Treatment of Alzheimer disease using combination therapy with plasma exchange and haemapheresis with albumin and intravenous immunoglobulin: Rationale and treatment approach of the AMBAR (Alzheimer Management By Albumin Replacement) study

Abstract

Introduction: There is a growing interest in new therapeutic strategies for the treatment of Alzheimer disease (AD) which focus on reducing the beta-amyloid peptide (Aβ) burden in the brain by sequestering plasma Aβ, a large proportion of which is bound to albumin and other proteins. This review discusses the concepts of interaction between Aβ and albumin that have given rise to AMBAR (Alzheimer's Disease Management by Albumin Replacement) project, a new multicentre, randomised, controlled clinical trial for the treatment of AD.

Development: Results from preliminary research suggest that Albutein(®) (therapeutic albumin, Grifols) contains no quantifiable levels of Aβ. Studies also show that Albutein(®) has Aβ binding capacity. On the other hand, AD entails a high level of nitro-oxidative stress associated with fibrillar aggregates of Aβ that can induce albumin modification, thus affecting its biological functions. Results from the phase ii study confirm that using therapeutic apheresis to replace endogenous albumin with Albutein(®) 5% is feasible and safe in patients with AD. This process resulted in mobilisation of Aβ and cognitive improvement in treated patients. The AMBAR study will test combination therapy with therapeutic apheresis and haemopheresis with the possible leverage effect of Albutein(®) with intravenous immunoglobulin replacement (Flebogamma(®) DIF). Cognitive, functional, and behavioural changes in patients with mild to moderate AD will be assessed.

Conclusions: the AMBAR study represents a new therapeutic perspective for AD.

Keywords: Albumin; Albúmina; Alzheimer disease; Beta amyloid peptide; Enfermedad de Alzheimer; Haemapheresis; Hemoféresis; Inmunoglobulina intravenosa; Intravenous immunoglobulin; Plasmaféresis; Plasmapheresis; Péptido betaamiloide.