Number of microparticles generated during acute myocardial infarction and stable angina correlates with platelet activation.
OBJECTIVE
Elevated levels of circulating microparticles (MPs) have been reported in patients with acute myocardial infarction (AMI) and coronary artery disease. Platelet activation and inflammation have been recognized during AMI and stable angina (SA). We hypothesize that the origin and count of MPs in AMI and SA patients are related to markers of inflammation and platelet activation.


METHODS
Platelet, monocytes and endothelial MPs and surface P-selectin were determined in 12 AMI patients, 10 SA patients and 9 controls by flow cytometry. Plasma P-selectin, CD40 ligand (sCD40L) and interleukin 6 (IL-6) levels were evaluated by ELISA methods.


RESULTS
The total MP count was compared in control subjects, AMI, and SA patients: 12,765 (8465) vs. 38,750 (11,931) vs. 29,715 (12,072) counts/μl (p = 0.01), respectively. Patients with AMI displayed higher levels of total and platelet origin- tissue factor-positive (CD42/CD142) MPs than patients with SA: 72.8 (6.2) vs. 56.2 (6.4) %, p = 0.001. Levels of soluble P-selectin were significantly elevated in patients with AMI as compared to SA patients: 146 (6.5) vs. 107 (2.7) ng/mL, p = 0.005; significant correlation between total MP count and relative number of CD34, CD51, CD42-positive MPs, and the P-selectin expression was observed in patients with AMI.


CONCLUSIONS
Platelet activation in AMI is associated with increased generation of MPs not only from platelets, but also monocytes and endothelial cells. It suggests that interactions between platelets, monocytes and endothelial cells play an important role in the pathogenesis of myocardial ischemia.
Department of Clinical Biochemistry, Jagiellonian University Medical College, Krakow, Poland. estepien@cm-uj.krakow.pl
Ewa
E
Stępień
Elżbieta
E
Stankiewicz
Jarosław
J
Zalewski
Jacek
J
Godlewski
Krzysztof
K
Zmudka
Iwona
I
Wybrańska
D000328:Adult; D000368:Aged; D060050:Angina, Stable / Q000097:blood* / Q000473:pathology; D015703:Antigens, CD / Q000097:blood / Q000378:metabolism; D015415:Biomarkers / Q000097:blood; D016022:Case-Control Studies; D002452:Cell Count; D055252:Cell-Derived Microparticles / Q000378:metabolism / Q000473:pathology*; D005260:Female; D006801:Humans; D007249:Inflammation / Q000097:blood / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000097:blood* / Q000473:pathology; D015539:Platelet Activation
D015703:Antigens, CD; D015415:Biomarkers