Benchmarking biomarker-based criteria for Alzheimer's disease: Data from the Swedish Dementia Registry, SveDem.

Introduction: New research guidelines for the diagnosis of Alzheimer's disease (AD) include biomarker evidence of amyloid-β (Aβ) and tau pathology. The aim of this study was to investigate what proportion of AD patients diagnosed in clinical routine in Sweden that had an AD-indicative cerebrospinal fluid (CSF) biomarker profile.
Methods: By cross-referencing a laboratory database with the Swedish Dementia Registry (SveDem), 2357 patients with data on CSF Aβ and tau biomarkers and a clinical diagnosis of AD with dementia were acquired.
Results: Altogether, 77.2% had pathologic Aβ42 and total tau or phosphorylated tau in CSF. These results were stable across age groups. Female sex and low mini-mental state examination score increased the likelihood of pathologic biomarkers.
Discussion: About a quarter of clinically diagnosed AD patients did not have an AD-indicative CSF biomarker profile. This discrepancy may partly reflect incorrect (false positive) clinical diagnosis or a lack in sensitivity of the biomarker assays.
(Copyright © 2015 The Alzheimer's Association. Published by Elsevier Inc. All rights reserved.)