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

Management of complications in surgery of the colon

BACKGROUND

General surgeons are frequently confronted with colorectal diseases in their daily practice, whereby colorectal cancer is the second most common malignant tumour, with almost 5000 new cases every year in Austria. The incidence of benign colon disorders requiring surgery (e.g. colon polyps, sigmoid diverticulitis) is also increasing. The first aim in colon surgery should be to avoid complications and if they occur to treat them properly.

METHODS

We basically distinguish between general and special complications. As general complications, prevention of malnutrition and support of the immune system should receive special attention. As the number of elderly patients increases, so does the risk not only of thrombembolic complications but also of critical cardiocirculatory situations, and renal and hepatic failure. Special complications depend either on the type of surgery (laparoscopic assisted, conventional open surgery) or the techniques employed (stapled, hand sutured). Handling of the tissue also plays a major role (e.g. dry versus wet pads).

RESULTS

Shortening of the postoperative stay decreases both hospital costs and the incidence of infections, meaning that minimally invasive surgery and postoperative "fast track nutrition" should be promoted. Emergency operations should be avoided (e.g. bridging through colonic stents), as morbidity and mortality are clearly increased in comparison to (semi-) elective operations. During the operation itself, new equipment and techniques (such as Ultracision®, Ligasure®) as well as a well coordinated team help to reduce complications and duration of surgery.

CONCLUSIONS

To avoid is better than to repair. If complications do occur, appropriate surgical and intensive - care measures should be taken immediately.

Pharmacokinetic/pharmacodynamic modeling of pegfilgrastim in healthy subjects

This analysis was conducted to characterize the pharmacokinetics and pharmacodynamics of pegfilgrastim and to develop a pharmacokinetic-pharmacodynamic model to describe the granulopoietic effects of pegfilgrastim and the homeostatic regulation of pegfilgrastim clearance in healthy subjects. Pegfilgrastim serum concentration data and differential white cell counts were obtained from an open-label, single-dose, dose escalation study. Healthy subjects (8 subjects/dose group) received a single subcutaneous dose of 30, 60, 100, or 300 microg/kg pegfilgrastim. Pegfilgrastim exhibited nonlinear pharmacokinetics; clearance decreased with increasing dose. A dose-dependent increase in absolute neutrophil count with an increase in the percentage of band cells was observed. A pharmacokinetic-pharmacodynamic model was developed that adequately described the nonlinear pharmacokinetics of pegfilgrastim, feedback regulation of pegfilgrastim clearance by neutrophils, and the differential effects of pegfilgrastim on neutrophil populations in blood.

Roles of leukocytosis and cysteinyl leukotriene in polymorphonuclear leukocyte-dependent plasma extravasation

The PMN-dependent plasma extravasation is a major mechanism of permeability enhancement in acute inflammation. To reveal the pathophysiological significance of the PMN-dependent plasma extravasation, we prepared a systemic leukocytotic guinea pig model by a daily injection of recombinant human (rh)G-CSF. The extent of the PMN-dependent plasma extravasation, regarded as the late-phase permeability induced by an intradermal injection of zymosan-activated guinea pig plasma (ZAP) or of rhC5a, clearly correlated to the circulating PMN number. The augmentation of local response following the systemic response seemed to be the characteristic feature of the PMN-dependent plasma extravasation. We then revealed the molecular mechanism of the PMN-dependent plasma extravasation. Neither the antihistaminic agent diphenhydramine, nor the bradykinin B2 receptor antagonist, HOE140, affected the ZAP-induced, late-phase extravasation. In contrast to this, pretreatment with an antagonist of cysteinyl leukotriene (cys-LT) 1 receptor, pranlukast, significantly reduced the late-phase extravasation. Similarly, it was reduced by pretreatment with a 5-lipoxygenase inhibitor, MK-886, indicating the participation of cys-LTs in the PMN-dependent plasma extravasation. Histologically, pretreatment with pranlukast or MK-886 did not affect the ZAP-induced PMN infiltration. Consistently, a combined treatment with pranlukast and diphenhydramine completely suppressed the early-phase extravasation. As pranlukast pretreatment did not affect plasma extravasation induced by mast cell degranulation, and depletion of platelets did not influence the pranlukast-inhibitable plasma extravasation induced by rhC5a injection, cys-LTs are most likely produced by transcellular biosynthesis involving PMNs and vascular wall cells.

Concurrent cisplatin-based chemoradiation for cervical carcinoma: tumor response, toxicity, and serum cytokine profiles

PURPOSE

To evaluate the relation between tumor response, treatment toxicity, and serum cytokine profiles in patients with cervical cancer receiving cisplatin-based chemoradiation.

PATIENTS AND METHODS

Forty-two patients with cervical carcinoma receiving chemoradiation were recruited. Hemogram, biochemistry profile, cytokine levels, tumor size, and toxicity were assessed weekly.

RESULTS

The absolute neutrophil count decreased accompanied by an increase in serum levels of G-CSF during chemoradiation. The sudden elevation of serum TGF-beta 1 and VEGF levels after the first fraction of brachytherapy accompanied with the development of greater radiation therapy (RT) morbidity. Lower pretreatment TGF-beta 1 and VEGF levels are associated with tumor response to chemoradiation.

CONCLUSION

The serial changes in serum cytokines during chemoradiation may correlate with tumor regression and treatment morbidity.

Rapid succession of peripheral blood progenitor cell mobilization cycles in patients with chronic heart failure: effects on the hematopoietic system

BACKGROUND

Circulating hematopoietic peripheral blood progenitor cells (PBPCs) may contribute to the regeneration of nonhematopoietic organs. An increase in circulating PBPC numbers may enhance this process. Therefore, an exploratory trial of repeated PBPC mobilization in patients with chronic heart failure was conducted. The safety and cardiovascular efficacy data have been described elsewhere. In the hematopoietic system, the trial offered an opportunity to study several new aspects of granulocyte-colony-stimulating factor (G-CSF) action.

STUDY DESIGN AND METHODS

Fourteen male patients with chronic heart failure were treated successively with G-CSF (four 10-day treatment periods interrupted by treatment-free intervals of equal length; daily dose adjustment to maintain a white blood cell [WBC] count of 45 x 10(9)-50 x 10(9)/L).

RESULTS

G-CSF induced a rapid increase in cells of all WBC lineages with return to levels equal to (neutrophilic, eosinophilic, and basophilic granulocytes) or lower than those before treatment (monocytes, lymphocytes) during the treatment-free intervals. Red cell counts remained unchanged, but platelet counts decreased followed by rebound thrombocytosis. The extent of CD34+ cell mobilization was highly variable. For each patient, the changes induced were identical through all cycles, but the G-CSF dose required in the first cycle was significantly higher than in subsequent cycles. In the cohort of patients, an inverse correlation was observed between the WBC level reached and the dose of G-CSF administered.

CONCLUSIONS

Rapid alternation between PBPC mobilization and recovery periods is feasible, with identical alterations in all treatment cycles. G-CSF responsiveness varies among patients and is increased by pretreatment with G-CSF.

The Effect of Stem Cell Mobilization by Granulocyte-Colony Stimulating Factor on Neointimal Hyperplasia and Endothelial Healing After Vascular Injury With Bare-Metal Versus Paclitaxel-Eluting Stents

OBJECTIVES

The goal of this study was to investigate the effect of mobilized stem cells by granulocyte-colony stimulating factor (G-CSF) on neointimal growth, the biologic impact on vascular healing process, and the utility of paclitaxel-eluting stent (PES) in this circumstance.

BACKGROUND

Questions have been raised on the safety of stem cell mobilization because of the tendency of neointimal overgrowth in a recent clinical trial, despite improvement of cardiac function.

METHODS

Rabbits underwent iliac artery injury with bare-metal stent (BMS) or PES and then received rhG-CSF or placebo for 6 days. Morphometric analysis and scanning electron microscopy for re-endothelialization were performed. The characteristics of mobilized peripheral blood mononuclear cells were determined in vitro, and the fate of these cells was evaluated by re-infusion with tagging in vivo.

