Dxau 5811

All clinical biochemistry and hematological measurements were performed at the hospital laboratory of the UMC Utrecht. Urea, creatinine, potassium, phosphate, sodium, calcium, magnesium, bicarbonate, lactate, osmolality, albumin, and LDH concentrations were analyzed with a routine chemistry analyzer (DxAU 5811, Beckman Coulter). Hemoglobin, leukocyte, and thrombocyte concentrations were analyzed with a routine hematology analyzer (CELL‐DYN Sapphire, Abbott Diagnostics). Free hemoglobin was measured using dual‐wavelength spectrophotometry. Venous blood gasses were analyzed using a blood gas analyzer (RAPIDLab type 1265; Siemens Medical Solutions Diagnostics B.V.).

Serum was obtained from blood collected into Vacutainer tubes (10 mL, Becton Dickinson, Oxford, UK). Samples were centrifuged at 1300× g for 10 min. Serum aliquots were obtained and stored at −80 °C until use. Serum ferritin was determined using an automated chemiluminescence immunoassay on a Unicel Dxl 800 (Beckman Coulter, Brea, CA, USA). Serum iron was estimated using a colorimetric assay on a DxAU 5811 (Beckman Coulter). Serum transferrin values were obtained via immunochemical turbidimetry on a DxAU 5811. Total iron binding capacity (TIBC) (μmol/L) was calculated as serum transferrin (g/L) × 25.14, and transferrin saturation as the ratio of serum iron to TIBC. As a marker for inflammation, C-reactive protein (CRP) was measured via immunochemical turbidimetry on a DxAU 5811.