Elevated Faecal Calprotectin in Patients with a Normal Colonoscopy: Does It Matter in Clinical Practice? A Retrospective Observational Study

Abstract

Introduction: Faecal calprotectin (FC) is commonly used as a diagnostic tool for patients with gastrointestinal (GI) symptoms. However, there is uncertainty in daily clinical practice how to interpret an elevated FC in patients with a normal colonoscopy. We investigated if patients with a normal colonoscopy but with an elevated FC more often were diagnosed with a GI disease in a 3-year follow-up period. Methods: Patients referred for colonoscopy (n = 1,263) to the Umeå University Hospital endoscopy unit between 2007 and 2013 performed a FC test (CALPRO®/) on the day before bowel preparation. A medical chart review was performed on all patients who had normal findings on their colonoscopy (n = 585, median age 64 years). Results: Thirty-four percent of the patients (n = 202) with normal colonoscopy had elevated FC (>50 μg/g), and these patients were more frequently diagnosed with upper GI disease during the follow-up period than patients with normal FC levels (9.9 vs. 4.7%; p = 0.015). The upper GI diseases were mainly benign (i.e., gastritis). In a binary logistic regression analysis controlling for age, gender, nonsteroid anti-inflammatory drug use, and proton-pump inhibitor use, there was no difference for a new diagnosis of upper GI disease in the follow-up period (multivariate OR 1.70; 95% CI: 0.77-3.74). There was no difference in a new diagnosis of lower GI disease (6.4 vs. 5.2%; p = 0.545) or cardiovascular disease/death (multivariate OR 1.68; 95% CI: 0.83-3.42) in the follow-up period between patients with elevated versus normal FC levels. Conclusions: In patients with a normal colonoscopy, a simultaneously measured increased FC level was not associated with an increased risk for significant GI disease during a follow-up period of 3 years.