Background:
Recent integration of biomarkers into clinical practice demonstrate that when combined with clinical and neuropsychological assessment, theyenhance diagnostic accuracy. However, studies investigating the association between blood-based biomarkers (BBB) and neuropsychological testperformance are still scarce in Brazilian older adult cohorts.We aimed to determine whether the plasma p-tau217 and other biological variables predict theperformance on neuropsychological tasks in a cross-sectional cohort of Brazilian older adults.
Methods:
Data from 110 older adults selected from the Cog-Aging cohort were analyzed. Were selected participants who underwent a comprehensiveclinical, neuropsychological and neuroimaging assessment to determine diagnosis. For this study, were assessed the memory-related neuropsychologicaltasks from Mattis Dementia Rating Scale (MDRS) memory and total score, and the Rey Auditory-Verbal Learning Test (RAVLT), including measures ofimmediate episodic memory (A6), delayed episodic memory (A7), and recognition. Plasma p-Tau217 concentrations were quantified using the SingleMolecule Array (SIMOA) platform. The associations between p-tau217, and performance on the RAVLT and MDRS were explored using a Generalized LinearModel (GLM) adjusted for age, sex, formal education, and estimated Glomerular Filtration Rate (eGFR).
Results:
The sample was predominantly female (62.73%), the mean age was 75.81 years (SD=±6.59), with a median formal education of 4.5 years (IQR= 7.00)and, 34.54% was ApoE allele ɛ4 carrier. Participants were classified as Cognitively Unimpaired (30.90%); 38.18% Mild Cognitive Impairment; 30% dementia;(Dementia of the Alzheimer’s type 27.27% and 3.63% Non-Alzheimer’s Disease Dementia). Analyses revealed significant negative associations between p-tau217 levels and performance on the RAVLT in immediate memory (ß= -.846; p=.165), delayed memory (ß= -1.402; p=.031), and recognition (ß= -3.267;p=.013). Additionally, a significant negative association was observed between p-tau217 and MDRS memory (ß= -0.112; p=.017). However, no significantassociation was found with the total MDRS score.
Conclusion:
In this study, p-tau showed a significant association with memory-related neuropsychological tasks, highlighting its potential value as abiomarker of memory impairment.