Simoa neurology 3 plex a advantage kit

Blood samples were drawn by the laboratory technician. Fasting venous blood was drawn from all subjects between 8 am and 10 am and collected in tubes containing ethylenediaminetetraacetic acid (EDTA). Samples were then centrifuged at 3000 × g for 10 min at 4°C to obtain plasma within 2 h of collection. The plasma was stored at −80°C until biochemical analysis. All measurements were performed on the Simoa HD-X analyser platform (Quanterix, Lexington, MA). Plasma Aβ42, Aβ40, and t-tau levels were measured using the Quanterix Simoa Neurology 3-Plex A Advantage kit (Lot 503205), and p-tau181 levels were measured using the p-tau181 Advantage V2 kit (Lot 502793), all according to the manufacturer’s instructions and standard procedures. The lower limits of detection of the Aβ42, Aβ40, t-tau, and p-tau181 assays were 0.045, 0.196, 0.019, and 0.028 pg/mL, whereas the lower levels of quantification were 0.142, 0.675, 0.063, and 0.338 pg/mL, respectively. The coefficients of variation for Aβ42, Aβ40, t-tau, and p-tau181 were 5.0%, 9.7%, 6.2%, and 4.7%, respectively. Samples were diluted 4× and tested in duplicate by the automatic HD-X analyser. Two quality control samples were run on each plate for each analyte.

Participants underwent venipuncture after an overnight 12-h fast, and within 1–2 h before BP monitoring. Blood samples were collected in EDTA tubes and used to determine levels of plasma AD biomarkers Aβ_1–42, Aβ_1–40, Ptau₁₈₁, and total tau. Ptau₁₈₁ samples were processed using the assay Simoa® pTau-181 Advantage V2 Kit (Quanterix). Accepted ranges for Ptau¹⁸¹ values were 0–424 pg/mL. Aβ_1–42, Aβ_1–40, and total tau samples were processed using the assay Simoa® Neurology 3-Plex A Advantage Kit (Quanterix). Accepted ranges were as follows: Aβ_1–42 = 0–240 pg/mL, Aβ_1–40 = 0–560 pg/mL, total tau = 0–400 pg/mL. Ratios were determined for Ptau₁₈₁:Aβ_1–42 and Aβ_1–42:Aβ_1–40.