Quantification of Plasma Biomarkers in Blood Samples

Blood was processed within 60 minutes of withdrawal. Blood was centrifuged twice (1000 x g followed by 10000 x g, both for 10 min at 4°C) to obtain platelet-free plasma and stored in aliquots at -80°C. Plasma MPO (Human Myeloperoxidase Quantikine ELISA Kit, Bio-Techne) and DNA-histone complexes (Cell Death Detection ELISA, Sigma-Aldrich) were quantified according to the manufacturer’s recommendations. NE levels were assessed with the Human Sepsis Magnetic Bead Panel 3 (EMD Millipore) in a Luminex MagPix instrument (Thermo Fisher Scientific) for AAA study samples or with PMN (Neutrophil) Elastase Human ELISA Kit (Thermo Fisher Scientific) for endotoxemia plasma samples. Citrullinated histone H3 (citH3) was measured as reported elsewhere [32 (link)]. Differential blood count was determined with a Sysmex XN-350 device. Biochemical parameters were assessed by the Vienna General Hospital routine laboratory.