S862 Rates and Outcomes of Histologic Healing in Crohn's Disease

Abstract

Introduction: Histologic healing (HH) has been associated with favorable outcomes in patients with ulcerative colitis but its clinical significance in Crohn’s disease (CD) remains unclear. We aimed to determine the prevalence, predictors, and outcomes of HH in patients with CD. Methods: This is a single center, retrospective review of CD patients age ≥18 from 1/1/2012-12/1/2021. Patients with and without endoscopic healing (defined as the absence of ulcers or erosions) were included. HH was defined as either normal or chronic inactive/quiescent inflammation on review of pathology reports. The primary outcomes were the prevalence and predictors of HH in both distal ileal and colonic CD. Secondary outcomes included rates of corticosteroid use, CD-related ED visits, surgeries, and hospitalizations analyzed individually and as a composite outcome. Continuous variables were analyzed using an unpaired student’s t-test. Categorical variables were analyzed using a chi-square test. Results: A total of 90 CD patients were included. The median age was 47 years (range 18-85), 52.0% were female, 63.3% had ileocolonic disease, and 72.2% had endoscopic healing. The overall rate of HH was 30.0%. Among patients with endoscopic healing (n=65), 41.5% (n=27) achieved HH. Ileal HH rate was 63.2% and colonic HH rate was 47.6%. There were no significant differences between the HH and non-HH groups in terms of baseline and disease characteristics (Table). The percentage of patients on biologic medications was 70.4% in the HH group vs. 50% in the non-HH group (p=0.1). In the HH group, the rate of corticosteroid initiation was 42.9% vs. 57.1%, (p=0.89) and the rates of ED visits, hospitalizations, and IBD-related surgeries were not significantly different between the two groups (Figure). The composite outcome was noted in 40.7% of patients with HH vs. 59.3% of patients without HH (p=0.91). Conclusion: In this pilot study, 30% of CD patients achieved HH, with a higher rate of ileal compared to colonic HH. Among patients with endoscopic healing, HH was not associated with any further decrease in adverse clinical outcomes. This study is limited by small sample size and potentially sampling error of endoscopic biopsies due to the patchy nature of CD inflammation. Larger studies are needed to identify predictors and significance of HH in CD.Figure 1.: Comparison of outcomes between histologic healing vs. no histologic healing (*Composite outcome is defined by either discontinuation of therapy/dose escalation, steroid use, ED visits and/or hospitalizations related to active CD). Table 1. - Comparison of Characteristics Between Histologic Healing vs. No Histologic Healing Patient characteristics Histologic Healing (n=27) No Histologic Healing (n=38) P-value Baseline characteristics Age (years), mean (SD) 52.6 (16.0) 48.7 (17.8) 0.36 Female sex, n (%) 13 (48.2) 26 (68.4) 0.10 Smoking, n (%) 5 (18.5) 4 (10.5) 0.36 Disease duration (years), median (IQR) 16 (7-21) 11.5 (4-21.8) 0.38 Disease characteristics Prior bowel resection, n (%) 6 (22.2) 9 (23.7) 0.89 Presence of extraintestinal manifestations, n (%) 7 (25.9) 11 (28.9) 0.79 Perianal disease, n (%) 8 (29.6) 11 (28.9) 0.95 Medication factors On biologic, n (%) 19 (70.4) 19 (50.0) 0.10 On immunomodulator, n(%) 6 (22.2) 7 (18.4) 0.71