Megakaryocyte progenitors in immune thrombocytopenic purpura (ITP).

Megakaryocyte colony formation was increased in 13 patients with ITP. Out of splenectomized ITP patients Colony Forming Unit-Megakaryocyte (CFU-Mk) number normalized in four but was lower than normal in the remaining two. The proportion of immature megakaryocytes was higher in ITP than in normals or in ITP patients after splenectomy. In conclusion, in ITP accelerated platelet destruction leads to stimulation of megakaryocytopoiesis, but some features of its ineffectiveness can be observed.