Perioperative treatment with filgrastim stimulates granulocyte function and reduces infectious complications after esophagectomy

G-CSF enhances resolution of Staphylococcus aureus wound infection in an age-dependent manner

This study tested the hypothesis that heightened bacterial colonization and delayed wound closure in aged mice could be attenuated by granulocyte colony-stimulating factor (G-CSF) treatment. Previously, we reported that aged mice had elevated bacterial levels, protracted wound closure, and reduced wound neutrophil accumulation after Staphylococcus aureus wound infection relative to young mice. In aseptic wound models, G-CSF treatment improved wound closure in aged mice to rates observed in young mice. Given these data, our objective was to determine if G-CSF could restore age-associated differences in wound bacterial burden and closure by increasing wound neutrophil recruitment. Young (3- to 4-month) and aged (18- to 20-month) BALB/c mice received three dorsal subcutaneous injections of G-CSF (250 ng/50 μL per injection) or saline control (50 μL per injection) 30 min after wound infection. Mice were killed at days 3 and 7 after wound infection, and bacterial colonization, wound size, wound leukocyte accumulation, and peripheral blood were evaluated. At days 3 and 7 after wound infection, bacterial colonization was significantly reduced in G-CSF-treated aged mice to levels observed in saline-treated young animals. Wound size was reduced in G-CSF-treated aged animals, with no effect on wound size in G-CSF-treated young mice. Local G-CSF treatment significantly enhanced neutrophil wound accumulation in aged mice, whereas there was no G-CSF-induced change in young mice. These data demonstrate that G-CSF enhances bacterial clearance and wound closure in an age-dependent manner. Moreover, G-CSF may be of therapeutic potential in the setting of postoperative wound infection or chronic nonhealing wounds in elderly patients.

Use of granulocyte colony-stimulating factor in patients with severe sepsis or septic shock

PURPOSE

The efficacy and safety of granulocyte colony-stimulating factor (G-CSF) in critically ill patients with severe sepsis or septic shock were evaluated.

SUMMARY

The medical literature was reviewed to identify published trials, case reports, and case series on the use of G-CSF in critically ill patients for treatment of severe sepsis or septic shock. G-CSF has been evaluated as an adjunct to standard care for critically ill patients. Initial studies involving critically ill patients with severe sepsis or septic shock found mortality benefits with G-CSF therapy; however, these findings are limited by factors such as small sample sizes, selection bias, and lack of an appropriate control group. Prospective, randomized, multicenter, double-blind studies failed to confirm the benefits in mortality for patients receiving G-CSF for the treatment of severe sepsis and septic shock. Due to the limitations in the design of the studies that report a mortality benefit and prospective, randomized, multicenter, double-blind studies that report the lack of a mortality benefit, a recommendation to add G-CSF as an adjunctive therapy in critically ill patients with severe sepsis and septic shock cannot be made at this time.

CONCLUSION

The available data, especially those from large, prospective, randomized, double-blind studies, do not support the use of G-CSF as an adjunct therapy to standard care for critically ill patients with severe sepsis or septic shock. Data from prospective, large, randomized, controlled, well-designed studies are needed to define the optimal G-CSF dosing regimen, the safety of this therapy, and the effects of G-CSF on patient morbidity and survival.

Hematologic effects of subcutaneous administration of recombinant human granulocyte colony-stimulating factor (filgrastim) in healthy alpacas

OBJECTIVE

To determine the effects of SC administration of filgrastim on cell counts in venous blood and bone marrow of healthy adult alpacas.

ANIMALS

10 healthy alpacas.

PROCEDURES

Alpacas were randomly assigned to receive treatment with filgrastim (5 microg/kg, SC; n=5) or an equivalent volume of physiologic saline (0.9% NaCl) solution (5) once a day for 3 days. Blood samples were obtained via jugular venipuncture 1 day prior to treatment and once a day for 5 days commencing 24 hours after the first dose was administered. Complete blood counts were performed for each blood sample. Bone marrow aspirates were obtained from the sternum of each alpaca 48 hours before the first treatment was administered and 72 hours after the third treatment was administered. Myeloid-to-erythroid cell (M:E) ratio was determined via cytologic evaluation of bone marrow aspirates.

