High levels of the protein suPAR in the blood of a person with COVID-19 may be a predictor of a more severe disease course.
A new study suggests that the protein soluble urokinase plasminogen activator receptor (suPAR) may help scientists predict who is likely to develop more severe COVID-19.
The research, published as a research letter in the journal Critical Care, may help clinicians identify people who are more likely to need intensive care support. It may also help them identify those who can safely manage the disease at home.
The sudden emergence and rapid spread of SARS-CoV-2, the virus that causes COVID-19, has put health services across the world at risk of being overwhelmed.
Patients who develop a severe infection of COVID-19 will often experience forms of respiratory failure, which, in turn, puts pressure on intensive care units (ICU).
Easing this pressure has been central to the responses of different governments. This has become known as “flattening the curve.”
If too many people require intensive care treatment in too short a time, ICUs might become overwhelmed and unable to care for all patients.
This is not only dangerous for the health of people with COVID-19 but for those with other illnesses who need treatment in an ICU.
Flattening the curve has predominantly occurred through social distancing measures. However, scientists have been investigating which instances of COVID-19 may become more severe.
If they can identify effective ways of predicting disease severity, then people who are likely to need intensive care support can stay in the hospital and potentially start receiving treatment.
Conversely, doctors can send those who are not likely to develop a severe case of the disease home. These people can then manage the disease through self-care, which will relieve pressure on ICUs.
In the present study, the authors looked at the relationship between high levels of suPAR in the blood of people with COVID-19 and the severity of the disease.
According to Prof. Jochen Reiser, the Ralph C. Brown, MD, Professor of Internal Medicine, Chairperson of the Department of Internal Medicine at Rush University, Chicago, and co-corresponding author of the study, “[i]f we measure suPAR as part of diagnosing COVID-19, we may know whom to watch more and whom to send home.”
“Plasma suPAR levels give us a window into the course of the disease, allowing for an improved monitoring and applying new and supportive treatments early.”
– Prof. Jochen Reiser
The study analyzed data from 15 COVID-19 patients from the Rush University Medical Center and 57 patients from the University of Athens Medical School in Greece.
After measuring the patients’ levels of blood suPAR, the researchers looked at how long it took before a patient required intubation, which involves ventilating a person by inserting a tube into their lungs.
The researchers found that those who had higher levels of suPAR in their blood needed intubation more quickly than those with lower levels.
According to Prof. Reiser, “[t]his is the first report in the world to show that suPAR is elevated in COVID-19 and is predictive.”
“Since suPAR is a reactant of the innate immune system, it’s an indicator of disease severity. These results show that the higher the plasma suPAR level, the worse the outcome will be in the lungs of these patients. The higher the suPAR level, the shorter the time before patients needed intubation.”
As Prof. Reiser notes, “[t]here is a body of literature that suPAR is associated with poor outcomes from acute respiratory distress syndrome (a condition in many patients with severe COVID-19) and poor lung functioning in critically ill patients.”
This study is small, so further research is necessary to confirm whether suPAR is an effective predictor of COVID-19 severity. A recent article in the BMJ notes that the reported performance of many COVID-19 prediction models in the current literature is “probably optimistic.”
Nonetheless, the findings point researchers in the right direction to carry out this future research, including whether targeting suPAR is a treatment option.