摘要
Objective To assess the correlation between hepatitis B virus (HBV) surface gene mutant infection and hepatitis B (HB) vaccination failure Methods Using sera from 106 infants who were born to HBV carrier mothers and failed in HB immunoprophylaxis, HBV S gene was amplified by PCR, transferred to nylon membranes for Southern blots, and then hybridized with oligonucleotide probes Eleven of non hybridizing samples were used for DNA sequencing Results 93 4% (99/106) of the samples were HBV DNA positive, and 30 3% (30/99) failed to hybridize with at least one of the four probes DNA sequencing confirmed that 10 of the 11 samples had an S gene mutation with amino acid (aa) change The identified mutants included nucleotide (nt) 546T→A(aa131N→T), nt531T→C (aa126I→T), nt491A→C (aa113T→P), nt491T→A (aa113S→T), nt533C→A (aa127P→T), nt581T→A (aa143S→T), nt636A→T (aa161Y→F), and nt679A→C (aa175L→F) The sequence in one mother infant pair was completely the same, with mutations at aa131 and aa161 Conclusions The prevalence of HBV surface mutants is about 30% in the children failing in HB vaccination HBV mutants can infect infants by maternal infant transmission
目的 对 10 6例免疫失败儿童研究分析HBVS变异株的感染和意义。方法 生于携带HBV母亲的 132 4名新生儿按 0、1、6程序接种乙型肝炎疫苗 ,联合应用HBIG ,定期临床随访和检测HBV血清学标志。其中 10 6例免疫失败者为研究对象 ,从血清中提取DNA ,经PCR扩增HBVS区基因片段 ,Southernblot转移至尼龙膜 ,与S区标准序列探针杂交 ,选择PCR阳性、与寡核苷酸探针不杂交的样本作序列分析。结果 免疫失败儿童中HBVDNA阳性 99例 (93.4 % ) ,99例阳性样本有 30份 (30 .3% )与探针不杂交。选择 11份作序列分析 ,10份存在核苷酸变异伴氨基酸改变 ,分别位于氨基酸残基 113(ST、TP)、12 6 (IT)、12 7(PT)、131(NT)、143(ST)、16 1(YF)和 175(LF)。同时对一对母婴测序结果显示其序列完全一致 ,均存在 131和 16 1位氨基酸被取代。结论 乙型肝炎主被动联合免疫失败儿童中 30 %存在S区基因变异。HBV变异株可经母婴传播。由于基因序列分析受试剂和仪器限制 ,难以常规在大样本中开展 ,应用寡核苷酸探针杂交是一种简便实用的方法。
