Effect of granulocyte colony stimulating factor on neutropenia induced by cytotoxic chemotherapy

A rare but severe complication of filgrastim in a healthy donor: splenic rupture

BACKGROUND

Granulocyte-colony stimulating factor (G-CSF) is widely administered to donors who provide peripheral blood stem cells (PBSCs) for individuals who undergo hematopoietic stem cell transplants. G-CSF administration is associated with a small but definite risks of serious adverse events like splenic rupture.

CASE STUDY

In this case, we report a 40 year old women, a healthy donor for her sister who has aplastic anemia, who had sharp left upper abdominal pain on the forth mobilization day. The diagnosis at CT scan was splenic rupture; irregular intrasplenic low-attenuation areas consistent with ruptured spleen and perisplenic high density fluid. Her bidimensional spleen size was 16×6 cm.

RESULTS

She was followed conservatively. One month later the CT scan signs of rupture disappeared.

CONCLUSION

We must pay attention to this rare but serious adverse event during filgrastim use.

Efficacy and safety analysis of once per cycle pegfilgrastim and daily lenograstim in patients with breast cancer receiving adjuvant myelosuppressive chemotherapy FEC 100: a pilot study

Background

Neutropenia is a common toxicity in patients receiving myelosuppressive chemotherapy. In this prospective pilot study, we compared the efficacy and safety profiles of pegfilgrastim administered subcutaneously once per cycle and lenograstim administered subcutaneously daily six times per cycle, for primary neutropenia prophylaxis in women with breast cancer receiving adjuvant anthracycline-based chemotherapy.

Materials and methods

Twenty women were enrolled. All patients received epirubicin 100 mg/m² with 5-fluorouracil 500 mg/m² and cyclophosphamide 500 mg/m² on day 1 and every 21 days thereafter, according to the FEC 100 chemotherapy regimen. Eight patients received a single dose of pegfilgrastim on day 2, while 12 patients were treated with daily administration of lenograstim from days five to ten. Absolute neutrophil count and duration of grade 3–4 neutropenia were monitored using seriated blood samples. The incidence of bone pain was evaluated using the visual analog scale (VAS).

Results

The incidence of grade 3–4 neutropenia was 75% in patients who received pegfilgrastim, and 25% in patients who received lenograstim. One case of febrile neutropenia was shown in pegfilgrastim patients. The mean duration of grade 3–4 neutropenia was 2 days in pegfilgrastim group versus 1.4 days in the lenograstim group. Bone pain was present in 37.5% of pegfilgrastim patients versus 58.3% of lenograstim patients. The mean duration of bone pain in the pegfilgrastim group was 4 days versus 6 days in the lenograstim group.

Conclusion

In our experience, a single injection of pegfilgrastim was less effective for controlling neutropenia than six daily injections of lenograstim. The safety profiles of pegfilgrastim and lenograstim were similar with a lower incidence of bone pain in patients treated with pegfilgrastim.

New G-CSF agonists for neutropenia therapy

INTRODUCTION

Granulocyte colony-stimulating factor (G-CSF; filgrastim) and its pegylated form (pegfilgrastim) are widely used to treat neutropenia associated with myelosuppressive chemotherapy and bone marrow transplantation, AIDS-associated or drug-induced neutropenia, and neutropenic diseases. G-CSF facilitates restoration of neutrophil counts, decreases incidence of infection/febrile neutropenia and reduces resource utilization. G-CSF is also widely used to mobilize peripheral blood stem cells for hematopoietic transplant.

AREAS COVERED

We review the therapeutic use, cost effectiveness and disease impact of G-CSF for neutropenia, development of G-CSF biosimilars and current next-generation discovery efforts.

EXPERT OPINION

G-CSF has impacted the treatment and survival of patients with congenital neutropenias. For chemotherapy-associated neutropenia, cost effectiveness and impact on survival are still unclear. G-CSFs are expensive and require systemic administration. Market entry of new biosimilars, some with enhanced half-life profiles, will probably reduce cost and increase cost effectiveness. There is no evidence that marketed or late development biosimilars display effectiveness superior to current G-CSFs. Second-generation compounds that mimic the activity of G-CSF at its receptor, induce endogenous ligand(s) or offer adjunct activity have been reported and represent attractive G-CSF alternatives, but are in preclinical stages. A significant therapeutic advance will require reduced depth and duration of neutropenia compared to current G-CSFs.

A (selective) history of Australian involvement in cytokine biology

This review focuses on contributions to cytokine biology made by Australians in Australia. It is clearly biased by my own experiences and selective recollections especially related to the colony-stimulating factors in which Australian involvement has been pre-eminent from discovery to clinical use. Nevertheless Australian scientists have also made profound contributions to other areas of cytokine and growth factor biology (including interferons, inflammatory cytokines, chemokines and epidermal, insulin-like and vascular endothelial growth factors) that are briefly described in this review as well as other chapters in this volume.

