Diagnostic accuracy of narrow band imaging for predicting colon polyp histology can be affected by polyp characteristics.

BACKGROUND/AIMS: Narrow band imaging (NBI) is an optical endoscopic technique for predicting polyp histology during colonoscopy. However, it has not been elucidated the impact of polyp characteristics on the diagnostic capabilities of NBI. We aimed to evaluate which polyp characteristics can influence the diagnostic accuracy of NBI for discriminating neoplastic from non-neoplastic colorectal polyps. METHODOLOGY: A total of 232 colorectal polyps from 134 patients undergoing screening or surveillance colonoscopy were retrospectively analyzed. White light imaging (WLI) and NBI images of polyps were assessed by two experienced endoscopists and two trainees and then compared with histopathology. RESULTS: When classified according to polyp morphology, NBI as well as WLI had a significantly lower sensitivity and diagnostic accuracy for non-polypoid lesions than for polypoid lesions in both experienced and trainee groups. In contrast, the specificity of NBI and WLI for non-polypoid lesions was higher than that for polpyoid lesions. As for polyp size, the diagnostic accuracy of NBI for polyps ≤5mm was significantly lower than for polyps of 6 to 9mm or ≤10mm in the experienced group. CONCLUSIONS: NBI had a significantly lower diagnostic accuracy for predicting polyp histology in non-polypoid or diminutive colorectal lesions.

Association of a genetic polymorphism of IL1RN with risk of acute pancreatitis in a Korean ethnic group.

BACKGROUND/AIMS: Several epidemiological studies have validated the association of interleukin gene polymorphisms with acute pancreatitis (AP) in different populations. However, there have been few studies in Asian ethnic groups. We aimed to investigate the relationships between inflammatory cytokine polymorphisms and AP as pilot research in a Korean ethnic group. METHODS: Patients who had been diagnosed with AP were prospectively enrolled. DNA was extracted from whole blood, and DNA sequencing was subsequently performed. Single-nucleotide polymorphisms (SNPs) of the interleukin 1ß (IL1B), interleukin 1 receptor antagonist (IL1RN), and tumor necrosis factor α (TNFA) genes of patients with AP were compared to those of normal controls. RESULTS: Between January 2011 and January 2013, a total of 65 subjects were enrolled (40 patients with AP vs. 25 healthy controls). One intronic SNP (IL1RN -1129T>C, rs4251961) was significantly associated with the risk of AP (odds ratio, 0.304; 95% confidence interval, 0.095 to 0.967; p = 0.043). However, in our study, AP was not found to be associated with polymorphisms in the promoter regions of inflammatory cytokine genes, including IL1B (-118C>T, c47+242C>T, +3954C/T, and -598T>C) and TNFA (-1211T>C, -1043C>A, -1037C>T, -488G>A, and -418G>A). CONCLUSION: IL1RN -1129T>C (rs4251961) genotypes might be associated with a significant increase of AP risk in a Korean ethnic group.