Platelet markers in WAS/XLT patients at day 0 and >30 days of eltrombopag treatment. Platelet count was measured in a Bayer-ADVIA autoanalyzer (A). The following makers were measured with and without agonist stimulation: (B) percentage of platelets positive for activated GPIIb-IIIa (measured by PAC1 binding), (C) mean fluorescence for activated GPIIb-IIIa (PAC1), (D) percentage of platelets positive for P-selectin, (E) mean fluorescence for P-selectin, and (F) percentage of cells positive for PS (measured by annexin V binding). Low ADP, 0.5 μM; high ADP, 20 μM; low TRAP, 1.5 μM; high TRAP, 20 μM; low convulxin, 1 ng/mL; and high convulxin, 5 ng/mL. Results are expressed as mean ± SEM with n = 3 for WAS/XLT patients and analyzed with Student t test (A) or 2-way ANOVA with Bonferroni posttest (B-F). *Significant difference (P < .05).