Clinical characteristics of microscopic Colitis in a single tertiary referral center

Background: Microscopic colitis (MC) is an increasingly recognized, frequent cause of chronic diarrhea. Its epidemiology was described in several Western countries, however epidemiologic data from Eastern Europe is lacking. We aimed to investigate MC cases in our single tertiary referral center cohort. Methods: All cases of microscopic colitis diagnosed at colonoscopy over a 17-year period (January 1997 – August 2014) were retrieved at the 1st Department of Pathology and retrospectively reviewed. The diagnostic criteria for lymphocytic colitis (LC) were ≥20 intraepithelial lymphocytes per 100 epithelial cells, and for collagenous colitis (CC) a collagenous layer of ≥10 µm. Several demographic and clinical parameters were analyzed. Results: 110 patients (91 patients with LC, and 19 patients with CC) were included in the study. 79 (71%) patients were female with a mean age of 52.0 years (SD ± 16.8) for LC and a mean age of 57.5 years (SD ± 17.0) for CC. Comparing the period 1997 – 2005 and 2006 – 2014, the incidence increased in both genders (30 females, 9 males vs. 49 females, 23 males). Chronic, watery diarrhea was the most common symptom (74%). The diagnosis of LC would have been missed in 11% of cases, if only left-sided biopsies had been taken, whereas all cases (100%) of CC were diagnosed with distal colonic biopsies alone. Osteodensitometry was performed in only 20% of cases, however it was pathological in 64% of the cases: osteoporosis was diagnosed in 46% and osteopenia in 18% of these cases. Among associated autoimmune diseases, celiac disease was the most common with 9%, followed by hypothyroidism (7.3%). 31.5% of patients were taking any of the previously associated drugs (proton pump inhibitors, ACE inhibitors, beta blockers, calcium antagonists, statins, acetylsalicylic acid or antidepressants). Conclusions: The incidence of MC is increasing in Hungary, but still below of that reported in Western countries. LC seems to be more common than CC, but this might be due to underdiagnosis. Our results should be further examined in multicenter studies. This study was supported by the Hungarian Scientific Research Fund (OTKA-K111743 grant).