Usefulness of Fecal Calprotectin in Clinical Practice in a District General Hospital

Abstract

Calprotectin is a calcium and zinc binding protein, mainly contained in neutrophils. If present in stools it is a marker of bowel inflammation. We evaluated the diagnostic value of fecal calprotectin (FC) as a non-invasive marker of bowel inflammation in routine out-patient gastroenterology clinic. A retrospective study of patients who had FC testing presenting with a multitude of gastrointestinal symptoms in a district general hospital over a 12 month period. The clinical, FC results and the endoscopic findings were recorded. FC level more than 50 μg/gm was considered positive. FC was requested for 72 patients. 44 were female (mean age 44 years) and 28 were male (mean age 47 years). FC was requested for various symptoms including chronic diarrhoea, abdominal pain, abdominal distension and per rectal bleeding. Patients were divided into 3 groups based on clinical practice of gastroenterologist. In the first group only FC was requested initially as a screening test to assess bowel inflammation. 31 patients fell in this group, 21 of 31 had negative FC and no further investigations were done, while 10 of 31 had positive FC (mean 150.3 μg/gm). Out of these 5 had no further investigations as symptoms settled on subsequent clinic visit and 5 went on to have further investigations (Colonoscopy +/− Capsule endoscopy) which were all normal. In the second group patient's had both FC and colonoscopy requested on initial out-patient review. There were 23 patients in this group. 13 of 23 had normal FC and colonoscopy and no further investigations were done. 2 of 23 had abnormal FC (mean 271.5 μg/gm) and colonoscopy. Both were diagnosed with IBD. 8 of 23 had raised FC (mean 171.25 μg/gm) but a normal colonoscopy. 5 of 8 had no further investigations done while 3 had small bowel investigations which were normal. 1 patient of these 3 was treated for presumed small bowel Crohn's due to raised FC despite normal capsule endoscopy with good effect. In the third group colonoscopy was the initial investigation of choice and was found to be normal but FC was done later in view of persistent symptoms to look for small bowel inflammation. 18 patients fell in this group. 12 of 18 had normal FC and had no further investigations. 6 of 18 had raised FC (mean 114.33 μg/gm). 3 patients with raised FC had small bowel investigation done and all were normal. In conclusion FC was beneficial when negative. It provided reassurance to the clinicians and helped avoid invasive investigations. However when FC was positive clinical judgment and patient symptoms dictated the need for further investigations. None of the patients diagnosed with IBD had a negative FC.