Clinical Performance of LucentAD Complete: A Multi-Analyte Algorithmic Blood Test for Detecting Brain Amyloid with a Scalable, Multiplexed Digital Immunoassay

INTRODUCTIONTo address an urgent need for a scalable, accurate blood test for brain amyloid pathology that provides a conclusive result for the greatest number of patients, we developed a multi-analyte algorithmic test combining p-Tau 217 with four other biomarkers. METHODSMultiplexed digital immunoassays measured p-Tau 217, A{beta}42/40, GFAP, and NfL in 730 individuals to establish an algorithm with cutoffs, then in 1,082 individuals with cognitive symptoms from three independent cohorts to identify brain amyloid pathology. RESULTSThe tests algorithmic risk score AUC was 0.92, yielding 90% agreement with amyloid PET and CSF. Positive predictive value was 92% at 55% amyloid prevalence. The multi-marker algorithm reduced the intermediate zone 3-fold to 12% vs. p-Tau 217 alone. Diagnostic performance was similar by race, ethnicity, sex, age, and apoE4 status. DISCUSSIONThe LucentAD Complete multi-analyte blood test demonstrated high clinical validity for brain amyloid pathology detection while substantially reducing inconclusive intermediate results.