Circulating Dipeptidyl Peptidase Activity Is a Potential Biomarker for Inflammatory Bowel Disease.

ABSTRACT:

Introduction

Dipeptidyl peptidase (DPP)-4 is part of a larger family of proteases referred to as DPPs. DPP4 has been suggested as a possible biomarker of inflammatory bowel disease (IBD). Circulating DPP4 (cDPP4) enzyme activity was investigated as a potential biomarker for IBD. Additionally, DPP enzyme activity and gene expression was quantified in colonic tissue of IBD and non-IBD patients.

Methods

In study 1, DPP enzyme activity was quantified in plasma samples from 220 IBD patients (Crohn's disease [CD] n = 130, ulcerative colitis [UC] n = 90), and non-IBD controls (n = 26) using colorimetric assay. In study 2, tissue and plasma samples were collected from 26 IBD patients and 20 non-IBD controls. Plasma C-reactive protein (CRP) was quantified in all patients. Colonic DPP4, DPP8, DPP9 and dibroblast activation protein (FAP) gene expression was determined by quantitative polymerase chain reaction. cDPP and cFAP enzyme activity were also measured. Sensitivity and specificity were determined by receiver operating characteristic curve analysis.

Results

In study 1, total cDPP activity was found to differentiate CD patients with active disease (n = 18) from those in remission (n = 19; sensitivity 78% and specificity 63%). In study 2, total cDPP and cFAP activity was 28% and 48% lower in patients with elevated CRP (>10 mg/L) respectively compared to patients with normal CRP. Gene expression of DPP4, FAP and DPP8 was also significantly higher in colonic biopsies from IBD patients compared to non-IBD (P < 0.05).

Discussion

Our findings implicate the DPP enzyme family in intestinal inflammation and suggest future biomarker applications to differentiate the pathophysiological aspects of IBD.

SUBMITTER: Jaenisch SE 

PROVIDER: S-EPMC8806366 | biostudies-literature |

REPOSITORIES: biostudies-literature