Autofluorescence imaging colonoscopy for the detection of dysplastic lesions in ulcerative colitis: a pilot study

Aim Autofluorescence imaging (AFI) is a novel technology for endoscopy, which enhances neoplastic lesions of the gastrointestinal tract. The aim of this investigation was to examine whether AFI colonoscopy can identify dysplasia in ulcerative colitis. Method We examined 48 patients with ulcerative colitis by AFI colonoscopy. Apparently flat, coarse granular mucosa and visible protruding lesions under conventional colonoscopy were observed by AFI. Those target areas were classified into low AF and high AF according to the colour under AFI colonoscopy. The grade of dysplasia was determined in the specimens obtained from the target areas. Results About 126 sites (35 protruding lesions and 91 flat areas) were examined by AFI colonoscopy. AF was determined to be high in 42 areas and to be low in 84 areas. The positive rate of dysplasia was higher in protrusions (31%) than in flat mucosa (3.3%, P < 0.0001). The rate of positive dysplasia was not statistically different between lesions determined to be low AF (14%) and those to be high AF (5%, P = 0.09). The positive rate of dysplasia in protruding lesions was significantly higher in low AF than in high AF (45.0% vs 13.3%, P = 0.043), while the value in flat lesions was not different between low AF and high AF (8.2% vs 0%, P = 0.3). Conclusions Autofluorescence imaging colonoscopy seems to have a role for the detection of dysplaia in ulcerative colitis.