Identifying new diagnostic markers for sepsis

Gwendolyn Vliegen, a PhD student working with Prof. Ingrid De Meester in the Laboratory for Medical Biochemistry just completed a study on identifying new diagnostic biomarkers for sepsis. Sepsis is a complex syndrome of which the underlying mechanisms are still not completely understood, and it has a high mortality rate (approximately 1 in 4 patients die). Symptoms include low blood pressure, fever, increased heart rate, and it can result in multiple organ failure. The diagnosis is often made too late to be able to start treatment. Thus, initiating treatment at an early stage is currently the only way of improving the outcome for sepsis patients. 

There  are currently no good diagnostic biomarkers that can help to identify patients with sepsis. For this reason, Gwendolyn and colleagues studied whether the enzymes dipeptidyl peptidase (DPP) 4, fibroblast activation protein α(FAP), prolyl oligopeptidase (PREP) and prolylcarboxypeptidase (PRCP) were dysregulated in plasma collected from 40 patients with septic shock (a more severe form of sepsis), by comparing them to 22 ICU controls that had received brain surgery. These specific enzymes were investigated as they play a role  in immune system and/or blood pressure regulation. Additionally, Gwendolyn and colleagues determined whether the enzymatic activities could be coupled to patient survival, and hence could be used as prognostic biomarkers.

Indeed, all 4 enzymes were dysregulated in septic shock patients. DPP4 and FAP were both decreased, while PREP and PRCP were increased. Especially, DPP4, FAP and PREP show potential as diagnostic biomarkers. Higher DPP4 activity was also associated with an increase in survival, thus showing its potential as a prognostic biomarker. In the future, larger clinical studies should be conducted to fully explore these enzymes in sepsis and septic shock. Robust biomarkers for sepsis could aid with early detection and diagnosis, so that treatment can be started at an early stage. This study was published in the journal PLOS ONE.

Gwendolyn Vliegen is a PhD student in the Laboratory for Medical Biochemistry, under supervision of Prof. Ingrid De Meester. She studies multiple proline-specific enzymes, with the aim of determining their functional role and to possibly identify them as biomarkers or therapeutic targets for disease. Gwendolyn will defend her PhD thesis in June 2020.