Effects of Abeta immunization (AN1792) on MRI measures of cerebral volume in Alzheimer disease.

摘要: Background: Alzheimer disease (AD) is characterized by progressive cerebral atrophy that may be measured using MRI. Reported are MRI findings of a Phase IIa immunotherapy trial in AD prematurely terminated owing to meningoencephalitis subset patients. Objective: To assess volume changes patients immunized with AN1792 (β-amyloid [Aβ] 1 42) who were antibody responders (anti-AN1792 IgG titer ≥1:2,200) compared placebo Methods: This randomized, multicenter, placebo-controlled, double-blind 225 μg plus QS-21 50 included 372 probable AD. Patients received one three injections AN1792/QS-21 or saline and assessed for 12 months. Volumetric was performed pre dose at month early termination. Brain, ventricular, hippocampal from registered scan pairs. Results: Two hundred eighty-eight had paired scans (mean interval 10.9 months). Antibody (n = 45) greater brain decrease (3.12 ± 1.98 vs 2.04 1.74%; p 0.007), ventricular enlargement as percentage baseline (1.10 0.75 0.48 0.40%; 0.124) than 57). Increased losses not reflected worsening cognitive performance; composite z score across Neuropsychological Test Battery showed differences favoring over (0.03 0.39 −0.24 0.45; 0.008). Conclusions: A dissociation between loss function observed responders. The reasons this remain unclear but include the possibility due amyloid removal associated fluid shifts.