Fecal proteolytic profiling of pediatric inflammatory bowel disease: A pilot study

• Published in: The FASEB journal Vol. 38; no. 9; pp. e23627 - n/a
• Main Authors: Haak, Wieke, Jagt, Jasmijn Z., Meij, Tim G. J., Bikker, Floris J., Brand, Henk S., Boer, Nanne K. H., Kaman, Wendy E.
• Format: Journal Article
• Language: English
• Published: United States 15-05-2024
• Subjects: Adolescent; biomarker; Case-Control Studies; Child; Child, Preschool; Colitis, Ulcerative - diagnosis; Colitis, Ulcerative - metabolism; Crohn Disease - diagnosis; Crohn Disease - metabolism; Crohn's disease; Feces - chemistry; Feces - enzymology; Female; Fluorescence Resonance Energy Transfer - methods; Humans; inflammatory bowel disease; Inflammatory Bowel Diseases - diagnosis; Inflammatory Bowel Diseases - metabolism; Male; Peptide Hydrolases - metabolism; Pilot Projects; protease; Proteolysis; ROC Curve; ulcerative colitis; protease; Crohn's disease; ulcerative colitis; biomarker; inflammatory bowel disease
• ISSN: 0892-6638; 1530-6860
• DOI: 10.1096/fj.202302190R

Colonoscopy is the gold standard for diagnosing inflammatory bowel disease (IBD). However, this invasive procedure has a high burden for pediatric patients. Previous research has shown elevated fecal amino acid concentrations in children with IBD versus controls. We hypothesized that this finding could result from increased proteolytic activity. Therefore, the aim of this study was to investigate whether fecal protease‐based profiling was able to discriminate between IBD and controls. Protease activity was measured in fecal samples from patients with IBD (Crohn's disease (CD) n = 19; ulcerative colitis (UC) n = 19) and non‐IBD controls (n = 19) using a fluorescence resonance energy transfer (FRET)‐peptide library. Receiver operating characteristic (ROC) curve analysis was used to determine the diagnostic value of each FRET‐peptide substrate. Screening the FRET‐peptide library revealed an increased total proteolytic activity (TPA), as well as degradation of specific FRET‐peptides specifically in fecal samples from IBD patients. Based on level of significance (p < .001) and ROC curve analysis (AUC > 0.85), the fluorogenic substrates W‐W, A‐A, a‐a, F‐h, and H‐y showed diagnostic potential for CD. The substrates W‐W, a‐a, T‐t, G‐v, and H‐y showed diagnostic potential for UC based on significance (p < .001) and ROC analysis (AUC > 0.90). None of the FRET‐peptide substrates used was able to differentiate between protease activity in fecal samples from CD versus UC. This study showed an increased fecal proteolytic activity in children with newly diagnosed, treatment‐naïve, IBD. This could lead to the development of novel, noninvasive biomarkers for screening and diagnostic purposes.
Proteolytic activity is increased in feces from children with newly diagnosed, treatment‐naïve, IBD as compared with non‐IBD controls. Fecal proteolytic profiling has shown its potential to distinguish children with IBD from controls, which could eventually evolve into novel, adjuvant, noninvasive biomarkers in the screening and diagnostic work‐up of pediatric IBD.