Differences in coated-platelet production between frontotemporal dementia and Alzheimer disease.
OBJECTIVE
Coated-platelets are a subset of platelets produced by dual-agonist activation with collagen and thrombin. These platelets retain full-length amyloid precursor protein on their surface and correlate inversely with disease severity in Alzheimer disease (AD). We have now investigated coated-platelet production and its relationship with disease severity in frontotemporal dementia (FTD) patients to determine whether our earlier observations were unique to AD.


METHODS
Coated-platelet levels were assayed in 40 FTD, 40 AD patients, and 40 controls. Both patient groups were equally divided between mild-stage (Clinical Dementia Rating < or =1) and advanced stage dementia (Clinical Dementia Rating >1).


RESULTS
Coated-platelet levels were not significantly different between patients with early-stage and advanced stage FTD (P=0.9), whereas early-stage AD patients had significantly higher levels than advanced stage AD (P<0.001). In addition, coated-platelet production was significantly elevated in early-stage AD versus early-stage FTD patients (P=0.01).


CONCLUSIONS
In contrast to AD, there is no significant relationship between disease severity and coated-platelet levels in FTD. Differences in coated-platelet levels between early-stage AD and early-stage FTD patients warrant further investigation for potential clinical applications in helping to differentiate between these 2 disorders.
Prodan
Calin I
CI
Neurology Service, Veterans Administration Medical Center, Oklahoma City, OK, USA. calin-prodan@ouhsc.edu
Ross
Elliott D
ED
Vincent
Andrea S
AS
Dale
George L
GL
D000368:Aged; D000544:Alzheimer Disease / Q000097:blood*; D001792:Blood Platelets / Q000378:metabolism*; D057180:Frontotemporal Dementia / Q000097:blood*; D006801:Humans; D015539:Platelet Activation / Q000502:physiology