Reduced Intensity Conditioning Regimen Followed by Allogeneic Peripheral Blood Stem Cell Transplantation for Acute Panmyelosis with Myelofibrosis

ABSTRACT

A 44-year-old male presented with a month history of exertional dyspnea and dizziness. A peripheral blood smear revealed a pancytopenia with 3% of blasts. We were not able to obtain a bone marrow aspirate, but a biopsy specimen showed hypercellularity, proliferation of trilineage cell lines (panmyelosis) with extensive myelofibrosis, and clusters of immature cells at the paratrabecular area. After remission induction therapy with idarubicin 12mg/m2 (D1-3) and cytosine arabinoside 100mg/m2 (D1-7), the bone marrow blast count was decreased, but the marrow fibrosis and pancytopenia persisted. Peripheral blood stem cell transplantation from his HLA-matched brother was performed after administering fludarabine 30mg/m2 for 5 days and busulfan 3.2mg/kg for 2 days. Early engraftment occurred and the bone marrow reticulin fibrosis disappeared. Full-donor chimerism was demonstrated at day 22 by performing short tandem repeats analysis and this was maintained for 1 year. The patient has survived 20 months after transplantation without any complication.