RESULTS

In filgrastim-treated alpacas, substantial increases in counts of WBCs and neutrophils were detected within 24 hours after the first dose was administered. Band cell count and percentage significantly increased 24 hours after the second dose. Counts of WBCs, neutrophils, and band cells remained high 48 hours after the third dose. Red blood cell counts and PCV were unaffected. The M:E ratio also increased significantly after treatment with filgrastim.

CONCLUSIONS AND CLINICAL RELEVANCE

Filgrastim induced rapid and substantial increases in numbers of circulating neutrophils and M:E ratios of bone marrow in healthy alpacas. Therefore, filgrastim may be useful in the treatment of camelids with impaired bone marrow function.

Toward improving mucosal barrier defenses: rhG-CSF plus IgG antibody

Epithelial cell functions ultimately define the ability of the extremely low birth weight human fetus to survive outside of the uterus. These specialized epithelial cell capacities manage all human interactions with the ex utero world including: (i) lung mechanics, surface chemistry and gas exchange, (ii) renal tubular balance of fluid and electrolytes, (iii) barrier functions of the intestine and skin for keeping bacteria out and water in, plus enabling intestinal digestion, as well as (iv) maintaining an intact neuroepithelium lining of the ventricles of the brain and retina. In Part I of this two part review, the authors describe why the gut barrier is a clinically relevant model system for studying the complex interplay between innate and adaptive immunity, dendritic &epithelial cell interactions, intraepithelial lymphocytes, M-cells, as well as the gut associated lymphoid tissues where colonization after birth, clinician feeding practices, use of antibiotics as well as exposure to prebiotics, probiotics and maternal vaginal flora all program the neonate for a life-time of immune competence distinguishing "self" from foreign antigens. These barrier defense capacities become destructive during disease processes like necrotizing enterocolitis (NEC) when an otherwise maturationally normal, yet dysregulated and immature, immune defense system is associated with high levels of certain inflammatory mediators like TNFa. In Part II the authors discuss the rationale for why rhG-CSF has theoretical advantages in managing NEC or sepsis by augmenting neonatal neutrophil number, neutrophil expression of Fcg and complement receptors, as well as phagocytic function and oxidative burst. rhG-CSF also has potent anti-TNFa functions that may serve to limit extension of tissue destruction while not impairing bacterial killing capacity. Healthy, non-infected neutropenic and septic neonates differ in their ability to respond to rhG-CSF; however, no neonatal clinical trials to date have identified a clear clinical benefit of rhG-CSF therapy. This manuscript will review the literature and evidence available for identifying the ideal subject for cytokine treatment using NEC as the model disease target.

THE EFFECTS OF GRANULOCYTE COLONY-STIMULATING FACTOR IN PRECLINICAL MODELS OF INFECTION AND ACUTE INFLAMMATION

The cytokine granulocyte colony-stimulating factor (G-CSF) is a potent endogenous trigger for the release of neutrophils from bone marrow stores and for their activation for enhanced antimicrobial activity. G-CSF has been widely evaluated in preclinical models of acute illness, with generally promising though divergent results. A recombinant G-CSF molecule has recently undergone clinical trials to assess its efficacy as an adjuvant therapy in community-acquired and nosocomial pneumonia, however, these studies failed to provide convincing evidence of benefit. We undertook a systematic review of the published literature reporting the effects of modulation of G-CSF in preclinical in vivo models to determine whether evidence of differential efficacy might explain the disappointing results of human studies and point to disease states that might be more likely to benefit from G-CSF therapy. G-CSF has been evaluated in 86 such studies involving a variety of different models. The strongest evidence of benefit was seen in studies involving intraperitoneal challenge with live organisms; benefit was evident whether the agent was given before or after challenge. G-CSF demonstrates anti-inflammatory activity in models of systemic challenge with viable organisms or endotoxin, but only when the agent is given before challenge; evidence of benefit after challenge was minimal. Preclinical models of intrapulmonary challenge only show efficacy when the cytokine is administered before the infectious challenge, and suggested harm in gram-negative pneumonia resulting from challenge with Escherichia coli or Klebsiella. There is little evidence for therapeutic efficacy in noninfectious models of acute illness. We conclude that the most promising populations for evaluation of G-CSF are neutropenic patients with invasive infection and patients with intra-abdominal infection, particularly those with the syndrome of tertiary, or recurrent, peritonitis. Significant variability in the design and reporting of studies of preclinical models of acute illness precludes more sophisticated data synthesis.

