Achieving Endoscopic Improvement in Ulcerative Colitis

Definition and Context

The American Gastroenterological Association defines endoscopic improvement as achieving Mayo endoscopic subscore 0 or 1, representing a 2-point improvement from baseline Mayo 3, requiring resolution of spontaneous bleeding and ulcerations 1, 2, 3, 4
Clinical trials for moderate-to-severe UC specifically enroll patients with Mayo Clinic Score 6-12 and an endoscopic subscore of 2 or 3, meaning Mayo 3 represents the most severe endoscopic disease included in these studies 1
Mayo endoscopic subscore 3 is defined as severe disease with spontaneous bleeding and ulcerations, representing the highest degree of mucosal inflammation 2

The American Gastroenterological Association recommends using higher or intermediate efficacy advanced therapies (TNF antagonists, JAK inhibitors, IL-12/23 antagonists, or S1P modulators) rather than lower efficacy options for patients with Mayo 3 disease 4
Consider extended induction or dose escalation for patients with severe disease (Mayo 3) who show inadequate initial response 4

Assess symptomatic response within 3 months of initiating advanced therapy 4
Perform endoscopic reassessment at 6-12 months to evaluate for endoscopic improvement/remission 4

Patients may achieve clinical remission (symptomatic improvement) while still having Mayo 3 endoscopic disease, requiring continued therapy escalation 4
Fecal calprotectin >150-250 mg/g can help identify persistent endoscopic inflammation in asymptomatic patients, though false positive rates exist 5