Argentina Alzheimer’s disease neuroimaging initiative (arg-ADNI): First year follow-up

The Argentina- Alzheimer's Disease Neuroimaging Initiative (Arg-ADNI) study is a longitudinal prospective cohort of 60 participants at a single institution from Buenos Aires, Argentina. The Arg-ADNI study is the first worldwide ADNI center in Latin America and the first Hispanic community-dwelling subjects worldwide. Baseline assessments have been done on 15 normal controls, 28 mild cognitive impairment (MCI) and 13 mild AD dementia subjects, with 4 participants lost to follow-up. For Arg-ADNI, the magnetic resonance imaging (MRI), cerebrospinal fluid (CSF) and the Pittsuburgh compound B positron emission tomography (11C-PiB PET) parameters of ADNI-II were adopted and neuropsychological tests were selected to permit comparison with ADNI data. Arg-ADNI has completed the first 12-month follow-up with available baseline results. All subjects underwent clinical assessment, 3 Tesla MRI scans, blood collection of immortalized lymphoblasts and ApoE testing, fluorodeoxyglucose (FDG) PET and 11C-PiB PET. At least 80% participants donated a sample of CSF via a lumbar puncture. Cross-sectional analysis of baseline data is revealing links between cognition, structural brain changes, and biomarkers. Among the 28 patients with MCI at baseline, 3 progressed to mild AD at 12 months for a progression rate of 10.7%. Baseline amyloid deposition by PIB-PET scan and CSF, and left hippocampal volume separated the normal controls, MCI and AD groups and correlated with the memory performance, one of the core impairment across the disease trajectory. Arg-ADNI finished the recruitment, baseline and annual assessments of 60 Argentine participants as part of a pilot phase. Subjects will undergo assessment of clinical, MRI, blood, and neuropsychological measures at 30 months after the inclusion. With the pilot phase of Arg-ADNI now underway, all investigators team hope to develop a new pathway to create a multi-site ADNI in Argentina, with the intention of using these preliminary results obtained to seek continuation funding from local and international agencies. Follow-up of a larger and more representative cohort, particularly related to CSF and brain biomarkers, will allow better characterization of AD in our country, and perhaps point to unique environmental factors influencing brain health in South America.