Serum suPAR associated with disease severity and mortality in elderly patients with community-acquired pneumonia

Severe community-acquired pneumonia (SCAP) in elderly has more atypical clinical presentation compared to younger patients. Timely recognition could improve clinical care. This study investigated the value of soluble urokinase-type plasminogen activator receptor (suPAR) on severity assessment and outcome prediction in elderly patients with CAP. We conducted a prospective, observational study between January 2014 and December 2016. A total of 230 patients ≥65 were enrolled in this study, of which 151 were CAP and 79 were SCAP. Serum suPAR levels were determined by ELISA essays within 24 h after hospitalization. Thirty-day and 1-year mortalities were recorded as outcomes. Serum suPAR level was significantly increased in patients with SCAP. Positive correlation was found between suPAR levels with CURB-65 and PSI score (r = 0.423 and r = 0.489; p < .001 for both). The AUC for suPAR to discriminate SCAP patients from CAP was 0.783 at a cut-off value 4.27 ng/mL. AUCs of suPAR for predicting 30-day and 1-year mortalities were 0.815 (95% CI 0.746-0.866) and 0.820 (95% CI 0.770-0.870). Regression result shows suPAR (≥8.92 ng/mL) was independent factor for 30-day mortality (HR = 2.83, 95% CI 1.04-7.69) and suPAR with cut-off value 6.18 ng/mL could predict 1-year mortality (HR = 2.44, 95% CI 1.09-5.44). suPAR was strongly associated with CAP severity and could be a prognostic indicator for 1-year survival in elderly.