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A Microfluidic Flow Chamber Model for Platelet Transfusion and Hemostasis Measures Platelet Deposition and Fibrin Formation in Real-time
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Platelet microparticles and calcium homeostasis in acute coronary ischemias

J N Katopodis1, L Kolodny, W Jy

  • 1The William J Harrington Center for Blood Diseases/Sylvester Comprehensive Cancer Center, University of Miami School of Medicine, Florida, USA.

American Journal of Hematology
|February 1, 1997
PubMed

Insights

Platelet activation markers, including calcium levels and microparticle shedding, are elevated in acute coronary syndromes. Leukocyte interaction is specifically heightened in unstable angina, indicating distinct pathophysiological roles.

Area of Science:

  • Cardiovascular Research
  • Hematology
  • Clinical Biochemistry

Background:

  • Platelet activation is a key event in acute coronary syndromes (ACS), involving increased cytoplasmic calcium.
  • Markers of platelet activation, such as platelet microparticles (PMP) and CD62p expression, are elevated in ACS.
  • Platelet-leukocyte (P/L) interactions are implicated in the pathophysiology of cardiovascular diseases.

Purpose of the Study:

  • To investigate markers of platelet activation, including free cytoplasmic calcium ([Ca2+]cyt), PMP, CD62p expression, and P/L interaction.
  • To compare these markers in patients with unstable angina (UA), recent myocardial infarction (MI), and control subjects (CTL).
  • To elucidate the role of platelet activation and calcium hemostasis in the pathophysiology of acute coronary ischemia.

Main Methods:

  • Prospective study of 55 patients undergoing coronary angiography for suspected coronary artery disease (CAD).
  • Measurement of [Ca2+]cyt using Fluo-3 and PMP, CD62p expression, and P/L interaction via flow cytometry.
  • Blood samples were collected before heparin infusion from UA, MI, and CTL groups.

Main Results:

  • Platelet microparticle (PMP) levels were significantly higher in both UA and MI groups compared to controls (P < 0.05).
  • Platelet/leukocyte (P/L) interaction was significantly elevated exclusively in the UA group (P < 0.05).
  • Resting [Ca2+]cyt, thrombin-induced Ca2+ influx, and internal calcium release were significantly higher in the combined UA + MI group versus controls (P < 0.001).

Conclusions:

  • Calcium hemostasis and PMP levels differ significantly in patients with acute coronary syndromes, suggesting a role in acute coronary ischemia pathophysiology.
  • Elevated P/L interaction in the UA group points to a specific role for leukocytes in unstable angina.
  • These findings highlight distinct platelet activation profiles in different acute coronary syndromes.
Abstract

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