Natural human antibodies to amyloid beta peptide

Properties of human, natural anti-Aβ antibodies and commercially available intravenous immunoglobulin (IVIg) have been examined in light of the beneficial effects of passive immunotherapy with IVIg for patients with mild to moderate Alzheimer's disease (AD). Anti-Aβ antibodies in IVIg recognize conformation-specific epitopes as well as linear epitopes from different regions of the Aβ peptide. Anti-Aβ antibodies in circulation, especially those with high avidity, are often masked by ligands and the avidity of these antibodies increases upon dissociation of the bound ligands from the antibodies. Such natural anti-Aβ antibodies have the capacity to prevent Aβ oligomer-induced neurotoxicity in N2A neuroblastoma cells. This neuro-protective effect may reflect the therapeutic potential of the natural anti-Aβ antibodies found in IVIg for the treatment of patients with AD.