PREDICTORS OF CLINICAL RELAPSE AMONG PATIENTS WITH ULCERATIVE COLITIS IN ENDO-HISTOLOGIC REMISSION

Abstract

In patients with ulcerative colitis (UC), endo-histologic (deep) remission has been increasingly recognized to reduce the risk of clinical relapse above and beyond attainment of endoscopic remission alone. However, relapse rates among patients in deep remission, and predictors of relapse in this population remain uncharacterized. We performed a retrospective cohort study utilizing electronic medical records at Tufts Medical Center to identify patients in deep remission, classified as having both endoscopic remission [Mayo Endoscopic Score [MES] of 0 or 1] and histologic remission [Nancy Histologic Index [NHI] of grade 0 or grade 1]. We evaluated the cumulative risk of clinical relapse following attainment of deep remission, defined as patient-reported outcome (PRO-2 > 2), adjusted for gender, age, disease duration, time duration of follow-up, baseline Mayo Endoscopic Score, and baseline depth of histologic remission. Among 128 patients with UC in deep remission, 69 were female (54%). The median age was 55 years with median disease duration of 13 years. At time of deep remission, n=29 (23%) had a MES score of 1 and n=92 (72%) had a MES score of 0, with n=82 (64%) demonstrating a NHI of 1, and n=38 (30%) with a NHI of 0. Over a median follow up time of 10.5 years, 33% of patients had clinical relapse and 66% remained in remission. The cumulative risk of relapse among patients in deep remission was 12.2% at one year and 23% at three years. On univariate analysis, age, gender, disease duration, and baseline MES score did not predict relapse risk. However, the depth of histologic remission at time of deep remission was predictive of clinical relapse, with those demonstrating normalized mucosa (NHI of 0) less likely to relapse than those with chronic architectural changes (NHI of 1) at one year (5% vs 16%, HR = 2.80, p < .05) and at three years (9% vs 27%) [Table 1, Figure 1]. Cumulative risk of relapse among patients in endo-histologic remission is as low as <15% and <25% at one and three years, respectively. Attainment of complete normalization reduces the risk of relapse to <5% over the first year compared to histologic remission with chronic architectural changes (<16%), with other clinical criteria unable to prognosticate risk of relapse. Achieving endo-histologic remission with complete normalization of mucosa may be the ideal clinical target in ulcerative colitis.Figure 1Probability of Relapse in Patients with NHI of Grade 1 versus Grade 0View Large Image Figure ViewerDownload Hi-res image Download (PPT)