Dipeptidyl peptidase-4 dysregulation and inflammatory cytokines as dual biomarkers in ulcerative colitis ‒ a case-control study

Introduction and aim. Ulcerative colitis (UC) is a chronic inflammatory bowel disease (IBD) characterized by immune dysregulation and mucosal inflammation. Current UC biomarkers lack specificity, underscoring the need for novel diagnostic tools. Dipeptidyl peptidase-4 (DPP-4), a serine protease implicated in immune modulation and inflammation, and interleukin-7 (IL-7), a cytokine linked to mucosal immune dysregulation, may serve as dual biomarkers. This study aimed to evaluate the diagnostic utility of serum levels of DPP-4, C-reactive protein (CRP), and IL-7 to differentiate UC patients with UC from healthy individuals. Material and methods. This research conducted a case-control study involving 130 individuals, 65 diagnosed with UC and 65 apparently healthy individuals serving as the control group. Blood samples were obtained to measure DPP-4, IL-7, insulin and C-reactive protein levels. Results. The study demonstrated a significantly higher level of inflammatory markers compared to the healthy controls with a significantly higher CRP (23.38±17.76 vs. 2.38±0.89 mg/dL, p<0.001) and IL-7 concentrations (62.39±19.7 vs. 22.86±4.73 ng/L, p<0.001). and lower level of DPP-4 activity (1.33±0.19 vs. 2.37±0.35 U/L, p<0.001). ROC curve analysis revealed the excellent diagnostic performance of DPP-4 and IL-7 in identifying UC. Conclusion. Reduced serum DPP-4 levels and elevated levels of inflammatory markers (CRP and IL-7) highlight their utility as dual biomarkers for the diagnosis and monitoring of UC disease. DPP-4 expression is inversely correlated with inflammation. These biomarkers demonstrate diagnostic potential for UC; however, longitudinal studies are needed to assess their role in monitoring disease progression and response to treatment.