Publications & Posters

Plasma P-tau181 to Aβ42 ratio is associated with brain amyloid burden and hippocampal atrophy in an Asian cohort of Alzheimer’s disease patients with concomitant cerebrovascular disease

Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association | March 31, 2021

Chong JR, Ashton NJ, Karikari TK, Tanaka T, Saridin FN, Reilhac A, Robins EG, Nai YH, Vrooman H, Hilal S, Zetterberg H, Blennow K, Lai MKP and Chen CP

Alzheimer’s & dementia : the journal of the Alzheimer’s Association. 2021


p-Tau181 in this study was analyzed using a Simoa homebrew assay.



There is increasing evidence that phosphorylated tau (P‐tau181) is a specific biomarker for Alzheimer’s disease (AD) pathology, but its potential utility in non‐White patient cohorts and patients with concomitant cerebrovascular disease (CeVD) is unknown.


Single molecule array (Simoa) measurements of plasma P‐tau181, total tau, amyloid beta (Aβ)40 and Aβ42, as well as derived ratios were correlated with neuroimaging modalities indicating brain amyloid (Aβ+), hippocampal atrophy, and CeVD in a Singapore‐based cohort of non‐cognitively impaired (NCI; n = 43), cognitively impaired no dementia (CIND; n = 91), AD (n = 44), and vascular dementia (VaD; n = 22) subjects.


P‐tau181/Aβ42 ratio showed the highest area under the curve (AUC) for Aβ+ (AUC = 0.889) and for discriminating between AD Aβ+ and VaD Aβ− subjects (AUC = 0.903). In addition, P‐tau181/Aβ42 ratio was associated with hippocampal atrophy. None of the biomarkers was associated with CeVD.


Plasma P‐tau181/Aβ42 ratio may be a noninvasive means of identifying AD with elevated brain amyloid in populations with concomitant CeVD.

p-Tau181 in this study was analyzed using a Simoa homebrew assay.