Establishing a murine model of the hematopoietic syndrome of the acute radiation syndrome

The authors have developed a murine model of the Hematopoietic Syndrome of the Acute Radiation Syndrome (H-ARS) for efficacy testing of medical countermeasures (MCM) against radiation according to the FDA Animal Rule. Ten- to 12-wk-old male and female C57BL/6 mice were exposed to the LD50/30-LD70/30 dose of total body irradiation (TBI, (137)Cs, 0.62-0.67 Gy min(-1)) in the morning hours when mice were determined to be most radiosensitive, and they were assessed for 30-d survival and mean survival time (MST). Antibiotics were delivered in drinking water on days 4-30 post-TBI at a concentration based on the amount of water that lethally-irradiated mice were found to consume. The fluoroquinolones, ciprofloxacin and levofloxacin, as well as the tetracycline doxycycline, and aminoglycoside neomycin, all significantly increased MST of decedent mice, while ciprofloxacin (p = 0.061) and doxycycline + neomycin (p = 0.005) showed at least some efficacy to increase 30-d survival. Blood sampling (30 μL/mouse every fifth day) was found to negatively impact 30-d survival. Histopathology of tissues harvested from nonmoribund mice showed expected effects of lethal irradiation, while moribund mice were largely septicemic with a preponderance of enteric organisms. Kinetics of loss and recovery of peripheral blood cells in untreated mice and those treated with two MCM, granulocyte-colony stimulating factor and Amifostine further characterized and validated this model for use in screening studies and pivotal efficacy studies of candidate MCM for licensure to treat irradiated individuals suffering from H-ARS.

Pegfilgrastim administered in an abbreviated schedule, significantly improved neutrophil recovery after high-dose radiation-induced myelosuppression in rhesus macaques

Conventional daily administration of filgrastim is effective in reducing the duration of severe neutropenia and enhancing survival following lethal radiation, myelosuppressive cytotoxic therapy or myeloablation and stem cell transplantation. A sustained-duration form of filgrastim, pegfilgrastim has significantly simplified scheduling protocols after chemotherapy-induced neutropenia to a single injection while maintaining the therapeutic effectiveness of daily administration of filgrastim. We examined the ability of a single or double (weekly) administration of pegfilgrastim to significantly improve neutrophil recovery in a rhesus macaque model of severe radiation-induced myelosuppression. Animals were exposed to potentially lethal 6 Gy total-body X radiation. After irradiation all animals received supportive care and were administered either pegfilgrastim at 300 μg/kg on day 1 or day 1 and day 7 post exposure, or filgrastim at 10 μg/kg/day initiated on day 1 post exposure and continued daily through neutrophil recovery. Pharmacokinetic parameters and neutrophil-related values for duration of neutropenia, neutrophil nadir, time to recovery to an absolute neutrophil count ≥500/μL or ≥2000/μL, and days of antibiotic support were determined. Effective plasma concentrations of pegfilgrastim were maintained in neutropenic animals until after the onset of hematopoietic recovery, which is consistent with neutrophil-dependent properties of elimination. Administration of pegfilgrastim at day 1 and day 7 was most effective at improving neutrophil recovery compared to daily administration of filgrastim or a single injection of pegfilgrastim on day 1, after severe, radiation-induced myelosuppression in rhesus macaques.

Different schedules of granulocyte growth factor support for patients with breast cancer receiving adjuvant dose-dense chemotherapy: a prospective nonrandomized study

PURPOSE

This prospective, nonrandomized study evaluates 4 schedules of granulocyte colony-stimulating factor (G-CSF) for patients with breast cancer receiving adjuvant dose-dense chemotherapy regarding febrile neutropenia, treatment delays, and costs.

PATIENTS AND METHODS

Two hundred and thirty-one patients were enrolled to receive adjuvant dose-dense chemotherapy with 4 G-CSF schedules: filgrastim (300 mcg) days 3 to 10 [n = 84 (36.4%) group A]; days 3 to 7 [n = 26 (11.3%) group B]; days 5, 7, 9, and 11 [n = 64 (27.7%) group C], or pegfilgrastim (6 mg) on day 2 [n=57 (24.6%) group D].

RESULTS

Thirteen patients were hospitalized due to 14 episodes of febrile neutropenia; 3 in group A, 3 in group B, 1 in group C, and 6 in group D. No statistically significant difference was observed among the 4 groups. Fewer febrile neutropenic events were observed in group C than in group D (P=0.041). No statistically significant differences were observed in treatment delays or other hematological toxicities. Average overall G-CSF cost per patient in groups A and D was $8500 versus $4400 in groups B and C.

CONCLUSIONS

We found a trend in favor of the shorter G-CSF schedule. A larger, prospective randomized trial should be carried out to evaluate shorter versus standard filgrastim and pegfilgrastim schedules with regard to clinical outcomes, hematological and nonhematological toxicities, and impact in costs.

