角膜烧伤

　　角膜重度碱烧伤后常发生顽固性溃疡，甚至溶解穿孔，在这个病理过程中，免疫学机制是否参与，一直是人们关注的问题；对碱烧伤后是否应用皮质激素治疗也一直存在着争论。为了探讨眼碱烧伤后的免疫反应，我们采用眼组织平片技术，对碱烧伤后的角膜及虹膜组织进行免疫组织化学研究，观察眼局部T淋巴细胞亚群、巨噬细胞、树突细胞、主要组织相容性复合物（major histocompability complex，MHC）-Ⅱ类抗原阳性细胞的动态变化。

　　角膜烧伤【Key words】　Cornea； Burn, chemical； Models，immunology； Immunohistochemistry； Wholemount

　　【Abstract】　Objective　To investigate the immune reaction of severe corneal alkali burns. Methods　 The models of severe corneal alkali burns were induced in rats. Immunohistochemistry was carried out on wholemounts of the cornea and iris at different time points after corneal burns to detect T-lymphocytes and their subpopulation, macrophages, dentritic cells and MHC class Ⅱ-positive cells. Results　 In the early stage of the burns, there were small increasing number of T-lymphocytes and MHC class Ⅱ-positive cells in the cornea and iris. At the period of corneal melting and perforation, a massive influx of lymphocytes (CD＋3, CD＋4, CD＋8), macrophages and dentritic cells was seen in the cornea adjacent to the limbus and iris. CD＋4 lymphocytes were much more than CD＋8 in number. T-cells and MHC class Ⅱ-positive cells were observed not only at the limbus but also in the melting area and corneal center. Morphological changes of these cells were also noted. In the restoration stage, a number of positive cells were still found in the iris. Conclusion　Immunological mechanism is involved in the pathological changes of the damage induced by corneal alkali burns, especially in the pathogenesis of the corneal melting and perforation.

　　CHEN Jiaqi, YANG Peizeng.

　　（Department of Ophthalmology, First Teaching Hospital, Chongqing University of Medical Sciences, Chongqing 400016，China）

ZHAO Min

Immunologic experimental studies on the alkali burn of cornea in rats

　　【摘要】　目的　探讨角膜碱烧伤后眼局部的免疫反应机制。 方法　在大鼠角膜上制作碱烧伤模型。在烧伤后的不同阶段，制备角膜、虹膜组织平片，采用标准的卵白素-生物素过氧化物酶复合物免疫组化(avidin-biotin complex ，ABC)方法，观察眼局部T淋巴细胞亚群、巨噬细胞、树突细胞、主要组织相容性复合物（major histocompability complex，MHC）-Ⅱ类抗原阳性细胞的动态变化。结果　碱烧伤后早期，角膜及虹膜即有T淋巴细胞浸润，以CD＋3淋巴细胞为主，MHC-Ⅱ类抗原阳性细胞也轻度增多。在角膜溶解穿孔阶段，T淋巴细胞浸润达到高峰，其中CD＋4淋巴细胞明显多于CD＋8淋巴细胞；巨噬细胞、树突细胞、MHC-Ⅱ类抗原阳性细胞大量出现。上述细胞密集分布于角膜缘，其中淋巴细胞及MHC-Ⅱ类抗原阳性细胞可见于角膜溶解处及中央区。在烧伤后期角膜溃疡已进入修复阶段，虹膜上依然可见多量各类阳性细胞。结论　免疫反应可能参与了角膜重度碱烧伤后的组织病变过程，在角膜溶解穿孔及眼内炎症的发生中起重要作用。