Short-term effect of granulocyte colony-stimulating factor in dogs with severe myxomatous mitral valve disease

BACKGROUND: Use of granulocyte colony-stimulating factor (G-CSF) to treat damaged myocardium is a relatively new concept. Clinical beneficial and safety outcomes are still controversial. OBJECTIVE: The aim of this study was to evaluate recruitment of hematopoietic stem cells and therapeutic efficacy of G-CSF in the treatment of myxomatous mitral valve disease (MMVD) of dogs. ANIMALS AND METHODS: Thirty client-owned MMVD dogs with clinical signs of heart failure were enrolled in a prospective double-blind, randomized, placebo-controlled study to compare the short-term effect of G-CSF (n = 17) with control group (n = 13) for identical periods. Clinical, hematological, and cardiovascular assessments were performed on days 0, 1, 3, and 7. Follow-up examination was conducted four weeks after the study. RESULTS: Dogs treated with G-CSF had a significantly elevated white blood cell (WBC) (×10(3)/μL) count at day 3 compared with baseline (from 10.23 ± 4.42 to 42.84 ± 11.84; P = .000). The WBC population was also changed (elevated neutrophils and decreased lymphocytes) and the numbers of CD34+ cells in the peripheral blood were also increased at day 3. However, the results of clinical, laboratory, and echocardiographic assessments did not differ significantly between the G-CSF treatment and control groups after four weeks. CONCLUSIONS: G-CSF administration elevated the peripheral WBC count, especially neutrophils, and recruited hematopoietic stem cells. However, positive effects of G-CSF on cardiac function were not detected during short-term monitoring.