RESULTS

At day 60 after stenting, neointimal overgrowth was observed at BMS with G-CSF. The tendency of neointimal overgrowth was substantially reduced on PES. Intriguingly, the delayed endothelial recovery on PES was restored to normal after G-CSF treatment. The G-CSF increased not only the endothelial progenitor cells, but also putative smooth muscle progenitor cells. Paclitaxel, at working concentration, preferentially inhibited proliferation of smooth muscle lineage cells rather than endothelial lineage cells.

CONCLUSIONS

Our findings demonstrate that G-CSF mobilizes putative vascular progenitor cells in peripheral blood, which induces neointimal overgrowth at stented vasculature. Unique differential action of paclitaxel results in the enhanced endothelial healing with reduced neointimal growth after G-CSF treatment, suggesting that drug-eluting stents might be the optimal modality for revascularization in cytokine-based stem cell therapy.

The Structure of SOCS3 Reveals the Basis of the Extended SH2 Domain Function and Identifies an Unstructured Insertion That Regulates Stability

SOCS3 is essential for regulating the extent, duration, and specificity of cellular responses to cytokines such as G-CSF and IL-6. Here we describe the solution structure of SOCS3, the first structure determined for any SOCS protein, in complex with a phosphotyrosine-containing peptide from the IL-6 receptor signaling subunit gp130. The structure of the complex shows that seven peptide residues form a predominantly hydrophobic binding motif. Regions outside the SOCS3 SH2 domain are important for ligand binding, in particular, a single 15 residue alpha helix immediately N-terminal to the SH2 domain makes direct contacts with the phosphotyrosine binding loop and, in part, determines its geometry. The SH2 domain itself is remarkable in that it contains a 35 residue unstructured PEST motif insertion that is not required for STAT inhibition. The PEST motif increases SOCS3 turnover and affects its degradation pathway, implying that it has an important regulatory role inside the cell.

Are shorter courses of filgrastim prophylaxis associated with increased risk of hospitalization?

BACKGROUND

In clinical trials in patients receiving myelosuppressive chemotherapy, 10-11 days of prophylaxis with filgrastim has been found to reduce the incidence of febrile neutropenia. In clinical practice, however, many patients receive shorter courses of therapy, even though the effectiveness of this regimen is unknown.

OBJECTIVE

To examine the relationship between duration of filgrastim prophylaxis and risk of hospitalization in patients receiving chemotherapy for non-Hodgkin's lymphoma (NHL), breast cancer, or lung cancer.

METHODS

Using a large, automated, US healthcare claims database, we identified all adults who received chemotherapy for NHL, breast cancer, or lung cancer between 1998 and 2002. For these patients, we identified their first course of chemotherapy and each unique cycle within that course. We then focused attention on all patient cycles in which filgrastim was administered on or before cycle day 5 (filgrastim prophylaxis). Pooling all such cycles, we examined the relationship between duration of filgrastim prophylaxis and risk of hospitalization for neutropenia or infection and risk of hospitalization for any reason, using generalized estimating equations.

RESULTS

Mean +/- SD duration of filgrastim prophylaxis was 6.5 +/- 3.1 days across 332 cycles for 133 NHL patients, 6.1 +/- 2.9 days across 482 cycles for 205 breast cancer patients, and 4.3 +/- 3.1 days across 522 cycles for 260 lung cancer patients. In multivariate analyses, risk of hospitalization for neutropenia or infection was found to decline with each additional day of filgrastim prophylaxis for patients with NHL (OR 0.81; p = 0.003), breast cancer (OR 0.77; p = 0.001), and lung cancer (OR 0.91; p = 0.084). Risk reductions with each additional day of prophylaxis ranged from 15% to 19% for patients with NHL, 17% to 23% for those with breast cancer, and 8% to 9% for those with lung cancer. Similar reductions in risk were noted for all-cause hospitalization.

CONCLUSIONS

Among patients with NHL, breast cancer, or lung cancer, shorter courses of filgrastim prophylaxis may increase the risk of hospitalization.

Frequency of Febrile Neutropenia in Breast Cancer Patients Receiving Epirubicin and Docetaxel/Paclitaxel with Colony-Stimulating Growth Factors: A Comparison of Filgrastim or Lenograstim with Pegfilgrastim

OBJECTIVE

Recombinant granulocyte colony-stimulating factors (G-CSF) have been shown to be effective in reducing the risk of infections associated with antitumour chemotherapy. This report describes a single-centre experience of the efficacy of pegfilgrastim compared with filgrastim or lenograstim in reducing the incidence of febrile neutropenia in patients receiving combination chemotherapy with taxane and epirubicin in a neoadjuvant and adjuvant setting.

METHODS

A total of 118 patients with breast cancer were treated with either epirubicin 75 mg/m(2) and docetaxel 75 mg/m(2) or epirubicin 90 mg/m(2) and paclitaxel 200 mg/m(2) every 3 weeks; 88 received G-CSF support with daily filgrastim or lenograstim and 30 with pegfilgrastim once per cycle.

RESULTS

Eight patients (9.1%) with prophylactic filgrastim or lenograstim support developed febrile neutropenia, as well as 1 patient (3.3%) in the pegfilgrastim group (p = 0.445). Febrile neutropenia occurred in 13 (2.7%) of 476 filgrastim or lenograstim supported chemotherapy cycles and in 2 (1.2%) of 172 cycles with pegfilgrastim support (p = 0.376). The frequency of chemotherapy delays and dose reductions was not significantly different between the two G-CSF treatment groups.

CONCLUSION

These data show a trend towards superiority of pegfilgrastim over filgrastim or lenograstim in reducing the frequency of febrile neutropenia in patients treated with taxane and epirubicin chemotherapy regimens for breast cancer.

Bi-weekly chemotherapy with cisplatin, epirubicin, folinic acid and 5-fluororacil continuous infusion plus g-csf in advanced gastric cancer: a multicentric phase II study

BACKGROUND

It has been demonstrated that the 3-weekly PELF regimen is superior to FAM and FAMTX in advanced gastric cancer. The aim of this multicentric phase II study was to evaluate the efficacy and tolerability of a PELF regimen, given every 2 weeks as a first-line therapy in patients with unresectable or metastatic gastric carcinoma.

METHODS

Fifty-nine patients were treated with the following schedule: cisplatin (40 mg/m2, day 1), epirubicin (30 mg/m2, day 1), 5-fluorouracil (400 mg/m2 bolus, followed by 600 mg/m2, 22 h continuous infusion, day 1 and 2) and folinic acid (100 mg/m2, 2-h infusion, day 1 and 2). G-CSF (5 microg/kg) was administered on day 6, 8, 10, and 12. Cycles were repeated every 2 weeks for a maximum of twelve courses.

RESULTS

Of the 52 evaluable patients, three (5.8%) complete responses, and 15 (28.8%) partial responses were observed, for an overall response rate of 34.6%. The median duration of response was 8 months. Nineteen patients had stable disease and 15 progressed on therapy. At a median follow-up of 12 months, the median time to progression was 8 months and the median survival duration was 13 months, with a 1-year survival rate of 53.5%. Grade 3 or 4 observed toxicities were: neutropenia in 26 patients (44%), thrombocytopenia in four patients (6.7%), and mucositis in seven patients (11.9%).

CONCLUSIONS

The bi-weekly PELF regimen seems to be feasible with an acceptable toxicity profile and an activity comparable to the 3-weekly schedule.