Leukocyte integrin activation mediates transient neutropenia after G-CSF administration

After administration of granulocyte colony-stimulating factor (G-CSF), there is a marked, albeit transient, drop in circulating neutrophils. To determine the role of leukocyte integrins in this disappearance, a dog having canine leukocyte adhesion deficiency (CLAD) or CLAD dogs who had undergone gene correction either by matched littermate allogeneic transplant or autologous gene therapy were evaluated. Shortly after G-CSF administration, a dramatic, yet transient, neutropenia was observed in the control littermates. This neutropenia was not as marked in the CLAD dogs. In all instances, it was CD18(+) neutrophils that preferentially egressed from the circulation. The association of CD18 with this rapid loss suggested leukocyte integrin activation after G-CSF administration. To determine the activation status of the integrin, a monoclonal antibody recognizing the activated α-subunit cation binding domain (mAb24) was used to evaluate human leukocytes after G-CSF administration. Mirroring the dramatic decrease in circulating neutrophil numbers, there was a dramatic and specific increase in the activation of the α-subunit after G-CSF expression on polymorphonuclear leukocytes. This activation, like the drop in neutrophil count, was transient. These results demonstrate that the leukocyte integrin on circulating neutrophils is transiently activated after G-CSF administration and mediates the transient neutropenia observed after G-CSF administration.

Nuclear phospholipid scramblase 1 prolongs the mitotic expansion of granulocyte precursors during G-CSF-induced granulopoiesis

PLSCR1-/- mice exhibit normal, steady-state hematologic parameters but impaired emergency granulopoiesis upon in vivo administration of G-CSF. The mechanism by which PLSCR1 contributes to G-CSF-induced neutrophil production is largely unknown. We now report that the expansion of bone marrow myelocytes upon in vivo G-CSF treatment is reduced in PLSCR1-/- mice relative to WT. Using SCF-ER-Hoxb8-immortalized myeloid progenitors to examine the progression of G-CSF-driven granulocytic differentiation in vitro, we found that PLSCR1 prolongs the period of mitotic expansion of proliferative granulocyte precursors, thereby giving rise to increased neutrophil production from their progenitors. This effect of PLSCR1 is blocked by a ΔNLS-PLSCR1, which prevents its nuclear import. By contrast, mutation that prevents the membrane association of PLSCR1 has minimal impact on the role of PLSCR1 in G-CSF-induced granulopoiesis. These data imply that the capacity of PLSCR1 to augment G-CSF-dependent production of mature neutrophils from myeloid progenitors is unrelated to its reported activities at the endofacial surface of the plasma membrane but does require entry of the protein into the nucleus, suggesting that this response is mediated through the observed effects of PLSCR1 on gene transcription.

Relationship between the cAMP levels in leukocytes and the cytokine balance in patients surviving gram negative bacterial pneumonia

Lipopolysaccharide-stimulated leukocytes secrete proinflammatory cytokines including tumor necrosis factor-α and interleukin-12. Over-activation of host defense systems may result in severe tissue damage and requires regulation. Granulocyte colony-stimulating factor and interleukin-10 are candidate cytokines for inducing tolerance to lipopolysaccharide re-stimulation. We compared cytokines secreted by lipopolysaccharide-stimulated blood cells from patients who had survived gram negative bacterial pneumonia (Pseudomonas aeruginosa, Escherichia coli or Proteus mirabilis, n = 26) and age-matched healthy volunteers (n = 18). Interleukin-12p70 and tumor necrosis factor-α expression was significantly lower in patients (p = 0.0039 and p<0.001) compared to healthy controls, while granulocyte colony-stimulating factor production was markedly higher in patients (p<0.001). Levels of interleukin-10 were comparable. Granulocyte colony-stimulating factor expression was inversely correlated with interleukin-12p70 (R = -0.71, p<0.001) and tumor necrosis factor-α (R = -0.64, p<0.001) expression; interleukin-10 showed no significant correlation. In unstimulated leukocytes from patients, cAMP levels were significantly raised (p = 0.020) and were correlated inversely with interleukin-12p70 levels (R = -0.81, p<0.001) and directly with granulocyte colony-stimulating factor (R = 0.72, p = 0.0020), matrix metalloproteinase-9 (R = 0.67, p = 0.0067) and interleukin-10 (R = 0.54, p = 0.039) levels. Our results demonstrate that granulocyte colony-stimulating factor production by lipopolysaccharide-stimulated leukocytes is a useful indicator of tolerance induction in surviving pneumonia patients and that measuring cAMP in freshly isolated leukocytes may also be clinically significant.

