Abstract
Background: Alzheimer’s disease (AD) is known to exhibit well characterized
pathologies including the extracellular accumulation of amyloid plaques, intra-axonal
presence of neurofibrillary tangles, and glial hypertrophy. Nevertheless, the nature of
myelin pathology in AD has not been well studied. Recent studies on animal models of AD,
however, revealed focal demyelination within amyloid-β plaques in
hippocampus.
Objectives: In a view of this finding, we decided to assess humoral response
against proteins of myelin sheath in AD, in the hope of identifying early biomarkers of
memory loss and neuropathological process characteristic of AD.
Methods: We assessed antibodies levels against proteins of the myelin
sheath: myelin oligodendrocyte glycoprotein (MOG), myelin basic protein (MBP),
myelin-associated glycoprotein (MAG), and proteolipoprotein (PLP) in sera of 26 AD
patients and 26 healthy controls, using commercially available ELISA system (Mediagnost,
Germany).
Results: In the AD patient subgroup, significantly higher titers were
observed for all types of assessed IgG autoantibodies compared to healthy control subjects
(anti-MOG, anti-MAG, anti-MBP, anti-PLP). The titers of most of the investigated IgM
antibodies were also higher in AD patients (p < 0.05), with the
exception of anti-MAG IgM antibodies (p > 0.05).
Conclusion: The study provides the evidence for the significantly increased
production of autoantibodies against proteins of myelin sheath in AD. These results can be
of importance in the light of emerging data from animal models of AD, indicating early
demyelination of hippocampal region. Further studies on larger population are necessary to
confirm whether these autoantibodies could serve as early biomarkers of AD in humans.
