Brahms pct sensitive kryptor

WBC count was measured as part of the on-site evaluation in the NIDIAG study, using available methods at the routine laboratories of the study sites, in line with NIDIAG good clinical laboratory practice standards [18 (link)]. For the present study, we measured CRP and PCT levels on archived serum samples from the NIDIAG study. After on-site processing, we divided each serum sample into 2 aliquots, stored them in liquid nitrogen, and shipped them on dry ice to the Institute of Tropical Medicine, Antwerp, Belgium, to be stored in the biobank at −80°C. Biomarker measurement took place in April–May 2018 using Vitros Chemistry Products CRP Slides (Ortho-Clinical Diagnostics, Rochester, NY, USA) on the Vitros 5600 Integrated System (Ortho-Clinical Diagnostics) and BRAHMS PCT-sensitive Kryptor (Thermo Fisher Scientific, BRAHMS GmbH, Hennigsdorf, Germany) on BRAHMS Kryptor Compact PLUS (Thermo Fisher Scientific, BRAHMS GmbH). These assays had a limit of detection of 5 mg/L for CRP and of 0.075 µg/L for PCT. CRP levels <10 mg/L and PCT levels <0.1 µg/L are considered the reference values by the manufacturers and will henceforward be referred to as “normal values.” For WBC count, the cutoff for normal values was set at 11 000/µL [20 ].

Procalcitonin testing was not obtained as part of clinical care and was therefore available as an independent comparator without risking incorporation bias. Procalcitonin was measured using serum or plasma, when available. Serum samples were measured on the Roche Elecsys 2010 analyzer (Roche Diagnostics) or miniVIDAS immunoassay (bioMérieux). Plasma samples were measured using B•R•A•H•M•S PCT sensitive KRYPTOR (Thermo Fisher Scientific). Measurements were treated equivalently regardless of platform. Values >0•25 µg/liter defined bacterial infection and values ≤0•25 µg/liter defined non-bacterial [24] (link). We compared procalcitonin and gene expression using McNemar's test.