Circulatory dipeptidyl peptidase 3 (cDPP3) is a potential biomarker for early detection of secondary brain injury after aneurysmal subarachnoid hemorrhage.

Abstract Introduction Delayed cerebral ischemia (DCI) is a common complication after aneurysmal subarachnoid hemorrhage (aSAH) that can culminate in secondary brain damage. Although it remains one of the main preventable causes of aSAH-related morbidity, there is still a lack of prognostic criteria for identification of patients at risk of developing DCI. Because elevated circulatory levels of the enzyme dipeptidyl peptidase 3 (cDPP3) were recently identified as a potential biomarker for outcome prediction in critically ill patients, we evaluated the time-course of changes in cDPP3 levels after aSAH. Materials and methods cDPP3 levels were quantified in serum obtained from 96 confirmed aSAH patients during the early (EP: d1–4), critical (CP: d5–8, d9–12, d13–15) and late (LP: d16–21) phase after aSAH onset. Associations between cDPP3 levels and demographic or clinical parameters were evaluated. The relations between cDPP3 levels and DCI, DCI-related infarctions and long-term clinical outcomes were examined by receiver operating characteristics (ROC) curve analysis and multivariate logistic regression. Results Significantly higher cDPP3 levels during CP (d5–8, d9–12, d13–15) were observed in patients with poor clinical (p  Conclusion Our results provide first evidence that cDPP3 could serve as a promising biomarker for early diagnosis of DCI-related infarctions in poor grade aSAH patients.