Recombinant human granulocyte-macrophage colony-stimulating factor in acquired or chemotherapy-induced neutropenia. An open clinical trial

Granulocyte-macrophage colony-stimulating factor treatment before doxorubicin and cyclophosphamide chemotherapy priming in women with early-stage breast cancer

PURPOSE

To determine if inhibition of stem-cell activity induced by granulocyte-macrophage colony-stimulating factor ([GM-CSF]; Sargramostim; Immunex Corporation, Seattle, WA) withdrawal or priming protects hematopoietic stem cells from the cytotoxic effects of adjuvant chemotherapy for early-stage breast cancer.

PATIENTS AND METHODS

Serial blood counts were performed in 20 women with early-stage breast cancer receiving four courses of cyclophosphamide and doxorubicin chemotherapy. By a double-blind, placebo-controlled, balanced randomization, subjects received GM-CSF priming on days 5 to 1 for courses 1 and 3 or courses 2 and 4.

RESULTS

Compared with before priming, after priming the times to neutrophil nadir (12.8 +/- 2.5 days v 14.8 +/- 1.5 days, respectively; P =.0001) and platelet nadir (mean +/- SD, 10.1 +/- 1.9 days v 11.1 +/- 2.2 days, P <.05) were shorter, indicating a shift of cytotoxicity to later progenitors. The neutrophil nadir was similar with and without priming (mean +/- SD, 490 +/- 310/microL v 550 +/- 350/microL, respectively; P =.2); however, on day 16 the mean neutrophil count was higher (mean +/- SD, 1030 +/- 580/microL v 690 +/- 370/microL, P =.004), and the proportion of patients with a neutrophil count less than 500/microL was lower after priming than before (six of 35 or 17. 1% v 12 of 34 or 35.3%, respectively; P =.04). The platelet nadir was higher (mean +/- SD, 166,000 +/- 51,000/microL after priming v 151,000 +/- 45,000/microL before priming, P =.007), and the duration of thrombocytopenia, ie, a platelet count less than 150,000/microL, was shorter (1.5 +/- 2.1 days v 2.8 +/- 2.9 days, P =.0025) after priming. Episodes of fever and neutropenia were not observed.

CONCLUSIONS

GM-CSF priming from days 5 to 1 before doxorubicin and cyclophosphamide chemotherapy was associated with an earlier neutrophil and platelet nadir. On day 16, a higher mean neutrophil count and a lower proportion of patients with severe (< 500/microL) neutropenia were observed. Beneficial effects on the severity and duration of thrombocytopenia were also noted. These observations support the hypothesis that GM-CSF priming protects hematopoietic progenitors from the cytotoxic effects of chemotherapy.

Granulocyte-macrophage colony-stimulating factor (GM-CSF)-coated implants and their potential for reducing biomaterial-associated infection in neutropenic hosts

The incidence of infections associated with the use of medical biomaterials is high for skin-penetrating devices, when microbes of the normal skin flora like coagulase-positive and coagulase-negative staphylococci dominate as causative organisms. The most serious ones are infections in immunocompromised individuals. A mouse model of subcutaneous staphylococcal infection yielding abscesses in cyclophosphamide-induced neutropenic mice implanted with heparinized polyethylene (H-PE) was used. The present study addresses the question of the effects of implant modification with recombinant granulocyte-macrophage stimulating factor (rGM-CSF) on the course of infection. Our findings demonstrate that such modification reduces the proliferation of bacteria within the abscess and as a consequence limits the dissemination of bacteria from the local infection induced in the neutropenic host.

Effects of granulocyte-macrophage colony stimulating factor (GM-CSF) on biomaterial-associated staphylococcal infection in mice

Staphylococcal infections are a major complication in the usage of biomaterials. Different modifications of polymers have been made to reduce the incidence of such infections. We studied the effects of modifying heparinized polyethylene (H-PE) with mouse recombinant granulocyte-macrophage stimulating factor (rGM-CSF). The elimination of staphylococci (Staphylococcus aureus, S. epidermidis) from the peritoneum of mice implanted with rGM-CSF-coated H-PE was slightly more effective than the elimination of the bacteria from the peritoneum of animals implanted with uncoated H-PE. Most interestingly, the number of staphylococci present in the biofilms covering rGM-CSF-coated implants were significantly lower than the number of bacteria detected on the surface of H-PE not coated with rGM-CSF. In vitro, rGM-CSF restored the anti-bacterial potency of the phagocytes, which had been reduced by surface contact with H-PE. The results suggest that modification of biomaterials with rGM-CSF could be one way of preventing staphylococcal infections; especially in neutropenic disorders, which constitute the highest risk factor for foreign body-associated infections.