ISAC XX Abstracts on Disc
Presented by Purdue University Cytometry Laboratories

Flow cytometric evaluation of P-selectin exposition on platelets in GPIIb-IIIa absence or blockade conditions.

Luciana Gallo, Rosaria Candolfi, Liliana Nobili, Francesca Rossi, Alberto Rosti, Edoardo Rossi

Ospedale l. Sacco
Servizio Trasfusionale - Laboratorio di Ematologia
via G.B.Grassi 74
Milano, Italy, 20157

Abstract Number: 6361     Clinical Cytometry  –  Platelets and Platelet Function
Platelet GPIIb-IIIa antagonist therapy is at length used to prevent ischemic complications of percutaneous coronary interventions. The aim of our study was to measure P-selectin exposition on platelet in presence of abciximab (ReoPro), the Fab fragment of a mouse/human chimeric version of the murine 7E3 antibody. We have studied whole blood samples obtained from 10 healthy volunteers, in vitro treated with 2.5 g/ml of abciximab, from 5 patients under abciximab therapy and from 5 patients with Glanzmann thrombasthenia. P-selectin exposition was evaluated by flow cytometry using CD62 (CLB-Amsterdam), in basal condition and after in vitro stimulation by TRAP and a stable tromboxane analogous (U46619-Sigma). P-selectin was measured as Antibody Binding Capacity (ABC) (absolute quantitation of the number of antibodies bound per cell) using Quantum Simply Cellular (FCSC- San Juan,PR). Glanzmann thrombasthenia patients platelets showed to have a major exposure of P-selectin than healthy subjects and other patients without treatment with abciximab. A greater amount of P-selectin was exposed on platelets treated with abciximab than those without GPIIb-IIIa antagonist both in healthy volunteers and patients.
Keywords: GPIIb-IIIa inhibitor