Ultra-High Magnification Endocytoscopy to Define Deep Endoscopic and Histologic Remission in Ulcerative Colitis

Aims Increasingly both endoscopic remission (ER) and histological remission (HR) are targets of therapy in ulcerative colitis (UC). We aimed to define deep remission in patients with UC by assessing cellular architecture and the correlation with endoscopic scores by using ultra-high-magnification endocytoscopy (ECS) and histological indices.

Methods We conducted a prospective study enrolling 29 UC patients (18 males, mean age 41y) referred for assessing ER. All patients underwent colonoscopies with 520-fold magnification endocytoscope using methylene blue spray(0.1 %). The inflammatory activity was scored using the Mayo Endoscopic Score (MES). ER was defined as MES 0. To assess the grade of inflammation using ECS we adapted an ECS score (ECSS) summarized in [table 1]. Targeted biopsies were taken and scored according to Nancy Histopathological Index (NHI) and Robarts Histopathological Index (RHI). HR was defined as NHI≤1, and RHI ≤ 3 without neutrophils in the epithelium and lamina propria. The accuracy and the correlation between ECSS and MES with histological scores were determined.

Results ECSS correlated strongly with RHI (r = 0.89 [95 % CI 0.51- 0.98] and NHI (r = 0.86 [95 % CI 0.42- 0.98] but poorly with MES (r = 0.28 [95 % CI-0.27 – 0.70]). We analysed the diagnostic accuracy of ECSS for predicting HR. The best value of ECSS total score was ≤ 3 for predicting HR by RHI with an AUROC 0.81 (95 %CI:0.66-0.97), specificity 0.89 (95 %CI:0.52-1), sensitivity 0.62 (95 %CI:0.31-0.86) and an accuracy 0.80 (95 %CI:0.57-0.87). Similarly, an ECSS total score ≤3 was the best cut-off for predicting HR defined by NHI with an AUROC of 0.77(95 %CI:0.59-0.95), specificity of 0.86 (95 %CI:0.43-1), sensitivity of 0.64 % (95 %CI:0.27-0.91), and an accuracy of 0.80 % (95 %CI:0.49- 0.90). Distance between crypts predicted HR best.

Conclusions ECS represents a reliable tool that may sit between endoscopy and histology but closer to the latter and may help in defining HR using endoscopic assessment.

Tab. 1 ECSS (*VF visual field)

Endocytoscopy items	Score
♦ Crypt architecture:
Normal, elongated	1
Irregular	2
Necrosis	3
♦ Infiltration of the cell between the crypts:
≤50 %	1
≥50 %	2
♦ Distance between the crypts:
Normal: 3 or more crypts in a VF *	1
Elongated = <2 crypts in a VF*	1
Intermediate= 2 ≤ crypts ≥ 3 in a VF* with infiltrating cells in LP	2
Drop-out/necrosis	3
♦ Visibility of superficial microvessels:
Not visible	0
Visible	1
ECS total score	3-9

Citation: Iacucci M, Nardone OM, Bazarova A et al. OP180 ULTRA-HIGH MAGNIFICATION ENDOCYTOSCOPY TO DEFINE DEEP ENDOSCOPIC AND HISTOLOGIC REMISSION IN ULCERATIVE COLITIS. Endoscopy 2021; 53: S73.

Publication History

Article published online:
19 March 2021