Premium
Upward drift in cerebrospinal fluid amyloid β 42 assay values for more than 10 years
Author(s) -
Schindler Suzanne E.,
Sutphen Courtney L.,
Teunissen Charlotte,
McCue Lena M.,
Morris John C.,
Holtzman David M.,
Mulder Sandra D.,
Scheltens Philip,
Xiong Chengjie,
Fagan Anne M.
Publication year - 2018
Publication title -
alzheimer's and dementia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.713
H-Index - 118
eISSN - 1552-5279
pISSN - 1552-5260
DOI - 10.1016/j.jalz.2017.06.2264
Subject(s) - cerebrospinal fluid , amyloid β , alzheimer's disease , immunoassay , amyloid (mycology) , β amyloid , tau protein , medicine , pathology , disease , immunology , antibody
The best‐established cerebrospinal fluid (CSF) biomarkers for Alzheimer's disease are levels of amyloid β 42 (Aβ42), total tau (tau), and phosphorylated tau 181 (ptau). We examined whether a widely used commercial immunoassay for CSF Aβ42, tau, and ptau provided stable measurements for more than 10 years. Methods INNOTEST assay values for CSF Aβ42, tau, and ptau from Washington University in St. Louis and VU Medical Center, Amsterdam, were evaluated. Results Aβ42 values as measured by the INNOTEST assay drifted upward by approximately 3% per year over the past decade. Tau values remained relatively stable, whereas results for ptau were mixed. Discussion Assay drift may reduce statistical power or even confound analyses. The drift in INNOTEST Aβ42 values may reduce diagnostic accuracy for Alzheimer's disease in the clinic. We recommend methods to account for assay drift in existing data sets and to reduce assay drift in future studies.