TPO and autoimmune thrombocytopenic purpura: Former reports have suggested that the relatively low TPO levels in ITP might be the result of preserved megakaryocyte mass in the bone marrow of patients with accelerated platelet destruction.[24, 27] With an increased number of c-Mpl positive megakaryocytes and continuous production of new platelets, the TPO uptake in nonpregnant ITP patients would not extremely decrease.