Clinical implications of histologic abnormalities in colonic biopsy specimens from patients with ulcerative colitis in clinical remission.

BACKGROUND: For patients with ulcerative colitis (UC) who have colonoscopy while their disease is in clinical remission, the clinical implications of finding histologic abnormalities of colitis are not clear.

METHODS: We reviewed the medical records of patients with UC who had elective colonoscopy at our VA Medical Center while their UC was in clinical remission and who had at least 6 months of follow-up data available. The Mayo endoscopic subscore was used to assess endoscopic disease activity. Biopsies were evaluated for specific changes in the following general categories: acute inflammation, chronic inflammation, epithelial damage, and architectural distortion.

RESULTS: We identified 51 patients with UC who had a total of 84 colonoscopies (at least 1 year apart) while they were in clinical remission. Forty colonoscopies revealed no endoscopic activity (Mayo subscore 0) and 44 showed endoscopic activity (Mayo subscore 1, 2, or 3). Although flares were approximately twice as common in patients with endoscopic activity as in those with an endoscopically normal mucosa, the difference was not statistically significant. On histologic evaluation, in contrast, the presence of basal lymphoplasmacytosis, basally located lymphoid aggregates, erosions and/or ulcerations of the epithelium, or moderate to marked architectural distortion all were significant predictors of clinical flares by 6 and 12 months.

CONCLUSIONS: For patients with UC who have colonoscopy while their disease is in clinical remission, colonic biopsy seems to provide important prognostic information beyond that provided by the endoscopic assessment of disease activity alone.