and 64.29%, respectively. For HCV 6a genotype, the mutation rates of Q80K and V170I were 95.45% and 100%, respectively. Conclusions Naturally occurring dominant resistance mutations to NS3/4A protease do pre-exist in the viruses obtained from the treatment-naiVe patients with various genotypes in China. Mutation frequency varies with the HCV genotype. HCV genotype lb showed fewer mutations, while HCV genotype 2b and 6a had more mutations.