Role of Inflammatory Markers as Predictors of Clinical Activity and Endoscopic Severity in Crohn’s Disease

Abstract

Objective: We aim to assess the role of inflammatory markers as predictors of clinical activity and endoscopic severity in Crohn's disease (CD). Methods: Patients attending for colonoscopy with known or suspected CD were recruited. Clinical disease activity was recorded as per the Crohn's Disease Activity Index (CDAI) and endoscopic activity was recorded using the simple endoscopic score (SES) for CD. Receiver operating characteristic analysis (ROC) determined the predictive value and optimal predictive thresholds for the inflammatory markers. Results: The folllowing parameters were significantly different between clinically active CD and CD in remission: SES, C-reactive protein (CRP), white blood cell count (WBC), neutrophil count, hemoglobin, platelet count, albumin and fecal calprotectin (FC). And the following parameters were significantly different between patients with mild (SES<7) and moderate to severe (SES≥7) endoscopic activity: CDAI, WBC, CRP, neutrophil count, albumin and FC. The cut-off value for CRP for the detection of moderate to severe endoscopic activity in CD patients was calculated as ≥11.5 mg/L using ROC analysis [Sensitivity: 70%, specificity: 100%, AUC: 0.790 (0.567-1.013), P=0.028] whereas this cut-off value was 487 µg/g for FC [Sensitivity: 70%, specificity: 90%, AUC: 0.805 (0.598-1.01), P=0.028]. All of the 6 patients with FC >487 µg/g and CRP>11.5 mg/L were found to have moderate to severe endoscopic activity. Conclusion: Increased concentrations of either CRP or FC are predictive of clinical and endoscopic disease activity.