Granulocyte colony-stimulating factor-induced blood stem cell mobilisation in patients with chronic heart failure--Feasibility, safety and effects on exercise tolerance and cardiac function

Bone marrow-derived stem cells may contribute to the regeneration of non-haematopoietic organs. In order to test whether an increase in circulating stem cell numbers improves impaired myocardial function we treated 16 male patients with chronic heart failure due to dilated (DCM; n = 7) or ischaemic cardiomyopathy (ICM; n = 9) with the stem cell mobilising cytokine granulocyte colony-stimulating factor (G-CSF; four 10-day treatment periods interrupted by treatment-free intervals of equal length). Safety and efficacy analyses were performed at regular intervals. Peak CD34+ cell counts remained constant from cycle to cycle. Cardiac side effects in ICM patients included occasional episodes of dyspnea or angina and one episode of fatal ventricular fibrillation. Nine (4 DCM, 5 ICM) of 12 patients receiving four full G-CSF cycles experienced an improvement by one New York Heart Association (NYHA) class and a statistically significant increase in six-minute walking distance. By contrast, none of 8 ICM historical controls had a change in NYHA class during a similar time period. Statistically significant changes in echocardiographic parameters were not recorded. Sequential administration of G-CSF is feasible and possibly effective in improving physical performance in patients with chronic heart failure. Patients with ICM may be at risk of increased angina and arrhythmias.

Once-per-cycle pegfilgrastim versus daily filgrastim in pediatric patients with Ewing sarcoma

The use of the recombinant human granulocyte colony-stimulating factor filgrastim to shorten the duration of severe neutropenia after cytotoxic chemotherapy has become an integral part of supportive care. However, due to its short serum half-life, filgrastim must be injected daily. Pegfilgrastim, a new long-lasting form of filgrastim administrated once per cycle, has been shown in adults to be as effective in reducing the duration of severe neutropenia as daily filgrastim. The aim of this study was to evaluate the effects of pegfilgrastim in pediatric patients. Five children with Ewing sarcoma were alternately treated with a single 100 microg/kg pegfilgrastim dose or daily doses of 10 microg/kg Filgrastim after a total number of 58 chemotherapy cycles. Pegfilgrastim was well tolerated. The duration of severe neutropenia and the incidence of febrile neutropenia after pegfilgrastim and filgrastim were comparable. By using pegfilgrastim, the number of subcutaneous injections could be reduced to one single injection per cycle.

Hematopoietic Stem Cell Mobilization Therapy Accelerates Recovery of Renal Function Independent of Stem Cell Contribution

Acute renal failure and tubular cell loss as a result of ischemia constitute major challenges in renal pathophysiology. Increasing evidence suggests important roles for bone marrow stem cells in the regeneration of renal tissue after injury. This study investigated whether the enhanced availability of hematopoietic stem cells, induced by stem cell factor and granulocyte colony-stimulating factor, to the injured kidney provides an adequate strategy for stem cell-based therapy to counteract renal ischemia/reperfusion injury. It is interesting that cytokine treatment before injury resulted in significant enhancement of function recovery of the kidney. This, however, was not due to increased incorporation of tubular epithelial cells from bone marrow origin. Importantly, cytokine treatment resulted in impaired influx of granulocytes into the injured kidney. Although cytokine treatment improved renal function rapidly after ischemic injury, the results show that the underlying mechanism likely is not based on stem cell transdifferentiation but rather on altered inflammatory kinetics.

Comparison of lenograstim and filgrastim: effects on blood cell recovery after high-dose chemotherapy and autologous peripheral blood stem cell transplantation

PURPOSE

The aim of the study was to evaluate whether glycosylated granulocyte colony-stimulating factor (G-CSF) (lenograstim) offers a benefit over non-glycosylated G-CSF (filgrastim) in clinically relevant end points after high-dose chemotherapy (HDC) and autologous peripheral blood stem cell transplantation (PBSCT).

METHODS

We retrospectively analyzed the outcome of 261 patients treated with either lenograstim (n=68) or filgrastim (n=193). Time to blood cell recovery, toxicities, and infectious complications were analyzed in a total of 469 G-CSF treatment cycles.

RESULTS

Mean time to leukocyte recovery was 10.7 days (SD+/-0.9) (lenograstim) and 10.8 days (SD+/-0.6) (filgrastim), respectively. Likewise, time to thrombocyte engraftment, febrile days, duration of therapeutic antibiotic treatment, severity of non-hematological toxicities, duration of in-hospital stay, and duration of G-CSF treatment were similar in both groups. Owing to the physicochemical and pharmacokinetic properties of lenograstim, the required dose until leukocyte recovery was significantly smaller as compared to filgrastim (38.5 vs 54.0 microg/kg of body weight).

CONCLUSIONS

Collectively, our data indicate that both G-CSF preparations are equally effective in hastening leukocyte recovery in the setting of high-dose chemotherapy followed by autologous PBSCT.

Responsiveness to G-CSF before leukopenia predicts defense to infection in high-dose chemotherapy recipients

An active assessment of the host capacity to prevent infection during myelosuppression should be beneficial in patients receiving high-dose chemotherapy. A single dose of granulocyte colony-stimulating factor (G-CSF) (5 μg/kg) was given to 57 patients with multiple myeloma early after the completion of 85 high-dose chemotherapy (melphalan 200 mg/m2) courses. This provoked a highly variable white blood cell (WBC) peak after 12 to 14 hours. The median WBC count was 21 000/μL (range, 6400-60 600/μL) after a first high-dose therapy (n = 50) and 13 500/μL (range, 4700-24 800/μL) after a second high-dose therapy (n = 35). The responsiveness to single G-CSF was associated with the risk of infection during subsequent cytopenia (P = .003). This association was significant after adjustment for neutropenia duration. Notably, the result of testing G-CSF responsiveness was opportunely available before the onset of leukopenia, and G-CSF responsiveness was more informative than neutropenia duration regarding the risk of infection. Furthermore, there was an association between the responsiveness to G-CSF and stem cell engraftment (P < .005), which remained significant after adjustment for the number of transplanted CD34+ cells. Our results show for the first time that G-CSF potentially could be used for an early in vivo assessment of defense to infection in recipients of high-dose chemotherapy.

Neulasta (pegfilgrastim): a once-per-cycle option for the management of chemotherapy-induced neutropenia

Neutropenia is a significant hematologic complication induced by cytotoxic chemotherapy. The clinical consequences of chemotherapy-induced neutropenia are often severe and can be potentially life-threatening. Patients who develop febrile neutropenia often need to be hospitalized, reducing their quality of life and increasing costs. Neutropenia can also compromise the ability to deliver chemotherapy at the full dose and on schedule. To help prevent the occurrence of neutropenia, patients with a high risk of developing chemotherapy-related infections may be given prophylactic colony-stimulating factors. Filgrastim is a recombinant human granulocyte colony-stimulating factor that has been widely used (in over 3 million patients) for over 12 years in the management of neutropenia. Pegfilgrastim is an approved, long-acting, next generation of granulocyte colony-stimulating factor that has similar clinical benefits to filgrastim but has novel pharmacokinetic properties. Pegfilgrastim shows at least comparable safety and efficacy to filgrastim, with the added benefit of simplified once-per-chemotherapy-cycle dosing. In addition, two randomized, controlled pivotal trials have shown that a single dose of pegfilgrastim given once per cycle led to a lower observed incidence of febrile neutropenia following myelosuppressive chemotherapy, compared with daily injections of filgrastim. Clinical trials are currently expanding the clinical experience with pegfilgrastim in a variety of solid tumors and hematologic malignancies. In addition to prevention of chemotherapy-induced neutropenia in 21- and 28-day regimens, future studies are examining the suitability of pegfilgrastim in dose-dense therapy and other cancer settings.

