Pre-clinical diagnosis of Alzheimer disease combining platelet amyloid precursor protein ratio and rCBF SPECT analysis

Platelet Amyloid Precursor Protein ratio of different abnormal forms and 99mTc-ECD SPECT perfusion analysis were evaluated in Mild Cognitive Impairment (MCI) subjects who progressed to Alzheimer Disease (AD) and in stable MCI. We report that their combined evaluation increases the discriminative power of the analysis in identifying presymptomatic AD. The positive predictive value of these combined markers in identifying progressive MCI was 0.87, and the negative predictive value was 0.90. This observation suggests that the interplay of different markers should be considered for enhancing diagnostic accuracy of pre-clinical AD.