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| Articles
by
Manu Vandijck |
Total Records (
2 ) for
Manu Vandijck |
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Maria C. Carrillo
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Kaj Blennow
,
Holly Soares
,
Piotr Lewczuk
,
Niklas Mattsson
,
Pankaj Oberoi
,
Robert Umek
,
Manu Vandijck
,
Salvatore Salamone
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Tobias Bittner
,
Leslie M. Shaw
,
Diane Stephenson
,
Lisa Bain
and
Henrik Zetterberg
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Recognizing that international collaboration is critical for the acceleration of biomarker standardization efforts and the efficient development of improved diagnosis and therapy, the Alzheimer's Association created the Global Biomarkers Standardization Consortium (GBSC) in 2010. The consortium brings together representatives of academic centers, industry, and the regulatory community with the common goal of developing internationally accepted common reference standards and reference methods for the assessment of cerebrospinal fluid (CSF) amyloid β42 (Aβ42) and tau biomarkers. Such standards are essential to ensure that analytical measurements are reproducible and consistent across multiple laboratories and across multiple kit manufacturers. Analytical harmonization for CSF Aβ42 and tau will help reduce confusion in the AD community regarding the absolute values associated with the clinical interpretation of CSF biomarker results and enable worldwide comparison of CSF biomarker results across AD clinical studies. |
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Niklas Mattsson
,
Ulf Andreasson
,
Staffan Persson
,
Maria C. Carrillo
,
Steven Collins
,
Sonia Chalbot
,
Neal Cutler
,
Diane Dufour- Rainfray
,
Anne M. Fagan
,
Niels H.H. Heegaard
,
Ging-Yuek Robin Hsiung
,
Bradley Hyman
,
Khalid Iqbal
,
D. Richard Lachno
,
Alberto Lleo
,
Piotr Lewczuk
,
Jose L. Molinuevo
,
Piero Parchi
,
Axel Regeniter
,
Robert Rissman
,
Hanna Rosenmann
,
Giuseppe Sancesario
,
Johannes Schroder
,
Leslie M. Shaw
,
Charlotte E. Teunissen
,
John Q. Trojanowski
,
Hugo Vanderstichele
,
Manu Vandijck
,
Marcel M. Verbeek
,
Henrik Zetterberg
,
Kaj Blennow
and
Stephan A. Kaser
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Background
The cerebrospinal fluid (CSF) biomarkers amyloid beta 1–42, total tau, and phosphorylated tau are used increasingly for Alzheimer's disease (AD) research and patient management. However, there are large variations in biomarker measurements among and within laboratories.
Methods
Data from the first nine rounds of the Alzheimer's Association quality control program was used to define the extent and sources of analytical variability. In each round, three CSF samples prepared at the Clinical Neurochemistry Laboratory (Molndal, Sweden) were analyzed by single-analyte enzyme-linked immunosorbent assay (ELISA), a multiplexing xMAP assay, or an immunoassay with electrochemoluminescence detection.
Results
A total of 84 laboratories participated. Coefficients of variation (CVs) between laboratories were around 20% to 30%; within-run CVs, less than 5% to 10%; and longitudinal within-laboratory CVs, 5% to 19%. Interestingly, longitudinal within-laboratory CV differed between biomarkers at individual laboratories, suggesting that a component of it was assay dependent. Variability between kit lots and between laboratories both had a major influence on amyloid beta 1–42 measurements, but for total tau and phosphorylated tau, between-kit lot effects were much less than between-laboratory effects. Despite the measurement variability, the between-laboratory consistency in classification of samples (using prehoc-derived cutoffs for AD) was high (>90% in 15 of 18 samples for ELISA and in 12 of 18 samples for xMAP).
Conclusions
The overall variability remains too high to allow assignment of universal biomarker cutoff values for a specific intended use. Each laboratory must ensure longitudinal stability in its measurements and use internally qualified cutoff levels. Further standardization of laboratory procedures and improvement of kit performance will likely increase the usefulness of CSF AD biomarkers for researchers and clinicians. |
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