Open science datasets from PREVENT-AD, a longitudinal cohort of pre-symptomatic Alzheimer's disease

Abstract

To move Alzheimer Disease (AD) research forward it is essential to collect data from large cohorts, but also make such data available to the global research community. We describe the creation of an open science dataset from the PREVENT-AD (PResymptomatic EValuation of Experimental or Novel Treatments for AD) cohort, composed of cognitively unimpaired older individuals with a parental or multiple-sibling history of AD. From 2011 to 2017, 386 participants were enrolled (mean age 63 years old ± 5) for sustained investigation among whom 349 have retrospectively agreed to share their data openly. Repositories are findable through the unified interface of the Canadian Open Neuroscience Platform and contain up to five years of longitudinal imaging data, cerebral fluid biochemistry, neurosensory capacities, cognitive, genetic, and medical information. Imaging data can be accessed openly at https://openpreventad.loris.ca while most of the other information, sensitive by nature, is accessible by qualified researchers at https://registeredpreventad.loris.ca. In addition to being a living resource for continued data acquisition, PREVENT-AD offers opportunities to facilitate understanding of AD pathogenesis.

Keywords: Biomarkers; Cerebrospinal Fluid proteins; Neuroimaging; Observational cohort; Open Science; Pre-symptomatic Alzheimer Disease.

Fig. 1

PREVENT-AD candidates enrolled between November 2011 and November 2017. 425 participants performed a baseline visit (BL) among which the datasets of 386 participants were shared with internal collaborators for analysis. 349 of these participants agreed to have their data openly shared, while one of them specifically refused to share data in the registered repository. MCI = Mild Cognitive Impairment, MRI = Magnetic Resonance Imaging.

Fig. 2

Timelines of observational cohort, INTREPAD trial. EL: eligibility visit; EN: enrolment visit; BL: Baseline visit; M: months.

Fig. 3

Workflow of the MRI acquisition protocol. Images from 308 scanning sessions are available in the open LORIS instance (https://openpreventad.loris.ca), while additional images of participants with incidental findings (from n = 37 participants) are shared in the registered LORIS instance (https://registeredpreventad.loris.ca). A: The observational cohort participants (PRE) and the INTREPAD trial participants (NAP) enrolled between 2011 and May 2016 underwent the same protocol with the exception that INTREPAD trial participants performed an additional 3-month time point. The task fMRI (referred as Encoding (Enc.) and Retrieval) was performed at enrollment for practice, with the actual task performed at baseline and follow-up visits at 12, 24 and 48 months. MRI coil:12-channel. B: Workflow of the MRI data acquisition protocol for the observational cohort enrolled in and after June 2016 (n = 48 participants). The task fMRI protocol was replaced by a Multi-echo qT2* at enrollment and by a high-resolution T2W, GRE T2 star and a MP2RAGE at baseline. The MRI coil was upgraded to a 32-channel for this protocol. T1W = MPRAGE (Magnetization Prepared Rapid Acquisition Gradient Echo); FLAIR = FLuid Attenuated Inversion Recovery; DWI = Diffusion Weighted Imaging; ASL = Pseudo-Continuous Arterial Spin Labeling: RSN = Resting State BOLD (Blood Oxygen Level Determination); GRE T2 star = GRadient Echo T2*; Multi-echo qT2* = 12-Echo T2*; T2W = T2 -weighted.