title: Acute thrombocytopenia in patients treated with the oral glycoprotein IIb/IIIa inhibitors xemilofiban and orbofiban: evidence for an immune etiology.
abstract: 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.
authors.affiliation: Blood Research Institute, Blood Center of Wisconsin, Milwaukee, WI 53201-2178, USA.
authors.forename: Jacqueline A
authors.initials: JA
authors.lastname: Brassard
authors.forename: Brian R
authors.initials: BR
authors.lastname: Curtis
authors.forename: Richard A
authors.initials: RA
authors.lastname: Cooper
authors.forename: John
authors.initials: J
authors.lastname: Ferguson
authors.forename: Wendy
authors.initials: W
authors.lastname: Komocsar
authors.forename: Maria
authors.initials: M
authors.lastname: Ehardt
authors.forename: Stuart
authors.initials: S
authors.lastname: Kupfer
authors.forename: Clement
authors.initials: C
authors.lastname: Maurath
authors.forename: Edward
authors.initials: E
authors.lastname: Swabb
authors.forename: Christopher P
authors.initials: CP
authors.lastname: Cannon
authors.forename: Richard H
authors.initials: RH
authors.lastname: Aster
mesh_terms: D000208:Acute Disease; D000409:Alanine / Q000008:administration & dosage / Q000009:adverse effects*; D001323:Autoantibodies / Q000097:blood; D015551:Autoimmunity; D001550:Benzamidines / Q000008:administration & dosage / Q000009:adverse effects*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010975:Platelet Aggregation Inhibitors / Q000008:administration & dosage / Q000009:adverse effects*; D019039:Platelet Glycoprotein GPIIb-IIIa Complex / Q000037:antagonists & inhibitors* / Q000276:immunology; D016553:Purpura, Thrombocytopenic, Idiopathic / Q000209:etiology / Q000276:immunology; D011759:Pyrrolidines / Q000008:administration & dosage / Q000009:adverse effects*; D012307:Risk Factors; D013921:Thrombocytopenia / Q000209:etiology* / Q000276:immunology
chemical_list: D001323:Autoantibodies; D001550:Benzamidines; D010975:Platelet Aggregation Inhibitors; D019039:Platelet Glycoprotein GPIIb-IIIa Complex; D011759:Pyrrolidines; C120234:orbofiban; D000409:Alanine; C091295:xemilofiban