First amyloid β1-42 certified reference material for re-calibrating commercial immunoassays

INTRODUCTION: Reference materials based on human cerebrospinal fluid were certified for the mass concentration of amyloid beta (Aβ)1-42 (Aβ42 ). They are intended to be used to calibrate diagnostic assays for Aβ42 . METHODS: The three certified reference materials (CRMs), ERM-DA480/IFCC, ERM-DA481/IFCC and ERM-DA482/IFCC, were prepared at three concentration levels and characterized using isotope dilution mass spectrometry methods. Roche, EUROIMMUN, and Fujirebio used the three CRMs to re-calibrate their immunoassays. RESULTS: The certified Aβ42 mass concentrations in ERM-DA480/IFCC, ERM-DA481/IFCC, and ERM-DA482/IFCC are 0.45, 0.72, and 1.22 μg/L, respectively, with expanded uncertainties (k = 2) of 0.07, 0.11, and 0.18 μg/L, respectively. Before re-calibration, a good correlation (Pearson's r > 0.97), yet large biases, were observed between results from different commercial assays. After re-calibration the between-assay bias was reduced to < 5%. DISCUSSION: The Aβ42 CRMs can ensure the equivalence of results between methods and across platforms for the measurement of Aβ42

A certified plasmid reference material for the standardisation of BCR-ABL1 mRNA quantification by real-time quantitative PCR

Serial quantification of BCR–ABL1 mRNA is an important therapeutic indicator in chronic myeloid leukaemia, but there is a substantial variation in results reported by diff

Occurrence des amibes libres en réseaux d’eau intérieurs

Les amibes libres sont des protozoaires (unicellulaires) très présents dans l’environnement et notamment dans les milieux hydriques et ont la capacité à s’y multiplier sans l’aide d’un hôte. Certaines espèces sont directement pathogènes pour l’homme mais d’autres peuvent également être responsables, de façon indirecte, d’infections en jouant le rôle de réservoir de bactéries pathogènes comme Legionella pneumophila. Afin d’évaluer l’occurrence des amibes libres en eau chaude sanitaire, une campagne d’analyse a été réalisée sur 36 réseaux intérieurs réels (eau froide et eau chaude). La campagne d’analyse sur sites a montré que les amibes libres thermophiles sont retrouvées dans 19 % des prélèvements effectués et les amibes mésophiles dans 46 %. Le genre amibien le plus retrouvé est Hartmanella. A priori, ce genre d’amibe n’est pas intrinsèquement pathogène pour l’homme. Sur quelques échantillons, des amibes du genre Acanthamoeba ont été retrouvées. Les points les plus fréquemment contaminés par les amibes libres sont l’eau froide et les points d’usage. Les caractéristiques des sites ont été mis au regard de la contamination par les amibes totales. Aucune corrélation n’a pu être trouvée entre la présence d’amibes et le type d’établissement, le type de production d’eau chaude, la qualité du bouclage, le type de matériaux. Très peu d’amibes sont retrouvées lorsque la température de l’eau est supérieure à 60 °C

A certified plasmid reference material for the standardisation of BCR-ABL1 mRNA quantification by real time quantitative PCR

Serial quantification of BCR–ABL1 mRNA is an important therapeutic indicator in chronic myeloid leukaemia, but there is a substantial variation in results reported by different laboratories. To improve comparability, an internationally accepted plasmid certified reference material (CRM) was developed according to ISO Guide 34:2009. Fragments of BCR–ABL1 (e14a2 mRNA fusion), BCR and GUSB transcripts were amplified and cloned into pUC18 to yield plasmid pIRMM0099. Six different linearised plasmid solutions were produced with the following copy number concentrations, assigned by digital PCR, and expanded uncertainties: 1.08±0.13 × 106, 1.08±0.11 × 105, 1.03±0.10 × 104, 1.02±0.09 × 103, 1.04±0.10 × 102 and 10.0±1.5 copies/?l. The certification of the material for the number of specific DNA fragments per plasmid, copy number concentration of the plasmid solutions and the assessment of inter-unit heterogeneity and stability were performed according to ISO Guide 35:2006. Two suitability studies performed by 63 BCR–ABL1 testing laboratories demonstrated that this set of 6 plasmid CRMs can help to standardise a number of measured transcripts of e14a2 BCR–ABL1 and three control genes (ABL1, BCR and GUSB). The set of six plasmid CRMs is distributed worldwide by the Institute for Reference Materials and Measurements (Belgium) and its authorised distributors (https://ec.europa.eu/jrc/en/reference-materials/catalogue/; CRM code ERM-AD623a-f)

