Figure 3.

PRT/H Abs activate platelets in a protamine-dependent manner. Washed ¹⁴C-serotonin–labeled platelets from healthy donors were incubated with or without protamine (PRT; 1.25 ug/mL) in the presence of 3 representative patient samples obtained at day 30 (CPB patients or control patients [CTRL]) with increasing amounts of unfractionated heparin (0, 0.25, 1, 100 U or 1U+ IV.3). ¹⁴C releasate was measured by liquid scintillation counting. These results are representative of 4 independent experiments.