OBJECTIVE: To investigate the effects of abciximab, eptifibatide and no GPIIb-IIIa antagonist (control) on soluble CD40 ligand (sCD40L) and the formation of leukocyte-platelet aggregates (LPA) in 98 ACS patients undergoing percutaneus coronary intervention (PCI).

BACKGROUND: sCD40L and LPA are increased in patients with ACS.

METHODS: sCD40L was measured by enzyme-linked immunosorbent assay (ELISA) and LPA by whole blood flow cytometry.

RESULTS: There were no baseline differences between the three groups in sCD40L and LPA. At the end of PCI, sCD40L was unchanged in the controls, decreased by 30% (P andlt; 0.001) in the abciximab group and by 11% (P andlt; 0.02) in the eptifibatide group. Eighteen to 24 h after PCI, sCD40L was unchanged in the controls, reduced 30% (P andlt; 0.001) in the abciximab-treated group and 9% (P andlt; 0.01) in the eptifibatide-treated group. At the end of PCI, circulating monocyte-platelet aggregates (MPA) were reduced by 12% (P = NS) in the abciximab-treated group, 13% in the eptifibatide-treated group (P = NS), but slightly increased in the controls (P = NS). Eighteen to 24 h after PCI, MPA were reduced by 41% (P andlt; 0.001) compared to baseline in the abciximab-treated group, by 23% (P = NS) in the eptifibatide-treated group, and 15% (P = NS) in the controls. In contrast to control patients presenting while on clopidogrel, control patients presenting not on clopidogrel demonstrated a reduction in sCD40L and LPA 18-24 h post-PCI (P = NS). At low receptor occupancy, GPIIb-IIIa antagonists did not augment the release of sCD40L or the number of circulating LPA.

CONCLUSIONS: GPIIb-IIIa antagonists reduce circulating sCD40L and LPA formation in patients with ACS undergoing PCI. At low receptor occupancy, GPIIb-IIIa antagonists do not activate platelets.