Clinical Implications of Histologic Abnormalities in Ileocolonic Biopsies of Patients with Crohn's Disease in Remission

Background: For patients with Crohn's disease (CD) who have colonoscopy during periods of clinical remission, the utility of taking ileocolonic biopsy specimens to assess disease activity is disputed. Goals: We explored the clinical implications of histologic disease activity in such patients. Study: We reviewed medical records of CD patients who underwent elective colonoscopy while in clinical remission at our VA Medical Center from 2000 to 2013, and who had at least 6 months of follow-up. We correlated endoscopic and histologic disease activity with the subsequent development of flares. Results: We identified 62 CD patients who had a total of 103 colonoscopies during clinical remission; 55 colonoscopies revealed complete endoscopic healing and 48 showed active disease. Flares within 6, 12, and 24 months of colonoscopy were not more common in patients with endoscopic activity than those with complete endoscopic healing. In contrast, patients with any of 5 histologic features of active inflammation (erosions, cryptitis, crypt abscess, increased neutrophils, or increased eosinophils in the lamina propria) had more flares than patients without those changes (P<0.05). Among the individual histologic features, an increase in eosinophils or neutrophils in the lamina propria and cryptitis were associated with higher flare rates (P<0.05). Conclusions: For CD patients who have a colonoscopy while in clinical remission, biopsy seems to provide important prognostic information beyond that provided by endoscopic assessment of disease activity alone. In particular, increased eosinophils or neutrophils in the lamina propria and cryptitis are strongly associated with an increased risk of clinical flares within 1 to 2 years.