Reactions of patient Abs and LIBS-specific mAbs against platelets pretreated with saturating concentrations of eptifibatide (E), tirofiban (T), and RGDW peptide (R; flow cytometry). For each Ab group, signals (median fluorescence intensity) obtained with (left) E, (center) T, and (right) R were expressed as “100%” and signals obtained with other ligands were expressed as a percentage of this value. Bars denote averages for 38 eptifibatide, 5 tirofiban, and 18 LIBS Abs. ***P < .001 compared with signal obtained with (left) E, (center) T, and (right) R. NS indicates not significant.