乙型肝炎病毒宫内传播机制的分子流行病学研究

为了解乙型肝炎病毒 ( HBV)宫内传播的危险因素与机制 ,笔者进行了病例对照研究与胎盘组织的免疫组化。收集陕西省妇幼保健院 2 4 2例 HBs Ag阳性的孕妇及其新生儿作为研究对象。结果显示 ,母亲 HBe Ag阳性 ( OR=32 .63)和先兆早产史 ( OR=2 2 .80 )是主要的危险因素。在 32例足月孕妇的免疫组化 HBs Ag阳性的胎盘组织中 ,HBs Ag阳性率在脱膜细胞层为 10 0 % ,滋养层细胞为 59.38% ,绒毛间质细胞为 65.50 % ,绒毛毛细血管内皮细胞为 39.38% ,表明 HBV感染从母面到胎儿血管呈逐渐下降趋势 ( P<0 .0 1)。而且绒毛毛细血管 HBs Ag阳性与婴儿宫内感染有关( OR=2 0 .86,P<0 .0 1)。根据上述结果 ,我们提出假设 :HBV宫内传播可能有两条途径 :经先兆早产等引起的胎盘血管渗漏的“血源传播”和 HBV经胎盘各层细胞“转移”至胎儿血循环的“细胞转移传播”。

A Molecular Epidemiologic Study on the Mechanism of Intrauterine Transmission of Hepatitis B Virus

A case-control study with examination of placentas using immunohistochemistry stain was reported in this paper. In the Maternal and Children Health Hospital of Shanxi Province, 242 consecutive HBsAg positive mothers and their babies were selected as subjects and 110 placentas of HBsAg positive mothers and 25 placentas of HBsAg negative mothers during the different period of pregnancy were collected for laboratory test. The results showed that maternal HBeAg positivity (OR = 32.63) and history of threatened premature labor (OR = 22.80) were important risk factors. Among full-term placentas with HBsAg positivity, HBsAg (biomarker of HBV infection) positive rates were 100% in decidual cell, 59.38% in trophoblastic cell, 65.50% in villous mesenchyme cell, and 39.38% in villous capillary endothelial cell (VCEC) with a decreasing trend (trend test, chi 2 = 30.5, P < 0.01) from mothers to fetus whereas HBsAg positive in VCEC was significantly related to intrauterine infection (OR = 20.86, P < 0.01). Results suggested that there might be two transmission routes on the mechanism of HBV intrauterine transmission, hemogenous by damage of placental vessels and cellular through placental cellular transfer of HBV.