In vivo induction of myeloid suppressor cells and CD4(+)Foxp3(+) T regulatory cells prolongs skin allograft survival in mice

Natural CD4(+)Foxp3(+) T regulatory (Treg) cells can promote transplantation acceptance across major histocompatibility complex (MHC) barriers, while myeloid-derived suppressor cells (MDSCs) inhibit effector T-cell responses in tumor-bearing mice. One outstanding issue is whether combining the potent suppressive function of MDSCs with that of Treg cells might synergistically favor graft tolerance. In the present study, we evaluated the therapeutic potential of MDSCs and natural Treg cells in promoting allograft tolerance in mice by utilizing immunomodulatory agents to expand these cells in vivo. Upon administration of recombinant human granulocyte-colony stimulating factor (G-CSF; Neupogen), or interleukin-2 complex (IL-2C), Gr-1(+)CD11b(+) MDSCs or CD4(+)Foxp3(+) Treg cells were respectively induced at a high frequency in the peripheral lymphoid compartments of treated mice. Interestingly, induced MDSCs exhibited a more potent suppressive function in vitro when compared to MDSCs from naive mice. Furthermore, in vivo coadministration of Neupogen and IL-2C induced MDSCs at percentages that were higher than those seen when either agent was administered alone, suggesting an additive effect of the two drugs. Although treatment with either IL-2C or Neupogen led to a significant delay of MHC class II disparate allogeneic donor skin rejection, the combinatorial treatment was superior to either alone. Importantly, histological assessment of surviving grafts revealed intact morphology and minimal infiltrates at 60 days posttransplant. Collectively, our findings demonstrate that concurrent induction of MDSCs and Tregs is efficacious in downmodulating alloreactive T-cell responses in a synergistic manner and highlight the therapeutic potential of these naturally occurring suppressive leukocytes to promote transplantation tolerance.

Ligand-independent toll-like receptor signals generated by ectopic overexpression of MyD88 generate local and systemic antitumor immunity

Although critical for initiating and regulating immune responses, the therapeutic use of individual cytokines as anticancer immunotherapeutic agents has achieved only modest clinical success. Consequently, many current strategies have focused on the use of specific immunotherapeutic agonists that engage individual receptors of innate immune networks, such as the Toll-like receptor (TLR) system, each resulting in specific patterns of gene expression, cytokine production, and inflammatory outcome. However, these immunotherapeutics are constrained by variable cellular TLR expression and responsiveness to particular TLR agonists, as well as the specific cellular context of different tumors. We hypothesized that overexpression of MyD88, a pivotal regulator of multiple TLR signaling pathways, could circumvent these constraints and mimic coordinated TLR signaling across all cell types in a ligand-independent fashion. To explore this hypothesis, we generated an adenoviral vector expressing MyD88 and show that Ad-MyD88 infection elicits extensive Th1-specific transcriptional and secreted cytokine signatures in all murine and human cell types tested in vitro and in vivo. Importantly, in vivo intratumoral injection of Ad-MyD88 into established tumor masses enhanced adaptive immune responses and inhibited local tumor immunosuppression, resulting in significantly inhibited local and systemic growth of multiple tumor types. Finally, Ad-MyD88 infection of primary human dendritic cells, tumor-associated fibroblasts, and colorectal carcinoma cells elicited significant Th1-type cytokine responses, resulting in enhanced tumor cell lysis and expansion of human tumor antigen-specific T cells. Thus, Ad-MyD88 initiated robust antitumor activity in established murine tumor microenvironments and in human contexts, suggesting its potential effectiveness as a clinical immunotherapeutic strategy.

Neurotrophic growth factors for the treatment of amyotrophic lateral sclerosis: where do we stand?

Amyotrophic lateral sclerosis (ALS) is a devastating neurodegenerative disease that results in progressive loss of motoneurons, motor weakness and death within 3–5 years after disease onset. Therapeutic options remain limited despite substantial number of approaches that have been tested clinically. Many neurotrophic growth factors are known to promote the survival of neurons and foster regeneration in the central nervous system. Various neurotrophic factors have been investigated pre-clinically and clinically for the treatment of ALS. Although pre-clinical data appeared promising, no neurotrophic factors succeeded yet in a clinical phase III trial. In this review we discuss the rationale behind those factors, possible reasons for clinical failures, and argue for a renewal of hope in this powerful class of drugs for the treatment of ALS.

The colony-stimulating factors and cancer

The four colony-stimulating factors (CSFs) are glycoproteins that regulate the generation and some functions of infection-protective granulocytes and macrophages. Recombinant granulocyte-CSF (G-CSF) and granulocyte-macrophage-CSF (GM-CSF) have now been used to increase dangerously low white blood cell levels in many millions of cancer patients following chemotherapy. These CSFs also release haematopoietic stem cells to the peripheral blood, and these cells have now largely replaced bone marrow as more effective populations for transplantation to cancer patients who have treatment-induced bone marrow damage.

Cataract associated with high-dose hematopoietic colony stimulating factor, case report and literature review

Granulocyte-colony stimulating factor (G-CSF) is a lineage-restricted hematopoietic growth factor. It induces proliferation and maturation of neutrophilic precursors and progenitors and activates neutrophil functions. It is used to ameliorate or prevent profound neutropenia and its consequences. G-CSF therapy in neutropenic disorders increases neutrophil count and improves infectious complications. However, it is not without side effects. Here, we discuss the case of a 2 years old patient with Kostmann's disease who developed cataracts following high-dose G-CSF therapy. We also review the relevant literature on G-CSF-related complications.

