感染肠道病毒71型尸检病例的分子病原学诊断

Molecular confirmation of enterovirus type 71 infection： a post-mortem study of two cases

目的探讨感染肠道病毒71型（EV71）的尸检病例石蜡包埋组织病原学分子检测的应用价值。方法尸体解剖2例怀疑因EV71感染死亡的患儿，对脑组织进行了组织学观察和免疫组织化学EnVision法标记；应用逆转录聚合酶链反应检测尸检后的石蜡组织中肠道病毒的核酸并测序分析。结果2例均有中枢神经系统脑于脑炎的病理学特点。坏死神经元周围可见大量的小胶质细胞（CD68阳性）和少量的中性粒细胞（CD15阳性）浸润。2例延髓石蜡组织中均检测出EV71的核酸序列，与GenBank最新公布的安徽阜阳暴发EV71感染的病毒株序列同源性为100％。结论从甲醛固定、石蜡包埋的Ev71感染患儿脑组织中检测出病毒特异性核酸序列，及时明确诊断临床误诊、漏诊的死亡病例，深化认识了手足口病，为公共卫生管理机构及时加强EV71病原学监测提供决策依据。

Objective To investigate the diagnostic application of molecular detection of enterovirus type 71 （EV71） infection using post-mortem paraffin-embedded tissue. Methods Two autopsy cases of EV71 infection were studied by histopathological and immunohistochemical methods. Reverse transcription polymerase chain reaction （ RT-PCR ） was performed to detect the viral RNA in paraffin-embedded tissue samples. Results Characteristic features of acute encephalitis were seen in the brain, with most prominent lesions found in the brain stem in both cases. Inflammatory cells were largely CD68-positive microglia with a few CDIS-positive neutrophils in the areas of neuronal necrosis. The 5＇-untranslated region of EV71 was detected in the medulla by RT-PCR using paraffin-embedded tissues of both cases. Sequencing analysis of the RT-PCR products showed 100% homology to the EV71 strain, recently submitted to the GenBank database from Fuyang, Anhui province. Conclusions Molecular detection of EV71 can be performed on formalin-fixed, paraffin-embedded tissue samples from fatally infected patients. Timely and accurate diagnosis of the infection by such molecular approach is crucial for the proper clinical and public health intervention.