Histological disease activity in patients with microscopic colitis is not related to clinical disease activity or long‐term prognosis

Abstract

Background: Microscopic colitis (MC) is a common cause of chronic watery diarrhea.Biopsies with characteristic histological features are crucial for establishing the diagnosis. The two main subtypes are collagenous colitis (CC) and lymphocytic colitis (LC) but incomplete forms exist. The disease course remains unpredictable varying from spontaneous remission to a relapsing course.Aim: To identify possible histological predictors of course of disease.Methods: Sixty patients from the European prospective MC registry (PRO-MC Collaboration) were included. Digitised histological slides stained with CD3 and Van Gieson were available for all patients. Total cell density and proportion of CD3 positive lymphocytes in lamina propria and surface epithelium were estimated by automated image analysis, and measurement of the subepithelial collagenous band was performed. Histopathological features were correlated to the number of daily stools and daily watery stools at time of endoscopy and at baseline as well as the clinical disease course (quiescent, achieved remission after treatment, relapsing or chronic active) at 1-year follow-up.Results: Neither total cell density in lamina propria, proportion of CD3 positive lymphocytes in lamina propria or surface epithelium, or thickness of collagenous band showed significant correlation to the number of daily stools or daily watery stools at any point of time. None of the assessed histological parameters at initial diagnosis were able to predict clinical disease course at 1-year follow-up. Conclusions:Our data indicate that the evaluated histological parameters were neither markers of disease activity at the time of diagnosis nor predictors of disease course.How to cite this article: Olsen LM, Engel PJH, Goudkade D, et al. Histological disease activity in patients with microscopic colitis is not related to clinical disease activity or long-term prognosis.

Intraepithelial and lamina propria lymphocytes do not correlate with symptoms or exposures in microscopic colitis

“…Although one might expect that the extent of inflammation, as measured by the percentage of lymphocytes, might correlate with symptoms, that has generally not been the case. Olsen et al ( 6 ) found that neither the total cell density in the lamina propria, proportion of CD3+ lymphocytes in the lamina propria, nor surface epithelium correlated with the number of daily stools or watery stools in 60 patients from a European prospective registry. Similarly, Shaz et al ( 24 ) found no association between symptoms and histologic findings.…”

“…Based on the number of intraepithelial lymphocytes and the thickness of the subepithelial collagen band, patients are classified as having lymphocytic or collagenous colitis. Both conditions have more intraepithelial lymphocytes, more than 20 for lymphocytic colitis and 10–20 for collagenous colitis ( 6 ). There are more lymphocytes in the lamina propria in both subtypes.…”

Editorial: The Dark Side of Microscopic Colitis

“…Over the last few years, the incidence and prevalence of this condition has risen, partly due to both greater awareness and increasing numbers of patients being diagnosed (2)(3)(4)(5). Diagnosis of MC is by colonoscopy, and histological analysis of multiple biopsy specimens collected along the colon is used to assess activity (6,7). However, heterogeneous immune profiles and disease characteristics among patients still make the pathogenesis of MC unclear (8,9).…”