Continuous subcutaneous injection reduces polymorphonuclear leukocyte activation by granulocyte colony-stimulating factor

The use of granulocyte colony stimulating factor (G-CSF) for recovery from neutropenia has been established; however, acute lung injury due to G-CSF-induced polymorphonuclear leukocyte (PMN) activation is a serious complication. This study was designed to compare the activation of PMN with single bolus administration and continuous administration of G-CSF. Healthy volunteers (age 33.8 ± 1.4 yr; n = 6) received a single bolus injection of 50 μm/m2of G-CSF (SI; n = 6) or continuous subcutaneous injection of 50 μm/m2of G-CSF for 24 h (CI; n = 6) and were followed for 48 h. Circulating leukocyte counts, markers of activation on PMN, and circulating levels of G-CSF, IL-6, and PMN elastase were measured. SI rapidly increased serum G-CSF levels, which peaked at 4 h, whereas CI gradually increased G-CSF levels, which remained at a steady level from 8 to 24 h. SI caused a rapid decrease in PMN counts at 0.5 h followed by sustained increase to peak at 12 h. CI gradually increased PMN counts, which peaked at 24 h, but the peak values were not significantly different between the groups. SI-induced activation of PMN, which was characterized by increased expression of CD11b, decreased expression of L-selectin, and increased F-actin content, led to increases in serum IL-6 and PMN elastase level. Such changes were all attenuated with CI ( P < 0.05). We conclude that continuous subcutaneous injection of G-CSF resulted in a marrow response similar to that to a single injection but yielded reduced PMN activation.

A randomized double-blind multicenter phase III study of fixed-dose single-administration pegfilgrastim versus daily filgrastim in patients receiving myelosuppressive chemotherapy

BACKGROUND

We evaluated the efficacy of a single fixed 6 mg dose of pegfilgrastim (a pegylated version of filgrastim) per cycle of chemotherapy, compared with daily administration of filgrastim, in the provision of neutrophil support.

PATIENTS AND METHODS

Patients (n = 157) were randomized to receive either a single 6 mg subcutaneous (s.c.) injection of pegfilgrastim or daily 5 mg/kg s.c. injections of filgrastim, after doxorubicin and docetaxel chemotherapy (60 mg/m(2) and 75 mg/m(2), respectively). Duration of grade 4 neutropenia, depth of neutrophil nadir, incidence of febrile neutropenia, time to neutrophil recovery and safety information were recorded.

RESULTS

A single 6 mg injection of pegfilgrastim was as effective as daily injections of filgrastim for all efficacy measures for all cycles. The mean duration of grade 4 neutropenia in cycle 1 was 1.8 and 1.6 days for the pegfilgrastim and filgrastim groups, respectively. Results for all efficacy end points in cycles 2-4 were consistent with the results from cycle 1. A trend towards a lower incidence of febrile neutropenia was noted across all cycles with pegfilgrastim compared with filgrastim (13% versus 20%, respectively). A single fixed dose of pegfilgrastim was as safe and well tolerated as standard daily filgrastim.

CONCLUSIONS

A single fixed dose of pegfilgrastim administered once per cycle of chemotherapy was comparable to multiple daily injections of filgrastim in safely providing neutrophil support during myelosuppressive chemotherapy. Pegfilgrastim may have utility in other clinical settings of neutropenia.

Pegfilgrastim

Granulocyte colony stimulating factor (G-CSF) has proven efficacy in the prophylaxis of chemotherapy induced neutropenia and is associated with a reduction in the duration of neutropenia, febrile neutropenia, hospitalisation and intravenous antibiotic use. It is an effective mobiliser of peripheral blood progenitor cells and is used in many countries to mobilise and provide a source of stem cells for autologous and allogeneic bone marrow transplantation. The longevity of G-CSF action is limited by its short half-life, necessitating daily injections. Pegfilgrastim (Neulasta, Amgen, Inc.) is a novel form of filgrastim (G-CSF) with a sustained duration of action. Single dose pegfilgrastim has been shown to be as safe and effective as daily filgrastim in reducing the incidence of chemotherapy induced neutropenia. Pegfilgrastim provides clinical and quality of life benefits for patients as a result of its once per cycle administration. It is licenced in the US for use in the prophylaxis and treatment of chemotherapy induced neutropenia. Clinical trials to evaluate its ability to mobilise peripheral blood progenitor cells are ongoing.

Granulocyte colony-stimulating factor: release is not impaired after burn wound infection

BACKGROUND

The production of granulocyte colony-stimulating factor (G-CSF), the lineage specific essential regulator of neutrophil progenitor cell proliferation and differentiation, has been thought to be impaired in the setting of burn infection. The ability to directly measure murine G-CSF allows the further delineation of the G-CSF response in a clinically relevant model of thermal injury and infection.

METHODS

We used a commercially available solid phase enzyme-linked immunoabsorbent assay to quantify G-CSF production after burn wound infection in mice. Bone marrow cells, splenic cells, and serum were obtained from BDF1 mice on day 3 after a 15% total body surface area full-thickness scald burn with or without Pseudomonas aeruginosa burn wound infection. G-CSF production of bone marrow cells or splenic cells and the serum level of G-CSF were measured. A clonogenic assay of bone marrow and spleen granulocyte-macrophage progenitor cells as well as blood leukocyte counts were also performed.

RESULTS

After burn sepsis, we noted that G-CSF production of the bone marrow and spleen was significantly increased; the numbers of progenitor cells in bone marrow and spleen were markedly enhanced; serum values of G-CSF were 14 times greater than control values; serum colony-stimulating activity was greater than in control mice; and total blood leukocyte counts were significantly depressed.

CONCLUSION

These findings support the notion that granulocytopoietic failure after burn sepsis is not significantly related to defective endogenous G-CSF synthesis. More likely, hyporesponsiveness of granulocyte progenitor cells to G-CSF, changes in the relative balance of granulocyte versus monocyte progenitors within the granulocyte-macrophage progenitor cell compartment, and enhanced release of monocyte lineage specific growth factors are the critical elements responsible for burn infection-induced hematopoietic failure.

Bone marrow necrosis with dyspnea in a patient with malignant lymphoma and plasma levels of thrombomodulin, tumor necrosis factor-alpha, and D-dimer

Non-Hodgkin's lymphoma (peripheral T cell, unspecified, clinical stage IIIEA) was diagnosed in a 54-year-old male. He was treated weekly with chemotherapy consisting of pirarubicin hydrochloride, cyclophosphamide, methotrexate, vincristine sulfate, etoposide, and prednisolone. After 6 weeks of treatment in a state of partial remission, he exhibited sudden dyspnea, chest pain, fever, and drowsiness. The patient had received 100 microg/day of granulocyte colony stimulating factor (G-CSF) for 6 days before the onset. Laboratory data showed an elevated lactate dehydrogenase (LDH) level, leukoerythroblastosis in the peripheral blood, and no decrease in the serum haptoglobin level. There were no findings of acute myocardial infarction or pulmonary thromboembolism. Bone marrow specimen showed the characteristic features of necrosis without any signs of the involvement of lymphoma cells. No indications of infections were found. This patient was diagnosed as having bone marrow necrosis (BMN) during the recovery phase of bone marrow with G-CSF treatment after chemotherapy for malignant lymphoma. After conservative therapy, inhalation of oxygen and stopping the administration of G-CSF, all clinical symptoms subsided except that the elevation of LDH continued for 1 month. The plasma level of tumor necrosis factor-alpha (TNF-alpha) was high just after the onset of BMN. The thrombomodulin (TM) level was high just before the onset of BMN and continued to be high for 2 weeks. Cross-linked fibrin degradation products (D-dimer) were also high just after the onset of BMN and continued to be high for 3 weeks after the onset. Although dyspnea is a rare symptom of BMN, it is important to rule out in BMN during the recovery phase of bone marrow with G-CSF treatment after chemotherapy for malignant lymphoma. Activated neutrophils in the small vessels of the lung by G-CSF and microthrombi, suggested by the elevation of D-dimer, may participate in the onset of dyspnea, which is a rare symptom of the onset of BMN.

Blinded, randomized, multicenter study to evaluate single administration pegfilgrastim once per cycle versus daily filgrastim as an adjunct to chemotherapy in patients with high-risk stage II or stage III/IV breast cancer

PURPOSE

This multicenter, randomized, double-blind, active-control study was designed to determine whether a single subcutaneous injection of pegfilgrastim (SD/01, sustained-duration filgrastim; 100 microg/kg) is as safe and effective as daily filgrastim (5 microg/kg/d) for reducing neutropenia in patients who received four cycles of myelosuppressive chemotherapy.

