嗜酸粒细胞性支气管炎气道炎症病理特征的探讨

目的： 观察嗜酸粒细胞性支气管炎（EB）气道粘膜炎症的病理特征，并与咳嗽变异型哮喘（CVA）进行比较。 方法： 对11例EB患者行纤支镜支气管粘膜活检，并以10例正常对照、10例CVA和14例典型支气管哮喘的支气管粘膜标本作对照。光镜下测量各组气道粘膜上皮的基底膜厚度，并通过免疫组化和特殊染色技术，计算EB和CVA组气道粘膜固有层中炎症细胞（嗜酸粒细胞、肥大细胞、T淋巴细胞）的浸润密度。 结果： EB组支气管粘膜基底膜厚度［2.92 μm(2.10-6.50)μm］显著高于对照组［2.08 μm(1.62-3.40 μm)］, P<0.05，同时显著低于CVA组［5.64 μm (3.23-8.48 μm)］, P<0.05，而CVA组的基底膜厚度又显著低于典型哮喘组［9.08 μm (6.61-11.99 μm)］, P<0.01；EB组气道粘膜固有层可见肥大细胞和嗜酸粒细胞散在分布，浸润密度分别为［75 cells/mm2(35-112 cells/mm2)］和［7 cells/mm2(0-31 cells/mm2)］，显著低于CVA组［148 cells/mm2(34-200 cells/mm2)，114 cells/mm2(1-768 cells/mm2)］, P<0.05，淋巴细胞浸润密度无显著差异。 结论： EB是以嗜酸细胞浸润为特征，涉及多种炎症细胞的慢性气道炎症性疾病，但气道粘膜基底膜厚度显著低于CVA和典型哮喘，炎症细胞浸润程度低于CVA，均可能是EB缺乏气道高反应性的重要机制。

Pathological features of airway inflammation in eosinophilic bronchitis

AIM: To explore the pathological features of airway inflammation in patients with eosinophilic bronchitis (EB) and compared to those with cough variant asthma (CVA). METHODS: Flexible fibre optic bronchoscopy was performed in 11 patients with EB, 10 with CVA, 14 with bronchial asthma and 10 normal controls. The mean thickness of the basement membrane was measured by light microscopy. Using immunohistochemical and special staining, the localization and density of inflammatory cells (eosinophils, mast cells, T lymphocytes) were detected in bronchial submucosa in EB and CVA patients. RESULTS: The mean thickness of the basement membrane was significantly increased in the subjects with EB ［2.92 μm (2.10-6.50 μm)］, CVA ［5.64 μm (3.23-8.48 μm)］ and bronchial asthma ［9.08 μm (6.61-11.99 μm)］ rather than that in the normal controls ［2.08 μm (1.62-3.40 μm)］. There were also significant differences among the three groups. The number of mast cells and eosinophils in the bronchial submucosal from subjects with EB ［75 cells/mm2 (35-112 cells/mm2), 7 cells/mm2 (0-31 cells/mm2)］ was substantially decreased than those in subjects with CVA ［148 cells/mm2 (34-200 cells/mm2), 114 cells/mm2 (1-768 cells/mm2); P<0.05］. There was no significantly difference in T lymphocyte counts between the EB and CVA. CONCLUSIONS: EB is an inflammatory disorder of the airways with the characteristics of various inflammatory cell (eosinophils, mast cells and T lymphocytes) infiltration. The mean thickness of the basement membrane is less severe than that in CVA and bronchial asthma and the level of infiltration of inflammatory cells is less than that in CVA, which may be one of the reasons that airway hyperresponsiveness is rarely seen in EB.