FECAL CALPROTECTIN: levels for the ethiological diagnosis in Brazilian patients with gastrointestinal symptoms.

BACKGROUND: Determination of fecal calprotectin can provide an important guidance for the physician, also in primary care, in the differential diagnosis of gastrointestinal disorders, meanly between inflammatory bowel diseases and irritable bowel syndrome. Objectives The aims of the present study were to prospectively investigate, in Brazilian adults with gastrointestinal complaints, the value of fecal calprotectin as a biomarker for the differential diagnosis between functional and organic disorders and to correlate the concentrations with the activity of inflammatory bowel diseases.

METHODS: The study included consecutive patients who had gastrointestinal complaints in which the measurement levels of fecal calprotectin were recommended. Fecal calprotectin was measured using a Bühlmann (Basel, Switzerland) ELISA kit.

RESULTS: A total of 279 patients were included in the study, with median age of 39 years (range, 18 to 78 years). After clinical and laboratorial evaluation and considering the final diagnosis, patients were allocated into the following groups: a) Irritable Bowel Syndrome: 154 patients (102 female and 52 male subjects). b) Inflammatory Bowel Diseases group: 112 patients; 73 with Crohn's disease; 38 female and 35 male patients; 52.1% (38/73) presented active disease, and 47.9% (35/73) had disease in remission and 39 patients with ulcerative colitis;19 female and 20 male patients; 48.7% (19/39) classified with active disease and 49.3% (20/39) with disease in remission. A significant difference (P<0.001) was observed between the median value of fecal calprotectin in Irritable Bowel Syndrome group that was 50.5 µg/g (IQR=16 - 294 µg/g); 405 µg/g (IQR=29 - 1980 µg/g) in Crohn's disease patients and 457 µg/g (IQR=25 - 1430 µg/g) in ulcerative colitis patients. No difference was observed between the values found in the patients with Crohn's disease and ulcerative colitis. Levels of fecal calprotectin were significantly lower in patients with inflammatory bowel diseases in remission when compared with active disease (P<0.001).

CONCLUSIONS: The present study showed that the determination of fecal calprotectin assists to differentiate between active and inactive inflammatory bowel diseases and between inflammatory bowel diseases and irritable bowel syndrome.