Thomas Jefferson University Hospital Philadelphia, Pennsylvania
Christine Shieh, MD, Divya Chalikonda, MD, Peter D. Block, MD, MSc, Brianna Shinn, MD, C. Andrew Kistler, MD, PharmD; Thomas Jefferson University Hospital, Philadelphia, PA
Introduction: Fecal calprotectin is a protein biomarker found in stool during inflammatory conditions involving the gastrointestinal tract. While elevated levels are seen in active inflammatory bowel disease (IBD), they are also detected in patients without evidence of IBD on imaging or endoscopy. In this study, we identified several gastrointestinal conditions with elevated calprotectin levels and aimed to establish a meaningful calprotectin level cutoff to help differentiate between the different diagnoses. Methods: This was a single center retrospective study at a tertiary care institution. 160 adult patients with elevated fecal calprotectin level >150 ug/g over the course of 2010-2019 were included in this study. Data recorded included fecal calprotectin level, initial gastrointestinal complaint, imaging and endoscopy findings, CRP, and final diagnosis. Univariate analysis was performed. Results: The variety of diagnoses with elevated fecal calprotectin levels is depicted in Figure 1. Significant differences in calprotectin levels were seen between different groups of diagnoses. CRP levels did not distinguish among the diagnoses. Only 10 patients had report NSAID use, which may influence calprotectin levels. ROC analysis established a predictive value for fecal calprotectin to distinguish between two groupings of diagnoses. Group 1 included IBD, other colitis, non-viral infections and Group 2 included viral infections, diarrhea without colitis (Figure 2). The optimal cutoff level for fecal calprotectin to make this distinction was 541 ug/g (sensitivity 87.8%, specificity 60.6%). Discussion: Elevated fecal calprotectin levels vary across a wide range of gastrointestinal conditions and can be significantly elevated in conditions. Level of elevation can help delineate gastrointestinal diseases, which in turn affects further workup and procedures. A calprotectin level of 541 ug/g has strong predictive value in distinguishing between IBD or non-IBD conditions that result in colitis on imaging and diarrhea without imaging findings of colitis. CRP did not show the same predictive value. Larger studies are warranted to validate this cutoff and help guide the differential diagnosis for a patient based on fecal calprotectin, thereby eliminating unnecessary endoscopic procedures.
Elevated fecal calprotectin levels across different gastrointestinal illnesses
ROC analysis of fecal calprotectin levels between two groups of diagnoses
Disclosures: Christine Shieh indicated no relevant financial relationships. Divya Chalikonda indicated no relevant financial relationships. Peter Block indicated no relevant financial relationships. Brianna Shinn indicated no relevant financial relationships. C. Andrew Kistler indicated no relevant financial relationships.