Thrombocytopenic episodes occurring in 18,845 patients treated with the GPIIb/IIIa inhibitors xemilofiban and orbofiban (fibans) were analyzed by a blinded review panel and 73 patients were classified as having possible fiban-induced thrombocytopenia. When the treatment codes were broken, a significant association between drug exposure and assignment to this group was found (p <0.001). Twenty-eight (82%) of 34 archived serum samples from these patients contained fiban-dependent antibodies specific for GPIIb/IIIa, but no such antibodies were found in 61 drug treated patients not classified as having possible fiban-induced thrombocytopenia (p <0.001). We conclude that fiban-dependent antibodies were the major cause of acute, severe thrombocytopenia in patients judged on the basis of clinical findings to have thrombocytopenia possibly-induced by xemilofiban and orbofiban. Measurement of drug-dependent antibodies may be helpful in determining the basis for acute thrombocytopenia in fiban-treated patients and possibly for identification of patients at risk to develop thrombocytopenia.
Print ISSN: 0340-6245
Volume: 88, 12/2002
Pages: 892 - 897