Increased levels of antigen-bound ?-amyloid autoantibodies in serum and cerebrospinal fluid of Alzheimer's disease patients.

ABSTRACT: Recent studies have suggested a protective role of physiological ?-amyloid autoantibodies (A?-autoantibodies) in Alzheimer's disease (AD). However, the determination of both free and dissociated A?-autoantibodies in serum hitherto has yielded inconsistent results regarding their function and possible biomarker value. Here we report the application of a new sandwich enzyme-linked immunosorbent assay (ELISA) for the determination of antigen-bound A?-autoantibodies (intact A?-IgG immune complexes) in serum and cerebrospinal fluid (CSF) of a total number of 112 AD patients and age- and gender-matched control subjects. Both serum and CSF levels of A?-IgG immune complexes were found to be significantly higher in AD patients compared to control subjects. Moreover, the levels of A?-IgG complexes were negatively correlated with the cognitive status across the groups, increasing with declining cognitive test performance of the subjects. Our results suggest a contribution of IgG-type autoantibodies to A? clearance in vivo and an increased immune response in AD, which may be associated with deficient A?-IgG removal. These findings may contribute to elucidating the role of A?-autoantibodies in AD pathophysiology and their potential application in AD diagnosis.

SUBMITTER: Maftei M 

PROVIDER: S-EPMC3715516 | biostudies-literature | 2013

REPOSITORIES: biostudies-literature