垂直传播中乙型肝炎病毒S区变异株检出及其流行病学意义

目的　研究垂直传播中乙型肝炎病毒Ｓ基因变异的流行病学意义。方法　以配偶无乙型肝炎病毒（ＨＢＶ） 标志的４ 名女性携带者与６ 名男性携带者及其子宫内感染ＨＢＶ 的胎儿为对象，以双脱氧链末端终止法检测母子、父子所携ＨＢＶＳ区４５１ ～６６０ 位核苷酸序列。结果　母子、父子间同源性９８ ％ ～１００ ％ ，检出４９１ 、４９４、５３０ 、５４６、５８１ 位点变异致使１１３ 、１１４、１２６ 、１３１、１４３ 位氨基酸替代，其中２ 对父母与胎儿检出１２６ 位变异。４ 例胎儿检出１３１ 位变异，其中２ 例胎儿合并检出１４３ 位变异。结论　ＨＢＶ垂直传播中存在Ｓ基因变异株，可能以１２６、１３１、１４３ 位氨基酸变异株为主，这些变异株可能使ＨＢ疫苗免疫失败。

Detection of S-gene mutation strain in vertical transmission of HBV and its significance

Objective To study S-gene mutation of hepatitis B virus (HBV) in its vertical transmission and its significance. Methods Nucleotides of S-gene nt451-660 of HBV were sequenced with dideoxy end termination technique in four female and six male carriers without HBV markers in their spouses and in their intrauterine infected fetuses. Results It was showed that homology of HBV nucleotide and amino acid sequences in the mothers, fathers and their fetuses was very high. Mutation at the sites 491,494,530,546 and 581 of S-gene resulted in amino acid substitution at the sites 113,114,126,131 and 143, respectively. Mutations at the sites 126 were detected in two pairs of mother or father and her or his fetuses and mutations at the sites 131 in four fetuses, respectively, including combined mutation at the site 143 in two fetuses. Conclusion Strains with S-gene mutation, mainly at the sites 126,131 and 143, could be found in HBV vertical transmissions, which could cause failure in HB vaccine immunization.