Biological activities of a human pluripotent hemopoietic colony stimulating factor on normal and leukemic cells

A novel optical tracer for VMAT2 applied to live cell measurements of vesicle maturation in cultured human β-cells

The islet β-cells integrate external signals to modulate insulin secretion to better regulate blood glucose levels during periods of changing metabolic demand. The vesicular monoamine transporter type 2 (VMAT2), an important regulator of CNS neurotransmission, has an analogous role in the endocrine pancreas as a key control point of insulin secretion, with additional roles in regulating β-cell differentiation and proliferation. Here we report on the synthesis and biological characterisation of a fluorescent ligand for VMAT2 suitable for live cell imaging. Staining for VMAT2 and dopamine in live β-cell cultures show colocalisation in specific vesicles and reveal a heterogeneous population with respect to cell size, shape, vesicle number, size, and contents. Staining for VMAT2 and zinc ion, as a surrogate for insulin, reveals a wide range of vesicle sizes. Immunohistochemistry shows larger β-cell vesicles enriched for proinsulin, whereas smaller vesicles predominantly contain the processed mature insulin. In β-cell cultures obtained from nondiabetic donors, incubation at non-stimulatory glucose concentrations promotes a shift in vesicle diameter towards the more mature insulin vesicles at the expense of the larger immature insulin secretory vesicle population. We anticipate that this probe will be a useful reagent to identify living β-cells within complex mixtures for further manipulation and characterisation.

Granulocyte-colony stimulating factor and umbilical cord blood cell transplantation: Synergistic therapies for the treatment of traumatic brain injury

Traumatic brain injury (TBI) is now characterized as a progressive, degenerative disease and continues to stand as a prevalent cause of death and disability. The pathophysiology of TBI is complex, with a variety of secondary cell death pathways occurring which may persist chronically following the initial cerebral insult. Current therapeutic options for TBI are minimal, with surgical intervention or rehabilitation therapy existing as the only viable treatments. Considering the success of stem-cell therapies in various other neurological diseases, their use has been proposed as a potential potent therapy for patients suffering TBI. Moreover, stem cells are highly amenable to adjunctive use with other therapies, providing an opportunity to overcome the inherent limitations of using a single therapeutic agent. Our research has verified this additive potential by demonstrating the efficacy of co-delivering human umbilical cord blood (hUCB) cells with granulocyte-colony stimulating factor (G-CSF) in a murine model of TBI, providing encouraging results which support the potential of this approach to treat patients suffering from TBI. These findings justify ongoing research toward uncovering the mechanisms which underlie the functional improvements exhibited by hUCB + G-CSF combination therapy, thereby facilitating its safe and effect transition into the clinic. This paper is a review article. Referred literature in this paper has been listed in the reference section. The datasets supporting the conclusions of this article are available online by searching various databases, including PubMed. Some original points in this article come from the laboratory practice in our research center and the authors’ experiences.

Translating G-CSF as an Adjunct Therapy to Stem Cell Transplantation for Stroke

Among recently investigated stroke therapies, stem cell treatment holds great promise by virtue of their putative ability to replace lost cells, promote endogenous neurogenesis,and produce behavioral and functional improvement through their "bystander effects." Translating stem cell in the clinic, however, presents a number of technical difficulties. A strategy suggested to enhance therapeutic utility of stem cells is combination therapy, i.e., co-transplantation of stem cells or adjunct treatment with pharmacological agents and substrates,which is assumed to produce more profound therapeutic benefits by circumventing limitations of individual treatments and facilitating complementary brain repair processes. We previously demonstrated enhanced functional effects of cotreatment with granulocyte-colony stimulating factor (GCSF)and human umbilical cord blood cell (hUCB) transplantation in animal models of traumatic brain injury (TBI). Here,we suggest that the aforementioned combination therapy may also produce synergistic effects in stroke. Accordingly, G-CSF treatment may reduce expression of pro-inflammatory cytokines and enhance neurogenesis rendering a receptive microenvironment for hUCB engraftment. Adjunct treatment of GCSF with hUCB may facilitate stemness maintenance and guide neural lineage commitment of hUCB cells. Moreover, regenerative mechanisms afforded by G-CSF-mobilized endogenous stem cells, secretion of growth factors by hUCB grafts and G-CSF-recruited endothelial progenitor cells(EPCs), as well as the potential graft–host integration that may promote synaptic circuitry re-establishment could altogether produce more pronounced functional improvement in stroked rats subjected to a combination G-CSF treatment and hUCB transplantation. Nevertheless, differences in pathology and repair processes underlying TBI and stroke deserve consideration when testing the effects of combinatorial G-CSF and hUCB cell transplantation for stroke treatment. Further studies are also required to determine the safety and efficacy of this intervention in both preclinical and clinical stroke studies.