PATIENTS AND METHODS

Sixty-two centers enrolled 310 patients who received chemotherapy with docetaxel 75 mg/m(2) and doxorubicin 60 mg/m(2) on day 1 of each cycle for a maximum of four cycles. Patients were randomized to receive on day 2 either a single subcutaneous injection of pegfilgrastim 100 microg/kg per chemotherapy cycle (154 patients) or daily subcutaneous injections of filgrastim 5 microg/kg/d (156 patients). Absolute neutrophil count (ANC), duration of grade 4 neutropenia, and safety parameters were monitored.

RESULTS

One dose of pegfilgrastim per chemotherapy cycle was comparable to daily subcutaneous injections of filgrastim with regard to all efficacy end points, including the duration of severe neutropenia and the depth of ANC nadir in all cycles. Febrile neutropenia across all cycles occurred less often in patients who received pegfilgrastim. The difference in the mean duration of severe neutropenia between the pegfilgrastim and filgrastim treatment groups was less than 1 day. Pegfilgrastim was safe and well tolerated, and it was similar to filgrastim. Adverse event profiles in the pegfilgrastim and filgrastim groups were similar.

CONCLUSION

A single injection of pegfilgrastim 100 microg/kg per cycle was as safe and effective as daily injections of filgrastim 5 microg/kg/d in reducing neutropenia and its complications in patients who received four cycles of doxorubicin 60 mg/m(2) and docetaxel 75 mg/m(2).

Granulocyte colony-stimulating factor exacerbates the acute lung injury and pulmonary fibrosis induced by intratracheal administration of bleomycin in rats

We investigated the effects of granulocyte colony-stimulating factor (G-CSF) on lung injury induced by intratracheal administration of bleomycin (BLM, 2 mg/200 micro1) in rats. In experiment 1, G-CSF (10, 30 and 100 microg/kg/day, s.c.) was administered to rats treated with BLM or saline for 7 days starting immediately after BLM administration. In rats receiving G-CSF alone, a large number of neutrophils were noted in the pulmonary capillaries, although there were no lung lesions. In rats receiving BLM alone, diffuse alveolar damage was observed. The administration of G-CSF to BLM-treated rats increased the total lung lesion per unit of pulmonary parenchyma (total lung lesion %) along with increases in the peripheral neutrophil count and the number of neutrophils infiltrating in the pulmonary lesion in a dose-dependent fashion. In experiment 2, 100 microg/kg/day of G-CSF was administered to rats treated with BLM or saline for up to 28 days starting immediately after BLM administration. The administration of 100 microg/kg/day of G-CSF to BLM-treated rats showed no effects at 14 days but it increased the lung lesion % and the score of lung fibrosis along with the increase in the number of neutrophils infiltrating in the pulmonary lesion at 28 days. These findings suggest that G-CSF administration to BLM-treated rats influenced and exacerbated the BLM-induced acute lung injury, and also exacerbated pulmonary fibrosis in a dose-dependent fashion. The exacerbation of lung injury coincided with the marked increase in the peripheral neutrophil count and the number of neutrophils infiltrating in the pulmonary lesion.

Isolation and characterization of an active compound from black soybean [Glycine max (L.) Merr.] and its effect on proliferation and differentiation of human leukemic U937 cells

Black soybean [Glycine max (L.) Merr.] has been used as a health food and herb in China for hundreds of years. In the present study, we purified a unique polysaccharide component from black soybean (PSBS) and found that it indirectly inhibits proliferation and induces differentiation of human leukemic U937 cells via activation of mononuclear cells (MNCs). We prepared conditioned media (MNC-CM) by incubating MNCs from human peripheral blood with or without PSBS (PSBS-MNC-CM and normal MNC-CM, respectively). Treatment of human leukemic U937 cells with PSBS-MNC-CM significantly inhibited proliferation of U937 cells, reducing their growth by 98.5%. Furthermore, PSBS-MNC-CM induced U937 cells to differentiate into mature monocytes/macrophages (83% by morphological examination and 90% by the nitroblue tetrazolium test). Neither PSBS alone nor normal MNC-CM had such effects. The molecular weight of PSBS was about 480 000 by gel filtration. Structural analysis of PSBS revealed that (1,6)-alpha-D-glucan might be its major active component. Our results suggest that the PSBS may inhibit proliferation and induce differentiation in human leukemic U937 cells by activating the immune response of MNCs.

Granulocyte colony-stimulating factor induces neutrophils to secrete macrophage colony-stimulating factor

In this work we provide evidence showing that granulocytes produce macrophage colony-stimulating factor (M-CSF) from the band cell stage and secrete this factor when induced to differentiate into polymorphonuclear cells by recombinant human granulocyte colony-stimulating factor (rhG-CSF). Using an enriched population of myeloid band cells from murine bone marrow, we identified the presence of M-CSF with a chromophore-labelled monoclonal anti-M-CSF antibody. Using ELISA we detected the secretion of M-CSF in the supernatants of cultures of enriched band cells when induced with rhG-CSF to differentiate into mature neutrophils. We also found that M-CSF is the only factor responsible for the colony forming activity in the supernatants and lysates of band cells treated with rhG-CSF.

Population pharmacokinetic-pharmacodynamic modeling of filgrastim (r-metHuG-CSF) in healthy volunteers

The pharmacokinetic-pharmacodynamic (PK-PD) relationship of the granulopoietic effects of Filgrastim in healthy volunteers was characterized via a population approach. Healthy male volunteers were enrolled into a four-way crossover clinical trial. Subjects received four single doses of Filgrastim (375 and 750 micrograms i.v. and s.c.) with an intervening washout period of 7 days. Serum concentrations of Filgrastim were determined using an enzyme-linked immunosorbent assay. Absolute neutrophil count (ANC) was determined. Data analysis was performed using mixed-effects modeling as implemented in the NONMEM software package. The final PKPD model incorporates a two-compartment PK model with bisegmental absorption from the s.c. site, first-order and saturable elimination pathways, and an indirect PD model. A sigmoidal Emax model for the stimulation of ANC input rate (kin) was superior to the conventional Emax model (mean +/- SE: Emax = 12.7 +/- 1.7; EC50 = 4.72 +/- 0.72 ng/ml; Hill = 1.34 +/- 0.19). In addition, a time-variant scaling factor for ANC observations was introduced to account for the early transient depression of ANC after Filgrastim administration. The absolute bioavailability of subcutaneously administered Filgrastim was estimated to be 0.619 +/- 0.058 and 0.717 +/- 0.028 for 375 micrograms and 750 micrograms s.c. doses, respectively. The time profiles of concentration and ANC, as well as the concentration approximately ANC relationship of Filgrastim in healthy volunteers were well described by the developed population PK-PD model.

The efficacy of recombinant TPO in murine And nonhuman primate models for myelosuppression and stem cell transplantation

Radiation-induced pancytopenia proved to be a suitable model system in mice and rhesus monkeys to study thrombopoietin (TPO) target cell range and efficacy. TPO was highly effective in rhesus monkeys exposed to the midlethal dose of 5-Gy (300 kV x-rays) TBI, a model in which it alleviated thrombocytopenia, promoted red cell reconstitution, accelerated reconstitution of immature CD34+ bone marrow (BM) cells and potentiated the response to growth factors such as GM-CSF and G-CSF. The accelerated reconstitution of BM CD34+ cells appeared to be reflected by a similar rise in peripheral blood CD34+ cells, both being augmented by concomitant GM-CSF. However, TPO was ineffective following transplantation of limited numbers of autologous BM or highly purified stem cells in monkeys conditioned with 8-Gy TBI. In the 5-Gy model, a single dose of TPO 24 h after TBI was effective in preventing thrombocytopenia and was augmented by GM-CSF. The strong erythropoietic stimulation may result in iron depletion and TPO treatment should be accompanied by monitoring of iron status. In mice, similar observations were made and the importance of dose and dose schedule for stimulation of multilineage repopulating cells versus the lineage-dominant thrombopoietic response studied in detail.

