Reduced levels of IgM autoantibodies against N-truncated pyroglutamate Aβ in plasma of patients with Alzheimer's disease.
In the present work, we investigated the level of IgM autoantibodies directed against different Aβ epitopes as potential diagnostic biomarker for Alzheimer's disease (AD). Anti-Aβ autoantibody levels were measured in 75 plasma samples from patients with AD, individuals with mild cognitive impairment (MCI), and healthy age- and sex-matched controls (HC). To validate the presence of anti-Aβ IgMs, pooled plasma samples were subjected to gel-filtration analysis. The mean level of pGluAβ-IgM (N-terminal truncated starting at position three with pyroglutamate) was significantly decreased in AD patients as compared to HC. In the group of MCI patients there was a significant positive correlation between pGluAβ-IgM and cognitive decline analyzed by MMSE (rho = 0.58, d.f. = 13, p = 0.022). These observations indicate that the level of IgM autoantibodies against pGluAβ is a promising plasma biomarker for AD and correlates with the cognitive status of individuals at risk to develop AD.
University Medicine of Goettingen, Department of Psychiatry, Goettingen, Germany.
Andrea
A
Marcello
Oliver
O
Wirths
Thomas
T
Schneider-Axmann
Malin
M
Degerman-Gunnarsson
Lars
L
Lannfelt
Thomas A
TA
Bayer
D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000097:blood / Q000175:diagnosis* / Q000276:immunology*; D016229:Amyloid beta-Peptides / Q000097:blood / Q000276:immunology*; D001323:Autoantibodies / Q000096:biosynthesis* / Q000097:blood; D015415:Biomarkers / Q000097:blood; D000939:Epitopes / Q000097:blood / Q000276:immunology; D005260:Female; D006801:Humans; D007075:Immunoglobulin M / Q000096:biosynthesis / Q000097:blood*; D008297:Male; D010446:Peptide Fragments / Q000097:blood / Q000276:immunology*; D011237:Predictive Value of Tests; D011761:Pyrrolidonecarboxylic Acid / Q000097:blood / Q000276:immunology*
D016229:Amyloid beta-Peptides; D001323:Autoantibodies; D015415:Biomarkers; D000939:Epitopes; D007075:Immunoglobulin M; D010446:Peptide Fragments; C075222:amyloid beta-protein (1-42); D011761:Pyrrolidonecarboxylic Acid