Two distinct subgroups of tirofiban-induced thrombocytopenia exist due to drug dependent antibodies that cause platelet activation and increased ischaemic events
| Autor: | Leonie Gaudry, Scott Dunkley, Susan E. Evans, Nigel Jepson |
|---|---|
| Rok vydání: | 2005 |
| Předmět: |
Male
Receptor complex Coronary Disease Platelet Glycoprotein GPIIb-IIIa Complex Flow cytometry Annexin medicine Humans Platelet Platelet activation Myocardial infarction Aged Autoantibodies Aged 80 and over Purpura Thrombocytopenic Idiopathic medicine.diagnostic_test biology business.industry Hematology General Medicine Tirofiban Middle Aged medicine.disease Platelet Activation Immunology Acute Disease biology.protein Tyrosine Female Antibody business Platelet Aggregation Inhibitors medicine.drug |
| Zdroj: | Platelets. 16(8) |
| ISSN: | 0953-7104 |
| Popis: | Tirofiban-associated thrombocytopenia is due to drug-dependent antibodies (DDAbs) directed against the GPIIb/IIIa complex which can bind after drug-induced conformational changes to the receptor complex. In such cases a higher incidence of myocardial infarction and mortality has been reported raising the possibility of platelet activation. We followed consecutive cases treated with tirofiban to determine the incidence of thrombocytopenia and confirmed that this was due to tirofiban-dependent antibodies. We then tested if these antibodies could cause platelet activation in vitro and correlated this with clinical outcome. In 871 treated patients, severe thrombocytopenia was observed in 11 cases, an incidence of 1.26%. Tirofiban dependent antibodies were confirmed in all cases using a flow cytometric assay. There were two distinct presentations of thrombocytopenia, one occurring acutely, and the second a delayed thrombocytopenia occurring after several days of tirofiban exposure and in keeping with a primary immune response. The effects of DDAbs on platelet activation was analysed by measuring P-selectin (CD62p) and annexin V, in the presence or absence of tirofiban, by flow cytometry. In addition, platelet activation was sought using the serotonin release assay. In six cases there was evidence of platelet activation and this was significantly associated with further coronary ischaemic events experienced at the time of acute thrombocytopenia. Tirofiban-induced thrombocytopenia due to DDAbs is a common occurrence and can lead to platelet activation and increased thrombotic events. |
| Databáze: | OpenAIRE |
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