Clinical performance of scalable automated p‐tau 217 multi‐analyte algorithmic blood test with reduced intermediate zone using multiplexed digital immunoassay

We developed a multi-analyte blood test for assessing brain amyloid status that significantly minimizes the ambiguous "intermediate zone," a key limitation of plasma phosphorylated tau (p-tau) 217 alone.Our test combines plasma levels of p-tau 217, amyloid beta 42/40 ratio, glial fibrillary acidic protein, and neurofilament light chain for a more comprehensive evaluation of amyloid status.We rigorously validated the test's clinical performance in > 1000 samples from symptomatic individuals across three independent cohorts, using cerebrospinal fluid biomarkers and amyloid positron emission tomography as comparators.