Editorial: Endoscopic Activity is an Essential Tool for Patients' Management, Even in Mild Crohn's Disease

Abstract

Endoscopic activity is one of the most relevant prognostic markers in Crohn's disease: worse endoscopic features and more severe endoscopic activity are associated with poorer outcomes, while healing of lesions is associated with more favourable outcomes [1, 2]. While most available evidence on the prognostic role of endoscopic activity is based on data from moderately to severely active Crohn's disease [3], a large proportion of patients report clinical remission or very mild disease activity during their lifespan [4].

Peraza and colleagues have reported their multicentre retrospective study on the prognostic role of endoscopic severity focusing on individuals with mild Crohn's disease of long duration [5]. The authors recruited 177 surgery-naïve patients with Crohn's disease, with a predominantly uncomplicated disease course; only 1 in 4 patients had previously undergone immunosuppressive treatment and only 1 in 10 had been treated with biologics. Perianal disease was present in only 1 in 10 patients and, despite a long disease duration (median 17 years; range 0–55), individuals had a remarkably low endoscopic disease activity score (2 out of 3 patients had a SES-CD score between 0 and 3 points). The authors reported a significantly elevated hazards ratio (HR) of 2.5 for patients with higher endoscopic activity (SES-CD ≥ 7), demonstrating that endoscopic activity affects Crohn's disease outcomes even in those with mild disease phenotypes.

There are some points to consider in interpreting the results. First, although most patients presented with mild clinical disease, those with a more severe endoscopic activity may have been treated more aggressively based on endoscopic findings, leading to an overestimation of the prognostic negative effects of such features. Second, endoscopic severity was graded prospectively in each institution, but only local scores recorded at the time of endoscopy were considered, and no image or video re-assessment was undertaken. As local readers tend to overestimate endoscopic scores [6], this could have biased the results. However, the authors reported a sensitivity analysis showing that even considering a ±1 point cut-off value (i.e., considering SES-CD of 6 or 8 and higher), HRs were not substantially different. Finally, the generalisability of the results may be limited by the specifics of the study population: it is unclear if the results can be extrapolated to newly diagnosed patients or those exposed to more advanced therapies.

It remains clear that it is difficult to define mild Crohn's disease effectively. Clinical features must be integrated with biomarkers (e.g., C-reactive protein and faecal calprotectin), but also with multidimensional non-invasive disease severity or disability indices like the Disease Severity Index [7] or the IBD Disk [8], eventually integrated with other patient-reported outcomes [9] and/or using e-health [10]. Nonetheless, endoscopic severity remains an essential element to consider even in those deemed to have clinically mild disease activity.

Marco Mendolaro: conceptualization, writing – original draft, writing – review and editing. Marco Daperno: conceptualization, supervision, writing – review and editing, writing – original draft.

This article is linked to Peraza et al paper. To view this article, visit https://doi.org/10.1111/apt.18492.