G-CSF as an adjunctive therapy with umbilical cord blood cell transplantation for traumatic brain injury

Traumatic brain injury (TBI), a major contributor to deaths and permanent disability worldwide, has been recently described as a progressive cell death process rather than an acute event. TBI pathophysiology is complicated and can be distinguished by the initial primary injury and the subsequent secondary injury that ensues days after the trauma. Therapeutic opportunities for TBI remain very limited with patients subjected to surgery or rehabilitation therapy. The efficacy of stem cell-based interventions, as well as neuroprotective agents in other neurological disorders of which pathologies overlap with TBI, indicates their potential as alternative TBI treatments. Furthermore, their therapeutic limitations may be augmented when combination therapy is pursued instead of using a single agent. Indeed, we demonstrated remarkable combined efficacy of human umbilical cord blood (hUCB) cell therapy and granulocyte-colony-stimulating factor (G-CSF) treatment in TBI models, providing essential evidence for the translation of this approach to treat TBI. Further studies are warranted to determine the mechanisms underlying therapeutic benefits exerted by hUCB + G-CSF in order to enhance its safety and efficacy in the clinic.

Leukocyte cell population analysis from the coulter automatic blood cell analyzer DxH800 to monitor the effect of G-CSF

BACKGROUND

Granulocyte colony-stimulating factor (G-CSF) induces the formation of toxic granulation neutrophils (TGNs), which are found in many inflammatory responses. Cell population data (CPD) may be able to clarify the effect of G-CSF, and potentially help doctors in discriminating the effect of G-CSF from other inflammatory situations.

METHODS

To achieve this, we performed analyses of leukocyte CPD from normal controls and healthy donors that had received G-CSF for peripheral blood stem cells (PBSCs) mobilization (G-CSF group).

RESULTS

Two hundred and seventy-one subjects were enrolled as normal controls, and 21 subjects were enrolled in the G-CSF group. Mean volume (MN-V)-neutrophils (NE), mean axial light loss (MN-AL2)-NE, and all standard deviation (SD) parameters increased significantly, whereas all light scattering parameters, mean median angle light scatter (MN-MALS)-NE, mean upper median angle light scatter (MN-UMALS)-NE, mean lower median angle light scatter (MN-LMALS)-NE, and mean low angle light scatter (MN-LALS)-NE reduced significantly in the G-CSF group. MN-V-lymphocytes (LY) from the G-CSF group showed no significant difference (P = 0.143), whereas MN-V-monocytes (MO) were significantly decreased (P < 0.001). Receiver operating characteristic (ROC) curves for the discrimination of the G-CSF group from normal controls showed excellent sensitivity in SD-LALS-NE (at 30.85, sensitivity 95.2%, specificity 76.0%), MN-AL2-NE (at 134.5, sensitivity 90.5%, specificity 83.0%), and SD-AL2-NE (at 16.4, sensitivity 95.2%, specificity 95.2). Several CPD parameters of lymphocytes and monocytes, as well as neutrophils can be used as markers for determining the effect of G-CSF.

CONCLUSION

Our data show that many CPD of leukocytes can be considered to be useful parameters of the effect of G-CSF.

Distinct expression patterns of CD123 and CD34 on normal bone marrow B-cell precursors ("hematogones") and B lymphoblastic leukemia blasts

We compared the expression of CD123, the alpha chain of the interleukin-3 receptor, on normal B-cell precursors in bone marrow ("hematogones") from 75 specimens and on leukemic blasts in 45 newly diagnosed B-acute lymphoblastic leukemias (B-ALL) cases. We found that the less mature hematogones (dim CD45+) that express CD34 lack CD123 expression, whereas the more mature hematogones (moderate CD45+) lack CD34 but always express CD123. In contrast with this discordant pattern of CD34 and CD123 expression in hematogones, blasts in 41 (91%) of 45 cases of B-ALL showed concordant expression of the 2 antigens: 80% (36 of 45) cases expressed both antigens, whereas 11% (5 of 45) expressed neither. We found that these distinct patterns of CD34/CD123 expression on hematogones (discordant) and B-ALL blasts (concordant) remain stable after chemotherapy and are useful in differentiating small populations of residual blasts from hematogones that may be simultaneously present.

