Cerebrospinal Fluid Levels of sAPPαand sAPPβin Lewy Body and Alzheimer's Disease: Clinical and Neurochemical Correlates
We measured cerebrospinal fluid (CSF) levels of the soluble isoforms of amyloid precursor protein (APP; sAPPαsAPPβ) and other CSF biomarkers in 107 patients with Alzheimer's disease (AD), dementia with Lewy body dementia (DLB), Parkinson's disease dementia (PDD), and normal controls (NC) using commercial kits. DLB and PDD were combined in a Lewy body dementia group (LBD). No differences were observed in sAPPαand sAPPβlevels between the groups. Significant correlations were observed between sAPPαand sAPPβand between sAPPβand Mini-Mental State Examination scores in the total group analysis as well as when LBD and AD groups were analyzed separately. sAPPαand sAPPβlevels correlated with Aβ38, Aβ40, Aβ42, and Tau in the LBD group. In AD, sAPPαcorrelated with p-Tau and sAPPβwith Aβ40. The differential association between sAPPαand sAPPβwith Aβand Tau species between LBD and AD groups suggests a possible relationship with the underlying pathologies in LBD and AD.