Histological Disease Activity as Predictor of Clinical Relapse, Hospitalization, and Surgery in Inflammatory Bowel Disease: Systematic Review and Meta-Analysis

Abstract Background The clinical impact of histological remission on short- and long-term clinical outcomes in patients with inflammatory bowel disease (IBD) is not well established. We assessed risk of clinical relapse, hospitalization, and need for surgery in patients achieving histological remission in comparison with active histological disease. Methods A systematic review was conducted using MEDLINE, Scopus, Cochrane CENTRAL, EMBASE, and conference abstracts from inception to November 2022. Our main outcome was the rate of clinical relapse in patients with IBD who reached histological remission vs patients with active histological disease. Secondary outcomes were clinical complications of IBD such as hospitalization and need for surgery. The endpoints were investigated at 2 time points, 6 to 12 months (short term) and >12 months (long term). Results Short-term outcome analysis showed that the risk of clinical relapse was significantly higher in ulcerative colitis patients with active histological disease in comparison with patients at histological remission (risk ratio [RR], 2.41; 95% confidence interval [CI], 1.69-3.44; P < .01). The risk of hospitalization in ulcerative colitis patients was not significant among the 2 groups (RR, 4.22; 95% CI, 0.91-19.62; P = .07). Long-term outcome analysis demonstrated that the risk of clinical relapse (RR, 2.07; 95% CI, 1.55-2.76; P < .01), need for surgery (RR, 3.14; 95% CI, 1.53-6.45; P < .01), and hospitalization (RR, 2.52; 95% CI, 1.59-4.00; P < .01) was significantly higher in patients with active histological disease. Conclusions Histological remission in IBD represents an important therapeutic goal that is not yet routinely pursued in clinical practice. In our study, patients who achieved histological remission have more favorable outcomes than those with active histological disease in ulcerative colitis.