Objective: The aim of this study was to perform a systematic review of the usefulness of suPAR as a prognostic marker in non-critical COVID-19 patients.
Materials and methods: We carried out a literature search in MEDLINE, Embase, and Web of Science using the following keywords: ("soluble urokinase receptor" OR "urokinase plasminogen activator receptor" OR "suPAR" OR "soluble uPAR" OR "soluble uPA receptor") AND ("COVID-19" OR "SARS-CoV-2"). We included observational studies (descriptive or analytic) that measured plasma suPAR on COVID-19 patients 18 years old or older, with non-critical disease at the beginning of the study.
Results: After screening and eligibility assessment, a total of 16 articles were included in the review. Most studies that measured mean differences found that suPAR levels were higher in patients with worse outcomes. The studies that measured diagnostic accuracy concluded that suPAR was highly sensitive and moderately specific to predicting bad outcomes. Studies that performed a survival analysis found that patients with high suPAR levels were more at risk of bad outcomes. Most of the studies included in this review were performed before extensive vaccination and omicron wave.
Conclusions: COVID-19 patients with moderate initial disease and elevated suPAR levels are more at risk of poor outcomes. Larger prospective clinical trials are needed to confirm the results obtained in this review.