Audrey Gabelle, Isabelle Quadrio, Benaïssa Elmoualij, Hugo Vanderstichele, Catherine Thomas-Antérion, Mathieu Pelpel, Susanna Schraen, Benoit Dumont, Jacques Touchon, Armand Perret-Liaudet, Sylvain Lehmann, Olivier Moreaud, Yannick Tholance, Pierre Krolak-Salmon, Gabor G. Kovacs, Arnaud Coudreuse, Eric Thouvenot, Willy Zorzi, Centre de recherche en neurosciences de Lyon - Lyon Neuroscience Research Center (CRNL), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Université Jean Monnet - Saint-Étienne (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Technical and QA Department, Innogenetics SARL, ADx Neurosciences (ADx), ADx Neurosciences NV, Institute of Human Histology-CRPP (CRPP), Université de Liège, Société Française de Biologie Clinique (SFBC), Centre de Recherche Jean-Pierre AUBERT Neurosciences et Cancer - U837 (JPArc), Université Lille Nord de France (COMUE)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Lille, Unité de Neuropsychologie, CHU Grenoble, Cellules souches normales et cancéreuses, Université Montpellier 1 (UM1)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Montpellier (UM), Neuropsychiatrie : recherche épidémiologique et clinique (PSNREC), Centre de Mémoire de Ressource et Recherche (CMRR), Centre Hospitalier Universitaire de Saint-Etienne [CHU Saint-Etienne] (CHU ST-E), Institute of Neurology, Medizinische Universität Wien = Medical University of Vienna, Centre de Transfert de Technologie du Mans (CTTM), Plan Alzheimer, National French Alzheimer effort, France, Région Wallone: W2002134 et l4531-iPCRqcontracts of Liège, European Project, INSERM U1028, Centre de recherche en neurosciences de Lyon (CRNL), Université de Lyon-Université de Lyon-Université Jean Monnet [Saint-Étienne] (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Université Jean Monnet [Saint-Étienne] (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Société Française de Biologie Clinique (SFBC), Société Française de Biologie Clinique-Société Française de Biologie Clinique, Université de Lyon-Université de Lyon-Université Jean Monnet [Saint-Étienne] (UJM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Société Française de Biologie Clinique, Centre de Recherche Jean-Pierre AUBERT Neurosciences et Cancer - U1172 Inserm - U837 (JPArc), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Lille Nord de France (COMUE)-Université de Lille, Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Montpellier 1 (UM1)-Université de Montpellier (UM), CHU Saint-Etienne-Hôpital Bellevue, Frei, Monique, and Neuroscreen FP6-LSHB-CZ-2006-037719 - INCOMING
International audience; Tau proteins and amyloid-β (Aβ) peptides are the current recognized cerebrospinal fluid (CSF) biomarkers used as an aid in the diagnosis of Alzheimer's disease (AD). However, there is no consensus on their clinical use due to non-qualified cut-off values, probably related to the observed high pre-analytical and analytical variability. Standardized pre-analytical protocols have therefore been proposed. Importantly, these recommend the use of polypropylene collection/sampling tubes while, to date, no broad comparison of these types of tubes has been conducted. In this study, we first compared, as part of a real clinical workflow, the impact of four different collection tubes on the CSF concentration of Aβ peptides (Aβ42, Aβ40) and total (hTau) and phosphorylated (P-Tau181P) tau proteins measured using routine ELISA kits. We then extended this study to 11 polypropylene tubes used by different clinical laboratories, and investigated their plastic polymer composition using differential scanning calorimetry and Fourier Transformed Infrared spectroscopy. Significant concentration variations linked solely to the use of different types of tubes were observed. This was particularly marked for Aβ peptides, with >50% disparity occurring in less than five minutes. Polymer composition analysis revealed that most polypropylene tubes were in fact copolymers with at least polyethylene. There was no clear correlation between tube composition and pre-analytical behavior. Our results show that the use of polypropylene tubes does not guarantee satisfactory pre-analytical behavior. They also point to collection/sampling tubes being a major pre-analytical source of variability that could impact the significance of AD biological diagnosis.