The Distinction of Amyloid-β Protein Precursor (AβPP) Ratio in Platelet Between Alzheimer's Disease Patients and Controls: A Systematic Review and Meta-Analysis.

To systematically assess the clinical significance of platelet amyloid-β protein precursor (AβPP) ratio between Alzheimer's disease (AD) patients and controls. 14 articles were selected in this analysis by search of databases including PubMed and Web of Science up to December 2016. Random effects models were used to calculate the standardized mean difference (SMD). Subgroup analyses were used to detect the cause of heterogeneity. The result showed a significant drop in platelet AβPP ratio in AD patients compared to controls [SMD: -1.871; 95% CI: (-2.33, -1.41); p < 0.001; I2 = 88.0% ]. Subgroup analysis revealed races or the quality of studies may be the cause of high heterogeneity. This meta-analysis concluded that there is a close association between platelet AβPP ratio and AD. It is necessary to design a sizable sample study to further support that platelet AβPP ratio can be a biomarker of AD.