ORIGINAL CONTRIBUTIONS: INFLAMMATORY BOWEL DISEASEClassification of Inflammation Activity in Ulcerative Colitis by Confocal Laser EndomicroscopyLi, Chang-Qing PhD1; Xie, Xiang-Jun PhD1,2; Yu, Tao MD1; Gu, Xiao-Meng MD1; Zuo, Xiu-Li MD1; Zhou, Cheng-Jun MD3; Huang, Wei-Qing MD4; Chen, Hua MD4; Li, Yan-Qing MD1Author Information 1Department of Gastroenterology, Qilu Hospital, Shandong University, Jinan, China 2Department of Gastroenterology, Qingdao Municipal Hospital, Qingdao, China 3Department of Pathology, The Second Affiliated Hospital, Shandong University, Jinan, China 4Department of Pathology, Qingdao Municipal Hospital, Qingdao, China Correspondence: Yan-Qing Li, MD, Department of Gastroenterology, Shandong University, Qilu Hospital, No. 107, Wenhuaxi Road, Jinan 250012, China. E-mail: firstname.lastname@example.org published online 24 November 2009 Received 8 June 2009; accepted 20 October 2009 American Journal of Gastroenterology: June 2010 - Volume 105 - Issue 6 - p 1391-1396 doi: 10.1038/ajg.2009.664 Buy Metrics Abstract OBJECTIVES: The assessment of inflammation activity in ulcerative colitis (UC) includes endoscopy and histology. Confocal laser endomicroscopy (CLE) combines real-time endoscopy and histology. This study was aimed at evaluating the application of CLE in the assessment of inflammation activity in UC. METHODS: In total, 73 consecutive patients with UC who visited Qilu Hospital for colonoscopy surveillance underwent CLE. Inflammation activity was first assessed by the colonoscopy Baron score, then by CLE with a 4-grade classification of crypt architecture, as well as by analysis of microvascular alterations and fluorescein leakage. Targeted biopsy samples were taken for histological analysis. Stored CLE images were subjected to post-CLE objective assessment. RESULTS: Both assessment of crypt architecture and fluorescein leakage with CLE showed good correlations with histological results (Spearman's rho, bothP<0.001). CLE seemed to be more accurate than conventional white-light endoscopy for evaluating macroscopical normal mucosa. More than half of the patients with normal mucosa seen on conventional white-light endoscopy showed acute inflammation on histology, whereas no patients with normal mucosa or with chronic inflammation seen on CLE showed acute inflammation on histology. Assessment of microvascular alterations by CLE showed good correlation with histological findings (P<0.001). On post-CLE objective assessment, subjective architectural classifications were supported by the number of crypts per image (P<0.001) but not fluorescein leakage results by gray scale (P=0.194). CONCLUSIONS: CLE is reliable for real-time assessment of inflammation activity in UC. Crypt architecture, microvascular alterations, and fluorescein leakage are promising markers in CLE evaluation. © The American College of Gastroenterology 2010. All Rights Reserved.