Urokinase-type plasminogen activator receptor as a predictor of poor outcome in patients with systemic inflammatory response syndrome

BACKGROUND Urokinase-type plasminogen activator (uPA) and urokinase-type plasminogen activator receptor (uPAR) are known as important factors, which mediate a variety of functions in terms of vascular homeostasis, inflammation and tissue repair. However, their role in systemic inflammatory response syndrome (SIRS) has been less well studied. This study aimed to test the hypothesis that the abnormalities of fibrinolysis and degradation of extracellular matrix mediated by uPA and uPAR are directly related to the patients with SIRS. We therefore analyzed their role and clinicopathological significance in patients with SIRS. METHODS A case-control study was conducted with 85 patients who were divided into two groups according to the diagnostic criteria of SIRS: SIRS group (n=50) and non-SIRS group (n=35). The SIRS group was divided into MODS group (n=26) and non-MODS group (n=24) by their severity, and survival group (n=35) and non-survival group (n=15) by their prognosis. Another 30 healthy adults served as normal controls. uPA and uPAR in plasma were detected by commercial enzyme-linked immunosorbent assay (ELISA) kits. RESULTS The plasma level of uPA was lower in the SIRS group than in the non-SIRS group and controls (P<0.001 and P<0.001). It was lower in sepsis patients and the MODS group than in the non-sepsis patients and the non-MODS patients (all P<0.05). However, there was no difference in uPA level between survivors and non-survivors (P>0.05). The plasma level of uPAR increased in the SIRS group compared with the non-SIRS group and controls (P<0.001 and P<0.001). There was a significant elevation of uPAR in sepsis patients, MODS patients and non-survivors as compared with non-sepsis patients, non-MODS patients and survivors respectively (all P<0.05). Plasma uPAR levels were positively correlated with APACHE II score (r=0.575, P<0.001) and SOFA score (r=0.349, P=0.013). AUCs for the prediction of SIRS mortality were 0.67 and 0.51, respectively, for uPA and uPAR. CONCLUSION uPAR could be a predictor of poor outcome in patients with SIRS.