Pegfilgrastim for prevention of chemotherapy-associated neutropenia in pediatric patients with solid tumors

BACKGROUND

Pegfilgrastim has similar efficacy to filgrastim in adults, but studies in pediatrics are limited. We report our institutional experience with pegfilgrastim following dose intensive chemotherapy for solid tumors.

PROCEDURE

We evaluated the initial four courses of myelosuppressive chemotherapy for 47 patients (total 176 courses) diagnosed between 1/1/07 and 2/6/08 who received chemotherapy with pegfilgrastim support (100 mcg/kg; 6 mg maximum dose) in this retrospective review. We collected demographic data, treatment characteristics, frequency of severe neutropenia (absolute neutrophil count (ANC) <200/mm(3)), duration of neutropenia, and frequency of neutropenic fever.

RESULTS

The median age of treated patients was 13 years (range 0.17-23 years) and the median weight was 50.8 kg (range 4-107 kg), including 16 (34%) <20 kg, and 22 (47%) <45 kg. Primary diagnoses included osteosarcoma, Ewing sarcoma, rhabdomyosarcoma, soft tissue sarcoma, neuroblastoma, Hodgkin disease, and other solid tumors. No significant adverse events secondary to pegfilgrastim were noted. Severe neutropenia occurred in 57% of courses. The median duration of severe neutropenia was 1 day (range 0-11 days). Febrile neutropenia occurred in 28% of courses. Eight patients were treated with interval-compressed (every 14 days) sarcoma chemotherapy. Of the 30-interval compressed courses, the median duration per course was 14 days (range 14-18 days).

CONCLUSIONS

Pegfilgrastim following dose intensive chemotherapy for solid tumors is feasible in children, including those <45 kg. The frequency and duration of severe neutropenia, as well as incidence of febrile neutropenia, were similar to filgrastim historic data.

Haematological Effects of RhGM-CSF in Dogs Exposed to Total-body Irradiation with a Dose of 2·4 Gy

It was the specific aim of this study to test the stimulatory effects of recombinant human GM-CSF (rhGM-CSF) on haemopoietic regeneration in dogs which had received total-body irradiation (TBI) with a dose of 2.4 Gy. In normal dogs rhGM-CSF given subcutaneously at 10 microgram/kg per day or 30 microgram/kg per day for 21 days caused strong but transient increases in the peripheral blood neutrophils. The monocyte counts also showed a transient rise during treatment in a dose-dependent fashion, whereas the lymphocyte counts increased only at the higher dose of rhGM-CSF and the platelet counts were transiently depressed during the course of the treatment. In the irradiated animals treatment with rhGM-CSF decreased the severity and shortened the duration of neutropenia but had no significant influence on monocyte or lymphocyte recovery. The granulocyte values showed a characteristic pattern of fluctuations with the first peak occurring at the same time (day 10 to day 13) when the abortive rise was observed in the untreated dogs. In contrast the GM-CFC in the peripheral blood remained depressed during the whole treatment course, similar to the untreated irradiated controls. These results indicate that treatment with GM-CSF can be an effective biological monotherapy for radiation-induced bone marrow failure, but that for higher radiation doses the number of GM-CSF responsive target cells will become a critical determinant of therapeutic efficacy.

G- and GM-CSF in oncology and oncological haematology

Administration of G- and GM-CSF increases the neutrophil counts in a number of clinical situations. GM-CSF shows the additional effect of increasing the number of monocytes and eosinophil granulocytes. Both G- and GM-CSF affect of neutrophil functions, in the case of GM-CSF there are some potentially negative effects on neutrophil migration and adhesiveness. The clinical relevance of the various effects on mature haematopoietic cells is not fully understood. Clinical data with G-CSF treatment indicate that increased levels of neutrophil granulocytes following cytotoxic chemotherapy may translate into clinical benefit such as a decreased rate of neutropenic infection and an increased cytotoxic chemotherapy dose even though the data are conflicting and the risk of "laboratory cosmetics" is apparent. Regarding treatment with GM-CSF following chemotherapy, the clinical benefit is unclear. The clinical benefit of GM-CSF-induced monocytes and eosinophils is unknown. G- and GM-CSF accelerates neutrophil recovery following autologous or allogeneic BMT. The influence on neutropenic infections is, however, less impressive. Pretreatment with G- or GM-CSF increases the yield of peripheral stem cell harvest, thereby reducing the number of leukaphereses needed. Transplantation of G- and GM-CSF primed autologous peripheral stem cells tends to reduce the period of post-transplant cytopenia, particularly thrombocytopenia, in comparison with traditional ABMT. In patients with MDS, G- and GM-CSF appear to increase the number of neutrophil granulocytes and there is some evidence that patients with severe infectious problems will benefit from this treatment. However, little influence was seen on the main clinical problems with these patients, which are anaemia and thrombocytopenia. In conclusion, G- and GM-CSF are two different proteins with different properties in vivo and in vitro. GM-CSF has, compared with G-CSF, more complex pharmacological effects and a more trouble-some side-effect profile. Early clinical development indicates that both compounds have a substantial influence on the levels of certain blood cells. Whether the increases in different blood cells translate into long-term clinical benefit for greater patient groups is the focus of ongoing research. The effects of G- and GM-CSF may be potentiated by other cytokines, an area which is presently being explored.

