核苷（酸）类药物治疗后慢性乙肝患者HBV逆转录酶区变异特征分析

Variability of reverse transcriptase gene in chronic hepatitis B patients treated with nucleos（t）ide analogue drugs

目的 探讨经核苷（酸）类药物治疗后慢性乙肝患者乙肝病毒逆转录酶（RT）基因变异情况.方法 应用PCR-直接测序方法对55例接受核苷（酸）类药物抗病毒治疗后慢性乙肝患者HBV基因组RT基因区进行扩增测序,分析不同核苷（酸）类药物治疗后RT区耐药相关位点和其他位点变异特征.结果 在11个经典耐药相关位点中检出7个耐药位点（rtL80、rtV173、rtL180、rtA181、rtM204、rtN236、rtN250）变异,未检出其他4个位点（rtI169、rtT184、rtA194、rtS202）变异.55例乙肝患者中有31例（56.4％）存在经典耐药相关位点变异,其中rtM204V/I变异检出率最高（27/31,87.1％）.rtM204I变异多伴rtL80I变异而rtM204V变异多伴随rtL180M变异出现.在RT区其他非经典耐药位点中发现rtA222T,、rtL229 F/S/W、rtS256C/G、rtQ267H等变异检出率较高,其中以rtA222T频率最高（40％,22/55）.结论 接受核苷（酸）类药物治疗后乙肝患者耐药相关位点变异模式复杂,还存在一些其他非经典耐药相关位点的变异,可能与耐药密切相关.乙肝治疗中应密切监测耐药相关位点变异,为及时合理调整治疗方案提供理论指导.

Objective The aim of this study was to analysis the variability of reverse transcriptase （RT） in chronic hepatitis B （CHB） patients treated with nucleos（t） ide analogue （NA） drugs.Methods Polymerase chain reaction （PCR） and direct-sequencing were performed to analysis the entire hepatitis B virus （HBV） RT gene of HBV isolates from 55 consecutive CHB patients treated with NA.Results Mutations were found at the 7 classical NA resistance （NAr） positions （rtL80,rtV173,rtL180,rtA181,rtM204,rtN236,rtM250）,but not at other 4 classical NAr positions （rtI169,rtT184,rtA194,rtS202）.Among the 55 HBV isolates,31 （56.4%） harboured classical NAr mutations,the rtM204V/I was the major mutation type （27/31,87.1%） in the patients treated with NA rtL80I was occurred in most of the patients with rtM204I （14/22,63.6%）.The rtL180 mol/L was often coexisted with the rtM204V （5/5,100%）.Non-classical mutations related to NAr were also found at other positions,including rtA222T,rtL229 F/S/ W,rtS256C/G,rtQ267H.The rtA222T mutation had a highest percentage （40%,22/55） in these nonclassical mutation positions.Conclusions The patterns of mutation within RT gene are complex in CHB patients treated with NA drugs.In the RT gene of patients treated with NA drugs,there were also had other mutation positions,which might be associate with NA resistance.Monitoring HBV drug resistance mutation markers and patterns in patients treated with NA drugs is benefit to adjust the regimens timely in clinical therapy.