Paradoxical Platelet Activation Was not Observed on Dissociation of Abciximab from GPIIb-IIIa Complexes

Summary

The ability of abciximab to bind and dissociate from platelets raises the question of the conformational state of GPIIb-IIIa complexes losing abciximab and the risk of paradoxical drug-induced platelet activation. Platelets incubated with abciximab and mixed in vitro with c7E3 Fab-free platelets lost the drug to the new platelets giving a single platelet population with a unimodal abciximab distribution within 17 h. Prelabeling the receiving platelets with phycoerythrin-labeled anti-GPIb monoclonal antibody (MoAb), permitted their identification by flow cytometry. Binding of PAC-1 and AP6, two MoAbs specific for activated GPIIb-IIIa, was then assessed to both losing and receiving platelet populations during transfer of abciximab. The subpopulation losing c7E3 Fab failed to show increased binding of these MoAbs. However, PAC-1 binding increased in both subpopulations after addition of ADP. Thus GPIIb-IIIa complexes are not in an activated state after dissociation of abciximab unless there is an additional source of activation.

Keywords

Platelet activation - GPIIb-IIIa complex - abciximab - antithrombotic therapy

• References

• 1 Coller BS. AntiGPIIb/IIIa drugs: Current strategies and future directions. Thromb Haemost 2001; 86: 428-44.
• 2 Shattil SJ, Kashiwagi H, Pampori N. Integrin signalling: The platelet paradigm. Blood 1998; 91: 2645-57.
• 3 Plow EF, Cierniewski CS, Xiao Z. et al. α IIbβ3 antagonism at the new millenium. Thromb Haemost 2001; 86: 34-40.
• 4 D’Souza SE, Ginsberg MH, Burke TA. et al. The ligand binding site of the platelet integrin receptor GPIIb-IIIa is proximal to the second calcium domain of its α subunit. J Biol Chem 1990; 265: 3440-6.
• 5 D’Souza SE, Ginsberg MH, Burke TA. et al. Localization of an Arg-Gly-Asp recognition site within an integrin adhesion receptor. Science 1988; 242: 91-3.
• 6 Puzon-McLaughlin W, Kamata T, Takada Y. Multiple discontinuous ligand-mimetic antibody binding sites define a ligand binding pocket in integrin αIIbβ3. J Biol Chem 2000; 273: 7796-802.
• 7 Peter KH, Schwarz M, Ylänne J. et al. Induction of fibrinogen binding and platelet aggregation as a potential intrinsic property of various glycoprotein IIb-IIIa (αIIbβ3) inhibitors. Blood 1998; 92: 3240-9.
• 8 Christopoulos C, Mackie I, Lahiri A, Machin S. Flow cytometric observations on the in vivo use of Fab fragments of a chimeric monoclonal antibody to platelet glycoprotein IIb-IIIa. Blood Coagul Fibrinolysis 1993; 04: 729-37.
• 9 Mascelli MA, Lance ET, Damaraju L. et al. Pharmacodynamic profile of short-term abciximab treatment demonstrates prolonged platelet inhibition with gradual recovery from GP IIb/IIIa receptor blockade. Circulation 1998; 97: 1680-8.
• 10 Taub R, Gould RJ, Garsky VM. et al. A monoclonal antibody against the platelet fibrinogen receptor contains a sequence that mimics a receptor recognition domain in fibrinogen. J Biol Chem 1989; 264: 259-65.
• 11 Nurden P, Humbert M, Piotrowicz RS. et al. Distribution of ligandoccupied αIIbβ3 in resting and activated human platelets determined by expression of a novel class of ligand-induced binding site recognized by monoclonal antibody, AP6. Blood 1996; 88: 887-99.
• 12 Macchi L, Clofent-Sanchez G, Marit G, at al. PAICA: A method for characterizing platelet-associated antibodies – its application to the study of idiopathic thrombocytopenic purpura and to the detection of platelet-bound c7E3. Thromb Haemost 1996; 76: 1020-9.
• 13 Bihour C, Durrieu-Jais C, Macchi L. et al. Expression of markers of platelet activation and the interpatient variation in response to abciximab. Arterioscler Thromb Vasc Biol 1999; 19: 212-9.
• 14 Nurden P, Poujol C, Durrieu-Jais C. et al. Labeling of the internal pool of GPIIb-IIIa in platelets by c7E3 Fab fragments (abciximab): flow and endocytic mechanisms contribute to the transport. Blood 1999; 93: 1622-33.
• 15 Gawaz M, Ruf A, Pogatsa-Murray G. et al. Incomplete inhibition of platelet aggregation and glycoprotein IIb-IIIa receptor blockade by abciximab: Importance of internal pool of glycoprotein IIb-IIIa receptors. Thromb Haemost 2000; 83: 915-22.
• 16 Schneider DJ, Taatjes DJ, Sobel BE. Paradoxical inhibition of fibrinogen binding and potentiation of α-granule release by specific types of inhibitors of glycoprotein IIb-IIIa. Cardiovasc Res 2000; 45: 437-46.
• 17 Kleimann NS. Pharmacology of the intravenous platelet receptor glycoprotein IIb-IIIa antagonists. Coronary Art Dis 1998; 09: 603-16.
• 18 Hezard N, Metz D, Nazeyrollas P. et al. Free and total platelet glycoprotein IIb/IIIa measurement in whole blood by quantitative flow cytometry during and after infusion of c7E3 Fab in patients undergoing PTCA. Thromb Haemost 1999; 81: 869-73.
• 19 Kleiman NS, Grazeiadei N, Maresh K. et al. Abciximab, ticlopidine, and concommitant abciximab-ticlopidine therapy: Ex vivo platelet aggregation inhibition profiles in patients undergoing percutaneous coronary interventions. Am Heart J 2000; 140: 492-501.
• 20 Jennings LK, Haga JH, Slack SM. Differential expression of a ligand induced binding site (LIBS) by GPIIb-IIIa ligand recognition peptides and parenteral antagonists. Thromb Haemost 2000; 84: 1095-102.
• 21 Dickfeld T, Ruf A, Pogatsa-Murray G. et al. Differential antiplatelet effects of various glycoprotein IIb-IIIa antagonists. Thromb Res 2001; 101: 53-64.
• 22 Zolotarjova NI, Hollis GF, Wynn R. Unusually stable and long-lived ligand-induced conformation of integrins. J Biol Chem 2001; 276: 17063-8.
• 23 Quinn M, Deering A, Stewart M. et al. Quantifying GPIIb/IIIa receptor binding using 2 monoclonal antibodies: discriminating abciximab and small molecular weight antagonists. Circulation 1999; 99: 2231-8.
• 24 Cox D, Smith R, Quinn M. et al. Evidence of platelet activation during treatment with a GPIIb/IIIa antagonist in patients presenting with acute coronary syndromes. J Am Coll Cardiol 2000; 36: 1514-9.
• 25 Quinn MJ, Cox D, Foley JB, Fitzgerald DJ. Glycoprotein IIb/IIIa receptor number and occupancy during chronic administration of an oral antagonist. J Pharmacol Exp Ther 2000; 295: 670-6.
• 26 Kong DF, Califf RM, Miller DP. et al. Clinical outcomes of therapeutic agents that block the platelet glycoprotein IIb/IIIa integrin in ischaemic heart disease. Circulation 1998; 98: 2839-45.