【关键词】  宫内感染
    Influence on serum hepatitis B virus transcripts in newborns by HBIG immunoblocking therapy during the later stage of pregnancy
　　【Abstract】 AIM: To investigate the significance of viral transcripts in earlystage diagnosis of HBV vertical transmission, and to observe the influence of HBIG immunoblocking therapy on serum HBV RNA in newborns from HBV carrier mothers. METHODS: Fortysix HBsAg positive pregnant women were treated with antiHBV immunotherapy (HBIG 200 IU/4 weeks and Limidazole was applied as liniment 10 mg/week) since 26week pregnancy. The other 23 were taken as controls without any antiHBV therapy. Viral nucleic acids were extracted from sera of mothers before therapy and from sera of newborns. HBV DNA and RNAs, including the fulllength and truncated RNA molecules, were amplified respectively through PCR and RTPCR targeted to the HBV X proteinencoding region. RESULTS: Serum HBV DNA in newborns was only found when their mothers had not been treated. Circulating viral RNA was detected in more than half of the newborns irrespective of treatment of mothers. However, in the newborns of treated mothers, serum RNA was uniformly of the truncated type. CONCLUSION: Application of serum HBV RNA is greatly helpful to the diagnosis of earlystage infection of newborns from HBV carrier mothers. Truncated RNA is transcribed from HBV templates in the newborns rather than being transmitted from mother to child, immunoblocking therapy does not interfere with intrauterine infection. However, it may interfere with the manifestion of a high replicative infection.
　　【Keywords】 hepatitis B virus; transcript; vertical transmission; intrauterine infection; immunotherapy
　　【摘要】 目的：探讨乙型肝炎病毒（HBV）转录体在早期诊断HBV母婴传播中的意义， 并观察母亲抗乙型肝炎病毒免疫球蛋白（HBIG）免疫阻断治疗对新生儿血清HBV转录体的影响．方法：治疗组46例HBV表面抗原（HBsAg）阳性孕妇自孕26 wk开始行抗HBV免疫治疗（HBIG im, 200 IU/4 wk; 同时使用左旋咪唑涂布剂10 mg/wk）；另23例HBsAg）阳性孕妇做为对照组未给予任何抗病毒治疗. 从孕妇治疗前血清及其新生儿血清中提取核酸，经PCR及RTPCR扩增HBV DNA，全长型RNA （fRNA）和顿挫型RNA（trRNA），琼脂糖凝胶电泳显示产物，Southern杂交进一步验证扩增产物. 结果： HBV DNA阳性仅存在于未接受免疫治疗的母亲所生新生儿中； 超过半数的新生儿血清中可检测到病毒转录体RNA， 并与其母亲是否接受免疫阻断治疗无关. 但是，治疗组母亲所生新生儿中仅可检测到顿挫型病毒转录体trRNA. 结论： 血清HBV转录体可早期诊断新生儿HBV感染的状态； 新生儿血清中trRNA的转录模板可能为新生儿体内的病毒DNA; HBIG免疫阻断治疗不能阻断HBV宫内感染，但可以阻止高复制性感染的发生.
　　【关键词】 乙型肝炎病毒；转录体；母婴传播；宫内感染；免疫疗法
　　0引言
　　母婴传播是形成慢性HBV感染的重要原因. 据估计我国的慢性HBV感染约有30%~50%是通过母婴传播发生的. 对于未接受治疗的母亲来讲单独HBsAg阳性母亲的婴儿，约40%在半岁内出现HBsAg阳性的所谓“突破性感染”［1-3］. 而HBsAg和HBeAg双阳性母亲的婴儿HBsAg阳性率高达90%以