The progression of severe aplastic anemia to hypoplastic leukemia in a long-term observation after the administration of pegylated rHuMGDF

Thrombopoietin (TPO) is a critical regulator of hematopoiesis. We previously reported that a severe aplastic anemia (SAA) who received a short-term administration of pegylated recombinant human megakaryocyte growth and development factor (rHuMGDF). A trilineage hematologic response was induced, however the patient was diagnosed with leukemia after nine years and eight months from administration of rHuMGDF. In recent reports, somatic mutations in myeloid cancer candidate genes were present in one-third of the AA. A mutant clone may be expanded by rHuMGDF in our patient. The long-term safety of patients treated with TPO and eltrombopag remains unknown. Careful observations are warranted hereafter.