Use of granulocyte colony-stimulating factor after high-dose chemotherapy and autologous peripheral blood stem cell transplantation: what is the optimal timing?

Administration of granulocyte colony-stimulating factor to patients undergoing high-dose chemotherapy and autologous peripheral blood stem cell transplantation accelerates neutrophil recovery and decreases hospitalization time. The optimal timing for granulocyte colony-stimulating factor infusion remains unknown. In this retrospective, case-controlled, two-armed study, we reviewed our experience at Hahnemann University Hospital to determine whether initiating granulocyte colony-stimulating factor infusions on posttransplant day 0 versus day 8 affects neutrophil recovery time, posttransplant discharge date, total hospital days after high-dose chemotherapy, and autologous peripheral blood stem cell transplantation. All patients hospitalized between 1994 and 1998 at Hahnemann University Hospital, Bone Marrow Transplantation Unit with breast cancer or non-Hodgkin's lymphoma, who underwent high-dose chemotherapy followed by autologous peripheral blood stem cell transplantation and received granulocyte colony-stimulating factor either on posttransplant day 0 (16 patients) or day 8 (16 patients). The day 0 and day 8 groups had no statistically significant differences in age, sex, weight, height, body surface area, disease characteristics, pretransplant harvesting or conditioning regimens, or transplant CD34+ cell counts. Our main outcome measure was the mean time to reach absolute neutrophil count greater than or equal to 0.5 x 10(9)/l, the number of hospital days after transplant, and the total hospital days. The mean days to neutrophil recovery (10.56 versus 9.68, p = 0.48), posttransplant hospital days (13.62 versus 12.81, p = 0.39), and total hospital days (20.25 versus 20.25, p = 1.00) were not significantly different between day 8 and day 0 groups, respectively. No significant effects on neutrophil recovery time, posttransplant hospital days, or total hospital days were observed with the initial granulocyte colony-stimulating factor infusion on day 0 versus day 8 after transplant. Delayed administration may allow substantial cost savings (US$200 x 8 approximately equal to US $1,600 per patient) without affecting clinical outcome. More studies are needed to determine whether greater delay is feasible.

Filgrastim in patients with pneumonia and severe sepsis or septic shock

STUDY OBJECTIVES

Evaluate the safety of filgrastim (recombinant methionyl human granulocyte colony-stimulating factor) administration, combined with standard therapy, in patients with pneumonia and either septic shock or severe sepsis who were receiving mechanical ventilation.

DESIGN

Multicenter, double-blind, randomized, placebo-controlled study.

SETTING

ICU, multicenter.

PATIENTS

Eighteen patients with pneumonia and hypotension, or in the absence of shock, two or more end-organ dysfunctions, were enrolled and treated. Baseline acute physiology and chronic health evaluation II scores and median age for the filgrastim (n = 12) and placebo (n = 6) groups were 25.0 and 49.5 years and 31.5 and 56.5 years, respectively.

INTERVENTION

Filgrastim (300 microg) or placebo was administered IV daily for up to 5 days.

MEASUREMENTS AND RESULTS

Study end points included safety; biological response, including endogenous cytokine levels, endotoxin levels, and neutrophil counts; and mortality. Cytokine and endotoxin levels were highly variable in both groups. By day 29, 3 of 12 filgrastim-treated patients and 4 of 6 placebo-treated patients had died. There were no differences in types and occurrences of adverse events, including ARDS, or in outcome between the two groups. Three of four placebo-treated patients had persistent bacterial growth on bronchoscopy repeated after 48 h compared with 2 of 10 filgrastim-treated patients.

CONCLUSION

Filgrastim appeared to be well tolerated in this population of patients with pneumonia and severe sepsis or septic shock. Larger studies to determine the benefit of filgrastim in patients with pneumonia and sepsis or organ dysfunction are warranted.

A possible relationship between abortions and placental embolism in pregnant rabbits given human granulocyte colony-stimulating factor

Developmental toxicity studies were conducted in rats and rabbits with a human G-CSF derivative (NTG). As reported for G-CSF, increases in abortions and fetal mortality were observed in rabbits, but not in rats given NTG. Histopathological examination of the rabbit placenta revealed accumulation of neutrophils in vessels and necrosis of the tissues surrounding these vessels. To assess the mechanism of abortion and fetal death in rabbits given G-CSF, 125I-labeled NTG was given intravenously on Day 18 of pregnancy after repeated administration of cold NTG on Days 6 through 17 of pregnancy, and the feto-maternal distribution of radioactivity was examined. In a rabbit given 20 micrograms/kg, high radioactivity was observed in the endometrium, placenta, and some parts of the decidua at 6 hr when the concentration of radioactivity in maternal blood had already decreased. At 24 hr after administration of 200 micrograms/kg NTG, high radioactivity was still detected in parts of the maternal placenta. These patterns of distribution suggest that embolism occurred in parts of the uterus and placenta which might have caused congestion. Radioactivity in the TCA precipitates in the fetus was low, suggesting that NTG does not readily transfer to the fetus. These results strongly suggest that neutrophils accumulated in the vessels of placenta and induced embolism leading to abortions and fetal mortality in the rabbits given G-CSF.

Factors influencing oral mucositis in patients receiving chemotherapy

PURPOSE

Oral mucositis is a painful complication of chemotherapy and can greatly affect patients' morbidity and mortality. Findings from two previous studies suggested a decrease in the prevalence of chemotherapy-induced mucositis in patients with solid tumors. The purposes of this study were to follow a large cohort of outpatients to determine the prevalence of mucositis and to identify whether certain clinical factors were significant in the development of mucositis.

DESCRIPTION OF STUDY

In this prospective study, a convenience sample of 199 outpatients was followed for three cycles or until mucositis developed. The clinical factors monitored included the following: pretreatment dental examination/repair; initial standard chemotherapy dosage; prophylactic use of colony-stimulating factors; and use of preventive mouthwashes or other prophylactic measures.

RESULTS

Oral mucositis developed in 50 patients (25.1%). Prechemotherapy dental examination/repair and initial standard chemotherapy dosage were equivalent among both groups. Of the 48 patients in whom mucositis developed, 10 (20.8%) received prophylactic colony-stimulating factors. Of 134 patients in whom mucositis did not develop, 46 (34.3%) received prophylactic colony-stimulating factors. This difference was statistically nonsignificant.

CLINICAL IMPLICATIONS

Differences in the clinical factors investigated could not explain the lower prevalence of oral mucositis among the current patient cohort. The reason for the diminishing prevalence of this side effect remains unclear, and additional parameters, particularly detailed oral hygiene practices, should be evaluated. In the meantime, oncology clinicians should consider the teaching of patients and urging them to use good oral hygiene practices as necessary and potentially preventive measures against chemotherapy-induced mucositis.

Colony stimulating factors in patients with fever and neutropenia

Colony stimulating factors (CSFs), are essential for the regulation of the hematopoietic system and were developed by the pharmaceutical biotechnology industry in the early 1990s for the prevention of serious neutropenic complication after myelosuppressive chemotherapy. Both G-CSF and GM-CSF consistently lead to an increase in circulating white blood cells and a reduction in the incidence of fever and neutropenia after myelosuppressive chemotherapy in patients with solid tumors, hematologic malignancies, and those undergoing stem-cell transplantation. Their role in improving response rates to chemotherapy and overall survival is less clear.

Late-onset neutropenia in very low birth weight infants

BACKGROUND

Neutropenia, defined as absolute neutrophil count (ANC) <1500/mm(3), affects 6% to 58% of premature infants in the first week of life. This early-onset neutropenia in premature infants has previously been correlated with sepsis, maternal hypertension, severe asphyxia, and periventricular hemorrhage. Late-onset neutropenia, defined as ANC <1500/mm(3) at a postnatal age of >/=3 weeks, has not been previously reported.

