Platelet subpopulation bearing leukocyte specific antigen and tissue factor

Abstract

Platelets bearing leukocyte antigen CD45 were identified in the blood of patients with myocardial infarction (MI) and healthy donors by flow cytofluorimetry. Part of these platelets contained tissue factor (TF)–primary initiator of blood clotting. The number of CD45⁺ and CD45⁺/TF⁺ platelets in MI patients at the first day was comparable with their level in healthy donors, but was increased at 8–12 days after MI onset. At that time in some patients the amount of CD45⁺ and CD45⁺/TF⁺ platelets reached 5–6 and 2–3% of their total number. It is assumed that CD45⁺/TF⁺ platelets could be formed as a result of platelet interaction with leukocytes or leukocyte produced membrane microparticles.