Prophylactic antibiotics or G-CSF for the prevention of infections and improvement of survival in cancer patients undergoing chemotherapy

BACKGROUND

Febrile neutropenia (FN) and other infectious complications are some of the most serious treatment-related toxicities of chemotherapy for cancer, with a mortality rate of 2% to 21%. The two main types of prophylactic regimens are granulocyte (G-CSF) or granulocyte-macrophage colony stimulating factors (GM-CSF); and antibiotics, frequently quinolones or cotrimoxazole. Important current guidelines recommend the use of colony stimulating factors when the risk of febrile neutropenia is above 20% but they do not mention the use of antibiotics. However, both regimens have been shown to reduce the incidence of infections. Since no systematic review has compared the two regimens, a systematic review was undertaken.

OBJECTIVES

To compare the effectiveness of G-CSF or GM-CSF with antibiotics in cancer patients receiving myeloablative chemotherapy with respect to preventing fever, febrile neutropenia, infection, infection-related mortality, early mortality and improving quality of life.

SEARCH STRATEGY

We searched The Cochrane Library, MEDLINE, EMBASE, databases of ongoing trials, and conference proceedings of the American Society of Clinical Oncology and the American Society of Hematology (1980 to 2007). We planned to include both full-text and abstract publications.

SELECTION CRITERIA

Randomised controlled trials comparing prophylaxis with G-CSF or GM-CSF versus antibiotics in cancer patients of all ages receiving chemotherapy or bone marrow or stem cell transplantation were included for review. Both study arms had to receive identical chemotherapy regimes and other supportive care.

DATA COLLECTION AND ANALYSIS

Trial eligibility and quality assessment, data extraction and analysis were done in duplicate. Authors were contacted to obtain missing data.

MAIN RESULTS

We included two eligible randomised controlled trials with 195 patients. Due to differences in the outcomes reported, the trials could not be pooled for meta-analysis. Both trials showed non-significant results favouring antibiotics for the prevention of fever or hospitalisation for febrile neutropenia.

AUTHORS' CONCLUSIONS

There is no evidence for or against antibiotics compared to G(M)-CSFs for the prevention of infections in cancer patients.

Granulocyte colony-stimulating factor (G-CSF) administration in individuals with sickle cell disease: time for a moratorium?

Granulocyte colony-stimulating factor (G-CSF) is used commonly in an attempt to reduce the duration of neutropenia and hospitalization in patients undergoing chemotherapy and to obtain hematopoietic stem cells (HSC) for transplantation applications. Despite the relative safety of administration of G-CSF in most individuals, including subjects with sickle cell trait, severe and life-threatening complications have been reported when used in individuals with sickle cell disease (SCD), including those who were asymptomatic and undiagnosed prior to administration. The administration of G-CSF has now been reported in a total of 11 individuals with SCD. Seven developed severe adverse events, including vaso-occlusive episodes, acute chest syndrome, multi-organ system failure and death. Precautions, including minimizing the peak white blood cell count, dividing or reducing the G-CSF dose and red blood cell transfusions to reduce sickle hemoglobin (HbS) levels, have been employed with no consistent benefit. These reported data indicate that administration of G-CSF in individuals with SCD should be undertaken only in the absence of alternatives and after full disclosure of the risks involved. Unless further data demonstrate safety, routine usage of G-CSF in individuals with SCD should be avoided.

Granulocyte colony-stimulating factor administration: adverse events

Recombinant human granulocyte colony-stimulating factor (G-CSF) has been in clinical use for approximately 2 decades. In healthy donors, it has been used to mobilize peripheral blood progenitor cells for hematopoietic stem cell transplantation and granulocytes for apheresis collection. In patients, it has been used to decrease the duration of neutropenia after chemotherapy and to offset the neutropenia due to myelodysplasia, acquired immunodeficiency syndrome, and genetic disorders of granulocyte production. As the number of uses of G-CSF in clinical practice grows, more side effects of this generally safe pharmaceutical agent are being recognized. Our objective in this article is to provide an in-depth review of the reported adverse events associated with the use of G-CSF.

