Pseudothrombocytopenia (see Thrombocytopenia, [[Thrombocytopenia]])
Epidemiology
In EPIC trial, the incidence of pseudothrombocytopenia with abciximab was 1.1%, whereas the incidence of true acute thrombocytopenia was 2.7% with abciximab
Mechanism: platelet clumping due to EDTA in collection tube -> miscounting on automated detectors
Platelet clumping has been reported with all 3 agents
Diagnosis of Platelet Clumping
Collect Blood in Citrate Tubes: may allow accurate counting in some, but not all cases of EDTA-associated clumping
Inspection of Smear: gold standard for accurate platelet count
Epidemiology: in EPIC trial, the incidence of pseudothrombocytopenia with abciximab was 1.1%, whereas the incidence of true acute thrombocytopenia was 2.7% with abciximab
Mechanism: believed to be due to preformed antibodies against neoepitopes exposed by alteration of the GP IIb/IIIa molecules
Clinical: can occur in a matter of hours
Hemorrhagic Adverse Effects Due to Platelet Dysfunction
Diffuse alveolar hemorrhage following administration of tirofiban or abciximab: A nemesis of platelet glycoprotein IIb/iIIa inhibitors. Catheterization and Cardiovascular Interventions Volume 49, Issue 2, pages 181–184, February 2000
Alveolar Hemorrhage: An Underdiagnosed Complication of Treatment with Glycoprotein IIb/IIIa Inhibitors. Journal of Interventional Cardiology Volume 19, Issue 4, pages 356–363, August 2006
Moll S, Poepping I, Hauck S, et al. Pseudothrombocytopenia after abciximab (Reopro) treatment. Circulation 1999; 100:1460
Dasgupta H, Blankenship J, Wood G, et al. Thrombocytopenia complicating treatment with intravenous IIb/IIIa receptor inhibitors: a pooled analysis. Am Heart J 2000; 140:206-211
