Atellica analyzer

Stable spirometry was performed according to the Spanish Society of Pulmonology and Thoracic Surgery (SEPAR) protocol [26] less than 1 year before admission. Patient age; sex; smoking status; number of moderate and severe ECOPD events 1 year before admission; comorbidities included in the Charlson index [27] ; basal mMRC dyspnea score; and dates of hospital admission, ICU admission and/or death during hospitalization were retrospectively recorded. The DECAF score [25] was calculated for all patients. The MDW and results of routine blood tests performed after arrival at the emergency department of each center were retrospectively collected.
Routine hematological and biochemical analytes were measured with automated assays. Specifically, C-RP was measured with Siemens traceable enzymatic method assays (Atellica Analyzer, Siemens, Germany).
MDW was measured in the emergency laboratory of each center with the same DxH 900 analyzer (Beckman Coulter. Inc., Brea, California, USA), according to the manufacturer´s instructions.

All serum samples were analyzed in duplicate for hepcidin, sEPO and sTfR (January-August 2022) and IL-6 (January 2022-February 2023). We used the following methodology: LC-MS/MS for hepcidin [23] (limit of detection (LoD) 0.3 nmol/L); Quantikine ELISA immunoassay for IL-6 (R&D Systems Inc, Minneapolis, MN, USA) (LoD=0.7 ng/L), chemiluminescence immunoassay on Atellica analyzer (Siemens Healthineers ® ) for sTfR (LoD=0.5 mg/L) and chemiluminescent immunometric assay on Immulite 2000 XPi analyzer for sEPO (LoD=1.5 IU/L). All samples from each subject were measured in the same analytical run and with the same reagent lot. All quality control results were within set limits.