溃疡性结肠炎窄带光成像肠镜下黏膜血管形态对炎症和血管生成的预测价值

Prediction of inflammation and angiogenesis in ulcerative colitis by assessment of mucosal vascular pattern under narrow-band imaging colonoscopy

目的探讨窄带光成像(narrow-band imaging,NBI)肠镜下溃疡性结肠炎(ulcerative colitis,UC)患者不同黏膜血管形态(mucosal vascular pattern,MVP)分型对UC患者肠黏膜炎症和血管生成的预测价值。方法2012—2015年在北京协和医院就诊的42例UC患者被纳入研究并接受NBI肠镜检查,NBI模式下对存在病变的肠段进行图像采集,并至少活检1块组织用于病理学分析。所有NBI图像经2位内镜医师讨论达成一致后,对MVP做出分型。采用结肠炎组织学评分标准对黏膜炎症程度进行0~4级的分级评分;血管内皮标记CD31免疫组织化学染色后,通过每视野血管计数对微血管密度进行定量分析;根据免疫组织化学结果对黏膜血管内皮生长因子(vascular endothelial growth factor,VEGF)的表达程度进行半定量分析。所有组织学指标由同一位不知道具体内镜相关资料的病理医师进行评价。结果42例UC患者的119处结肠或直肠肠段根据NBI肠镜下MVP分型标准,其中34处肠段被定义为清晰,58处肠段被定义为模糊,27处肠段被定义为消失。NBI肠镜下MVP分型与黏膜炎症程度之间具有显著的相关性(r=0.824,P<0.001)。MVP从清晰型、模糊型至消失型,黏膜的微血管密度(P<0.001)和VEGF表达水平(P<0.001)均呈现出显著递增的趋势。黏膜活检组织的微血管密度和VEGF表达水平之间存在显著的正相关(r=0.961,P<0.001)。结论NBI肠镜下MVP分型可以预测UC患者的黏膜炎症程度和血管生成水平。

Objective To explore the predictive value of mucosal vascular pattern(MVP)for inflammation and angiogenesis in ulcerative colitis(UC)under narrow-band imaging(NBI)colonoscopy.Methods Forty-two patients with UC were recruited for NBI colonoscopy between 2012 and 2015 at Peking Union Medical College Hospital.For each segment with lesion,the NBI image was saved and at least one biopsy specimen was obtained for histological assessment.MVP of each image was determined by two trained endoscopists with consensus.The degree of inflammation was graded by using a histological colitis score from zero to four.The immunohistochemical staining of endothelin marker CD31 was performed and microvascular density was assessed by vessel count.Semi-quantitative vascular endothelial growth factor(VEGF)expression was evaluated immunohistochemically.The histological variables were assessed by a pathologist who was blinded to the endoscopic findings.Results MVP in 119 colorectal segments from 42 patients was assessed under NBI colonoscopy.The results showed 34 segments of clear MVP,58 of obscure MVP and 27 MVP absence.The classification of MVP was correlated with the degree of inflammation(r=0.824,P<0.001).There was a trend towards a growing level of microvascular density(P<0.001)and VEGF expression(P<0.001),with the varying classifications of MVP.A significantly positive relationship(r=0.961,P<0.001)between microvascular density and VEGF expression was observed.Conclusion The classification of MVP under NBI colonoscopy may be a useful tool for prediction of the grade of mucosal inflammation and angiogenesis in UC.