P110 ASSOCIATION OF FECAL CALPROTECTIN WITH ENDOSCOPIC AND HISTOLOGY ACTIVITY IN PEDIATRIC INFLAMMATORY BOWEL DISEASE PATIENTS

Abstract

Abstract Background Inflammatory bowel disease (IBD) treatment strategies have evolved to target mucosal healing, which has been shown to be associated with clinical remission and reduced complications. Fecal calprotectin (FC) is a non-invasive marker of intestinal inflammation, and has been shown to correlate with disease activity in IBD patients, though values which correlate with mucosal healing vary across studies. We aim to examine the association of quantitative FC levels with endoscopic and histologic severity, and compare FC in IBD patients with endoscopic remission with a control population. Methods We conducted a retrospective chart review of patients who had a FC completed between 30 and 1 days before colonoscopy at UH Rainbow Babies and Children’s Hospital between 2014 and 2018. IBD patients had disease severity endoscopically graded using the SES-CD or Mayo UC score, and had disease severity histologically graded using the Geboes method. Severity was classed as no disease, mild, moderate or severe. FC values of IBD patients with mucosal healing and the control population (those without gastrointestinal pathology or diagnosis on evaluation) were compared. Results 331 cases were included in the study; 107 IBD cases and 224 controls. 63 patients (19%) had a diagnosis of Crohn’s disease (CD) and 44 patients (13%) had ulcerative colitis (UC). When assessing endoscopic scoring of IBD patients, the median FC was lowest in those with no disease (181 ug/g), followed by those with mild and moderate disease (499, 599 ug/g) and highest in those with severe disease (921 ug/g). There was significance comparing no disease to moderate and severe disease (p=0.019, 0.003), and between mild and severe disease (p=0.012). When assessing histology, the median FC was lowest in IBD patients with no disease (328 ug/g), followed by those with mild and moderate disease (399 ug/g, 674 ug/g) and highest in those with severe disease (895 ug/g). There was significance comparing no disease to moderate and severe disease (p=0.021, 0.018). In CD patients, there was significance in FC between no disease and moderate and severe disease (p=0.047, 0.0047) on endoscopic scoring. In UC patients, there was significance in FC between no disease and moderate disease (p=0.023) for histologic scoring. When comparing FC of endoscopically normal patients, the control group had a significantly lower median FC than the IBD population with endoscopic remission (43 ug/g vs 181 ug/g, p=0.018). Conclusion FC showed association with disease severity on gross endoscopy and histology and significance between severities in our IBD cohort. Additionally, normal cut-off values of FC may depend on the presence or absence of underlying disease. While larger studies are needed, this noninvasive test may help mitigate frequency of invasive procedures.