Factors associated with long-term clinical outcome in microscopic colitis.

BACKGROUND AND AIMS: Microscopic colitis has been increasingly recognized as a cause of chronic diarrhoea. We aimed to characterize the role of disease-related factors and treatments on the clinical outcomes of microscopic colitis.

METHODS: We retrospectively reviewed the medical records of patients with microscopic colitis who were treated at the University of Chicago and Oregon Health & Science University between August 2010 and May 2016. Patient characteristics and treatments were evaluated as predictors of clinical outcomes using univariate and multivariate analyses. Clinical remission was defined as no symptoms associated with microscopic colitis based on physician assessment and histologic remission was defined as no evidence of histological inflammation of microscopic colitis.

RESULTS: Seventy-two patients with microscopic colitis were included in the study (28 with lymphocytic colitis and 44 with collagenous colitis). Non-steroidal anti-inflammatory drugs, proton pump inhibitors and selective serotonin reuptake inhibitors were used in 23 (31.9%), 14 (19.4%) and 15 (20.8%), respectively, at the time of diagnosis. Among 46 patients with adequate follow-up data, 25 (54.3%) patients achieved clinical remission. Response to budesonide ( p  = .0002) and achieving histologic remission ( p  = .0008) were associated with clinical remission on univariate analysis. On multivariate analysis, budesonide response ( p  = .0052) was associated with clinical remission (odds ratio 25.00, 95% confidence interval 2.63-238.10). Among 22 patients who underwent a follow-up colonoscopy, five patients (22.7%) achieved histologic remission. All patients with histologic remission maintained clinical remission without medication, whereas only two patients (11.8%) were able to discontinue medical therapy when histologic inflammation was present ( p  = .0002).

CONCLUSIONS: In the present cohort of patients with microscopic colitis, a favourable response to budesonide was significantly associated with long-term clinical remission, and all patients achieving histological remission were able to maintain clinical remission without further medical therapy. Larger studies are required to confirm these findings.