Effect of biological response modifiers against pulmonary candidiasis in neutropenic mice

We investigated the prophylactic and therapeutic effects of biological response modifiers (rHG-CSF, M-CSF, rhIL-2) on pulmonary candidiasis in neutropenic mice. Cyclophosphamide treated mice were injected by the intratracheal route with 5 x 10(6) Candida yeast cells. Prophylactic treatment with rhG-CSF afforded significant protection against pulmonary candidiasis in neutropenic mice. Treatment with rhG-CSF also increased the number of peripheral blood neutrophils. The histopathological investigations in our experiments showed that the assembly of PMNs to the infected lung at 24 hrs after bacterial challenge was more remarkable in the rhG-CSF treated mice than that in the vehicle alone. Number of viable candida cells in the infected lung in the rhG-CSF treated mice were significantly decreased. The combination of rhG-CSF and fluconazole was more effective than those of each monotherapy. Prophylactic treatment with M-CSF or rhIL-2 had no influence on pulmonary candidiasis. These results show the possibility that rhG-CSF could be of help for treating human deep candidiasis not successfully treated with antimicrobial agents alone.