腹泻型肠易激综合征患者食物不耐受、症状指数及回盲部肥大细胞变化的相关性

目的:比较食物不耐受(food intolerance,FI)在腹泻型肠易激综合征患者(diarrhea-dominant irritable bowel syndrome,D-IBS)及健康人群中的存在情况,分析D-IBS患者食物不耐受严重程度、症状指数与回盲部肥大细胞数量变化之间的关系,以探讨食物不耐受在D-IBS发病中的意义及可能机制.方法:选取符合罗马Ⅲ诊断标准的D-IBS患者22例为病例组,无消化系症状的健康体检者21例为对照组,分别接受结肠镜检查.应用食物不耐受状况评价问卷对2组进行食物不耐受状况评分;用功能性肠病症状严重指数(functional bowel disorder severity index,FBDSI)和IBS病情尺度调查表(IBS symptomseverity scale,IBS-SSS)对病例组进行IBS症状严重程度评分.所有研究对象均接受结肠镜检查,在距回盲瓣4cm处取活检组织2块,采用甲苯胺蓝染色法计数黏膜肥大细胞数量,并与食物不耐受严重程度指数、IBS症状严重程度评分进行相关性分析.结果:D-IBS患者回盲部肠黏膜肥大细胞计数(4.68±0.55)个/高倍镜视野,健康对照组为(1.33±0.54)个/高倍镜视野,P<0.001,差异具有统计学意义;病例组食物不耐受存在情况明显高于对照组(P<0.05);食物不耐受严重程度与IBS症状严重程度指数间呈正相关(FBDSI:r=0.992,P<0.001;IBS-SSS:r=0.970,P<0.001);回盲部肥大细胞计数与I B S症状严重程度指数间呈正相关(FBDSI:r=0.957,P<0.001;IBS-SSS:r=0.985,P<0.001);食物不耐受严重程度与IBS患者回盲部肥大细胞计数间呈正相关(r=0.964,P<0.001),健康对照组中食物不耐受者回盲部肥大细胞计数明显高于无食物不耐受者(P<0.05).结论:D-IBS临床症状与肠道肥大细胞数量增多密切相关,食物抗原的刺激作用可能是D-IBS患者回盲部肥大细胞数目增多的原因之一;D-IBS患者食物不耐受存在情况普遍,食物不耐受可加重D-IBS患者肠道症状.

Relationship among food intolerance, severity of symptoms and the number of mast cells in the ileocecal junction in patients with diarrhea-predominant irritable bowel syndrome

AIM: To analyze the relationship among food intolerance, severity of symptoms and the number of mucosal mast cells (MCs) in the ileocecal junction (ICJ) in patients with diarrhea-predominant irritable bowel syndrome (D-IBS), and to explore the influence of food intolerance on the pathogenesis of D-IBS. METHODS: Twenty-two patients with D-IBS fulfilling the Rome III criteria and 21 asymptomatic healthy controls underwent colonoscopy in which two adjacent biopsy samples were taken from the ICJ. Mucosal MCs were detected by toluidine blue staining. The Food Intolerance Questionnaire was used to evaluate the perceived food intolerance status of D-IBS patients and controls. The Functional Bowel Disorder Severity Index (FBDSI) and IBS Symptom Severity Scale (IBS-SSS) were used to evaluate the severity of symptoms in D-IBS patients. The relationship among the scores of FBDSI and IBS-SSS, the number of MCs and the scores of food intolerance in D-IBS patients was analyzed. RESULTS: The number of mucosal MCs in the ICJ was significantly higher in patients with D-IBS than in controls (4.68 ± 0.55/HP vs 1.33 ± 0.54/HP, P<0.001). Compared to controls, perceived FI was more frequent in patients with D-IBS (P<0.05). The scores of FBDSI and IBSSSS were positively correlated with that of food intolerance in D-IBS patients (FBDSI: r = 0.992, P <0.001; IBS-SSS: r = 0.970, P<0.001), and with the number of mucosal MCs in the ICJ (FBDSI: r = 0.957, P<0.001; IBS-SSS: r = 0.985, P<0.001). The scores of food intolerance in D-IBS patients were positively correlated with the number of mucosal MCs in the ICJ (r = 0.964, P<0.001). The number of mucosal MCs in the ICJ were significantly higher in healthy subjects with selfreported food intolerance than in those without food intolerance (P<0.05). CONCLUSION: The symptoms of D-IBS are positively correlated with increased number of enteric mucosal MCs which might be caused by food antigen. Food intolerance is more frequent in D-IBS patients than in controls. D-IBS symptoms may be caused or exacerbated by food intolerance.