suPAR as a biomarker for risk of readmission and mortality in the acute medical setting

Introduction: The urokinase-type plasminogen activator receptor (uPAR) and its ligand (suPAR) are involved in numerous physiological and pathological pathways. Previous studies have shown that an elevated plasma suPAR level is associated with disease severity and mortality. The aim of this prospective observational study was to determine if the suPAR level was associated with readmission and mortality in the acute medical setting. Methods: Plasma suPAR levels were measured in 1,036 patients at admission. Follow-up ranged 3-10 months. Cox proportional hazards model was used to assess the relative contribution of different risk factors to mortality and readmission. The ANOVA test and Pearson's chi-squared test were used to compare suPAR tertile level with various variables. Results: The highest suPAR tertile level was significantly associated with mortality within 30 days after discharge, with a 6.66 hazard ratio (HR). Similar associations were found with readmission within the maximum observation period (HR = 2.26) and within 30 days (HR = 2.08), although the latter became insignificant when covariates were included. Conclusions: This study confirms previous findings of increased mortality and adds the finding that increased long-term readmission rates are associated with elevated suPAR levels. The present data do, however, not indicate that suPAR may serve as an independent biomarker for increased risk of short-term readmission in the acute medical setting.