Amyloid beta peptides in plasma in early diagnosis of Alzheimer's disease: A multicenter study with multiplexing.
We measured concentrations of Abeta peptides 1-42 and 1-40, and their ratio in plasma of patients carefully categorized clinically and neurochemically as having AD or other dementias with a newly commercially available multiplexing assay, characterized by reasonable laboratory performance (intra-assay imprecision in the range of 1.3-3.8% for Abeta1-42, and 1.8-4.1% for Abeta1-40, inter-assay imprecision for Abeta1-42, Abeta1-40, and Abeta1-42/Abeta1-40 concentration ratio in the range of 2.3-11.5%, 2.2-10.4% and 4.2-9.7%, respectively). Patients with AD or mild cognitive impairment of AD type (MCI-AD) whose clinical diagnosis was supported with CSF biomarkers (n=193) had significantly lower Abeta1-42 plasma concentrations (p<0.007), and Abeta1-42/1-40 ratios (p<0.003) compared to patients with other dementias and MCI of other types (n=64). No significant differences between persons with MCI of AD type and patients with early AD were observed, or between MCI of other types versus patients with early dementia of other types. Our findings reconfirm the hypothesis that alterations of biomarker concentrations occur early in a preclinical AD stage and that these alterations are also reflected in plasma.
Lewczuk
P
P
Department of Psychiatry and Psychotherapy, University of Erlangen-Nuremberg, Erlangen, Germany.
Kornhuber
J
J
Vanmechelen
E
E
Peters
O
O
Heuser
I
I
Maier
W
W
Jessen
F
F
Bürger
K
K
Hampel
H
H
Frölich
L
L
Henn
F
F
Falkai
P
P
Rüther
E
E
Jahn
H
H
Luckhaus
Ch
Ch
Perneczky
R
R
Schmidtke
K
K
Schröder
J
J
Kessler
H
H
Pantel
J
J
Gertz
H-J
HJ
Vanderstichele
H
H
de Meyer
G
G
Shapiro
F
F
Wolf
S
S
Bibl
M
M
Wiltfang
J
J
D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000097:blood / Q000134:cerebrospinal fluid / Q000175:diagnosis*; D016229:Amyloid beta-Peptides / Q000097:blood* / Q000134:cerebrospinal fluid; D015415:Biomarkers / Q000097:blood* / Q000134:cerebrospinal fluid; D003704:Dementia / Q000097:blood / Q000134:cerebrospinal fluid / Q000175:diagnosis; D042241:Early Diagnosis; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D008297:Male; D008875:Middle Aged; D010446:Peptide Fragments / Q000097:blood* / Q000134:cerebrospinal fluid; D011237:Predictive Value of Tests
D016229:Amyloid beta-Peptides; D015415:Biomarkers; D010446:Peptide Fragments; C078592:amyloid beta-protein (1-40); C075222:amyloid beta-protein (1-42)