Granulopoiesis-stimulating factors to prevent adverse effects in the treatment of malignant lymphoma

BACKGROUND

Granulopoiesis-stimulating factors, such as granulocyte-colony-stimulating factor (G-CSF) and granulocyte-macrophage-colony-stimulating factor (GM-CSF), are being used to prevent febrile neutropenia and infection in patients undergoing treatment for malignant lymphoma. The question of whether G-CSF and GM-CSF improve dose intensity, tumour response, and overall survival in this patient population has not been answered yet. Since the results from single studies are inconclusive, a systematic review was undertaken.

OBJECTIVES

To determine the effectiveness of G-CSF and GM-CSF in patients with malignant lymphoma with respect to preventing neutropenia, febrile neutropenia and infection; improving quality of life, adherence to treatment protocol, tumour response, freedom from treatment failure (FFTF) and overall survival (OS); and adverse effects.

SEARCH STRATEGY

We searched The Cochrane Library, MEDLINE, EMBASE, CancerLit, and other relevant literature databases; Internet databases of ongoing trials; and conference proceedings of the American Society of Clinical Oncology and the American Society of Hematology (1980 - 2007). We included full-text and abstract publications as well as unpublished data.

SELECTION CRITERIA

Randomised controlled trials comparing prophylaxis with G-CSF or GM-CSF versus placebo/no prophylaxis in adult patients with malignant lymphoma undergoing chemotherapy were included for review. Both study arms had to receive identical chemotherapy and supportive care.

DATA COLLECTION AND ANALYSIS

Trial eligibility and quality assessment, data extraction and analysis were done by two reviewers independently. Authors were contacted to obtain missing data.

MAIN RESULTS

We included 13 eligible randomised controlled trials with 2607 randomised patients. Compared with no prophylaxis, both G-CSF and GM-CSF did not improve overall survival (hazard ratio 0.97; 95% CI 0.87 to 1.09) or FFTF (hazard ratio 1.11; 95% CI 0.91 to 1.35). Prophylaxis significantly reduced the relative risk (RR) for severe neutropenia (RR 0.67; 95% confidence interval (CI) 0.60 to 0.73), febrile neutropenia (RR 0.74; 95% CI 0.62 to 0.89) and infection (RR 0.74; 95% CI 0.64 to 0.85). There was no evidence that either G-CSF or GM-CSF reduced the number of patients requiring intravenous antibiotics (RR 0.82; 95%CI 0.57 to 1.18); lowered infection related mortality (RR 0.93; 95% CI 0.51 to 1.71); or improved complete tumour response (RR 1.03; 95% CI 0.95 to 1.10).One study evaluated quality of life parameters and found no differences between the treatment groups.

AUTHORS' CONCLUSIONS

G-CSF and GM-CSF, when used as a prophylaxis in patients with malignant lymphoma undergoing conventional chemotherapy, reduce the risk of neutropenia, febrile neutropenia and infection. However, based on the randomised trials currently available, there is no evidence that either G-CSF or GM-CSF provide a significant advantage in terms of complete tumour response, FFTF or OS.

Enhancement of tendon-bone osteointegration of anterior cruciate ligament graft using granulocyte colony-stimulating factor

BACKGROUND

Whereas anterior cruciate ligament rupture usually requires reconstruction, the attachment between the tendon and the bone is the weakest region in the early posttransplantation period. In this process, the acquisition of appropriate vascularity is a key for early bone-tendon healing.

HYPOTHESIS

Granulocyte colony-stimulating factor has an effect on the maturation of bone-tendon integration of anterior cruciate ligament reconstruction.

STUDY DESIGN

Controlled laboratory study.

METHODS

Twenty-eight healthy adult beagle dogs underwent bilateral anterior cruciate ligament reconstruction using the ipsilateral flexor digitorum superficialis tendon and were divided into 2 groups. A granulocyte colony-stimulating factor-incorporated gelatin surrounded the graft in the granulocyte colony-stimulating factor group, and the same gelatin without granulocyte colony-stimulating factor was used as the control group. Assessment was done at 2 and 4 weeks.

RESULTS

Histological analysis at week 2 demonstrated that, in addition to more Sharpey fibers, microvessels were significantly enhanced in the granulocyte colony-stimulating factor group's grafts. Computed tomography at week 4 showed a significantly smaller tibial bone tunnel in the granulocyte colony-stimulating factor group. Real-time polymerase chain reaction revealed significantly elevated messenger ribonucleic acid expression levels of vascular endothelial growth factor and osteocalcin in the tibial bone tunnel and graft compared with controls. Furthermore, biomechanical testing of force during loading to ultimate failure at week 4 demonstrated a significant increase in strength in the granulocyte colony-stimulating factor group.

CONCLUSION

This study demonstrated that a local application of granulocyte colony-stimulating factor-incorporated gelatin significantly accelerates bone-tendon interface strength via enhanced angiogenesis and osteogenesis.

CLINICAL RELEVANCE

Granulocyte colony-stimulating factor has therapeutic potential in promoting an environment conductive to angiogenesis and osteogenesis in bone tunnels.

