应用PCR病毒定量评价免疫预防对阻断母婴垂直传播乙型肝炎价值的研究

目的：探讨HBsAg阳性孕妇孕前、产前降低血清HBV—DNA含量水平，对阻断HBV母婴传播的意义。方法：应用荧光定量聚合酶链反应（PCR）技术。结果：检测血清乙型肝炎病毒表面抗原（HBsAg）阳性的234例孕妇及配对新生儿血清HBV—DNA含量，婴儿HBV传播率为31．2％。乳汁排毒率32．9％。根据孕妇HBV—DNA测定值高低分组，其中，孕前治疗组62例；孕前未接受治疗孕中免疫阻断组97例；对照组75例。三组比较母婴传播率，均有显著性差异（P〈0．01）。且传播率依次为11．3％、29．9％及49．3％。三组间的乳汁排毒率均有显著性差异（P〈0．001），排毒率依次为9．7％、29．9％及56．0％。分娩前HBV—DNA值〈10^4copies／ml的67例孕妇，其产婴儿未检测出HBV感染。结论：孕妇于孕前抗病毒治疗（有效降低HBV携带量）及孕期通过HBIG免疫，可有效预防HBV宫内感染。

Study on the Blockage of Mother-Infant HBV Transmission Through Reduction of Maternal Blood HBV-DNA Content (Measured Quantitatively with PCR Technic) with Pre-and/or Intrapartal Antiviral Therapy

Objective To study the effect of pre - and/or intrapartal reduction of maternal blood content of HBV - DNA on the blockage of mother - infant HBV transmission in HBsAg positive pregnant women. Methods This study involved 234 HBsAg positive pregnant women of three groups ： ① 62 women found to be HBsAg positive before pregnancy were treated with lamivudine until the serum HBV - DNA contents dropped to below 10^6 copies/ml. They were allowed to be pregnant and furthur treated with HBIg from 28 week gestation on. ② 97 women were found to be HBsAg positive only after pregnancy and were treated intrapartally only with HBIg from 28 week gestation on. ③ 75 women were found to be HBsAg positive just before labor and received on anti - viral therapy. Serum HBV - DNA contents were measured quantitatively with PCR technic in these women just before delivery. The milk specimens on d2 - 5 post - patum and the neonates＇ serum specimens were examined for HBV - DNA quantitatively. Results As a whole, the positive rate of HBV - DNA in the neonates was 31.2% （73/234） and the positive milk rate was 32.9% （77/234）. In the 62 women with pre - and intrapartal treatment, only 7 neonates were positive （ 11.3% ） and the milk positive rate was only 9.7% （6/62）. The corresponding figures for the other two groups were： 29 （29.9%）, 29.9% （29/97） and 37 （49.3%）, 56.0% （42/75） respectively. Differences between the respective figures were all significant （ P 〈 0.01 ）. The most significant finding was that in the 67 pregnant women with post -treatment HBV -DNA contents below 10^4 copies/ml, none of the neonates were positive for HBV infection. Conclusion Pre - and/or intrapaxtal anti - viral treatment in pregnant women can substantially reduce intrauterine HBV infection of fetus thus block the mother- infant HBV transmission.