MPO and acute respiratory distress syndrome: We acknowledge the inherent limitations of the study of critically ill patients with limited patient samples for study, and limitations in our COVID-19-ARDS whole blood samples treated with 4% PFA to inactivate SARS CoV2 virus [final 2% PFA], leading to non-availability of plasma samples to perform ELISA studies on biomarkers and MPO-DNA complexes of NET-remnants.