Is suPAR the strongest marker for COVID-19 risk identification?
Fri Jun 26 2020
By: Jesper Eugen-Olsen, PhD, Copenhagen University Hospital Hvidovre, Denmark
The corona virus SARS-CoV-2 pandemic puts tremendous pressure on hospital resources and capacity. Clinical markers of progression are urgently needed in order to quickly discharge patients, who will not develop severe disease, to own home isolation. They are also needed to identify those who will develop more severe symptoms and should be admitted to the medical ward, or to the ICU.
A biomarker or a combination of biomarkers that can predict the disease progression may be useful for discharging patients. At the same time it would be valuable to detect the patients with a moderate disease risk and where further progression is low.
There has been reports on hyper-immune activation and cytokine storm in patients with a severe response to infection with the SARS-CoV-2 virus.1 However, cytokines are unstable and fluctuating according to sample handling, making them unsuitable for routine clinical decision
Several routine biomarkers have been shown to be associated with severe illness and mortality in patients with COVID-19. These include increased white blood cell count, decreased lymphocyte and platelet counts, alanine aminotransferase, creatinine kinase, lactate dehydrogenase, ferritin, C-reactive protein, Interleukin-6, and D-dimer.2
“It is expected that suPAR is a strong biomarker of disease severity and progression in patients with COVID-19.”
Dr. Jesper Eugen-Olsen
We speculate that suPAR, a stable biomarker of immune activation, is a strong biomarker for development of severe disease and respiratory failure in patients with COVID-19 symptoms (Fig. 1). There are at least five reasons why suPAR may be a suitable marker for this purpose:
- suPAR is a marker of chronic inflammation. Patients with high suPAR have a chronically activated immune system that is not capable of fighting disease.
- suPAR is elevated in elderly with comorbidities and capture the most fragile patients. In acute medical patients in general, suPAR is a strong marker of 30- day readmission and mortality.3,4
- suPAR has been investigated in several viral infections, including HIV, HCV, Crimean-Congo hemorrhagic fever, and hantavirus. In all cases, suPAR is associated with clinical severity and mortality.5,6,7,8
- suPAR is elevated and associate to disease severity in patients with respiratory diseases including pneumonia9 and COPD10, and predicts risk of acute respiratory distress syndrome in patients with sepsis.11
- The SARS-CoV-2 viral infection is likely to induce highly elevated suPAR in the most severe cases. This may cause acute kidney injury12,13, a disease often observed in COVID-19 patients in the intensive care department.
Fig. 1. Hypothesis: the baseline plasma suPAR level can differentiate whether patients with COVID-19 will have a mild or a severe outcome of the infection.
In summary, it is expected that suPAR is a strong biomarker of disease severity and progression in patients with COVID-19 and may provide an important tool for the managing of patients suspected of having this virus.
Clinical studies documenting this are warranted.