Beta-amyloid auto-antibodies are reduced in Alzheimer's disease

Accumulation and cytotoxicity of amyloid beta (A beta) are understood as the major cause of Alzheimer's disease (AD). There is evidence that naturally occurring antibodies against amyloid beta (A beta) protein play a role in A beta-clearance, and such a mechanism appears to be impaired in AD. In the present study, the anti-A beta antibodies in the serum from individuals with and without late onset AD were measured using ELISA and dot-blot methods. A beta auto-antibodies in serum were mainly targeted to A beta 1-15 epitope and its titer was significantly lower in AD patients than elderly non-AD controls (NC). The dot-blot analysis further demonstrated that auto-antibodies against fibrillar A beta 42, A beta 1-15 and A beta 16-30 epitopes were all in a lower level in AD than in NC. The isotypes of the auto-antibodies were mainly non-inflammatory IgG2 type. We also analyzed the relationship of auto-A beta antibody levels with the genotypes of apolipoprotein E (ApoE) and ANKK1/DRD2 gene. Published by Elsevier B.V.