IL-17在中枢神经系统感染发病机制及鉴别诊断中的作用

Role of IL-17 in the pathogenesy and differential diagnosis of CNS infections

目的探讨IL-17有无参与结核性脑膜炎（TBM）、隐球菌性脑膜炎（CM）、病毒性脑膜脑炎（VM）这3类中枢神经系统感染的免疫反应和对这3类中枢神经系统感染的鉴别诊断有无提示意义。方法选择自2008年2月至2009年12月在中山大学附属第三医院住院治疗的中枢神经系统感染患者112例，根据感染源不同分为TBM组、CM组和VM组。同时选择同期在该院住院的非中枢神经系统感染性疾病及非自身免疫疾病患者36例，归入对照组。用ELISA法测定IL-17、IL-12、IFN—γ在4组患者脑脊液中的浓度。结果4组对象脑脊液中IL-17水平差异有统计学意义（P〈0．05），由高到低依次是CM组、TBM组、VM组和对照组。4组患者间IL-12、IFN-γ水平差异也有统计学意义（P〈0．05），其中TBM组和CM组患者脑脊液中的IL-12、IFN-γ的水平较VM组和对照组患者明显增高。TBM组患者脑脊液中IL—17与IL-12呈负相关（r=-0．311，P=-0．033），IL-17、IL-12、IFN-γ与脑脊液白细胞数均呈正相关（r=0．219，0．434，0．341；P=-0．031，0．027，0．001）。利用脑脊液中IL-17的水平建立这3种疾病的ROC曲线，曲线下面积均大于0．7。结论Th17免疫途径广泛的参与了这3种中枢神经系统感染的免疫应答，且可能与Th1免疫途径相互影响。IL-17检测有助于这3类中枢神经系统感染的鉴别诊断。

Objective To study the role of IL-17 in the pathogenesy and differential diagnosis of the 3 types of CNS infections （tubercular meningitis [TBM], cryptococcal meningitis [CM], viral meningoencephalitis [VM]）. Methods One hundred and twelve patients with CNS infections, admitted to out hospital from February 2008 to December 2009, were chosen and divided into ＂IBM group, CM group and VM group; another 36 patients without CNS infections either autoimmune disease at the same period were chosen as control group. ELISA was employed to determine the levels of IL-17, IL-12, IFN-y in the cerebrospinal fluid in these 4 groups. Results IL-17 level in the cerebrospinal fluid of the 3 groups with CNS infections were obviously different, but all of them were significantly higher than that in control group （P〈0.05）, with CM group enjoying the highest level, following by TBM group, VM group and control group. The levels of IL-12 and IFN-y in patients with TBM and CM were higher than those in patients with VM and controls. Through the correlation analysis of IL-17, IL-12 and IFN-y in patients with TBM, we found that IL-17 level was negatively correlated with IL-12 level （r=-0.311, P=0.033）; the levels of these 3 cytokines were positively correlated with the quantity of leucocytes （r= 0.219, 0.434 and 0.341, P=-0.031, 0.027 and 0.001）. ROC curves were established for differential diagnosis among these 3 groups according to CSF IL-17 levels, and all of the areas under the curve were bigger than 0.7. Conclusion Thl7 pathway is widely involved in the immune responses of CNS infection, and interacts with Thl pathway. The different levels of IL-17 in the cerebrospinal fluids in patients with various CNS infections may contribute to differential diagnosis.