Vitronectin dictates intraglomerular fibrinolysis in immune-mediated glomerulonephritis

During human glomerulonephritis, the severity of injuries correlates with glomerular fibrin deposits, which are tightly regulated by the intraglomerular fibrinolytic system. Here, we evaluated the role of vitronectin (VTN; also known as complement S protein), the principal cofactor of the plasminogen activator inhibitor-1 (PAI-1), in a mouse model of acute glomerulonephritis. We found that in mice subjected to nephrotoxic serum, the absence of VTN resulted in a lower glomerular PAI-1 activity and a higher glomerular fibrinolytic activity. Challenged VTN-/- mice displayed significantly less fibrin deposits, proteinuria, and renal failure than their wild-type counterparts. Notably, this protective effect afforded by VTN deficiency was still observed after a C3 depletion. Finally, the injection of VTN+/+ serum in VTN-/- mice induced the glomerular deposition of VTN, increased PAI-1 deposition, decreased glomerular fibrinolytic activity, and aggravated glomerular injury. As in mice, abundant glomerular VTN deposits were also observed in patients with severe glomerulonephritis. Here, we show that plasma-exchange therapy, admittedly beneficial in this clinical context, induces a significant depletion in circulating VTN, which might modulate PAI-1 activity locally and accelerate the clearance of fibrin deposits in the glomeruli. Collectively, these results demonstrate that VTN exerts a deleterious role independently from complement, by directing PAI-dependent fibrinolysis in the glomerular compartment.-Mesnard, L., Rafat, C., Vandermeersch, S., Hertig, A., Cathelina, D., Xu-Dubois, Y. -C., Jouanneau, C., Castro Keller, A., Ribeil, J. -A., Leite-de-Moraes, M. C., Rondeau, E. Vitronectin dictates intraglomerular fibrinolysis in immune-mediated glomerulonephritis. FASEB J. 25, 3543-3553 (2011). www.fasebj.orgInstitut National de la Sante et de la Recherche Medicale (INSERM)Faculte de Medecine Pierre et Marie CurieAcademie de MedecineEuropean Renal Association-European Dialysis and Transplant Association (ERA-EDTA)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Univ Paris 06, INSERM, UMR S702, Hop Tenon, F-75020 Paris, FranceUniv Paris 06, Hop Tenon, APHP, F-75020 Paris, FranceHop Necker Enfants Malad, CNRS, UMR 8147, Paris, FranceHop Necker Enfants Malad, APHP, Fac Med Rene Descartes, Dept Biotherapie, Paris, FranceUniversidade Federal de São Paulo, Div Nephrol, São Paulo, BrazilUniversidade Federal de São Paulo, Div Nephrol, São Paulo, BrazilFAPESP: 2007/07120-0CNPq: 501848/2009-6Web of Scienc

A certified plasmid reference material for the standardisation of BCR-ABL1 mRNA quantification by real-time quantitative PCR

Serial quantification of BCR-ABL1 mRNA is an important therapeutic indicator in chronic myeloid leukaemia, but there is a substantial variation in results reported by different laboratories. To improve comparability, an internationally accepted plasmid certified reference material (CRM) was developed according to ISO Guide 34:2009. Fragments of BCR-ABL1 (e14a2 mRNA fusion), BCR and GUSB transcripts were amplified and cloned into pUC18 to yield plasmid pIRMM0099. Six different linearised plasmid solutions were produced with the following copy number concentrations, assigned by digital PCR, and expanded uncertainties: 1.08 +/- 0.13 x 10(6), 1.08 +/- 0.11 x 10(5), 1.03 +/- 0.10 x 10(4), 1.02 +/- 0.09 x 10(3), 1.04 +/- 0.10 x 10(2) and 10.0 +/- 1.5 copies/mu l. The certification of the material for the number of specific DNA fragments per plasmid, copy number concentration of the plasmid solutions and the assessment of inter-unit heterogeneity and stability were performed according to ISO Guide 35:2006. Two suitability studies performed by 63 BCR-ABL1 testing laboratories demonstrated that this set of 6 plasmid CRMs can help to standardise a number of measured transcripts of e14a2 BCR-ABL1 and three control genes (ABL1, BCR and GUSB). The set of six plasmid CRMs is distributed worldwide by the Institute for Reference Materials and Measurements (Belgium) and its authorised distributors (https://ec.europa.eu/jrc/en/reference-materials/catalogue/;CRM code ERM-AD623a-f)