Histologic remission does not offer additional benefit for ulcerative colitis patients in endoscopic remission

BACKGROUND: Histologic remission in ulcerative colitis (UC) patients may be associated with positive outcomes. It is unclear whether UC patients in endoscopic remission obtain additional benefit from achieving histologic remission. AIM: To evaluate the relationship between time to relapse and histological activity among UC patients in endoscopic remission. METHODS: In this retrospective study using an observational database, we identified UC patients who had achieved endoscopic remission (Mayo endoscopic subscore 0). Index colonoscopy was the first colonoscopy when endoscopic remission was achieved. Histologic activity was classified as normal, inactive or active colitis. The primary outcome was time to relapse. Secondary outcomes included reasons for relapse and the association between baseline variables and risk of relapse. A Cox proportional hazards model evaluated baseline factors and the outcome of relapse. RESULTS: We included 269 patients. The Kaplan-Meier survival curve showed no significant difference between the presence or absence of histologic activity and time to relapse (log rank P = 0.85). There was no difference in time to clinical relapse of patients with histologically active colitis compared to inactive colitis (adjusted hazard ratio [AHR] 1.17, 95% CI 0.58-2.32, P = 0.67]). 5-aminosalicylate use (AHR 0.42, 95% CI 0.21-0.82, P = 0.011), pancolitis (AHR 0.32, 95% CI 0.13-0.75, P = 0.008), left-sided colitis (AHR 0.46; 95% CI 0.22-0.98; P = 0.044) and older age (AHR 0.96, 95% CI 0.94-0.99, P = 0.002) were significantly associated with reduced time to clinical relapse. CONCLUSION: Histologic remission did not influence time to relapse in UC patients who had achieved endoscopic remission.