P195 Is fecal calprotectin truly valuable in the management of isolated small bowel Crohn’s disease?

Abstract

Abstract Background Crohn’s disease (CD) is a complex inflammatory bowel disease (IBD) with different locations and behaviors. Although fecal calprotectin (FC) is recommended [1, 2] and has been used to monitor IBD, clinical practice has raised doubts about its utility in small bowel (SB) CD. Even though initial studies did not find a role for FC in SB CD, recent literature confirmed its acuity in SB active inflammation [2]. In fact, recent studies have confirmed a correlation between FC values and the degree in inflammatory activity in magnetic resonance enterography (MRE) [3, 4, 5, 6]. However, all these studies included patients with simultaneous colonic disease. Therefore, we evaluated the role of FC in predicting active inflammation in patients with isolated SB CD. Methods 40 patients with L1 CD according to Montreal classification [7] who underwent MRE, FC and C-reactive protein (CRP) assessment [maximum time between all exams was 60 days] were included. MRE data included disease location and extension, SB wall thickness and contrast enhancement, presence of SB dilation, fistulous tracts, inflammatory masses or abscesses, mesenteric findings. FC was both evaluated as a continuous variable and divided into 3 categorical variables: < 50 mg/g (“negative”), 50-150 mg/g (“low”) and > 150 mg/g (“high”). CRP was also divided in < 0.5 mg/dl (“negative”), 0.5-1 mg/dl (“low”) and > 1 mg/dl (“high”). Non parametric tests were used to correlate MRE findings with continuous FC and CRP values and Pearson’s chi-squared test was used to correlate categorical FC and CRP values. Results FC values ranged from 0 to 2872 mg/g, with an average of 301 mg/g. 31.7% had “negative”, 24.4% “low” and 43.9% “high” FC values. Table 1 represents MRE findings. We found a significant statistical correlation between both continuous and categorical FC values with positive mesenteric findings (p=0.0283 and p=0.037), increased bowel wall thickness (p=0.0455 and p=0.039) and presence of stenotic segments (p=0.0193 and p=0.05). All stenosis had signs of active inflammation. We did not find any correlation between FC and disease location or extension, bowel wall contrast enhancement or presence of penetrating disease. CRP values did not correlate with any of MRE findings. Conclusion Although imaging exams are essential for initial evaluation and treatment response in ileal disease, FC is a useful tool to evaluate active disease in isolated SB CD with both inflammatory (B1) and stenotic (B2) disease, in predominantly inflammatory stenosis. Our results do not support FC use to monitor penetrating (B3) disease.