Perioperative granulocyte colony-stimulating factor does not prevent severe infections in patients undergoing esophagectomy for esophageal cancer: a randomized placebo-controlled clinical trial

OBJECTIVE

Esophagectomy for esophageal cancer is associated with substantial postoperative morbidity as a result of infectious complications. In a prior phase II study, granulocyte colony-stimulating factor (G-CSF) was shown to improve leukocyte function and to reduce infection rates after esophagectomy. The aim of the current randomized, placebo-controlled, multicenter phase III trial was to investigate the clinical efficacy of perioperative G-CSF administration in reducing infection and mortality after esophagectomy for esophageal cancer.

PATIENTS AND METHODS

One hundred fifty five patients with resectable esophageal cancer were randomly assigned to perioperative G-CSF at standard doses (77 patients) or placebo (76 patients), administered from 2 days before until day 7 after esophagectomy. The G-CSF and placebo groups were comparable as regards age, gender, risk, cancer stage, frequency of neoadjuvant radiochemotherapy, and type of esophagectomy (transthoracic or transhiatal esophageal resection).

RESULTS

Of 155 randomized patients, 153 were eligible for the intention-to-treat analysis. The rate of infection occurring within the first 10 days after esophagectomy was 43.4% (confidence interval 32.8-55.9%) in the placebo and 44.2% (confidence interval 32.1-55.3%) in the G-CSF group (P = 0.927). 30-day mortality amounted to 5.2% in the G-CSF group versus 5.3% in the placebo group (P = 0.985). Similar results were found in the per-protocol analysis.

CONCLUSION

Perioperative administration of G-CSF failed to reduce postoperative morbidity, infection rate, or mortality in patients with esophageal cancer who underwent esophagectomy.

Influence of surgical intervention in the immune response of severely injured patients

OBJECTIVE

Primary events such as severe injury and elective surgery cause a deterioration of the immune response measurable by reduction of expression of HLA-DR on monocytes or ex vivo LPS-induced TNFalpha production. The further influence of secondary surgery after severe injury on the immune response remains unresolved.

DESIGN

Prospective observation study.

SETTING

Surgical intensive care unit of an university hospital.

PATIENTS

Sixteen severely injured patients with an ISS >25 points.

MEASUREMENTS AND RESULTS

On day 1 after trauma and immediately before secondary surgery, mean fluorescence intensity (MFI) of HLA-DR expression on monocytes and TNFalpha ex vivo synthesis was significantly reduced compared to healthy donors. Overall, surgical intervention during the second week after trauma caused no further reduction of HLA-DR expression on monocytes and of the ex vivo TNFalpha-synthesis. However, major surgery such as intramedullary nailing or pelvic osteosynthesis caused reduction of the HLA-DR expression and TNFalpha-synthesis, whereas, minor surgical interventions such as osteosynthesis on peripheral joints exhibited no significant effects on the immune response. Surgical intervention performed to clear septic foci normalised immune response by elevating HLA-DR expression on monocytes and ex vivo TNFalpha synthesis. Severe injury caused elevated serum IL-10 levels, whereas secondary surgery did not induce a further increase in serum IL-10 levels.

CONCLUSION

This study shows that initial trauma as well as major secondary surgery causes a suppression of immune functions, whereas minor secondary surgery does not cause significant immune disturbance.

