Biomarkers.

Area of Science:

• Neuroscience
• Biomarker Discovery
• Clinical Diagnostics

Background:

• Plasma tau assays demonstrate high diagnostic accuracy for Alzheimer's disease (AD).
• The influence of renal function on plasma tau levels varies across different assays.
• Understanding assay-specific effects of kidney function is crucial for clinical implementation.

Purpose of the Study:

• To compare the diagnostic performance of various plasma tau assays for AD.
• To investigate the differential impact of renal function on plasma tau biomarkers.
• To assess the association of plasma tau markers with cerebrospinal fluid (CSF) tau levels.

Main Methods:

• Analysis of paired CSF and plasma samples from 105 donors (24 AD, 81 controls).
• Measurement of plasma and CSF tau markers (p-tau217, p-tau181, p-tau231, p-tau212, BD-tau) using Simoa platform.
• Statistical analysis including linear regression, adjusting for age, sex, and renal function (eGFR, CKD).

Main Results:

• Plasma p-tau217 assays exhibited the highest diagnostic accuracy (AUC=0.97) for AD.
• Plasma p-tau212 and p-tau217 showed strong associations with CSF tau levels.
• Chronic kidney disease (CKD) was associated with elevated levels in most plasma tau assays, except for p-tau212.

Conclusions:

• Plasma tau assays are valuable tools for AD diagnosis, with p-tau217 showing high accuracy.
• Plasma p-tau212 demonstrates a potentially lower association with renal dysfunction compared to other tau markers.
• Further research on p-tau212 is warranted to explore its clinical utility and reduced susceptibility to renal impairment.