Early microscopic findings in preclinical inflammatory bowel disease.

BACKGROUND: The immune response involved in the pathogenesis of Inflammatory Bowel Disease (IBD) may be present years before the diagnosis, but the characteristics of the disease during the preclinical period have been scarcely investigated. AIM: To describe the microscopic findings of preclinical IBD and its relationship with the natural history of the disease. METHODS: Medical records from all patients with an incidental diagnosis of IBD during a screening colonoscopy were included in this multicentric and retrospective study. We assessed 15 histologic items in the biopsy samples at diagnosis, and the Geboes score was calculated in patients with Ulcerative Colitis (UC). The main outcome was the development of gastrointestinal symptoms during follow-up. RESULTS: We included 110 patients (79 UC, 24 Crohn's Disease (CD) and 7 with unclassified disease). In UC the most common histologic findings were acute or chronic inflammatory infiltrate and crypt epithelial polymorphs, while in CD we observed acute or chronic neutrophilic infiltrate and epithelial irregularity. Granuloma were only observed in 4% of CD patients. Crypt distortion and the infiltration of neutrophils in the epithelium were associated with a higher risk of developing symptomatic disease. CONCLUSIONS: Preclinical IBD shows specific microscopic findings and they are associated with the progression to symptomatic disease.

Characteristics and Progression of Preclinical Inflammatory Bowel Disease.

BACKGROUND & AIMS: Inflammatory bowel disease (IBD) is a chronic disease usually diagnosed after the appearance of gastrointestinal symptoms. Little is known about IBD progression during its early and even preclinical phases. We aimed to determine the number of new incidental diagnoses of IBD in an older population, and evaluate disease progression from its early stages. METHODS: We performed a retrospective analysis of 31,005 colonoscopies performed during colorectal cancer screening of patients with positive results from fecal immunochemical tests, at 11 centers in the Basque Country (Spain) from 2009 through 2014. We collected clinical and laboratory data from all asymptomatic individuals suspected to have IBD during screening colonoscopies, with histologic confirmation. RESULTS: Colonoscopy screening led to 79 new diagnoses of ulcerative colitis, 24 of Crohn's disease, and 7 of unclassified colitis (average patient age, 57 y; interquartile range, 52-62 y; 57% male). Eleven patients had symptoms before colonoscopy and were excluded from the analysis. Among those patients who were asymptomatic at diagnosis, 36% developed symptoms after a follow-up period of 25 months (interquartile range, 10.5-42 mo), mostly rectal bleeding and diarrhea. Treatment was prescribed for 81 patients (88%), and 2 cases required surgery. CONCLUSIONS: We analyzed data from a large cohort of patients with IBD diagnosed at early or even preclinical stages, from an older population. New incidental diagnoses of IBD were made in 0.35% of individuals undergoing a population-based screening colonoscopy-most were classified as ulcerative colitis. Approximately one third of patients developed symptoms during the follow-up period.