Clinical response to romiplostim. Trilineage response to romiplostim therapy. (A) PLT, (B) ANC, (C) Hb, and (D) WBC counts are shown for affected individuals: Family A, III-6 and Family C, II-5. Arrow indicates date of BMT. Gray shading indicates timeframe of platelet and erythrocyte transfusion dependence. Dotted line indicates initiation of romiplostim therapy. Note difference in time scale (x-axis) between left and right panels.