Usefulness of fecal calprotectin as a biomarker of microscopic colitis in a cohort of patients with chronic watery diarrhoea of functional characteristics.

ABSTRACT

BACKGROUND: Information on the use of fecal markers in microscopic colitis screening is limited. AIM: To evaluate the risk variables associated with a diagnosis of microscopic colitis including fecal calprotectin. METHODS: Patients submitted for a colonoscopy due to chronic watery diarrhea fulfilling criteria of functional disease were evaluated. Colonic mucosa was normal but mild erythema and edema was allowed. Fecal calprotectin was analyzed. A logistic regression was used to evaluate variables associated with both raised fecal calprotectin and a diagnosis of microscopic colitis. RESULTS: 94 patients were included, 30 were diagnosed with microscopic colitis and 64 made up the control group. Median calprotectin levels were 175 (IQR, 59-325) for the microscopic colitis and 28 (IQR, 16-111) for the control group (p < 0.001). The optimal cut-off for fecal calprotectin was >100 µg/g (AUC, 0.73), with 67% sensitivity and 75% specificity. The number of drugs used ≥3 (OR, 3.9; CI, 1.4-10.4) and microscopic colitis diagnosis (OR, 6; CI, 2.2-16.3) were associated with raised calprotectin levels. Age >60 years (OR, 3.8; CI, 1.4-10.1) and calprotectin levels (OR, 5.3; CI, 2-14.1) were associated with a risk of microscopic colitis. CONCLUSIONS: Elevated fecal calprotectin concentrations are often seen in microscopic colitis, and may be helpful in the diagnosis of women over 60 with chronic watery diarrhea.