肥大细胞和类胰蛋白酶在腹泻型肠易激综合征升结肠黏膜中的表达及意义

Clinical signifi cance of mast cell infi ltration and tryptase expression in the colon of patients with diarrhea-predominant irritable bowel syndrome

目的:探讨升结肠肥大细胞的数量及类胰蛋白酶在腹泻型肠易激综合征(diarrhea-predominant irritable bowel syndrome,IBS-D)发病机制中的作用.方法:收集符合RomeⅢ诊断标准的IBS-D患者24例及健康体检对照组12例,肠镜检查时分别于升结肠取黏膜组织4块,1块甲醛固定后制成石蜡切片,采用甲苯胺蓝染色的方法,于高倍镜下计数测定肥大细胞.另3块新鲜活检标本称质量后、生理盐水里漂洗、迅速在2mLHBSS平衡盐液置37℃下孵育1h,离心后将上清液用酶联免疫吸附试验法检测类胰蛋白酶水平.IBS-D患者进行胃肠道症状评分.结果:IBS-D患者升结肠MC数量是(6.33±1.64)个/HPF,健康对照组为(3.08±0.77)个/HPF,差异有显著性意义(P=0.000).IBS-D患者升结肠黏膜组织类胰蛋白酶浓度为0.072μg/g±0.023μg/g,健康对照组为0.026μg/g±0.014μg/g,差异有显著性意义(P=0.000).肥大细胞数量与胃肠道症状评分(GSRS)无相关(r=0.209,P=0.326),而类胰蛋白酶浓度与GSRS呈正相关(r=0.581,P=0.003).结论:IBS-D患者升结肠肥大细胞和类胰蛋白酶的增加可能与其发病机制有关.

AIM： To determine the number of mast cells and the content of tryptase in the ascending colon of patients with diarrhea-predominant irritable bowel syndrome （IBS-D） and to explore the role of tryptase in the pathogenesis of the disease. METHODS： Twenty-four patients meeting the Rome III diagnostic criteria for IBS-D and twelve healthy controls were included in this study. Four biopsy samples were collected during a colonoscopy from the ascending colon of each subject： one was used for toluidine blue stain-ing to detect mast cells, and the other three were used for detection of tryptase by enzyme-linked immunosorbent assay （ELISA） and for evaluation of gastrointestinal symptoms using the gastrointestinal symptom rating scale （GSRS）. The correlation among the number of mast cells, the content of tryptase and GSRS score was then analyzed. RESULTS： The number of mast cells in the ascending colon of patients with IBS-D was （6.33 ± 1.64） cells/HPF, signifi cantly higher than that in controls （P = 0.000）. The content of tryptase in IBS-D patients was 0.072 μg/g ± 0.023 μg/g, also signif icantly higher than that in controls （P = 0.000）. The number of mast cells was not correlated with GSRS score （r = 0.209, P = 0.326）, while the content of tryptase was positively correlated with GSRS score （r = 0.581, P = 0.003）. CONCLUSION： Mast cell inf iltration and tryptase expression in the colon may be involved in the pathogenesis of IBS-D.