SAA2 and Alzheimer disease: In support of this idea, growing population-based studies found an inverse (and independent from HDL-C plasma concentration) association between “protective” HDL accessory proteins (in particular PON1 and Lp-PLA2) and the risk of AD; at the opposite, the levels of prooxidant and proinflammatory MPO and SAA have been often found to be higher in AD compared with healthy controls.