Reduction of Alzheimer’s Disease Amyloid-β in Plasma by Hemodialysis and Its Relation to Cognitive Functions

BACKGROUND/AIMS: Rapid removal of plasma amyloid-β (Aβ) by blood purification may serve as a peripheral Aβ sink from the brain for Alzheimer's disease therapy. We investigated the reduction of plasma Aβ during hemodialysis and cognitive states. METHODS: Aβ concentrations and Mini-Mental State Examinations (MMSE) were investigated in 37 hemodialysis patients (68.9 ± 4.1 years). RESULTS: The dialyzers effectively removed Aβ(1-40) and Aβ(1-42), 63.9 ± 14.4 and 51.6 ± 17.0% at 4 h dialysis, resulting in the reduction of Aβs in whole-body circulation by 51.1 ± 8.9 and 32.7 ± 12.0%, respectively. Although the plasma Aβs before dialysis (750.8 ± 171.3 pg/ml for Aβ(1-40)) were higher than those reported for Alzheimer's disease patients, the cognitive states of hemodialysis patients were relatively normal, especially of longer dialysis vintages. CONCLUSIONS: Dialyzers effectively reduced Aβs in whole-body circulation. Repeated rapid decrease of plasma Aβs might maintain cognitive state.