COVID-19 and Pneumonia Blood Sampling

Blood from patients with COVID-19 pneumonia, community acquired pneumonia and from volunteers was drawn by venipuncture (21-gauge needles) or aspiration through venous catheters (Safety-Multifly, Sarstedt AG & Co, Nümbrecht, Germany). In ICU patients (COVID-19 ARDS or sepsis), blood sampling was performed at admission to the intensive care facility using 20-gauge catheters within the radial artery (8 cm polyethylene catheter, Vygon, Aachen, Germany). In a previous study, we showed that arterial vs. venous blood sampling has non-significant effects on EV miRNA expression (19 (link)). Blood was drawn into 9 ml serum collection tubes (S-Monovette, Sarstedt AG&Co, Nümbrecht, Germany), allowed to clot for 30 min and centrifuged at 3,400 x g for 10 min at room temperature. Within 10 min of separation, serum was aliquoted and immediately stored at -80°C. Whole blood samples for cellular RNA extraction were collected in PAXgene tubes (PAXgene, Qiagen, Hilden, Germany) in accordance with the supplier’s protocol.