乙型肝炎病毒RT区原发性耐药变异的研究

Study on primary drug resistance mutation in the reverse transcriptase region of hepatitis B virus

目的探讨核苷(酸)类似物(NA)治疗前乙型肝炎病毒(HBV)RT区原发性耐药变异的发生情况。方法采用PCR产物直接测序技术对61例未接受NA治疗的慢性HBV感染者进行HBV RT区序列测定,分析NA治疗前HBV RT区原发性耐药变异的发生率。结果通过HBV基因扩增、PCR产物直接测序后,共获得61个HBV RT区基因序列,采用HBV RT区基因进化树基因分型共分出B型42例(42/61,68.85%),C型19例(19/61,31.15%),未检出其他基因型。通过核苷酸序列及氨基酸序列分析,对NA常见的10个耐药变异位点(rtI169T、rtV173L、rtL180M、rtA181V/T、rtT184G/S/A/I、rtA194T、rtS202I/G、rtM204I/V、rtN236T、rtM250V)进行比对后,61例患者中共检出HBV RT区变异3例(rtM204I 2例,rtM204I+L180M 1例),自然耐药变异的检出率为4.92%。结论慢性HBV感染者存在少量RT区原发性耐药变异位点,与原发性无应答有关。

Objective To explore the occurrence of primary drug resistance mutation in the reverse transcriptase（RT） region of hepatitis B virus（HBV） before nucleotide（acid） analogue（NA） treatment.Methods HBV RT region sequence of 61 NA-untreated patients with chronic HBV infection that were determined by direct sequencing incidence of primary drug resistance mutation before NA administration was analyzed.Results 61 sequences of HBV RT region were gained by gene amplification and direct sequencing PCR products.Phylogenetic tree analysis of HBV RT region revealed 42 cases of genotype B（42/61,68.85%）and 19 cases of genotype C（19/61,31.15%）and no other genotype was detected.After nucleotide sequence and amino acid sequence analyzed,3 patients were detected mutation in the RT region（2 rtM204I and 1 rtM204I＋L180M） by comparative analysis with 10 common mutation sites of resistance（rtI169T,rtV173L,rtL180M,rtA181V/T,rtT184G/S/A/I,rtA194T,rtS202I/G,rtM204I/V,rtN236T and rtM250V）.The relevance ratio of primary drug resistance mutation was 4.92%.Conclusion Small amounts of primary drug resistance mutations have been found in RT region of patients with chronic HBV infection,which was correlated with primary non-response.