Predictive Markers of Crohn's Disease in Small Bowel Capsule Endoscopy: A Retrospective Study of Small Bowel Capsule Endoscopy

Abstract

To distinguish between functional gastrointestinal disorders like irritable bowel syndrome (IBS) and mild small bowel Crohn's disease (CD) can be a burden. The diagnosis of CD often requires small bowel capsule endoscopy (SBCE). The main goal of this research was to find predictive markers to rule out clinically significant small bowel CD without SBCE. A retrospective study of 374 patients who underwent SBCE for suspected small bowel CD in Turku University Hospital in 2012-2020 was conducted. We gathered the patient's laboratory, imaging and endoscopic findings at the time of SBCE. SBCE findings were graded along CECDAI (Capsule Endoscopy Crohn's Disease Activity Index)-scoring system. Fecal calprotectin (FC), serum albumin and ESR were significantly different with patients diagnosed with CD and those with not. Hb and CRP had no significant differences between the two groups. Sensitivity, specificity, PPV and NPV for FC < 50 ug/g were 96.4%, 19.6%, 34.6% and 92.5% and for CECDAI (cut-off value 3) 98.2%, 90.3%, 81.1% and 99.1%, respectively. A CECDAI-score of 3 would be a reasonable cut-off value for small bowel CD. Small bowel CD is possible with FC < 100 ug/g. Our results suggest a follow-up with FC before SBCE for patients with no endoscopic ileitis, negative imaging results and FC < 50 ug/g before SBCE.