Abnormal expression of cyclin B1/D3, TRAIL, caspase-8, and caspase-3 in megakaryocytes. (A) Cultured with control IgG, megakaryocytes expressed cyclin B1 with a reduction from 44.3% at day 5 to 21.6% at day 9 and a limited expression of cyclin D3 (3.5%) at day 9. Although cultured with patient IgG (from groups A and B), megakaryocytes expressed cyclin B1 at a persistently low level (20.5%) and almost did not express cyclin D3 during the whole culture time. (B) Cultured with whole plasma, TRAIL expression on the surface of megakaryocytes did not differ significantly among ITP patients in groups A, B, C, and controls at day 6. At days 10 and 14, TRAIL expression in group A was remarkably lower than that in controls (P < .0001), but there was no significant difference among groups B, C, and control group. (C) Cultured with whole plasma, caspase-8 expression in megakaryocytes did not differ significantly among ITP patients in groups A, B, C, and controls at day 6. At days 10 and 14, caspase-8 expression in group A was remarkably lower than that in controls (P = .015 and P = .004), but there was no significant difference between groups B, C, and controls. (D) Cultured with whole plasma, caspase-3 expression in megakaryocytes did not differ significantly among ITP patients in groups A, B, C, and controls at day 6. At days 10 and 14, caspase-3 expression in group A was remarkably lower than that in controls (P = .023 and P < .0001), but there was no significant difference among groups B, C, and controls.