Development of thresholds and a visualization tool for use of a blood test in routine clinical dementia practice

Alzheimers Dement. 2024 Sep;20(9):6115-6132. doi: 10.1002/alz.14088. Epub 2024 Aug 3.

Abstract

Introduction: We developed a multimarker blood test result interpretation tool for the clinical dementia practice, including phosphorylated (P-)tau181, amyloid-beta (Abeta)42/40, glial fibrillary acidic protein (GFAP), and neurofilament light (NfL).

Methods: We measured the plasma biomarkers with Simoa (n = 1199), applied LASSO regression for biomarker selection and receiver operating characteristics (ROC) analyses to determine diagnostic accuracy. We validated our findings in two independent cohorts and constructed a visualization approach.

Results: P-tau181, GFAP, and NfL were selected. This combination had area under the curve (AUC) = 83% to identify amyloid positivity in pre-dementia stages, AUC = 87%-89% to differentiate Alzheimer's or controls from frontotemporal dementia, AUC = 74%-76% to differentiate Alzheimer's or controls from dementia with Lewy bodies. Highly reproducible AUCs were obtained in independent cohorts. The resulting visualization tool includes UpSet plots to visualize the stand-alone biomarker results and density plots to visualize the biomarker results combined.

Discussion: Our multimarker blood test interpretation tool is ready for testing in real-world clinical dementia settings.

Highlights: We developed a multimarker blood test interpretation tool for clinical dementia practice. Our interpretation tool includes plasma biomarkers P-tau, GFAP, and NfL. Our tool is particularly useful for Alzheimer's and frontotemporal dementia diagnosis.

Keywords: Alzheimer; biomarker; blood test; dementia; glial fibrillary acidic protein; neurofilament light; phosphorylated tau; plasma.

MeSH terms

  • Aged
  • Alzheimer Disease / blood
  • Alzheimer Disease / diagnosis
  • Amyloid beta-Peptides* / blood
  • Biomarkers* / blood
  • Cohort Studies
  • Dementia / blood
  • Dementia / diagnosis
  • Female
  • Frontotemporal Dementia / blood
  • Frontotemporal Dementia / diagnosis
  • Glial Fibrillary Acidic Protein* / blood
  • Humans
  • Lewy Body Disease / blood
  • Lewy Body Disease / diagnosis
  • Male
  • Middle Aged
  • Neurofilament Proteins* / blood
  • Peptide Fragments / blood
  • ROC Curve
  • tau Proteins* / blood

Substances

  • Biomarkers
  • tau Proteins
  • Neurofilament Proteins
  • Glial Fibrillary Acidic Protein
  • neurofilament protein L
  • Amyloid beta-Peptides
  • GFAP protein, human
  • Peptide Fragments
  • amyloid beta-protein (1-42)

Grants and funding