OBJECTIVES

The purposes of this study were to determine the prevalence of late-onset neutropenia in very low birth weight (VLBW) infants and to examine the factors that may be associated with this phenomenon.

METHODS

A weekly complete blood cell count (CBC) was performed routinely in all premature infants with birth weight </=1500 g (n = 225) admitted to the neonatal intensive care in a 3-year period who survived until discharge. CBC and differentials were recorded at day 1, day 3, and then weekly until discharge. The clinical data of the study infants were collected by reviewing the medical records retrospectively.

RESULTS

Late-onset neutropenia was detected in 51 infants (22%). In both neutropenic (n = 51) and nonneutropenic infants (n = 174), ANC increased postnatally, remained above 5000/mm(3) for the first 3 weeks of life, and had a marked decrease at approximately 4 weeks of age. Thereafter, ANC decreased to a level of approximately 1400/mm(3) in the neutropenic infants and 4000/mm(3) in the nonneutropenic infants. The neutropenic infants had a significantly lower nadir ANC, lower hemoglobin, and higher reticulocyte count than did the nonneutropenic infants with similar platelet counts. None of the study infants received erythropoietin during their hospitalization. This late-onset neutropenia occurred at postnatal age of 6 +/- 2 weeks (range: 3-10 weeks). The duration of neutropenia was 1.7 +/-.7 weeks (range: 1-3 weeks). All of the neutropenic infants had anemia of prematurity with high reticulocyte count and normal platelet count. The neutropenic infants were stable, growing on full oral feedings, and had no signs or symptoms of sepsis. No adverse effects of late-onset neutropenia were apparent in these infants.

CONCLUSION

Late-onset neutropenia is a common incidental finding in stable, growing VLBW infants that has not been previously reported. Late-onset neutropenia is a phenomenon that occurs in anemic premature infants who have marked reticulocytosis. Normal regulation of hematopoiesis is accompanied by a balance between colony-stimulating factors, such as erythropoietin and granulocyte colony-stimulating factor, which regulate erythropoiesis and granulopoiesis. We speculate that imbalance of these factors with increased reticulocytopoiesis in response to anemia of prematurity may explain this phenomenon. We recommend avoiding institution of aggressive, potentially harmful therapy for this phenomenon in healthy, growing VLBW infants.

A practical approach to evaluating and treating neutropenia in the neonatal intensive care unit

Neutropenia is a relatively common problem in the NICU, recognized in as many as 8% of patients at some time during their hospital stay. In most instances, neutropenia among NICU patients is of short duration and has little influence on outcome. In other cases it is prolonged and severe, and constitutes a serious antimicrobial defense deficiency. When a neonatologist discovers a low blood neutrophil count, choices must be made regarding further evaluation and treatment. The authors hope that the information provided in this article is useful in making these choices.

Enhancement of platelet recovery after myelosuppressive chemotherapy by recombinant human megakaryocyte growth and development factor in patients with advanced cancer

PURPOSE

To explore the influence of dose and schedule on the ability of pegylated recombinant human megakaryocyte growth and development factor (PEG-rHuMGDF) to abrogate thrombocytopenia after multiple cycles of chemotherapy and to mobilize peripheral-blood progenitor cells (PBPC).

PATIENTS AND METHODS

In this open-label study, 68 patients with advanced cancer were randomized to receive PEG-rHuMGDF subcutaneously at different doses and durations before administration of carboplatin 600 mg/m(2), cyclophosphamide 1,200 mg/m(2), and filgrastim 5 microgram/kg/d. PEG-rHuMGDF was not given after the first cycle of chemotherapy but was given after the second and subsequent cycles. Chemotherapy was given every 28 days for up to six cycles.

RESULTS

In patients who received the same dose of chemotherapy for at least two cycles, the platelet nadir was significantly higher (47.5 x 10(9)/L v 35.5 x 10(9)/L; P =.003) and duration of grade 3 or 4 thrombocytopenia significantly shorter (0 v 3 days; P =.004) when PEG-rHuMGDF was administered after chemotherapy. There was no evidence of an effect of PEG-rHuMGDF when it was given before chemotherapy. Platelet recovery after the first cycle of chemotherapy was no different for different PEG-rHuMGDF regimens, and there was no difference between patients treated with PEG-rHuMGDF and historical controls treated with identical chemotherapy. There was a modest dose-related increase in progenitor cell levels after administration of PEG-rHuMGDF alone. Peak levels of PBPC occurred later in cycle 2 than in cycle 1 but were not different in magnitude.

CONCLUSION

PEG-rHuMGDF abrogated severe thrombocytopenia after dose-intensive chemotherapy. However, it had only a modest effect on progenitor cell levels and did not enhance progenitor cell mobilization after chemotherapy and filgrastim.

Leukocyte behavior in a free-flap model following chemotherapy and application of granulocyte colony-stimulating factor (GCSF)

Free-flap reconstruction following tumor resection and chemotherapy is used increasingly in sarcoma patients. Granulocyte colony-stimulating factor (GCSF) is used to stimulate polymorphnuclear leukocytes (PMNs). In this study we used a free-flap model to investigate PMN behavior after chemotherapy and GCSF stimulation. Eighteen Lewis rats were divided into three groups: (1) chemotherapy + vehicle; (2) chemotherapy + GCSF; and (3) control. Group 1 received vinblastine; group 2 received vinblastine plus 300 microg rhGCSF. Blood was drawn for total white cell and PMN counts for 9 days. Free-flap surgery was simulated by isolating the cremaster muscle on its pedicle and anastomosing the artery. Leukocyte-endothelium interaction was assessed by observation of leukocytes rolling and sticking. Leukocyte sequestration was measured by counting leukocytes in the lungs and the abdomen. We found that leukocyte rolling and sticking were significantly increased, while sequestration was decreased in the chemotherapy + GCSF group. We conclude that leukocytes-endothelium interaction after chemotherapy and GCSF administration is increased in the microcirculation. This augments the risk of microvascular compromise and subsequent flap failure, as capillary flow may be altered.

Exclusive expression of G-CSF receptor on myeloid progenitors in bone marrow CD34+ cells

Although granulocyte colony-stimulating factor (G-CSF) has been reported to act on cells of neutrophilic lineage, the administration of G-CSF to induce the mobilization of various haematopoietic progenitors into the circulation. We analysed the expression of receptors for G-CSF (G-CSFR) on human bone marrow and G-CSF-mobilized peripheral blood CD34+ cells, and examined the proliferation and differentiation capabilities of sorted CD34+G-CSFR+ and CD34+G-CSFR- cells using methylcellulose clonal culture. Flow cytometric analysis showed that G-CSFR was expressed on 14.9 +/- 4.9% of bone marrow CD34+ cells, most of which were included in CD34+CD33+ and CD34+CD38+ cell fractions. In clonal cultures, CD34+G-CSFR+ cells produced only myeloid colonies, whereas CD34+G-CSFR- cells produced erythroid bursts, megakaryocyte and multilineage colonies. When incubated with the cytokine cocktail for 5 d, CD34+G-CSFR- cells generated CD34+G-CSFR+ myeloid progenitors. In G-CSF-mobilized peripheral blood, CD34+ cells contained 10.8 +/- 5.8% of G-CSFR+ cells, most of which were also myeloid progenitors, although CD34+G-CSFR- cells contained a substantial number of myeloid progenitors. These results indicated that the expression of G-CSFR on CD34+ cells is restricted to myeloid progenitors, suggesting that the specific activity of G-CSF on myelopoiesis depends on the exclusive expression of its receptor on myeloid progenitors, and that the mobilization of various haematopoietic progenitors is not a direct effect of G-CSF in humans.

