Recombinant human granulocyte-macrophage colony-stimulating factor reverses neutropenia and reduces secondary infections in visceral leishmaniasis.

Twenty-four patients with acute visceral leishmaniasis and leukopenia (< 1500 neutrophils/mm3) due to Leishmania chagasi were studied, 4 in an open-label pilot study and 20 in a double-blind, placebo-controlled trial. Patients received granulocyte-macrophage colony-stimulating factor (GM-CSF), 5 micrograms/kg daily, or placebo for 10 days, plus 10-20 mg/kg pentavalent antimony daily for 20 days. In GM-CSF recipients, neutrophil counts increased threefold and fourfold over baseline at 5 and 10 days, respectively, and were significantly higher than those in placebo recipients (P < .02). Eosinophil and monocyte counts were significantly increase in GM-CSF recipients at 10 days (P < or = .03). Secondary infections occurred in 3 GM-CSF and in 8 placebo recipients (P = .04). All patients had complete resolution of their leishmaniasis at 3 months. Few adverse events were recorded. GM-CSF, 5 micrograms/kg daily for 10 days, was safe, rapidly reversed neutropenia, and reduced the number of secondary infections in patients with leishmaniasis.