Treatment of acute monoblastic leukaemia by combination of recombinant human macrophage colony-stimulating factor and low dose of ara-C.

We present a patient with acute monoblastic leukaemia (AMoL) who achieved a complete remission on combination therapy with macrophage colony-stimulating factor (M-CSF) and low dose of cytosine arabinoside (ara-C). This 26-year-old man was admitted with a relapse of AMoL which proved refractory to several chemotherapeutic regimens. To kill dormant leukaemic cells, we administered 20 mg/m2 ara-C by continuous intravenous infusion and 800 x 10(4) unit M-CSF by 30 min drip intravenous infusion together for 14 d. The blasts disappeared, followed by a recovery of normal blood cells. The patient continued the complete remission for 5 months. This observation suggests that a combination M-CSF and a low dose of ara-C may be useful in treating some patients with AMoL.