Li heparin

Blood samples were taken by venipuncture and collected using Li-Heparin, serum gel and EDTA-buffered collection monovettes (Sarstedt, Nümbrecht, Germany). TNF-α, LBP, IL-1β, IL-8 and IL-10 concentrations were determined using the chemiluminescence immunoassay method (DPC Biermann Immunoassay Analyzer Immulite 1000). Ferritin and IL-6 concentrations were detected by the electrochemiluminescence immunoassay method “ECLIA” (Roche immunoassay analyzer COBAS 8000 (e 801 module)). CRP was determined by turbidimetric measurement (Cobas c system). Leukocytes and platelets were measured using the Sysmex reference method for enumeration and counting. The measurement was performed by the Institute of Clinical Chemistry, University of Ulm. EDTA anticoagulated blood samples were centrifuged at 2500 g for 10 min and the plasma was stored on average for ∼6 months (SD = 1.69, range = 2–8 months) at minus 80 °C until the final quantification of analytes. KYN was determined using the protocol established by Bizjak et al. (2021) (link).
Concentrations below the limit of detection at t₀ (IL-1β < 1.5 pg/ml [10 of 61], IL-6 < 1.5 pg/ml [39 of 49], IL-8 < 2.0 pg/ml [1 of 49], IL-10 < 1.0 pg/ml [20 of 48], CRP <0.6 mg/ml [39 of 61]) were replaced by half of the detection limit. Due to numerous missing values (values below detection limit), CRP and IL-6 could not be evaluated in this study.