Multiplex Mass Spectrometry Analysis of Amyloid Proteins in Human Plasma for Alzheimer's Disease Diagnosis.

Direct analysis of amyloid proteins in human plasma will promote rapid screening of brain amyloidosis, the earliest pathological signature of Alzheimer's disease. We developed a microflow liquid chromatography-targeted mass spectrometry assay for quantitation of four intact β-amyloid proteins starting from 1 mL of human plasma samples. This method showed 90% accuracy for predicting brain amyloid using plasma Aβ42/Aβ40 values from 36 cognitively normal individuals in a prospective clinical study (raw data deposited in MassIVE, Data set ID MSV000087451). Our method may contribute to early diagnosis of Alzheimer's disease.