PAPPA and Alzheimer disease: The biological attributes used contain neutrophils (HMT8), 18F-florbetapir (AV45), 18fluorodeoxyglucose—positron emission tomography (FDG-PET), Spatial Pattern of Abnormalities for Recognition of Early Alzheimer’s disease (SPARE_AD) and Pregnancy-Associated Protein-A (PAPP-A) measurements.