Successful treatment with nonmyeloablative allogeneic hematopoietic stem cell transplantation in a patient with acute myeloid leukemia complicated with pulmonary infection.

We describe the case of a 48-year-old man with acute myeloid leukemia complicated with pulmonary infection that was successfully treated by nonmyeloablative allogeneic peripheral blood stem cell transplantation with conditioning by low-dose total body irradiation and fludarabine. The disease was diagnosed immunophenotypically as myeloid/natural killer cell precursor acute leukemia. After two courses of induction therapy, complete remission was achieved. However, the patient developed pneumonia from prolonged severe neutropenia. Nonmyeloablative allogeneic transplantation was performed because of the active pulmonary infection and the patient's poor performance status. Myelosuppression after transplantation was mild, and the pulmonary infiltration was well controlled during the course of treatment. At the time of this report the patient was an outpatient in our clinic, and on day 500, his disease was in remission with well-controlled chronic graft-versus-host disease. Nonmyeloablative transplantation may provide a new therapeutic strategy for treating patients with active infection who cannot tolerate conventional transplantation with high-dose chemoradiotherapy.