A Novel Blood Test for the Early Detection of Alzheimer's Disease

Research output: Contribution to journalArticle


Despite a variety of testing approaches, it is often difficult to make an accurate diagnosis of Alzheimer's disease (AD), especially at an early stage of the disease. Diagnosis is based on clinical criteria as well as exclusion of other causes of dementia but a definitive diagnosis can only be made at autopsy. We have investigated the diagnostic value of a 96-gene expression array for detection of early AD. Gene expression analysis was performed on blood RNA from a cohort of 203 probable AD and 209 cognitively healthy age matched controls. A disease classification algorithm was developed on samples from 208 individuals (AD = 103; controls = 105) and was validated in two steps using an independent initial test set (n = 74; AD= 32; controls = 42) and another second test set (n = 130; AD= 68; controls = 62). In the initial analysis, diagnostic accuracy was 71.6 +/- 10.3%, with sensitivity 71.9 +/- 15.6% and specificity 71.4 +/- 13.7%. Essentially the same level of agreement was achieved in the two independent test sets. High agreement (24/30; 80%) between algorithm prediction and subjects with available cerebrospinal fluid biomarker was found. Assuming a clinical accuracy of 80%, calculations indicate that the agreement with underlying true pathology is in the range 85%-90%. These findings suggest that the gene expression blood test can aid in the diagnosis of mild to moderate AD, but further studies are needed to confirm these findings.


  • Phil D. Rye
  • Birgitte Boonstra Booij
  • Gisle Grave
  • Torbjorn Lindahl
  • Lena Kristiansen
  • Hilde-Marie Andersen
  • Peter O. Horndalsveen
  • Harald A. Nygaard
  • Mala Naik
  • Dagne Hoprekstad
  • Peter Wetterberg
  • Christer Nilsson
  • Dag Aarsland
  • Praveen Sharma
  • Anders Lonneborg
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Neurology


  • Alzheimer's disease, biomarker, blood, diagnostic test, gene, expression, RNA
Original languageEnglish
Pages (from-to)121-129
JournalJournal of Alzheimer's Disease
Issue number1
Publication statusPublished - 2011
Publication categoryResearch

Bibliographic note

The information about affiliations in this record was updated in December 2015. The record was previously connected to the following departments: Department of Psychogeriatrics (013304000)