Preanalytical sample handling recommendations for Alzheimer's disease plasma biomarkers

Abstract

Abstract Introduction We examined the influence of common preanalytical factors on the measurement of Alzheimer's disease–specific biomarkers in human plasma. Methods Amyloid β peptides (Aβ[1‐40], Aβ[1‐42]) and total Tau plasma concentrations were quantified using fully automated Roche Elecsys assays. Results Aβ(1‐40), Aβ(1‐42), and total Tau plasma concentrations were not affected by up to three freeze/thaw cycles, up to five tube transfers, the collection tube material, or the size; circadian rhythm had a minor effect. All three biomarkers were influenced by the anticoagulant used, particularly total Tau. Aβ concentrations began decreasing 1 hour after blood draw/before centrifugation and decreased by up to 5% and 10% at 2 and 6 hours, respectively. For separated plasma, time to measurement influenced Aβ levels by up to 7% after 6 hours and 10% after 24 hours. Discussion Our findings provide guidance for standardizing blood sample collection, handling, and storage to ensure reliable analysis of Alzheimer's disease plasma biomarkers in routine practice and clinical trials.

Keywords

• Alzheimer's disease‐specific biomarkers
• Elecsys immunoassay
• Plasma
• Sample handling
• Amyloid
• Tau