Soluble Urokinase Plasminogen Activator Receptor as a Decision Marker for Early Discharge of Patients with COVID-19 Symptoms in the Emergency Department

Abstract

Background: Severe acute respiratory syndrome coronavirus 2 (The Covid-19 pandemic) strains health care capacity. Better risk stratification, with discharge of patients with a predicted mild disease trajectory, can ease this burden. Elevated blood-soluble urokinase plasminogen activator receptor (suPAR) has previously been shown to be associated with risk of intubation in confirmed COVID-19 patients.

Objective: To evaluate whether point-of-care measures of suPAR in patients presenting to the emergency department (ED) with symptoms of COVID-19 can identify patients that can be safely discharged.

Methods: Observational cohort study including all patients in the ED with symptoms of COVID-19 from March 19 to April 3, 2020. SuPAR was measured at first presentation. Review of electronic patient records 14 days after admission was used to assess disease trajectory. Primary endpoints were mild, moderate, severe, or very severe trajectory. The predictive value of suPAR, National Early Warning Score (NEWS), C-reactive protein (CRP), and duration of symptoms was calculated using receiver operating characteristics (ROC).

Results: Of 386 patients, 171 (44%) had a mild disease trajectory, 79 (20%) a moderate, 63 (16%) a severe, and 73 (19%) a very severe disease trajectory. Low suPAR was a strong marker of mild disease trajectory. Results suggest a cut-off for discharge for suPAR < 2.0 ng/mL if suPAR is used as a single parameter, and <3.0 ng/mL when combined with NEWS ≤ 4 and CRP < 10 mg/L.

Conclusion: suPAR is a potential biomarker for triage and safe early discharge of patients with COVID-19 symptoms in the ED. suPAR can be used even before SARS-CoV-2 status is known.

Keywords: CRP; Covid-19; ED overcrowding; Early discharge; Early warning score; Point-of-care test; Triage; suPAR.