Microscopic colitis may increase risk for incident IBD
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Patients with microscopic colitis were at increased risk for incident inflammatory bowel disease, according to study results.
Hamed Khalili, MD, of the Crohn’s and Colitis Center at Massachusetts General Hospital, and colleagues wrote that some experts have suggested that microscopic colitis is a weaker form of IBD that can transform in some patients.
“The disease is distinct from ‘classical’ IBD in its nearly normal-appearing colonic mucosa and histologic findings consistent with increased lymphocytic infiltrates with or without expansion of collagen fiber,” they wrote. “Although the pathophysiology is largely unknown, the disease appears to have shared pathogenic mechanisms with Crohn’s disease and ulcerative colitis.”
Researchers conducted a prospective cohort study of adults in Sweden who were diagnosed with microscopic colitis between 1990 and 2017. They explored the association between microscopic colitis and IBD by matching patients with microscopic colitis (n = 13,957) to five general population controls (n = 66,820), as well as to unaffected siblings (n = 13,943).
Through 2017, investigators identified 323 cases of UC and 108 cases of CD among patients with microscopic colitis compared with 94 and 42 cases among the general population, respectively. In their analysis, Khalil and colleagues determined that microscopic colitis was associated with an adjusted HR of 12.6 (95% CI, 8.8-18.1) for CD, 17.3 (95% CI, 13.7-21.8) for UC and 16.8 (95% CI, 13.9-20.3) for IBD.
Compared with their unaffected siblings, patients with microscopic colitis were at higher risk for CD (aHR = 5.4; 95% CI, 3.2-9.2) and UC (aHR = 9.4; 95% CI, 6.4-13.8).
Khalili and colleagues called for future studies to explore the underlying mechanisms of these associations.
“Considering the typical age of diagnosis of microscopic colitis, it’s likely that the disease may only represent a risk factor for older-onset IBD, which accounts for a smaller proportion of all cases,” they wrote. “In clinical practice, gastroenterologists’ awareness of this relationship will allow for timely diagnostic evaluation as the nature of gastrointestinal symptoms in patients with history of microscopic colitis changes.” – by Alex Young
Disclosures: Khalili reports receiving consultant fees from AbbVie and grant support from Pfizer and Takeda. Please see the study for all other authors’ relevant financial disclosures.
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