Biological effects of pegfilgrastim on circulating neutrophils in breast cancer patients undergoing dose-dense chemotherapy

Cytomodulatory characteristics of Granulocyte-Macrophage Colony-Stimulating Factor (GM-CSF) against cypermethrin on skin fibroblast cells (HFF-1)

The hematopoietic factor granulocyte macrophage-colony stimulating factor (GM-CSF) has been identified via its capacity to promote bone marrow progenitors' development and differentiation into granulocytes and macrophages. Extensive pre-clinical research has established its promise as a critical therapeutic target in an assortment of inflammatory and autoimmune disorders. Despite the broad literature on GM-CSF as hematopoietic of stem cells, the cyto/geno protective aspects remain unknown. This study aimed to assess the cyto/geno protective possessions of GM-CSF on cypermethrin-induced cellular toxicity on HFF-1 cells as an in vitro model. In pre-treatment culture, cells were exposed to various GM-CSF concentrations (5, 10, 20, and 40 ng/mL) with cypermethrin at IC50 (5.13 ng/mL). Cytotoxicity, apoptotic rates, and genotoxicity were measured using the MTT, Annexin V-FITC/PI staining via flow-cytometry, and the comet assay. Cypermethrin at 5.13 ng/mL revealed cytotoxicity, apoptosis, oxidative stress, and genotoxicity while highlighting GM-CSF's protective properties on HFF-1. GM-CSF markedly attenuated cypermethrin-induced apoptotic cell death (early and late apoptotic rates). GM-CSF considerably regulated oxidative stress and genotoxicity by reducing the ROS and LPO levels, maintaining the status of GSH and activity of SOD, and suppressing genotoxicity in the comet assay parameters. Therefore, GM-CSF could be promising as an antioxidant, anti-apoptotic, genoprotective and cytomodulating agent.

Comparison of the effects of pegylated granulocyte-colony stimulating factor and granulocyte-colony stimulating factor on cytopenia induced by dose-dense chemotherapy in breast cancer patients

Background:

Myelosuppression is one of the frequent side effects of chemotherapy in breast cancer patients. Granulocyte-colony stimulating factor (G-CSF) and pegylated G-CSF are used for the prevention of neutropenia after chemotherapy. Pegylated G-CSF has longer half-life of action and can be used as a single dose in comparison to G-CSF. The aim of this study is to compare the grade of cytopenia and side effects between G-CSF and biosimilar pegylated G-CSF in breast cancer patients treated with dose-dense chemotherapy.

Materials and Methods:

In the cross-over clinical trial study, 24 women with breast cancer were randomly divided into two groups and treated with dose-dense chemotherapy. The first group was treated with single dose of 6 mg biosimilar pegylated G-CSF 24 h after the first course of chemotherapy and the second course was followed by 300 μg daily injection of G-CSF for 6 days. The chemotherapy regimen was combination of doxorubicin 60 mg/m² and cyclophosphamide 600 mg/m². The second group was treated with G-CSF after the first course and pegylated G-CSF after the second course. Cell blood count (CBC) and side effects were evaluated 1 and 2 weeks after both courses of chemotherapy.

Results:

In this study, no significant carryover effect and treatment effect about the CBC parameters was found between pegylated G-CSF and G-CSF. Patients who were treated with biosimilar pegylated G-CSF had significantly higher side effects such as bone pain (P = 0.09) and gastrointestinal effects (P = 0.005) in comparison to G-CSF.

Conclusion:

G-CSF and biosimilar pegylated G-CSF are effective in reducing cytopenia in breast cancer patients treated with dose-dense chemotherapy, but side effects induced by pegylated G-CSF (Pegagen) are higher.

The First Case of Pseudomonas aeruginosa Bacteremic Pneumonia in a Cancer Patient Receiving Pegfilgrastim

A single dose of pegfilgrastim or the daily administration of colony-stimulating factors can be used to prevent febrile neutropenia. This may delay the detection of rapidly progressive infections among cancer patients undergoing chemotherapy. We report a case of Pseudomonas aeruginosa bacteremic pneumonia that occurred in a patient receiving pegfilgrastim.

