肠道病毒71型在脑干脑炎婴幼儿脑干中的分布及感染机制

Distribution of Human Enterovirus 71 in Brainstem of Infants with Brain Stem Encephalitis and Infection Mechanism

目的观察人肠道病毒71型(enterovirus 71,EV71)以及细胞间黏附分子1(intercellular adhesionmolecules-1,ICAM-1)在脑干脑炎死亡的婴幼儿脑干中的表达及分布特点,探讨EV71进入中枢神经系统的机制以及ICAM-1的参与作用。方法收集22例尸检确认为脑干脑炎婴幼儿的脑干组织为实验组,并以10例先天性心脏病死亡婴幼儿的脑干组织作为对照组。选择实验组中镜下小血管呈典型的"袖套样"改变的切片进行EV71-VP1免疫组织化学染色,然后对EV71-VP1阳性的切片进行ICAM-1免疫组织化学染色。染色结果经图像分析和统计学处理,比较实验组和对照组的染色结果。结果 (1)实验组EV71-VP1免疫组织化学阳性染色呈深棕黄色,主要位于脑干星形胶质细胞内,对照组染色呈阴性。(2)ICAM-1阳性呈深棕黄色,在脑干血管周围炎症细胞、胶质小结内的炎症细胞及胶质细胞表达升高,与对照组比较差异具有统计学意义(P<0.05)。结论EV71可作为脑干脑炎致死婴幼儿法医病理诊断的筛选依据。EV71可能通过血源性侵染脑干,ICAM-1可能在脑干炎症改变过程中起重要作用。

Objective To explore the mechanism that how human enterovirus 71（EV71） invades the brainstem and how intercellular adhesion molecules-1（ICAM-1） participates by analyzing the expression and distribution of human EV71,and ICAM-1 in brainstem of infants with brain stem encephalitis.Methods Twenty-two brainstem of infants with brain stem encephalitis were collected as the experimental group and 10 brainstems of fatal congenital heart disease were selected as the control group.The sections with perivascular cuffings were selected to observe EV71-VP1 expression by immunohistochemistry method and ICAM-1 expression was detected for the sections with EV71-VP1 positive expression.The staining image analysis and statistics analysis were performed.The experiment and control groups were compared.Results（1） EV71-VP1 positive cells in the experimental group were mainly astrocytes in brainstem with nigger-brown particles,and the control group was negative.（2） ICAM-1 positive cells showed nigger-brown.The expression in inflammatory cells（around blood vessels of brain stem and in glial nodules） and gliocytes increased.The results showed statistical difference comparing with control group（P0.05）.Conclusion The brainstem encephalitis can be used to diagnose fatal EV71 infection in infants.EV71 can invade the brainstem via hematogenous route.ICAM-1 may play an important role in the pathogenic process.