Introduction

In ulcerative colitis (UC) patients in remission, the usefulness of endoscopic scores, such as the Mayo Endoscopic Subscore (MES), Ulcerative Colitis Endoscopic Index of Severity (UCEIS), and Ulcerative Colitis Colonoscopic Index of Severity (UCCIS), and biomarkers such as fecal calprotectin (FC) for predicting relapse has been reported. However, no studies have compared the predictive abilities of the Ulcerative Colitis Endoscopic Index of Severity (UCEIS) and the Ulcerative Colitis Colonoscopic Index of Severity (UCCIS), which assesses the entire colon.

Aim

To analyze the relative efficacy of endoscopic scores (MES, UCEIS and UCCIS) against that of biomarker (FC) in predicting relapse in UC patients in clinical remission.

Patient Profile

75 patients with UC in clinical and endoscopic remission with a clinical activity index (CAI) of ≤ 4

Method

Study Design

• Retrospective, single-centre observational study
• Clinical activity of UC was evaluated using the CAI
• Endoscopic scores were assessed using MES, UCEIS, and UCCIS
• MES was evaluated according to the following criteria: 0, normal or inactive disease; 1, mild disease with erythema, decreased vascular pattern, and mild friability; 2, moderate disease with marked erythema, absence of vascular patterns, friability, and erosions; and 3, severe disease with spontaneous bleeding and ulceration
• UCEIS score was evaluated by calculating the sum of three descriptors: vascular pattern (score 0-2), erosions and ulcers (score 0-3), and bleeding (score 0-3)
• UCCIS score was assessed using the following descriptors in the five segments of the ascending colon, transverse colon, descending colon, sigmoid colon, and rectum: vascular pattern (score 0-2), granularity (score 0-2), erosions and ulcers (score 0-4), and bleeding/friability (score 0-2)
• Clinical remission was defined as CAI <4, and mucosal healing was defined as MES 0 or MES 1
• Clinical relapse was defined as an increase in CAI above baseline due to the worsening of diarrhea and abdominal pain or frequent or bloody stools requiring modification or addition of treatment

Endpoints

• Primary outcome: assessment of the association between relapse within 12 mo and MES, UCEIS, UCCIS, and FC
• Secondary outcome: comparison between endoscopic scores and biomarkers in patients with UC with mucosal healing

Results

Efficacy

• FC and UCCIS were significantly higher in the MES 1 group versus the MES 0 group (P < 0.001 for both)
• FC and UCCIS significantly correlated with UCEIS (r = 0.537, P < 0.001 and r = 0.957, P < 0.001, respectively)
• Receiver-operating characteristic (ROC) analysis to predict MES 0 showed cut-off values of FC 385 mg/kg and UCCIS 6.6, with an area under the curve (AUC) of 0.858 and 0.987, respectively
• The AUC of UCCIS was significantly higher than that of FC (P < 0.01)
• During the 1-year observation period, the baseline FC and UCCIS values were significantly higher in the relapse group than in the remission group (P < 0.001 for both)
• The cut-off values for predicting relapse were set at FC = 323 mg/kg and UCCIS = 10.2 as per the ROC analysis
• The accuracy of the endoscopic scores and biomarkers in predicting relapse was 86.7% for UCCIS, 85.3% for UCEIS, 76.0% for FC, and 73.3% for MES (Figure 1)

Figure 1: Accuracy of endoscopic scores and biomarker in predicting relapse

Conclusion

• MES, UCEIS, UCCIS, and FC were useful for predicting relapse in patients with UC in clinical remission
• Among the three endoscopic scores evaluated, UCCIS comprehensively evaluated the endoscopic activity of UC, however, its complexity posed a challenge
• UCEIS may be the most useful in terms of ease of evaluation and predictive accuracy

World J Gastroenterol. 2023; 29(47): 6111-6121