Effects of exogenous recombinant human granulocyte colony-stimulating factor (filgrastim, rhG-CSF) on neutrophils of critically ill patients with systemic inflammatory response syndrome depend on endogenous G-CSF plasma concentrations on admission

OBJECTIVE

To investigate the effects of exogenous recombinant human granulocyte colony-stimulating factor (rhG-CSF; filgrastim) application on the neutrophils of patients at risk of sepsis following major trauma or operation.

DESIGN

Randomized controlled trial.

SETTING

Surgical intensive care unit and research laboratory of a university hospital.

PATIENTS

Twenty-seven patients with systemic inflammatory response syndrome (SIRS).

INTERVENTIONS

Thirteen patients were treated with filgrastim (1 micro g.kg.24 h) for 10 days as a continuous infusion. Fourteen patients served as controls.

MEASUREMENTS AND RESULTS

Surface expression of FcgammaR type I (CD64), phagocytosis of E. coli, and the E. coli-induced oxidative burst of neutrophils were tested by flow cytometry. On the first postoperative/posttraumatic day, endogenous G-CSF plasma concentrations were <300 pg/ml in seven controls (subgroup 1) and nine filgrastim patients (subgroup 3), and were already elevated with >500 pg/ml in seven controls (subgroup 2) and four filgrastim patients (subgroup 4). G-CSF values ( P=0.0026, subgroup 1/3; P=0.0167, 2/4), neutrophil counts ( P=0.0026, 1/3; P=0.0167, 2/4), and CD64 expression ( P=0.0013, 1/3) were higher in filgrastim-treated than non-treated subgroups, but not phagocytic and burst activities. From day zero to day 1, phagocytosis decreased in subgroups 1 (5/7 patients) and 3 (5/9), but increased in subgroups 2 (5/7) and 4 (3/4), and respiratory burst activity decreased in subgroup 3 (8/9).

CONCLUSIONS

Besides activation of neutrophil maturation, low-dose rhG-CSF application in postoperative patients with SIRS has different effects on neutrophil functions, in part depending on already endogenously produced G-CSF.

Multicenter, double-blind, placebo-controlled study of the use of filgrastim in patients hospitalized with pneumonia and severe sepsis

OBJECTIVE

To determine the safety and efficacy of filgrastim (r-metHuG-CSF) in combination with intravenous antibiotics to reduce the rate of mortality in patients with pneumonia and sepsis.

DESIGN

This study was multicenter, double-blind, and randomized.

SETTING

Intensive care units PATIENTS Adult patients with bacterial pneumonia, either acquired or nosocomial, as confirmed by chest radiograph and positive culture or Gram-negative stain, and severe sepsis, defined as sepsis-induced hypotension or organ dysfunction.

INTERVENTIONS

Standard antibiotic therapy with or without filgrastim (300 microg/day) or placebo administered as a 30-min intravenous infusion. The study drug was started within 24 hrs of enrollment and was continued for 5 days or until the white blood cell count reached >75.0 x 10(9) cells/L.

MEASUREMENTS AND MAIN RESULTS

The primary end point was the occurrence of mortality through day 29; secondary end points included occurrence of subsequent organ dysfunction, time to discharge from intensive care unit, number of days on mechanical ventilatory support, and time to death. Study-related observations were recorded through day 10 and included vital signs, onset of organ dysfunction, clinical laboratory variables, and adverse events. Filgrastim increased the white blood cell count to a median peak of 31.7 x 10(9) cells/L from a baseline of 12.3 x 10(9) cells/L. The two groups were well matched and did not differ significantly with regard to severe adverse events, time to death, occurrence of end-organ dysfunction, days of intensive care unit hospitalization, or days on mechanical ventilatory support. Mortality was low in both treatment groups; the mortality rate in patients with adult respiratory distress syndrome was similar between the two groups.

CONCLUSIONS

The addition of filgrastim to the antibiotic and supportive care treatment of patients with pneumonia complicated by severe sepsis appeared to be safe, but not efficacious in reducing mortality rates or complications from this infection.

