current medicine research and practice 5 (2015) 50
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Soluble urokinase plasminogen activator receptor: A new biomarker Gunjan Garg, Atul Gogia, Atul Kakar* Ganga Ram Institute of Post-Graduation Medical Education (GRIPMER), New Delhi, India
article info Article history: Received 29 November 2014 Accepted 10 January 2015 Available online 11 February 2015
Soluble urokinase plasminogen activator receptor (suPAR) is a soluble form of urokinase receptor. It is a 3 homologous domains connected to the various cell surfaces including neutrophils, lymphocytes, monocytes/macrophages, endothelial and tumour cells. After cleavage from the cell surface, suPAR can be found in the blood and other organic fluids like urine, CSF in various concentrations depending upon immune system activation. suPAR is involved in various immunological regulatory functions, including cell adhesion, migration, chemotaxis, proteolysis, immune activation and signal transduction. Moderately elevated suPAR levels indicate increased lifestyle disease risk. Higher suPAR level denotes critical condition of the patient and increased mortality risk. Levels above 5.5 ng/ml in females and greater than 5 ng/ml in males signify high risk of sepsis in patients. Therefore, it helps us in triaging the patients according to sepsis severity. The decrement in suPAR levels from the initial value signifies the patient improvement. The study conducted by Suberviola B et al reflected that suPAR was better prognosticating tool than C-reactive protein (CRP) or procalcitonin in patients admitted to ICU. A total of 137 septic patients were studied. The area under the curve (AUC) for the prediction of in-hospital mortality for APACHE II and SOFA scores was 0.82 and 0.75 respectively. AUC for suPAR was 0.67, higher than CRP (0.50)
and PCT (0.44). The combination of severity scores and each biomarker did not provide superior AUCs.1 However, the study conducted by Gustafsson A et al concluded that the suPAR level was significantly elevated in sepsis patients compared to controls, but not significantly higher in nonsurvivors than survivors. Total 27 patients were included and 90-day mortality was registered. The weak correlation between suPAR and other inflammatory markers (CRP, PCT, IL-6 or IL-10) might recommend that suPAR reflects general activation of the immune system rather than exercising inflammatory activities.2 The diagnostic value of suPAR in sepsis has not been well defined, especially as compared to other more established biomarkers, such as CRP and procalcitonin. On the other hand, suPAR levels have been shown to predict outcome in various kinds of bacteraemia and recent data suggest they may have predictive value, similar to that of severity scores, in critically ill patients.
1. Suberviola B, Castellanos-Ortega A, Ruiz Ruiz A, Lopez~ ez M. Hospital mortality prognostication in Hoyos M, Santiban sepsis using the new biomarkers suPAR and proADM in a single determination on ICU admission. Intensive Care Med. 2013;39:1945e1952. 2. Gustafsson A, Ljunggren L, Bodelsson M, Berkestedt I. The prognostic value of suPAR compared to other inflammatory markers in patients with severe sepsis. Biomark Insights. 2012;7:39e44.
* Corresponding author. Medident Clinic, 31 e South Patel Nagar, New Delhi 8, India. Tel.: þ91 (0) 9811110802 (mobile). E-mail address: [email protected]
(A. Kakar). http://dx.doi.org/10.1016/j.cmrp.2015.01.001 2352-0817