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

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.