In critically ill patients, the suPAR level is significantly increased. suPAR is an independent prognostic marker, and the change over time correlates with organ dysfunction.
suPAR is elevated and has a prognostic value in patients with:
- SIRS (systemic inflammatory response syndrome)1,2
- Sepsis/septic shock3-9
- Burn injuries10
- Traumatic brain injuries11
The suPAR level reflects the body’s immune response to infections, and the level increases with the severity of the infection. In patients with organ dysfunction, the suPAR value is often a two-digit value. In particular hepatic and renal dysfunction affects the suPAR level3-5.
suPAR has been studied in patients with SIRS who were acutely admitted to the emergency department (n=902). The studies showed that suPAR is a stronger marker of 2-day, 30-day, and 90-day mortality than age, CRP, IL-6, creatinine, and procalcitonin. However, for diagnostic purposes, IL-6 and CRP are superior to suPAR in predicting a positive blood culture1,2.
A Greek multicenter study including 1914 patients with sepsis showed that suPAR is a strong predictor of mortality, and that a suPAR level above 12 ng/mL is linked to a >80% sensitivity for mortality and a negative predictive value of 94.5%6.
In addition, the prognostic value of suPAR in patients with sepsis is independent of relevant covariates like APACHE score, CRP, etc.6-9.
In patients with burn injuries and inhalation trauma requiring mechanical ventilation, the plasma suPAR level and BAL fluid level correlate to IL-6 and coagulation factors. An elevated plasma suPAR level is associated with prolonged ICU stay and the duration of mechanical ventilation10.
The suPAR level is elevated in patients with traumatic brain injury. In trauma patients who suffered a brain injury within 12 hours prior to blood sampling, the mean suPAR level is 14.9 ng/mL ± 6.9 vs. 2.8 ng/mL ± 0.7 in control subjects. In these patients suPAR is associated with severity of the brain injury and with mortality11.
1. Raggam RB, Wagner J, Pruller F et al. Soluble urokinase plasminogen activator receptor predicts mortality in patients with systemic inflammatory response syndrome. J Intern Med 2014;276(6):651-658.
2. Koch A, Tacke F. Why high suPAR is not super–diagnostic, prognostic and potential pathogenic properties of a novel biomarker in the ICU. Crit Care 2011;15(6):1020.
3. Koch A, Voigt S, Kruschinski C et al. Circulating soluble urokinase plasminogen activator receptor is stably elevated during the first week of treatment in the intensive care unit and predicts mortality in critically ill patients. Crit Care 2011;15(1):R63.
4. Koch A, Zimmermann HW, Gassler N et al. Clinical relevance and cellular source of elevated soluble urokinase plasminogen activator receptor (suPAR) in acute liver failure. Liver Int 2014;34(9):1330-1339.
5. Meijers B, Poesen R, Claes K et al. Soluble urokinase receptor is a biomarker of cardiovascular disease in chronic kidney disease. Kidney Int 2015;87(1):210-216.
6. Giamarellos-Bourboulis EJ, Norrby-Teglund A, Mylona V et al. Risk assessment in sepsis: a new prognostication rule by APACHE II score and serum soluble urokinase plasminogen activator receptor. Crit Care 2012;16(4):R149.
7. Donadello K, Scolletta S, Covajes C, Vincent JL. suPAR as a prognostic biomarker in sepsis. BMC Med 2012;10:2. doi: 10.1186/1741-7015-10-2.:2-10.
8. Backes Y, van der Sluijs KF, Mackie DP et al. Usefulness of suPAR as a biological marker in patients with systemic inflammation or infection: a systematic review. Intensive Care Med 2012;38(9):1418-1428.
9. Eugen-Olsen J, Giamarellos-Bourboulis EJ. suPAR: The unspecific marker for disease presence, severity and prognosis. Int J Antimicrob Agents 2015;(15):10.
10. Backes Y, van der Sluijs KF, Tuip de Boer AM et al. Soluble urokinase-type plasminogen activator receptor levels in patients with burn injuries and inhalation trauma requiring mechanical ventilation: an observational cohort study. Crit Care 2011;15(6):R270.
11. Yu L, Wu X, Wang H, et al.. Diagnostic and prognostic significance of suPAR in traumatic brain injury. Neurol India 2014;62(5):498-502.