Induction and regulation of endogenous granulocyte colony-stimulating factor formation

Granulocyte colony-stimulating factor (G-CSF) is one of the most prominent endogenous proteins in broad clinical use. While its biological and clinical effects are relatively well studied, little is known about its endogenous formation in health and disease. However, such knowledge is crucial to decide in which situations G-CSF should be applied efficiently in the clinic, ie. when endogenous production does not suffice. The dramatic changes induced by G-CSF in the differential blood cell count are directly immunomodulatory, strengthening the innate defence by multiplying neutrophilic granulocytes. A multitude of further immunomodulatory effects contribute to the regulation of the concerted host defence. In this review, following a short introduction into the biology of G-CSF, the available data on endogenous formation in a number of animal models and human diseases is compiled. The cellular sources and inducers of G-CSF formation are reviewed and the regulation of G-CSF expression on both the transcriptional and translational level are discussed. The emerging understanding of the role and regulation of endogenous G-CSF formation opens up possibilities to define therapeutic windows as well as targets for diagnostics or drug development. Lastly, the modulation of G-CSF formation by various pharmacological agents alerts to putative side effects of these drug treatments.

Granulocyte colony-stimulating factor enhances host defenses against bacterial pneumonia following peritonitis in nonneutropenic rats

OBJECTIVE

Polymorphonuclear cell functions frequently are impaired in critically ill patients, and restoration of normal functions could help to prevent nosocomial infections. The aim of this study was to evaluate the effects of pretreatment with granulocyte colony-stimulating factor (G-CSF) on bacterial pneumonia induced 48 hrs after peritonitis (cecal ligation and puncture [CLP]) in rats.

DESIGN

Controlled animal study.

SETTING

Research laboratory of an academic institution.

SUBJECTS

Male Sprague-Dawley rats.

INTERVENTIONS

First, the CLP model was characterized. Second, alveolar endotoxin instillation allowed us to evaluate the ability of neutrophils to migrate to airspaces after CLP was assessed. In the last set of experiments, CLP was followed by G-CSF treatment as a preventive therapy for subsequent bacterial superinfection induced by alveolar instillation.

MEASUREMENTS AND MAIN RESULTS

CLP induced a brief increase in proinflammatory cytokines (tumor necrosis factor-alpha, interleukin-1beta) at the 6th hr followed by a longer-lived anti-inflammatory response (interleukin-10 increase from days 1 to 3) in plasma, compared with healthy rats. Impaired neutrophil migration to alveolar spaces denoting immunoparalysis was evidenced after endotracheal endotoxin instillation following CLP, compared with non-CLP rats challenged with endotoxin. No such impairment was found when G-CSF (100 microg/kg: glycosylated recombinant human G-CSF, Lenograstim) was given before endotoxin. G-CSF (100 microg/kg 24 and 48 hrs after CLP) given before endotracheal instillation increased bacterial clearance, as shown by counts in both bronchoalveolar lavage (8.9 x 10 +/- 2.8 x 10 colony-forming units/mL vs. 3.3 x 10 +/- 1.5 x 10 colony-forming units/mL with saline) and lung tissue (4.2 x 10 +/- 1.0 x 10 colony-forming units/g vs. 1.5 x 10 +/- 0.6 x 10 colony-forming units/g with saline). Furthermore, G-CSF pretreatment kept clearance in CLP rats similar to that in non-CLP rats challenged with.

CONCLUSION

These results suggest that G-CSF (Lenograstim) may enhance host defenses in rats with peritonitis and immunoparalysis.

Granulocyte colony-stimulating factor improves deficient in vitro neutrophil transendothelial migration in patients with advanced liver disease

