title: Elevated platelet microparticles in transient ischemic attacks, lacunar infarcts, and multiinfarct dementias.
abstract: Platelets release microparticles (PMP) upon activation. Elevated levels of PMP were observed in patients with immune thrombocytopenic purpura (ITP), sometimes associated with a syndrome resembling transient ischemic attack (TIA), suggesting a thrombogenic potential for PMP. To determine if this association applies to TIA and other cerebrovascular accidents (CVA) without ITP, we studied PMP profiles in 71 patients with ischemic CVA: 28 with small vessel CVA (SCVA), either lacunar infarcts or TIA; 24 with large vessel CVA (LCVA); 19 with multiinfarct dementia (MID); 12 with Alzheimer's dementia (AD); and 31 healthy controls. The mean PMP values were: MID = 3.71 +/- 0.51; SCVA = 3.48 +/- 0.63; LCVA = 1.97 +/- 0.28; AD = 1.19 +/- 0.27; controls = 0.88 +/- 0.09, (all units x 10(7)/mL). PMP values in all groups except AD were significantly above normal (p < 0.01). However, the elevation in SCVA was more marked than in LCVA (p < 0.01). Administration of the calcium channel blocker, nifedipine, to 11 TIA patients reduced PMP significantly.
authors.affiliation: William J. Harrington Center for Blood Diseases, Department of Medicine, University of Miami, Florida 33136.
authors.forename: Y J
authors.initials: YJ
authors.lastname: Lee
authors.forename: W
authors.initials: W
authors.lastname: Jy
authors.forename: L L
authors.initials: LL
authors.lastname: Horstman
authors.forename: J
authors.initials: J
authors.lastname: Janania
authors.forename: Y
authors.initials: Y
authors.lastname: Reyes
authors.forename: R E
authors.initials: RE
authors.lastname: Kelley
authors.forename: Y S
authors.initials: YS
authors.lastname: Ahn
mesh_terms: D000328:Adult; D000368:Aged; D000544:Alzheimer Disease / Q000097:blood / Q000188:drug therapy; D001792:Blood Platelets / Q000378:metabolism*; D002544:Cerebral Infarction / Q000097:blood* / Q000188:drug therapy; D015161:Dementia, Multi-Infarct / Q000097:blood* / Q000188:drug therapy; D005260:Female; D006801:Humans; D002546:Ischemic Attack, Transient / Q000097:blood* / Q000188:drug therapy; D008297:Male; D008875:Middle Aged; D009543:Nifedipine / Q000627:therapeutic use; D010316:Particle Size
chemical_list: D009543:Nifedipine