感染后肠易激综合征患者结肠黏膜肥大细胞与IL-2、IFN-γ的表达及意义

Relationship between mast cells and expressions of interleukin-2 and interferon-γ on colonic mucosa in patients with post-infective irritable bowel syndrome

目的:光镜、电镜下观察肠易激综合征(IBS)患者肠黏膜肥大细胞(MC)的改变及其与白细胞介素(IL-2)、干扰素(IFN-γ)表达的关系,探讨其在IBS病理生理机制中的可能作用和临床意义。方法:经结肠镜钳取10名正常人和30例感染后IBS患者的乙状结肠黏膜标本,应用特殊组织化学染色法(甲苯胺蓝改良染色法)、免疫组织化学染色法,分别对MC和IL-2、IFN-γ进行染色,在光镜下观察,计算每10个高倍视野下染色阳性表达细胞的平均数。再取其中12例采用石蜡连续切片及原位包埋法透射电镜观察MC的形态变化及其相邻组织结构。并应用病理图像分析软件进行分析。结果:IBS患者乙状结肠MC明显增多(P<0.05),大量MC表现为活跃的脱颗粒状态。同时IL-2、IFN-γ表达水平显著升高。结论:活动期IBS患者MC传递了免疫反应信息,可能是免疫机制和神经机制的中间环节;IL-2、IFN-γ(属于Th1炎症细胞因子)的表达增强,可导致内脏高敏化;感染并非导致IBS患者肠黏膜MC改变的惟一原因。

Objective：To investigate the change of the mast cells（MCs） and its relationship with the expression of Thl cytokines（ IL- 2, IFN-γ）, and to elucidate their possible roles in visceral hypersensitivity in patients with irritable bowel syndrome （IBS）. Methods： The mucosa specimens were taken from the sigmoid colon of l0 normal controls and 30 patients with post-infective IBS. The MCs,IL-2 and IFN-γ were stained by histochemical and immunobisto-chemical methods respectively, and color image analyzer was applied to investigate the results qualitatively and quantitatively. The ultrastructure of ceils in colic mucosa and the changes of the MCs were studied through an ultra-microscopy using situs embedding technique and a light microscopic study in serial sections. The results were analyzed by image analysis software. Results：The number of MCs in the sigmoid colon of patients with IBS was significantly elevated （P 〈 0.05） , and MCs in IBS presented prominent variations. Significant increase of the IL-2 and IFN-γ was found in the intestinal mucosa of IBS compared to the control. Conclusions：The Expressions of MCs,IL-2 and IFN-γ are significantly increased in patients with postinfective-IBS, which indicates that the activation of colonic MCs is involved in the visceral sensitization. The MCs may be the middle link of immunity mechanism and nerve mechanism. High expressions of IL-2 and IFN-γ may partly explain the sensitization of the internal organs. Infection is not the only factor leading to the changes of mast cells in patients with IBS.