乙型肝炎病毒S基因变异、基因型与宫内感染免疫失败的关系

The relationship between hepatitis B virus S gene variation, genetype and immunoprophy｜axis failure to intrauterine infection of hepatitis B virus

目的探讨HBV S基因变异、基因型与宫内感染免疫失败的关系。方法选择东南大学附属南京第二医院出生的35例宫内感染免疫失败的幼儿及其母亲，实时荧光定量PCR法检测血清HBV DNA含量；并扩增其HBV S基因序列，测序并通过DNASTAR软件与基因库标准序列比对。结果幼儿及其母亲HBV DNA定量检测结果均〉1×10^6拷贝／mL；幼儿及母亲HBVS基因核苷酸变异率分别为11．4％和17．1％；母婴序列同源性〉99．3％；35对母婴中，23对HBV基因型为C型，血清型为adr亚型，12对为B型，血清型为adw亚型，母婴基因型相同。结论HBV S基因是否变异可能不是高病毒血症患者宫内感染免疫失败的主要因素；基因分型并不能预测和评价新生儿是否发生宫内感染和免疫失败。

Objective To explore the relationship between hepatitis B virus （HBV） S gene variation, genetype and immunoprophylaxis failure to intrauterine infection of HBV. Methods The serum HBV DNA levels of 35 pairs of mothe〉infants were amplified and quantified by real-time fluorescent quantitative polymerase chain reaction （PCR）. Thereafter, the sequences of HBV S gene were determined by sequencing and compared with Genbank standard sequence using DNASTAR software. Results HBV DNA levels of the 3S pairs of mother-infants were all above 1× 10^6 copy/mL. Nueleotide diversity rates were 11.4% in the children and 17. 1%in their mothers. The sequence homology between paired mother and infant was beyond 99.3 0%. The HBV genotype and serotype in 23 pairs of mother-infants was C and adr respectively, while that was B and adw in the other 12 pairs. The HBV genotype and serotype were identical between paired mothers and infants. Conclusions HBV S gene variation may not be a crucial factor for immune failure to HBV intrauterine infection in women with high level viremia. Genotyping could not predict and evaluate the risk of immunoprophylaxis failure to HBV intrauterine infection in neonates.