Intestinal ultrasound accurately predicts future therapy failure in Crohn's disease patients in a biologics-induced remission.

Background: Intestinal ultrasound (IUS) is used to assess disease activity, complications, and treatment follow-up in Crohn's disease (CD). Less is known about the association of disease activity on IUS with the risk of future disease relapse during biologically sustained clinical remission in CD.

Aim: The study aimed to investigate the association between IUS activity parameters and subsequent therapy failure in asymptomatic biologically treated patients with CD.

Methods: A retrospective cohort study examined the association between IUS parameters and forthcoming therapy failure (drug discontinuation, dose escalation, corticosteroid use, hospitalization, or surgery) in CD patients on biological therapy in remission.

Results: A total of 57 patients with ileal (65%) or ileocolonic (35%) CD on biological therapy were included in the study. Therapy failure occurred in 50.8% [defined as need for dose escalation (31%), drug discontinuation (51.7%), steroid use (10.5%), and hospitalization (6.8%)] during a median follow-up of 5 (SD + 9.5) months after IUS. On univariate analysis, a bowel wall thickness (BWT) of 2.5 vs. 4 mm ( P  = 0.005), the existence of an enlarged lymph node ( P  = 0.02), and the loss of bowel wall stratification ( P  = 0.01) were correlated with therapy failure. On multivariable analysis, only BWT ≥ 4 mm was associated with the risk of future treatment failure (hazard ratio, 3.7; 95% confidence interval, 0.6-15; P  = 0.02).

Conclusion: Our findings suggest that BWT ≥4 mm during clinical remission is associated with subsequent treatment failure in patients with CD treated with biologics. Our results support the use of IUS for monitoring CD during remission and may point to a novel threshold for predicting disease reactivation.