Alzheimer Disease Cerebrospinal Fluid Biomarkers in an Early Parkinson Disease Cohort

Biomarkers of Alzheimer disease (AD) in cerebrospinal fluid (CSF) have been used in clinical practice and research. In this study, the common AD biomarkers were measured in 416 patients with early Parkinson disease (PD) and in 192 healthy controls. CSF amyloid-beta 1 to 42 (Aβ42), total tau (t-tau), and phosphorylated tau (p-tau) were measured at the threonine 181 position.

Compared with controls, the PD group had lower CSF t-tau (median, 157.7 pg/mL; range, 80.9–467.0), p-tau (median, 13.4 pg/mL; range, 8.0–40.1), and Aβ42 (median, 846.2 pg/mL; range, 238.8–3707.0). Of the PD group, 31.5% had pathologically low levels of CSF Aβ42 at baseline. During 3 years of follow-up, the PD group had a greater decline in mean CSF Aβ42 and CSF p-tau leve…