Celiac Disease Is Associated with Microscopic Colitis in Refractory Cases in Adults: A Systematic Review and Meta-Analysis of Observational Studies

Background: Microscopic colitis and Celiac disease have been shown to occur concomitantly, but their relationship has yet to be systematically evaluated. Some patients with refractory microscopic colitis may have simultaneous celiac disease, and the converse is also true. Aims: We performed a systematic review and meta-analysis of observational studies to assess the prevalence and possible association between these two conditions. Methods: PubMed, Embase, Cochrane, Web of Science, SciELO, and CINAHL Plus were systematically searched through January 26, 2021, to include relevant observational studies assessing the prevalence of microscopic colitis in celiac disease population or vice versa. DerSimonian-Laird approach using random effects was used to pool data and compare outcomes. Pooled prevalence, 95% confidence interval (CI), and p values (where applicable) were calculated. Results: Five studies (with 2589 patients, age range 39.5–52 years and females 66.6%) and 21 studies (with 7186 patients, age range 46.4–65.8 years and females 76.3%) were included assessing the prevalence of microscopic colitis in refractory celiac disease and celiac disease in refractory microscopic colitis cohort. The overall prevalence was 4.5% (2.6–6.3%) and 6.7% (5.2–8.1%), respectively. Five studies showed higher odds of celiac disease diagnosis in the refractory microscopic colitis population compared to the control group (OR 8.12, CI 4.92–13.41, p < 0.001). Conclusion: Celiac disease and microscopic colitis are concomitantly prevalent in a subset of population with either refractory diagnosis. Clinicians should explore alternate diagnosis when one condition has been appropriately treated and patients continue to have refractory symptoms.