Abstract
Glycoprotein (GP) IIbIIIa inhibitors are used in the treatment of acute coronary syndromes. Transient immune-mediated acute thrombocytopenia is a recognized side effect of GPIIbIIIa inhibitors. We provide evidence that GPIIbIIIa inhibitor-induced antibodies can affect megakaryocytes in the presence of eptifibatide. In a patient with acute coronary syndrome, acute thrombocytopenia occurred after a second exposure to eptifibatide 20 days after the initial treatment. Despite the short half-life of eptifibatide (t(1/2) = 2 hours), thrombocytopenia less than 5 x 10(9)/L and gastrointestinal and skin hemorrhage persisted for 4 days. Glycoprotein-specific enzyme-linked immunosorbent assay showed eptifibatide-dependent, GPIIbIIIa-specific antibodies. Bone marrow examination showed predominance of early megakaryocyte stages, and platelet transfusion resulted in an abrupt platelet count increase. Viability of cultured cord blood-derived megakaryocytes was reduced in the presence of eptifibatide and patient IgG fraction. These findings can be explained by impaired megakaryocytopoiesis complicating anti-GPIIbIIIa antibody-mediated immune thrombocytopenia. This mechanism may also apply to some patients with autoimmune thrombocytopenia.
Publication types
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Case Reports
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Research Support, Non-U.S. Gov't
MeSH terms
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Acute Coronary Syndrome / blood
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Acute Coronary Syndrome / immunology
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Acute Coronary Syndrome / therapy
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Aged
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Autoantibodies / blood
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Autoantibodies / immunology*
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Autoimmune Diseases / blood
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Autoimmune Diseases / chemically induced*
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Autoimmune Diseases / immunology*
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Autoimmune Diseases / therapy
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Eptifibatide
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Gastrointestinal Hemorrhage / blood
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Gastrointestinal Hemorrhage / chemically induced
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Gastrointestinal Hemorrhage / immunology
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Humans
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Immunoglobulin G / blood
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Immunoglobulin G / immunology*
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Male
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Megakaryocytes / immunology*
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Peptides / administration & dosage
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Peptides / adverse effects*
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Platelet Aggregation Inhibitors / administration & dosage
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Platelet Aggregation Inhibitors / adverse effects*
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Platelet Count
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Platelet Glycoprotein GPIIb-IIIa Complex / antagonists & inhibitors
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Platelet Glycoprotein GPIIb-IIIa Complex / immunology*
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Platelet Transfusion / methods
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Thrombocytopenia / blood
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Thrombocytopenia / chemically induced*
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Thrombocytopenia / immunology*
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Thrombocytopenia / therapy
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Thrombopoiesis / immunology
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Time Factors
Substances
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Autoantibodies
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Immunoglobulin G
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Peptides
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Platelet Aggregation Inhibitors
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Platelet Glycoprotein GPIIb-IIIa Complex
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Eptifibatide