The Soluble Urokinase Plasminogen Activator Receptor as a Severity Biomarker in Children With Acute COVID-19 or Multisystem Inflammatory Syndrome

BACKGROUND

Elevated soluble urokinase plasminogen activator receptor (suPAR) has been associated with a poor prognosis in serious infections. The aim of this study was to evaluate the clinical value of suPAR in children with acute coronavirus disease 2019 (COVID-19) or multisystem inflammatory syndrome (MIS-C).

METHODS

Serum suPAR was measured using the suPARnostic AUTO Flex enzyme-linked immunosorbent assay in hospitalized children with COVID-19, MIS-C, bacterial pneumonia, and healthy controls.

RESULTS

A total of 211 children with a mean (±SD) age of 6.9 ± 4.96 years were tested; with COVID-19: 59 (28%), MIS-C: 36 (17%), pneumonia: 78 (37%) and healthy controls: 38 (18%). In the acute phase, the levels of suPAR (mean ± SD) were: MIS-C: 8.11 ± 2.80 ng/mL, COVID-19: 4.91 ± 1.90 ng/mL, pneumonia: 4.25 ± 1.44 ng/mL and controls: 2.09 ± 0.47 ng/mL ( P < 0.001). Children with acute COVID-19 and a severe or moderate clinical presentation had higher values than those with mild symptoms: 5.79 ± 1.58 versus 5.40 ± 1.94 versus 3.19 ± 0.73 ng/mL, respectively ( P < 0.001). In the MIS-C group, children hospitalized in the intensive care unit and in need of mechanical ventilation had higher suPAR than those who were not admitted to an intensive care unit: 9.32 ± 3.06 versus 7.13 ± 2.19 ng/mL, respectively ( P = 0.023). In children with COVID-19 or MIS-C, a correlation was detected between suPAR values and length of hospitalization ( rs = 0.418, P < 0.001).

CONCLUSIONS

The findings suggest that suPAR may be a valuable biomarker of disease severity in children with COVID-19 or MIS-C. This could facilitate the identification of children in need of intensive anti-inflammatory treatment, as it has been shown in adults with severe COVID-19.