Pilot study: effects of G-CSF on neutrophil ex-vivo function post bone marrow transplantation

The effects of human recombinant granulocyte colony stimulating factor (G-CSF) on neutrophil recovery have been studied in patients undergoing bone marrow transplantation for haematological disease. Nine patients (five autografts and four allografts) were studied while receiving daily doses of G-CSF (range 2-20 micrograms/kg body weight) were compared to eight patients (four autografts and four allografts) who did not receive G-CSF as a control group. In both groups flow cytometry was used to determine neutrophil IgG Fc receptor (FcRII, FcRIII) expression. Phagocytosis and metabolic burst was assessed using IgG opsonized bacteria. The patients' neutrophils were studied prior to conditioning in autografts and donor cells were studied in allografts. Studies were repeated at neutrophil recovery (neutrophil count 1.0 x 10(9)/l) and ten days post recovery. At recovery FcRII expression was slightly increased in all groups, whereas the number of cells expressing FcRIII was reduced. This reduction was significant in the patients receiving rG-CSF at recovery and post recovery compared to the pretreatment levels. The ability to phagocytose bacteria in cells from patients receiving G-CSF was also reduced. The associated metabolic burst was significantly reduced in the autograft group but not the allograft group receiving rG-CSF. The reduced function and reduced expression of FCRIII suggests the presence of immature neutrophils in patients receiving rG-CSF post BMT.

Granulocyte colony-stimulating factor: molecular mechanisms of action during steady state and 'emergency' hematopoiesis

Neutrophils are phagocytes whose principal function is to maintain anti-bacterial immunity. Neutrophils ingest and kill invading bacteria, releasing cytotoxic, chemotactic and inflammatory mediators at sites of infection. This serves to control the immediate host immune response and attract other cells, such as macrophages and dendritic cells, which are important for establishing long-term adaptive immunity. Neutrophils thus contribute to both the initiation and the maintenance of inflammation at sites of infection. Aberrant neutrophil activity is deleterious; suppressed responses can cause extreme susceptibility to infection while overactivation can lead to excessive inflammation and tissue damage. This review will focus on neutrophil regulation by granulocyte colony-stimulating factor (G-CSF), the principal cytokine controlling neutrophil development and function. The review will emphasize the molecular aspects of G-CSF-driven granulopoiesis in steady state (healthy) conditions and during demand-driven or 'emergency' conditions elicited by infection or clinical administration of G-CSF. Understanding the molecular control of granulopoiesis will aid in the development of new approaches designed to treat disorders of neutrophil production and function.

Optimization of the AT-content of codons immediately downstream of the initiation codon and evaluation of culture conditions for high-level expression of recombinant human G-CSF in Escherichia coli

Enhanced therapeutic importance of recombinant human granulocyte colony stimulating factor (rhG-CSF) has encouraged us to develop a processing method for its high-level expression in E. coli. In this study, we established a high-yielding clone by incorporation of silent mutations at N-terminal region of human G-CSF gene. We studied and optimized various parameters of culture conditions connected with the expression of rhG-CSF. The maximum expression was obtained in a defined medium supplemented with 1% glucose. The gene in pET-3a vector in E. coli BL21 (DE3) PLysS host strain was induced with 2 mM isopropyl beta-D: -1-thiogalacto pyronoside. The cell growth and productivity was enhanced about 1.6- and 1.5-folds, respectively when inducing the culture at OD(600) value of 6 than 2. The protein expression was significantly increased by addition of rifampicin at concentration of 200 microg/ml. The AT content of 51.8% with suitable codon sequences at N-terminal region and the concentration of rifampicin were identified as the key factors with a significant impact on protein expression. The specific productivity of 104 mg/OD/l (68.7% of total cellular protein) of rhG-CSF was obtained toward the end of the study, which is almost 1.5 times higher yield than reported so far in the literature.

Pegfilgrastim: current and future perspectives in the treatment of chemotherapy-induced neutropenia

Myeloid colony-stimulating factors (granulocyte colony-stimulating factor [G-CSF] and granulocyte-macrophage colony-stimulating factor) are commonly used in clinical practice for the prevention of anticancer chemotherapy-induced neutropenia and its potentially life-threatening complications. Pegfilgrastim is a novel recombinant human G-CSF pharmaceutically developed by covalent binding of a polyethylene glycol molecule to the N-terminal sequence of filgrastim. Due to its unique neutrophil-mediated clearance, pegfilgrastim can be administered once per chemotherapy cycle. Clinical trials have demonstrated that a single, fixed, subcutaneous dose of pegfilgrastim is comparable in safety and efficacy to daily injections of filgrastim for decreasing the incidence of infection following myelosuppressive chemotherapy in patients with cancer. Recent trials have been conducted to evaluate the use of pegfilgrastim in different clinical settings, including support of dose-dense regimens, mobilization and transplantation of hematopoietic stem cells.