Evaluation of two automated immunoassays for procalcitonin measurement: Kryptor® (Brahms) and Vidas® (BioMerieux)

Procalcitonin (PCT) is an excellent marker of sepsis and bacterial. infections. PCT was measured, in our laboratory, by an automated immunoassay on the Kryptor system (Brahms). Recently, a new automated immunoassay has become available on the Vidas system (Brahms-BioMerieux). The plasma samples of 108 patients were stored at a temperature of -20 degrees C and thawed in two series of 54 samples. The measurement of PCT was performed simultaneously on the two systems. Comparison by regression analysis showed PCT values determined by both tests in good agreement (r = 0.98) (Passing-Bablock regression tine: Vidas = 1.26, Kryptor = 0.09), but the Vidas system is slightly less sensitive than Kryptor. The performance characteristics of the Vidas PCT assay are fully compatible with intended clinical use, but new clinical, cut-off values need to be determined for lowest levels of PCT (<0.3 ng/ml). (C) 2008 Elsevier Masson SAS. Tous droits reserves.