Early Intestinal Ultrasound Accurately Predicts Long-Term Endoscopic Response to Biologic Therapy in Ulcerative Colitis

A treat-to-target strategy with close monitoring of treatment response is recommended in ulcerative colitis (UC). Colonoscopy is the gold standard for assessing disease activity. However, intestinal ultrasound (IUS) is a noninvasive, safe, and accurate technique routinely used in clinical practice to detect changes related to treatment response. Milan ultrasound criteria (MUC) is a validated ultrasonographic score able to grade endoscopic activity in UC, with a score ≤6.2 predictive of a Mayo endoscopic score (MES) ≤1. However, few studies have compared the responsiveness of IUS and colonoscopy. 

In this single-center, prospective, observational study, 49 patients starting biologic therapy for active UC (MES >1) underwent both colonoscopy and IUS at baseline and reassessment within one year, with a further IUS examination at week 12. The investigators evaluated the predictive value of ultrasound improvement (MUC ≤6.2) at week 12 for treatment response and endoscopic improvement (MES ≤1) at reassessment. 

MUC values significantly decreased after 12 weeks of treatment and at reassessment, with a high positive correlation between MES and MUC scores. MUC ≤6.2 at week 12 was the only independent predictor of endoscopic improvement (odds ratio [OR], 5.80; P=.010) and remission (OR, 10.41; P=.041) at reassessment, with a negative predictive value of 96% for detecting endoscopic remission. A reduction of ≥2 points in the MUC score predicted achievement of endoscopic improvement (area under the receiver operating characteristics [AUROC], 0.806) and remission (AUROC, 0.816), with MUC ≤4.3 as the most accurate cut-off value for an MES of 0.