Peripheral inflammatory cytokines as biomarkers in Alzheimer's disease and mild cognitive impairment.
BACKGROUND
Several lines of evidence in the literature have shown that inflammation is involved in the pathogenesis of Alzheimer's disease (AD). However, the results from the evaluation of serum inflammatory markers in AD patients have been controversial.


OBJECTIVE
To determine if any differences exist in the monocytic secretion pattern of IL-1beta, IL-6, IL-12 and TNF-alpha from mild cognitive impairment (MCI) and AD patients, when compared with healthy age-matched controls.


METHODS
To evaluate the percentage of peripheral monocytes secreting IL-1beta, IL-6, IL-12 and TNF-alpha along with the relative levels of these proteins, a cytofluorimetric analysis was conducted under basal conditions and after lipopolysaccharide-induced cell activation.


RESULTS
We found, in AD and MCI patients, a significant raise in the percentage of monocytes producing the studied cytokines (under basal conditions and after the exposure to an inflammatory stimulus), as well as a decreased competence of these cells to respond to inflammatory challenges, when compared with controls.


CONCLUSIONS
These results agree with a persistent inflammatory status in AD, reinforcing the hypothesis of a progressive impairment of the immune response in this disorder and suggesting that monocytes may be good targets to study the progression from MCI to AD.
Guerreiro
Rita João
RJ
Center for Neuroscience and Cell Biology, Faculty of Medicine, Coimbra University, Coimbra, Portugal.
Santana
Isabel
I
Brás
José Miguel
JM
Santiago
Beatriz
B
Paiva
Artur
A
Oliveira
Catarina
C
D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000097:blood*; D000704:Analysis of Variance; D015415:Biomarkers / Q000097:blood; D016022:Case-Control Studies; D003072:Cognition Disorders / Q000097:blood*; D016207:Cytokines / Q000145:classification / Q000378:metabolism*; D005260:Female; D005434:Flow Cytometry / Q000379:methods; D006801:Humans; D007249:Inflammation / Q000139:chemically induced / Q000378:metabolism*; D008070:Lipopolysaccharides / Q000494:pharmacology; D008297:Male; D008875:Middle Aged; D009000:Monocytes / Q000187:drug effects / Q000378:metabolism
D015415:Biomarkers; D016207:Cytokines; D008070:Lipopolysaccharides