Xe 2100 system

Eosinophil count (×10³ cells/μl) were measured using Automated Hematology Blood Analyzer (XE2100–system; Sysmex, Japan). In the main analyses, absolute eosinophil count was utilized. Absolute eosinophil count was calculated by multiplying the relative eosinophil count by the total leukocyte count.

Prior to the NEO study visit, participants completed a questionnaire about demography, lifestyle and medical history and fasted for at least 10 hours. Participants came to the research site in the morning to undergo several baseline measurements including anthropometric measurements, and blood sampling. Hemoglobin (Hb) was measured by the SLS hemoglobin detection method and hematocrit (Hct) by the RBC cumulative pulse height detection method with a Sysmex XE-2100 system (Sysmex, UK).
Extensive physical examination was conducted, including anthropometry and blood pressure measurements. Blood pressure was measured three times in a seated position on the right arm with a 5 minutes resting interval using a validated automatic oscillometric device (OMRON, Model M10-IT, Omron Health Care Inc., IL, USA). Prehypertension and hypertension were diagnosed according to JNC 7 criteria [25] (link).

Complete blood count (CBC), including white blood cell (WBC) count, neutrophil count, lymphocyte count, hemoglobin concentration, platelet count, and mean platelet volume (MPV), were analyzed using an XE-2100 system (Sysmex Corporation, Japan). The concentrations of thyroid stimulating hormone (TSH), free thyroxine (FT4), total triiodothyronine (TT3), anti-thyroid peroxidase antibody (anti-TPO), and anti-thyroglobulin antibody (anti-Tg) were measured using a Cobas e601 analyzer (Roche Diagnostics, Mennheim, Germany). CRP concentrations were measured using Labospect 008AS (Hitachi, Japan), and ESR was analyzed using TEST 1 (Alifax, Padova, Italy). The neutrophil-to-lymphocyte ratio (NLR) was calculated as the neutrophil count/lymphocyte count (23 (link)–25 (link)), and the platelet-to-lymphocyte ratio (PLR) as the platelet count/lymphocyte count (25 (link), 26 (link)). Reference ranges were defined as 4,800–10,800/µL for WBC, 1,800–7,800/µL for neutrophil count, 1,000–4,800/µL for lymphocyte count, 12–18 g/dL for hemoglobin concentration, 130,000–450,000/µL for platelet count, 7.4–10.4 fL for MPV, 0.4–4.8 µIU/mL for TSH concentration, 0.8–1.71 ng/dL for FT4 concentration, 0.6–1.6 ng/mL for TT3 concentration., <34IU/ml for anti-TPO, <115 IU/mL for anti-Tg, <0.3 mg/dL for CRP concentration, and <20 mm/hr for ESR.

Each included patient had a blood sample drawn at ICU admission for blood cell counts and automated analysis of leukocyte differentials using the XE-2100 system (Sysmex, Kobe, Japan). The immature granulocyte population was composed of promyelocytes, myelocytes, and metamyelocytes, but not blasts. As described elsewhere [16 (link)], a lysing reagent was used to lyse the erythrocytes and to create ultramicroscopic pores in the leukocyte cell membranes that allowed the entry of a polymethine dye with high affinity for nucleic acids. The leukocytes were then analyzed based on nucleic-acid fluorescence and side scatter [17 (link)].

In Lifelines, blood samples were collected in the morning after an overnight fast. The blood samples were placed at 4 °C and transported from the Lifelines research site to the Lifelines laboratory, under tightly controlled and continuously monitored conditions. From the Lifelines laboratory, part of the samples were directly transferred to the central laboratory of the University Medical Center Groningen, to perform routine clinical chemistry assays on fresh samples. Hemoglobin, total leucocytes, and thrombocytes were measured using routine procedures on a XE2100-system (Sysmex, Japan). In EUMDS, a complete blood count was performed at entry of the study as part of routine clinical care in the local hospital.