P150 Histologic features predicting prognosis and their relationship with endoscopic findings in Ulcerative Colitis patients with mucosal healing

Shin, S.(1);Choi, C.W.(1);Moon, J.M.(1);Kim, H.S.(2);Choi, C.H.(1);

(1)Chung-Ang University College of Medicine, Internal medicine, Seoul, Korea- Republic Of;(2)Chung-Ang University College of Medicine, Pathology, Seoul, Korea- Republic Of

Background

Mucosal healing (MH) is one of the treatment targets in patients with ulcerative colitis (UC). However, it has been suggested that even in patients with MH, disease prognosis depends on histologic activity. This study aimed to evaluate histologic features predicting disease prognosis and their relationship with endoscopic findings in UC patients with MH.

Methods

We retrospectively reviewed the data of patients with UC who underwent colonoscopy or sigmoidoscopy with biopsy and evaluated eight histological features, including chronic inflammatory infiltrate, neutrophils in epithelium, ulceration, acute inflammatory cell infiltrate, basal plasmacytosis and serrated architectural abnormalities, as well as Nancy index (NI). Histologic variables predicting disease progression defined as starting corticosteroid, biologics, or small molecule agent, or undergoing clinical relapse or surgical operation were evaluated, and correlated with endoscopic findings.

Results

A total 194 biopsy specimens of 103 patients were evaluated. The highest grades of each histologic item were analyzed when biopsies were performed at multiple sites in one patient. 30.6% showed NI ≤ 1 (no acute inflammatory infiltrate) in 49 patients with endoscopic remission. Among 68 patients with MH, only 24.8% achieved NI ≤ 1. Mucosal friability in endoscopic findings was significantly associated with moderate-to-severe active histologic status (NI ≥3) (46.2% vs 80.0%, P=0.013), and patients with NI ≥3 showed significantly higher rates of disease progression during 13.7-month follow-up period (5.1% vs 19.0%, P=0.21). Ulceration and serrated architectural abnormalities were significantly associated with disease progression, and serrated architectural abnormalities was an independent risk factor in multivariate analysis (odds ratio 2.691 (95% confidence interval: 1.047-6.915), P=0.04).

Conclusion

Mucosal friability in endoscopic findings reflects moderate-to-severe active histologic status, and presence of serrated architectural abnormalities predicts disease progression in UC patients with MH. These findings may help identify patients need closer monitoring.