Recombinant human granulocyte colony-stimulating factor after kidney transplantation: a retrospective analysis to evaluate the benefit or risk of immunostimulation

BACKGROUND

Leukopenia due to immunosuppressive drugs represents a well-known complication in graft recipients, which might put patients at an increased risk for infections. In this study, recombinant human granulocyte colony-stimulating factor (rhG-CSF), a hematopoietic growth factor that selectively stimulates neutrophil colony formation and neutrophil cell differentiation, was tested for safety and efficacy.

METHODS

We evaluated 30 episodes of leukopenia (<2000/mm3) in 19 kidney graft recipients treated with rhG-CSF. This cohort was compared with an age- and sex-matched historical control group without therapy. Peripheral and differential blood cell counts were analyzed, and the duration of leukopenia was estimated. Furthermore, the occurrence of infections associated with leukopenia was investigated.

RESULTS

All patients responded to rhG-CSF therapy. Peripheral leukocyte counts increased from 1756+/-582 to a peak of 8723+/-3038/mm3 (P<0.0001). On the average, the peak was reached after 2.7 days (range 1 to 8). Furthermore, the effect was fairly persistent, because in 22 of 30 episodes leukocyte counts were within the normal range after 7 days. The elevation of total leukocytes was mainly due to a specific increase in neutrophil granulocytes from 1143+/-514 to 6895+/-1950/mm3 on the peak day (P<0.0001). Patients in the G-CSF group were leukopenic for a mean of 1.29+/-0.59 days, whereas in the control group leukopenia persisted for at least 7 days. Consequently, the rate of infections was significantly higher (P<0.045) in nontreated patients.

CONCLUSION

rhG-CSF was safe and effective in leukopenic kidney graft recipients. Leukopenic episodes in treated patients were significantly shorter, and infections occurred at a significantly lower rate. No evidence was found that rhG-CSF therapy might trigger rejection episodes, and no side effects were observed.

Neutropenia, neutrophil dysfunction, and bacterial infection in patients with human immunodeficiency virus disease: the role of granulocyte colony-stimulating factor

Neutropenia frequently complicates infection due to human immunodeficiency virus (HIV). The etiology of neutropenia in this setting includes bone marrow infection or infiltration, myelosuppressive therapies, the presence of antibodies to HIV, and accelerated apoptosis. Protection against microbial invaders by neutrophils is further compromised by impaired chemotaxis and phagocytosis, production of toxic oxygen species, and expression of cellular adhesion molecules. Neutropenia is a significant risk factor for bacterial infection in HIV-infected patients. Endogenous cytokines, such as granulocyte colony-stimulating factor (G-CSF) and granulocyte-macrophage colony-stimulating factor, regulate neutrophil count and function. Treatment with recombinant human methionyl G-CSF (filgrastim) has lessened neutropenia in patients with HIV infection. Clinical trials have shown that the incidence of bacterial infections and the number of consequent days of hospitalization for HIV-infected patients receiving filgrastim therapy are lower. Filgrastim treatment also allows administration of larger doses of myelosuppressive agents.

Biopharmaceutical drug development: Filgrastim (r-metHuG-CSF) use in patients with HIV infection

Hematopoietic growth factors are well known to increase neutrophil counts and support the administration of myelotoxic and myelosuppressive therapies, especially chemotherapies. Filgrastim (r-metHuG-CSF) has been used in the setting of HIV disease to treat neutropenia and HIV-associated neutrophil defects. This article reviews the biology, product characteristics, and preclinical and clinical development of Filgrastim. Emphasis is given on the use of Filgrastim in the setting of HIV infection and AIDS.

Randomized, placebo-controlled, double-blind, multicenter trial of efficacy and safety of granulocyte colony-stimulating factor in liver transplant recipients

BACKGROUND

Infection and rejection are two common complications after liver transplants. In a preliminary study, administration of granulocyte colony-stimulating factor (G-CSF) to liver transplant recipients was associated with a decrease in sepsis episodes, sepsis-related deaths, and rejection compared with a historical control group of patients. The purpose of this study was to evaluate further the efficacy of G-CSF in liver transplant patients in a randomized, placebo-controlled, double-blind, multicenter trial.

METHODS

Adult patients with a United Network Organ Sharing classification of 1 or 2 were randomized to receive a placebo, 100 microg/day of G-CSF or 300 microg/day of G-CSF. The study drug was started preoperatively and then continued after the transplant for a maximum of 21 days. Patients were evaluated for microbiologically-documented infection, biopsy-proven rejection, number of treatments for rejection, length of stay in the intensive care unit and hospital, graft survival, death, and adverse events.

RESULTS

During the first 30 days after the transplant, the median peak white blood cell count was 16.5x10(9)/L, 34.6x10(9)L, and 54.8x10(9)/L for the placebo, low-dose G-CSF, and high-dose G-CSF patients, respectively. The incidence of infection was 30% in G-CSF patients (34 of 114 patients) and 34% in placebo patients (20 of 58 patients). Except for more nosocomial pneumonias in the G-CSF patients (7 in 114 patients vs. 0 in 58 patients, P=0.056), the types of infections and causative organisms were also similar in both treatment groups. Although the number of treatments for clinically suspected or proven rejection was similar in the G-CSF and placebo patients, biopsy-proven rejection occurred more often in G-CSF patients (34 of 114 patients or 30%) than placebo patients (11 of 58 patients or 19%) (P=0.093). There were no cases of graft loss caused by rejection. G-CSF had no effect on length of stay in the intensive-care unit or hospital. There were 22 G-CSF patients (18%) and 10 placebo patients (15%) who died within 120 days after the transplant. No serious adverse events were attributed to G-CSF.

CONCLUSION

Despite producing substantial increases in the white blood cell count after the transplant, G-CSF had no beneficial effects on infection, rejection, or survival in this study. Biopsy-proven rejection and nosocomial pneumonias were more common in patients treated with G-CSF compared with those taking the placebo. No serious adverse events were attributed to G-CSF.

Autocrine growth regulation by granulocyte colony-stimulating factor and granulocyte macrophage colony-stimulating factor in human gliomas with tumor progression

Granulocyte colony-stimulating factor (G-CSF) and granulocyte macrophage colony-stimulating factor (GM-CSF) and/or their receptors are increasingly detected in solid human tumors, although little is known about their function in tumor growth and invasion. We analyzed RNA and protein expression of both factors and their receptors in 22 human gliomas (WHO grade II, III, and IV) and derived cell cultures. G-CSF, GM-CSF, and/or their receptors were expressed in all tumors and derived cell cultures, but coexpression of both factors and receptors was almost exclusively found in grade IV glioblastomas and thus correlated with advanced tumor stage. The functional significance of G-CSF and GM-CSF as regulators for glioma cells was demonstrated by 1) stimulation of proliferation and migration in tumor cells expressing one or both receptors by the corresponding factor; 2) inhibition of growth and migration of glioma cells expressing G-CSF, GM-CSF, and their receptors by neutralizing antibodies to both factors. These results indicate a significant role for both factors in the autocrine regulation of growth and migration in late-stage malignant gliomas and suggest a shift from paracrine to autocrine regulation with tumor progression. The implication of G-CSF and GM-CSF in glioblastoma growth regulation could make these factors further prognostic indicators and raises questions concerning their use in cancer therapy.

The effect of G-CSF on the composition of human bone marrow

The effects on bone marrow cellularity and morphology of 6 days' treatment with granulocyte colony-stimulating factor (G-CSF) in 35 patients were studied. Examination of trephine biopsies showed a highly significant increase in cellularity (P < 10-13). Assessment of aspirates revealed an increase in the myeloid to erythroid (M : E) ratio (P = 0.00006), the proportion of myeloid cells (P < 10-8), myelocytes (P = 0.00007), metamyelocytes (P = 0.04), band forms (P = 0.0005) and neutrophils (P = 0.02). This study presents a comprehensive analysis of the effects of six days' administration of G-CSF on human bone marrow.