Microscopic Colitis is a Risk Factor for Ulcerative Colitis and Crohn’s Disease

Microscopic colitis is associated with an increased risk of both Crohn’s disease (CD) and ulcerative colitis (UC), according to a poster to be presented at the annual American College of Gastroenterology (ACG) 2020 conference.

Investigators from Case Western Reserve University in Cleveland, Ohio conducted a retrospective, population-based study of more than 65 million patients’ electronic health records from multiple health care systems in order to examine the association between microscopic colitis and inflammatory bowel disease (IBD). The study authors wrote that while microscopic colitis and IDB share a pathogenesis, other studies have suggested that the association between the 2 diseases is limited.

The investigators identified patients both with and without microscopic colitis from the cohort and compared patient characteristics – such as CD and UC status – between the groups. They determined that the prevalence of microscopic colitis is 0.5 per 100,000 patients or 350 patients out of about 73 million.

Of those 350 patients identified, 11% developed CD. Additionally, the study authors found, 19% of those developed UC. To compare, of the cohort without microscopic colitis, 0.32% had CD and 0.26% had UC, the investigators reported, resulting in a 30% chance vs. 0.6% chance of IBD in patients with and without microscopic colitis, respectively.

The study authors also found that other factors, such as female gender, Caucasian race, and older age were significantly associated with microscopic colitis. For example, among 350 patients they identified with microscopic colitis, 100 were male and 250 were female. Furthermore, 330 were Caucasian and the remaining patients were classified as African American or other races. More patients fell into the age group of 65 years or older than those that were aged between 18 and 65 years, they said.

“In our study, we found that microscopic colitis is associated with an increased risk of both CD and UC.” We do not have clinical prospective data to evaluate the effect of early intervention of microscopic colitis on the development of IBD,” the study authors concluded, noting that further evidence is needed to evaluate this.

Other reporting from HCP Live, as early as 2010, explains that microscopic colitis can feature symptoms such as chronic watery diarrhea with either gradual or sudden onset, which can occur intermittently or continuously. It is also typically accompanied by cramping and/or weight loss. Not only is there some overlap with IBD, but also potentially with Celiac disease.

The incidence of microscopic colitis appears to be increasing, the 2010 interview with William J. Tremaine, MD, explained. Physicians should begin with a physical examination (despite the fact that patients may appear normal, or have some weight loss and dehydration) followed by the exclusion of palpable mass, focal tenderness, bruits, and perianal disease.

The reporting continued by adding that there are few agents available to treat microscopic colitis, but budesonide is typically used for induction and maintenance. Additionally, azathioprine has shown efficacy for maintenance in some studies.