Adaptation of the Atellica (TM) Siemens (TM) urine benzodiazepines kit to serum matrix
Résumé
Benzodiazepines (BZD) are responsible for many drug poisonings, treated in our hospital. At the Amiens University Hospital, benzodiazepines immunoassays are performed on 2 CH 900 Atellica (TM) analysers from Siemens (TM) according to a method called ``CH Bnz'', since 2020. As the technical documentation of the test does not include the blood matrix, the pharmacology-toxicology laboratory conducted a study in order to adapt this urine screening kit to the serum matrix, by checking the detection thresholds. The experience consisted of testing serum samples spiked with a known benzodiazepine, at various concentrations close to the positivity thresholds pre-established by Siemens (TM) in the ``CH Bnz'' data sheet; the concentrations were verified by HPLC-MS/MS. The laboratory chose to test 12 benzodiazepines, selecting the most common among those available in the laboratory. The cut-off values determined in the serum matrix are around those established for the urinary matrix for alprazolam, clonazepam, diazepam and nitrazepam. The thresholds are lower for the 8 other benzodiazepines tested (bromazepam, clobazam, flurazepam, midazolam, nordiazepam, oxazepam, prazepam and temazepam). It should also be noted that the thresholds evaluated on our site are in accordance with low or therapeutic concentrations for most of the molecules tested. This work enabled the adaptation of the documentation provided by Siemens (TM) to the serum matrix in order to maintain its accreditation in flexible standard A scope by the French Accreditation Committee (COFRAC), according to standard NF EN ISO 15189. It also took into consideration the requirements of the opposable document HS REF 08. (C) 2021 Societe Francaise de Toxicologie Analytique. Published by Elsevier Masson SAS. All rights reserved.