Effects of stem cell factor and granulocyte colony-stimulating factor on granulocyte recovery and Candida albicans infection in granulocytopenic mice.

The combined action of stem cell factor (SCF) and granulocyte colony-stimulating factor (G-CSF) on granulocyte recovery and infection with Candida albicans was studied. In mice rendered granulocytopenic with 200 mg/kg cyclophosphamide, daily coinjection of SCF (100 micrograms/kg) and G-CSF (10 micrograms/kg) for 5 days synergistically stimulated granulocyte recovery compared with either factor alone. Growth of C. albicans in the kidneys of granulocytopenic mice with experimental C. albicans infection was reduced by the combined regimen to 25% of that in vehicle-treated controls (P = .018), whereas either factor administered alone in the same doses had no effect. The combined regimen also significantly protected against lethal infection with C. albicans (P < .01). Either factor administered alone in the same doses had no effect on lethality compared with vehicle-treated controls. The combination of SCF and G-CSF may be useful in the treatment of infections with C. albicans in the granulocytopenic host.