E Crawford et al. JPGN Reports 2021; 22 – Issue 4 – p e129. Open Access: Association of Fecal Calprotectin With Endoscopic and Histologic Activity in Pediatric Inflammatory Bowel Disease

This retrospective study used data from 331 patients (n=107 with IBD). Fecal calprotectin (FC) was done between 30 days and 1 day before colonoscopy.

Key findings:

• Correlation with endoscopy: median FC was lowest for all IBD patients with no active disease (181 μg/g) and highest in severe disease (921 μg/g), with significant difference between no disease and moderate and severe disease (P = 0.019, 0.003), and between mild and severe disease (P = 0.012)
• Correlation with histology: median FC was lowest with no active disease (328 μg/g) and highest in severe disease (895 μg/g), with significant difference between no disease and moderate and severe disease (P = 0.021, 0.018)
• The control population had median FC of 35.5 compared to 181 μg/g for the IBD population in endoscopic remission (P = 0.018).

My take: Calprotectin levels are particularly helpful as a screen for IBD (probably using threshold of at least 120) and its use to monitor clinical response. This study shows it has some utility in predicting disease severity.