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Platelet Adhesion and Aggregation Under Flow using Microfluidic Flow Cells
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Formation of occlusive platelet aggregates in whole blood caused by low concentrations of ADP

M W Hall1, P D Goodman, K A Solen

  • 1Department of Chemical Engineering, Brigham Young University, Provo, Utah 84602, USA.

ASAIO Journal (American Society for Artificial Internal Organs : 1992)
|December 8, 2000
PubMed

Insights

Minute concentrations of adenosine diphosphate (ADP) form rigid microaggregates (MA) in blood. This platelet aggregation, detected by a new light scattering whole blood aggregometer, has implications for extracorporeal circulation.

Area of Science:

  • Biomedical Engineering
  • Hematology
  • Cardiovascular Science

Background:

  • Platelet activation by adenosine diphosphate (ADP) is crucial in hemostasis.
  • Extracorporeal circulation exposes blood to shear stress, releasing low ADP concentrations.
  • Current methods do not detect significant platelet function changes at these low ADP levels.

Purpose of the Study:

  • To investigate the impact of minute ADP concentrations on platelet aggregation.
  • To characterize the formation and properties of microaggregates (MA) induced by low ADP levels.
  • To assess the potential relevance of these findings to extracorporeal circulation.

Main Methods:

  • Development and utilization of a novel light scattering whole blood aggregometer (LSWBA).
  • Measurement of ADP-induced platelet aggregation dose-response (0-2 microM) in heparinized human blood.
  • Assessment of aggregate rigidity using constant pressure filtration (50 mm Hg).

Main Results:

  • Low ADP concentrations (0-2 microM) induced the formation of rigid microaggregates (MA).
  • The LSWBA successfully detected this aggregation dose-response.
  • While MA appeared reversible by LSWBA, filtration tests indicated they remained rigid for up to 6 minutes.

Conclusions:

  • Minute ADP concentrations can induce significant platelet aggregation, forming rigid microaggregates.
  • The newly developed LSWBA is sensitive to low-level ADP-induced platelet aggregation.
  • Findings suggest potential risks associated with microaggregate formation during extracorporeal circulation.

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