Pegfilgrastim for the prevention of chemotherapy-induced febrile neutropenia in patients with solid tumors

INTRODUCTION

Neutropenia and febrile neutropenia are the most common and most severe bone marrow toxicities of chemotherapy. Recombinant granulocyte-colony stimulating factors (G-CSFs), both daily (filgrastim and biosimilars, and lenograstim) and long-acting (pegfilgrastim and lipegfilgrastim) formulations, are currently available to counteract the negative consequences of these side effects.

AREAS COVERED

The purpose of this article is to review the physiopathology of chemotherapy-induced febrile neutropenia and its consequences, and the current evidence regarding the pharmacological properties, clinical efficacy and cost-effectiveness of pegfilgrastim as a strategy to prevent chemotherapy-induced febrile neutropenia in patients with solid tumors.

EXPERT OPINION

Chemotherapy-induced febrile neutropenia and its complications are still a major health-care concern, and the inappropriate employment of G-CSFs in clinical practice can partially explain its burden. Pegfilgrastim has pharmacological advantages over daily G-CSFs that makes it easily administrable, thus reducing the chance of incorrect delivery. The once-per-cycle administration might explain the findings derived from observational studies suggesting a possible superior efficacy of pegfilgrastim over daily G-CSFs. For patients at higher risk of failure with daily G-CSF prophylaxis (e.g. risk of non-compliance, difficulties on performing regular hemograms, high risk of developing febrile neutropenia), pegfilgrastim might be the most appropriate option.

Mechanisms affecting neutrophil migration capacity in breast cancer patients before and after chemotherapy

PURPOSE

To investigate the mechanisms affecting neutrophil migration capacity in breast cancer patients before and after chemotherapy.

METHODS

Peripheral venous blood was collected at the time of diagnosis and immediately prior to the 4th cycle of an anthracycline-based chemotherapy regimen for patients diagnosed with different stages of breast cancer (n = 30), for experimental assays. Blood samples were also collected from a healthy control group (n = 17).

RESULTS

IL-8 serum concentrations were higher in the patient group than in the control group (p = 0.02), and chemotherapy did not further affect this increase. Levels of TNF-α, IL-6, and IL-10 did not differ between controls and patients, or in relation to chemotherapy. Serum levels of nitric oxide (NO) metabolites were elevated following chemotherapy compared to levels detected prior to treatment (p = 0.01). When the supernatants of lipopolysaccharide-stimulated mononuclear cells and neutrophils obtained from the patients were assayed for levels of nitrite, these levels were significantly higher and unchanged, respectively, compared with controls. Expression levels of the chemokine receptors, CXCR1 and CXCR2, were significantly reduced in patients compared to controls, and chemotherapy did not further affect these differences. Furthermore, filamentous actin content for IL-8-activated neutrophils was reduced with chemotherapy (median 8.85; range 3.38-13.43) compared to the content detected prior to treatment (median 9.23; range 2.86-22.16) (p = 0.001).

CONCLUSION

Elevated systemic levels of IL-8 and NO, desensitization to CXCR activation, and reduction in actin polymerization may affect neutrophil motility in patients before and after chemotherapy.

Kinetics of neutrophils in mice exposed to radiation and/or granulocyte colony-stimulating factor treatment

Astronauts have the potential to develop the hematopoietic syndrome as a result of exposure to radiation from a solar particle event (SPE) during exploration class missions. This syndrome is characterized by a reduction in the number of circulating blood cells (cytopenias). In the present study the effects of SPE-like proton and γ radiation on the kinetics of circulating neutrophils were evaluated during a one-month time period using mice as a model system. The results revealed that exposure to a 2 Gy dose of either SPE-like proton or γ radiation significantly decreased the number of circulating neutrophils, with two nadirs observed on day 4 and day 16 postirradiation. Low circulating neutrophil count (neutropenia) is particularly important because it can increase the risk of astronauts developing infections, which can compromise the success of the mission. Thus, two granulocyte colony-stimulating factors (G-CSFs), filgrastim and pegfilgrastim were evaluated as countermeasures for this endpoint. Both forms of G-CSF significantly increased neutrophil counts in irradiated mice, however, the effect of pegfilgrastim was more potent and lasted longer than filgrastim. Using the expression of CD11b, CD18 and the production of reactive oxygen species (ROS) as markers of neutrophil activation, it was determined that the neutrophils in the irradiated mice treated with pegfilgrastim were physiologically active. Thus, these results suggest that pegfilgrastim could be a potential countermeasure for the reduced number of circulating neutrophils in irradiated animals.