P288 Fecal leukocyte esterase level can predict endoscopic activity for Inflammatory Bowel Disease patients

Abstract

Abstract Background The urine leukocyte esterase (LE) strip is widely employed to detect leukocyte presence in human body fluids due to its simplicity, speed, and cost-effectiveness. Our previous study demonstrated that fecal LE (FLE) correlated with fecal calprotectin (FC) which serves as a surrogate marker reflecting disease activity in inflammatory bowel disease (IBD) patients. This study aims to assess the correlation between FLE and endoscopy severity. Methods This prospective study included IBD patients at National Taiwan University Hospital from December 2021 to November 2023. FLE and FC in the same stool sample, which was collected within one month of endoscopy, were analyzed. The correlation between FLC, FC, and endoscopic severity scores was assessed using the Pearson method. Active disease in ulcerative colitis (UC) and Crohn's disease (CD) patients was defined as Mayo endoscopic score (MES) ≥ 2 and simple Endoscopic Score for Crohn's Disease (SESCD) ≥ 8, respectively. Sensitivity, specificity, positive and negative predictive values (PPV and NPV, respectively), and the Area Under the Receiver Operating Characteristic curve (AUROC) were analyzed by using SPSS. Results A total of 177 IBD patients (93 with UC, 84 with CD) were included. The correlation between FLE and FC levels was moderately positive (r=0.305, p<0.001). The correlation between FLE and endoscopic severity in UC and CD patients was 0.442 (p<0.001) and 0.293 (p=0.007), respectively. Among UC patients, the area under the receiver operating characteristic curve (AUROC) for predicting MES ≥ 2 by FLE and FC was 0.717 and 0.787 (p=0.241), with an optimal cutoff of 2+ for FLE and 42.5 mg/kg for FC, respectively. At this cutoff point, FLE demonstrated a sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for predicting MES ≥ 2 as 52.3%, 81.6%, 71.8%, and 65.6%, respectively. For CD patients, the AUROC for predicting SESCD ≥ 8 by FLE and FC was 0.761 and 0.869 (p=0.203), with an optimal cutoff of 2+ for FLE and 225 mg/kg for FC, respectively. FLE exhibited a sensitivity, specificity, PPV, and NPV of 81.8%, 64.4%, 74.3%, and 95.9% for predicting SESCD ≥8 respectively, at this cutoff. Conclusion Our results demonstrated that FLE can predict endoscopic activity, which is a cheaper and widely available monitoring tool, might be an alternative choice to FC for IBD monitoring.