There is increasing evidence that in Lewy body-associated
dementias (encompassing
Parkinson's disease with
dementia (PDD) and
dementia with Lewy bodies (DLB)), the adaptive immune system is altered and the degenerative process includes glial cells in addition to neuronal structures. We therefore aimed to determine levels of
autoantibodies against
amyloid and glial-derived structures in these
dementia types. Using a newly developed
Enzyme-linked
immunosorbent assay (ELISA), we measured levels of
IgG autoantibodies against neuronal and glial structures in serum and cerebrospinal fluid of a total of 91 subjects (13 PDD, 14 DLB, 11
Alzheimer's disease (
AD), 11 frontotemporal dementia (FTD), 11
vascular dementia patients (VaD), and 31 healthy controls).
Autoantibody levels against α-
synuclein,
amyloid-β₄₂ (Aβ₄₂),
myelin oligodendrocyte glycoprotein (MOG),
myelin basic protein (MBP), and S100B were determined. In all groups,
autoantibody levels were about three magnitudes higher in serum than in CSF. Serum
autoantibody levels against α-
synuclein, Aβ₄₂, MOG, MBP, and S100B were higher in PDD/DLB compared to tau-associated
dementias (AD, FTD), VaD, and controls, respectively, with most of them reaching highly significant p-values. In cerebrospinal fluid (CSF), levels of
antibodies against oligodendrocyte-derived
antigens (MOG, MBP) were significantly increased in PDD/DLB. Increased levels of
autoantibodies against both neuronal- and glial-derived
antigens in serum and CSF of Lewy body-associated
dementias indicate an altered activity of the adaptive immune system in these
dementia types. The potential of neural-derived
IgG autoantibodies as part of a
biomarker panel for the diagnosis of Lewy body-associated
dementias should be further evaluated.