The synergistic effect of thrombopoietin in erythropoiesis and myelopoiesis from human bone marrow cells

We sought to determine whether recombinant human thrombopoietin (TPO) acts synergistically with recombinant human erythropoietin (EPO) and/or recombin ant human interleukin-3 (IL-3) on erythroid burst formation and granulocyte -macrophage colony formation from human bone marrow (BM). BM cells were fro m 5 adults and 15 children who underwent bone marrow examination because of a clinical suspicion of malignancy; their bone marrows as well as the comp lete blood counts were normal and were cultured in a methylcellulose system . TPO has a synergistic effect with EPO or EPO + IL-3 on erythropoiesis of human BM, as the addition of TPO to EPO significantly gave rise to more ery throid bursts (p = 0.0001) and the addition of TPO to EPO + IL-3 might give rise to more erythroid bursts (p = 0.05). TPO also has a synergistic effec t with recombinant human granulocyte colony-stimulating factor (G-CSF) on m yelopoiesis of human BM, since the addition of TPO to G-CSF gave rise to si gnificantly more granulocyte-macrophage colonies (p = 0.0001). Besides its well-known significant role in megakaryopoiesis, TPO also has synergistic e ffects on erythropoiesis and myelopoiesis. Copyright (C) 2000 S. Karger AG, Basel.