No association of salivary total tau concentration with Alzheimer's disease

Neurobiol Aging. 2018 Oct:70:125-127. doi: 10.1016/j.neurobiolaging.2018.06.014. Epub 2018 Jun 20.

Abstract

There is a need for an accessible biomarker that can complement current cerebrospinal fluid and imaging biomarkers in an accurate and early diagnosis of Alzheimer disease (AD). Saliva is a rich source of potential biomarkers and proteins related to neurodegenerative disorders have been shown to be present in this matrix, including tau. In this study, we quantified salivary total tau (t-tau) concentration in 160 healthy elderly control, 68 mild cognitive impairment, and 53 AD participants using ultrasensitive Single molecule array (Simoa) technology. No median difference in salivary t-tau concentration was found between AD and mild cognitive impairment or healthy elderly control (12.3 ng/L, 9.8 ng/L and 9.6 ng/L, respectively, p = 0.219). In addition, there was no association of salivary t-tau concentration with neurophysiological assessment or structural magnetic resonance imaging. Despite a nominal increase in AD, due to the large overlaps in concentrations between clinical groups, we conclude that salivary t-tau is a suitable biomarker neither for AD nor for cognitive impairment.

Keywords: Alzheimer's disease; Biomarkers; Diagnosis; Fluid-biomarkers; Immunoassays; Saliva; Tau.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Aged, 80 and over
  • Alzheimer Disease / diagnosis
  • Alzheimer Disease / diagnostic imaging
  • Alzheimer Disease / metabolism*
  • Biomarkers / metabolism
  • Brain / diagnostic imaging
  • Cognitive Dysfunction / diagnosis
  • Cognitive Dysfunction / diagnostic imaging
  • Cognitive Dysfunction / metabolism
  • Female
  • Humans
  • Male
  • Neuropsychological Tests
  • Saliva / metabolism*
  • tau Proteins / analysis
  • tau Proteins / metabolism*

Substances

  • Biomarkers
  • MAPT protein, human
  • tau Proteins