Title

The Alzheimer's Association External Quality Control Program for Cerebrospinal Fluid Biomarkers

Document Type

Article

Publisher

Elsevier

Faculty

Faculty of Computing, Health and Science

School

School of Medical Sciences / Centre of Excellence for Alzheimer's Disease Research and Care

RAS ID

13135

Comments

This article was originally published as: Mattsson, N., Andreasson, U., Persson, S., Arai, H., Batish, S., Bernardini, S.,...Blennow, K. (2011). The Alzheimer's Association external quality control program for cerebrospinal fluid biomarkers. Alzheimers and Dementia, 7(4), 386-395. Original article available here

Abstract

Background The cerebrospinal fluid (CSF) biomarkers amyloid β (Aβ)-42, total-tau (T-tau), and phosphorylated-tau (P-tau) demonstrate good diagnostic accuracy for Alzheimer’s disease (AD). However, there are large variations in biomarker measurements between studies, and between and within laboratories. The Alzheimer’s Association has initiated a global quality control program to estimate and monitor variability of measurements, quantify batch-to-batch assay variations, and identify sources of variability. In this article, we present the results from the first two rounds of the program.

Methods The program is open for laboratories using commercially available kits for Aβ, T-tau, or P-tau. CSF samples (aliquots of pooled CSF) are sent for analysis several times a year from the Clinical Neurochemistry Laboratory at the Mölndal campus of the University of Gothenburg, Sweden. Each round consists of three quality control samples.

Results Forty laboratories participated. Twenty-six used INNOTEST enzyme-linked immunosorbent assay kits, 14 used Luminex xMAP with the INNO-BIA AlzBio3 kit (both measure Aβ-(1-42), P-tau(181P), and T-tau), and 5 used Meso Scale Discovery with the Aβ triplex (AβN-42, AβN-40, and AβN-38) or T-tau kits. The total coefficients of variation between the laboratories were 13% to 36%. Five laboratories analyzed the samples six times on different occasions. Within-laboratory precisions differed considerably between biomarkers within individual laboratories.

Conclusions Measurements of CSF AD biomarkers show large between-laboratory variability, likely caused by factors related to analytical procedures and the analytical kits. Standardization of laboratory procedures and efforts by kit vendors to increase kit performance might lower variability, and will likely increase the usefulness of CSF AD biomarkers.

 

Link to publisher version (DOI)

10.1016/j.jalz.2011.05.2243