Effects of Recombinant Human Granulocyte-Colony Stimulating Factor on Neutrophil Functions in Diabetic Patients with Foot Infections

Peck, Kyong Ran; Kim, Sungmin; Song, Jae Hoon; Oh, Myoung don; Choe, Kangwon

Abstract

BACKGROUND
Treatment of diabetic foot infection remains difficult, due partly to defective neutrophil functions. Granulocyte-colony stimulating factor (G-CSF) increases neutrophil counts in peripheral blood and enhances neutrophil functions in healthy peoples and patients with hematologic diseases. We performed this study to evaluate neutrophil functions in diabetic patients with foot infections and the effect of rhG-CSF on neutrophil functions in vitro.
METHODS
Twelve patients with diabetic foot infections and 12 normal volunteers were enrolled. Venous blood was collected in heparin-containing tubes, and neutrophils were isolated immediately. The isolated neutrophils were incubated with rhG-CSF (50 ng/mL) for 20 minutes. Assays of superoxide anion production of neutrophils were based on the reduction of ferricytochrome C. Assays of phagocytosis by neutrophils were done using Staphylococcus aureus and the weighted phagocytic index (WPI) was calculated by counting the number of phagocytosing neutrophils on the slides.
RESULTS
Superoxide anion production of neutrophils in diabetic patients was 4.7 (unit: nmol/2105cells/30min), which was significantly lower than that of controls (7.6) (P<0.05). rhG-CSF increased the superoxide anion production of neutrophils to 9.8 in diabetic patients and to 15.6 in the controls (P<0.05). WPI in diabetic patients was 0.77, which was not significantly different from that of the controls (0.69). WPI was increased significantly by rhG-CSF in diabetic patients (0.88) and in controls (0.79).
CONCLUSION
rhG-CSF enhanced neutrophil functions in vitro, which were evaluated by superoxide anion production and phagocytosis in diabetic patients with foot infections. These results suggest that rhG-CSF can be useful in the treatment of diabetic foot infections.