Bacterial infections are frequent complications in patients with liver cirrhosis. Cirrhotic patients present abnormalities in both innate and adaptive immune responses, including a deficient neutrophil recruitment to infected sites. The purpose of this study was to assess neutrophil-endothelium interactions in cirrhotic patients and evaluate the effects of G-CSF on this process. We studied neutrophil adhesion and transendothelial migration in 14 cirrhotic patients and 14 healthy controls. We also analyzed neutrophil expression of the adhesion molecules CD62L and CD11b in whole blood by flow cytometry. Cirrhotic patients expressed higher levels of CD11b than healthy controls, whereas CD62L expression was significantly lower, suggesting exposure of neutrophils to activating agents within the bloodstream. Neutrophils from cirrhotic patients showed increased adhesion to both resting and tumor necrosis factor alpha-stimulated microvascular endothelial cells and decreased transendothelial migration. Granulocyte colony-stimulating factor (G-CSF) (100 ng/ml) significantly enhanced neutrophil adhesion to microvascular endothelial cells in healthy controls but not in cirrhotic patients. G-CSF also significantly improved neutrophil transmigration in cirrhotic patients and healthy controls. In conclusion, cirrhotic patients exhibit increased neutrophil adhesion to microvascular endothelium and deficient transendothelial migration. G-CSF enhances neutrophil transendothelial migration in cirrhotic patients despite having no effect on neutrophil adhesion. Therefore, G-CSF may be able to increase neutrophil recruitment into infected sites in these patients.

Immune-stimulating effects of low-dose perioperative recombinant granulocyte-macrophage colony-stimulating factor in patients operated on for primary colorectal carcinoma

BACKGROUND

Surgery induces a postoperative immunosuppression, thereby possibly facilitating the outgrowth of pre-existing occult metastases or the seeding of disseminated tumour cells in patients with primary colorectal carcinoma operated on with curative intent. The hypothesis that adjuvant therapy with perioperative recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) would minimize postoperative immunosuppression was investigated in this pilot study.

METHODS

Patients were allocated randomly to receive daily subcutaneous injections with either saline (n = 8) or rhGM-CSF 2.8 microg per kg body-weight (n = 8) from 3 days before operation until 4 days afterwards. Phytohaemagglutinin (PHA) skin test reactivity, monocyte human leucocyte antigen (HLA) DR expression and the extent of the acute-phase response, by determination of white blood cell count and differentiation, plasma interleukin (IL) 6 levels and body temperature in the perioperative period, were examined.

RESULTS

rhGM-CSF treatment minimized postoperative suppression in PHA skin test reactivity and increased the numbers of neutrophils and monocytes while enhancing the expression of HLA-DR in the postoperative period. Additionally, both postoperative plasma IL-6 levels and the incidence of fever tended to be higher in the rhGM-CSF group.

CONCLUSION

In this pilot study, perioperative administration of low-dose rhGM-CSF stimulated certain immune functions that are normally depressed after operation. The implications for the antitumour responses directly after operation and the formation of liver metastases are currently under investigation.

Increase of anti-inflammatory cytokines in patients with esophageal cancer after perioperative treatment with G-CSF

Granulocyte colony-stimulating factor (G-CSF) has been shown to effectively stimulate granulopoiesis, in both neutropenic and in non-neutropenic patients. Recently, other effects of G-CSF on the immune system have attracted interest in treating non-neutropenic patients with a high risk of severe infection. In this phase II trial, we measured the effects of G-CSF on the serum cytokine levels in patients with esophageal cancer undergoing esophagectomy. Twenty subsequent patients (study group, 19 evaluable) received G-CSF (rhG-CSF, Filgrastim) at standard doses (300 microg or 480 microg) subcutaneously 2 days before and up to 7 days after surgery. G-CSF was well tolerated. Leukocytes increased from 7600/microl at study entry (day -2) to a maximum of 45 100/microl (day 6). In the study patients, we found a highly significant (P<0.001) postoperative increase of G-CSF, IL-1ra, sTNFRp55 and sTNFRp75 as compared with the baseline level. In contrast, IL-8 levels were decreased by a factor of 6.8; there were no changes in the very low TNF-alpha levels. The comparison of the study group with a control group of 21 cancer patients undergoing major surgery who were not treated with G-CSF showed significant differences in the serum levels of G-CSF, sTNFRp55, sTNFRp75, and IL-1ra, respectively. There was no infection in the study group up to 10 days after surgery as compared with 29.9% in a historical control group (P=0.008). Thus, the induction of anti-inflammatory cytokines and the downregulation of pro-inflammatory cytokines by G-CSF might be a promising adjuvant treatment of infectious complications in patients undergoing esophagectomy.