Neuroimaging analyses from a randomized, controlled study to evaluate plasma exchange with albumin replacement in mild-to-moderate Alzheimer's disease: additional results from the AMBAR study

Research & Innovation Unit, Althaia Xarxa Assistencial Universitària de Manresa, Carrer Dr. Joan Soler 1-3, 08242, Manresa, Spain. Department of Nuclear Medicine, Hospital Universitari Vall d'Hebrón, Universitat Autònoma de Barcelona, Barcelona, Spain. Department of Nuclear Medicine, Hospital Universitari Vall d'Hebrón, Universitat Autònoma de Barcelona, Barcelona, Spain. Alzheimer's Research Group, Grifols, Barcelona, Spain. Ace Alzheimer Center Barcelona - Universitat Internacional de Catalunya, Barcelona, Spain. Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED), Instituto de Salud Carlos III, Madrid, Spain. Departments of Neurology and Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA. Radiology Department (IDI), Hospital Universitari Vall d'Hebron, Barcelona, Spain.

European journal of nuclear medicine and molecular imaging. 2022
PURPOSE This study was designed to detect structural and functional brain changes in Alzheimer's disease (AD) patients treated with therapeutic plasma exchange (PE) with albumin replacement, as part of the recent AMBAR phase 2b/3 clinical trial. METHODS Mild-to-moderate AD patients were randomized into four arms: three arms receiving PE with albumin (one with low-dose albumin, and two with low/high doses of albumin alternated with IVIG), and a placebo (sham PE) arm. All arms underwent 6 weeks of weekly conventional PE followed by 12 months of monthly low-volume PE. Magnetic resonance imaging (MRI) volumetric analyses and regional and statistical parametric mapping (SPM) analysis on (18)F-fluorodeoxyglucose positron emission tomography ((18)FDG-PET) were performed. RESULTS MRI analyses (n = 198 patients) of selected subcortical structures showed fewer volume changes from baseline to final visit in the high albumin + IVIG treatment group (p < 0.05 in 3 structures vs. 4 to 9 in other groups). The high albumin + IVIG group showed no statistically significant reduction of right hippocampus. SPM (18)FDG-PET analyses (n = 213 patients) showed a worsening of metabolic activity in the specific areas affected in AD (posterior cingulate, precuneus, and parieto-temporal regions). The high-albumin + IVIG treatment group showed the greatest metabolic stability over the course of the study, i.e., the smallest percent decline in metabolism (MaskAD), and least progression of defect compared to placebo. CONCLUSIONS PE with albumin replacement was associated with fewer deleterious changes in subcortical structures and less metabolic decline compared to the typical of the progression of AD. This effect was more marked in the group treated with high albumin + IVIG. TRIAL REGISTRATION (AMBAR trial registration: EudraCT#: 2011-001,598-25; ID: NCT01561053).
Study details
Language : eng
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