Plasma amyloid-β,Aβ 1-42,load is reduced by haemodialysis

Patients with chronic renal failure treated with haemodialysis have vascular risk factors that, in the general population, are associated with increased prevalence of Alzheimer's disease (AD). Patients in haemodialysis, however, present different kinds of dementia but they do not have an increased risk of AD. We have hypothesized that amyloid-β (Aβ)_1-42 is washed out from plasma during the dialysis and that this procedure enhances Aβ elimination and reduces the risk of AD. We have measured plasma Aβ_1-42 levels in 11 patients with renal failure, before and after haemodialysis. A single procedure reduced the plasma Aβ levels in all subjects with a mean decrement of 30% of baseline. Since Aβ deposition could be altered by certain metals like Cu and Zn, we have also measured the effects of dialysis on the levels of these ions in plasma. We found no changes in levels of Cu and Zn after dialysis. Haemodialysis, therefore, reduces very effectively plasma Aβ without modifying Cu and Zn levels. The potential use of this strategy in patients with AD requires further investigation.