Abstract and Introduction
Background An association between microscopic colitis and coeliac disease (CD) has been suggested in literature; however, population-based data are limited.
Aims To estimate the degree of association between these two diseases and to identify possible risk factors for disease concomitance.
Methods A population-based review of all patients diagnosed with CD and microscopic colitis in a large Canadian centre over a 5-year period. Endoscopy and pathology databases were searched to identify all cases of CD and microscopic colitis diagnosed within the Calgary Health Region between 2004 and 2008. Incidence rates were age-standardised and gender-standardised to 2006 Canadian Census data. standardised incidence ratios (SIR) were used to assess disease concomitance.
Results Over 5 years, 763 patients were diagnosed with CD, and 1106 were diagnosed with microscopic colitis. The standardised incidence of CD ranged from 10.4 to 15.7 per 100 000 population. The standardised incidence of microscopic colitis ranged from 16.9 to 26.2 per 100 000 population. Forty patients were diagnosed with both CD and microscopic colitis, 21 of whom were middle aged (40–60 years) females. Within the CD cohort, microscopic colitis occurred at an annual rate of 11.4 per 1000 cases of CD with an overall SIR of 52.7.
Conclusions There exists a strong association between microscopic colitis and CD with disease concomitance being approximately 50-times that expected in the general population. The concomitant diagnosis of CD and microscopic colitis largely occurs in middle-aged women. Therefore, middle-aged women with CD and diarrhoea as a presenting or persistent symptom should undergo lower endoscopy with biopsies to rule out microscopic colitis.
Microscopic colitis (MC) is an inflammatory disorder of colonic mucosa that causes chronic nonbloody diarrhoea. It is characterised using distinct microscopic findings on colonic tissue biopsy in an otherwise endoscopically and radiographically normal colon. These features lead to many years of the diagnosis being overlooked; however, it has now become well known as a common cause of chronic watery diarrhoea, especially in elderly women. Collagenous colitis (CC) and lymphocytic colitis (LC) are the two recognised forms of MC, each with characteristic histopathological features.[2,3] The aetiology of MC is unclear, but is generally thought to be the result of an immune reaction to an infectious or drug trigger.[4–8] Patients at high risk of acquiring MC are typically older women and patients with malignancies.[3,8]
Coeliac disease (CD) is a common autoimmune disorder with a prevalence of one percent in western populations. It is well established that the prevalence of CD is higher in certain populations. In a systematic review by Dube et al., CD prevalence was reported to be 16% in first-degree relatives of CD patients, up to 15% in those with iron-deficiency anaemia, up to 6% in type 1 diabetes and up to 3% in patients with osteoporosis. Common features of CD in adults include diarrhoea, iron-deficiency anaemia and malabsorption, and to some extent these symptoms determine the high risk populations.
An association between MC and CD has been suggested. However, this association has been based largely based on small studies with varied patient cohorts.[11–16] Population data on the degree of association between CD and MC is lacking. Furthermore, it is unknown whether this association affects all patients with CD and MC or whether a distinct 'at risk' group can be characterised. In the context of CD being more likely to be diagnosed at a younger age and MC more likely to be diagnosed at an older age, it will be especially interesting to determine the age at which patients are diagnosed with both diseases. To address these interesting questions, we undertook a population-based study to evaluate the association between CD and MC.
The aim of this study was to determine incidence rates in Calgary, Alberta, by reviewing pathological findings of all patients diagnosed with CD, LC and CC over a 5-year period. Using the gold standard of histological examination as the sole diagnostic criterion, this study was intended to capture disease incidence in the context of actual clinical practice in a large urban centre. We wanted to quantify the concomitant diagnosis of CD and MC and determine if the putative association is stable or rising. Finally, as CD and MC have such disparate risk factors, we wanted to know whether there was an identifiable 'at risk' population, where CD and MC were diagnosed more frequently.
Aliment Pharmacol Ther. 2011;33(12):1340-1349. © 2011 Blackwell Publishing
Cite this: The Association of Coeliac Disease and Microscopic Colitis - Medscape - Jun 01, 2011.