Altered function and surface marker expression of neutrophils induced by rhG-CSF treatment in severe congenital neutropenia

Neutrophils from patients suffering from severe congenital neutropenia (SCN), who were receiving recombinant human granulocyte colony-stimulating factor (rhG-CSF), were investigated in order to analyze the previously described decrease in chemotaxis. This study demonstrated the decreased chemotaxis to five well-known chemoattractants, FMLP, C5a, IL-8, LTB4 and PAF. To further investigate this impairment of patients' neutrophils, receptors and receptor turnover for chemoattractants were examined using flow cytometry. We found 1) increased FMLP receptor and decreased C5a receptor expression, 2) a normal expression of intracellular FMLP receptors after incubation with PMA, 3) increased loss and decreased re-expression of FMLP receptors after incubation with this peptide, 4) normal expression of adhesion glycoproteins CR3 (CD11b/CD18) and LFA1 (CD11a/CD18), 5) further signs of in vivo preactivation: high expression of Fc gamma-RI (CD64) and Fc gamma-RII (CD32), decreased expression of Fc gamma-RIII (CD16), increased expression of CD14, and low expression of HLA-DR. These data demonstrate that the decrease of chemotaxis of neutrophils from SCN patients is not due: a) to a decrease in the number of intra- or extracellular FMLP receptors; b) to a decrease of adhesion molecules. However, the decreased chemotaxis could result from an altered FMLP receptor turnover. The relevance of the altered Fc gamma-receptor pattern for the in vivo occurrence of side-effects, e.g. the necrotic vasculitis, of G-CSF treatment is discussed.

G- and GM-CSF in oncology and oncological haematology

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

Pharmacologic rationale for early G-CSF prophylaxis in cancer patients and role of pharmacogenetics in treatment optimization

The use of recombinant human granulocyte colony stimulating factors (G-CSF) has become an integral part of supportive care during cytotoxic chemotherapy. Current guidelines recommend the use of G-CSF in patients with substantial risk of febrile neutropenia. However, little consensus exists about optimal timing and tailoring of this therapy. Based on the known effects of chemotherapy and G-CSF on bone marrow compartments, we propose a model that supports the prophylactic rather than therapeutic use of G-CSF therapy. In addition, several genetic alterations in G-CSF signalling pathway have been described. These genetic variants may predict the risk of febrile neutropenia and response to G-CSF. Thus, future pharmacogenetic/omics studies in this field are warranted. Through the identification of patients at risk and the knowledge of biological basis for optimal timing, hopefully we should soon be able to improve the application of the existing guidelines for G-CSF therapy and patient's prognosis.

Interrelationship between platelet count, red cell count, white cell count and weight in men

In 83 healthy normotensive males aged 20-55 years the platelet count is positively correlated with the red cell count (r = 0.371; P = 0.0006), the white cell count (r = 0.358; P = 0.0009), and with weight (r = 0.252; P = 0.0269). The red cell count is also positively related with the white cell count (r = 0.242; P = 0.0278) and with weight (r = 0.326; P = 0.0039); while the white cell count is slightly correlated with weight (r = 0.210; P = 0.067). These findings provide further indirect evidential support for a haemopoetic growth factor acting on a single pluripotent stem cell.

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

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

Haemopoietic growth factors: their relevance in osteoclast formation and function

The major recent advance in our knowledge of the haemopoietic system has been the purification and characterization of a family of haemopoietic growth factors, and their availability in recombinant form. In the bone marrow the sequences of differentiation and proliferation leading to the production of mature cells that these factors regulate may be determined by the relative availability of the factors in microenvironmental domains. The observation that growth factor-producing cells and haemopoietic progenitor cells are not evenly distributed in the bone marrow leads us to expect that the overall effect of growth factors (and other regulatory molecules) on the production and function of macrophages and osteoclasts may differ when in vivo or in vitro assays are used as end-points and, in the latter case, when whole marrow or purified cell populations are tested. The availability of an in vitro assay in which osteoclast-like cells are generated will allow these concepts to be tested.

Development and validation of a sensitive ELISA for quantitation of Grastim® (rhG-CSF) in rat plasma: application to a pharmacokinetic study

Grastim is bacterially produced recombinant counterpart of human granulocyte colony stimulating factor (G-CSF). It has biological activity similar to that of endogenous G-CSF. In the present work a sensitive, accurate, precise and enzyme-linked immunosorbent assay (ELISA) for the quantitation of G-CSF in rat plasma was developed and validated. The ELISA method employed a technique in which anti-human-G-CSF was adsorbed onto 96-well maxisorp plates and used to capture the G-CSF in rat plasma samples. The captured G-CSF was then detected using streptavidin-HRP amplification system. Absolute recovery was >90% from rat plasma. The validation includes assessments of method accuracy and precision, range of reliable response, lower limit of quantitation (LLOQ), storage stability (30 days) in rat plasma and assay specificity. The standard curve for G-CSF was linear (R2 > 0.996) in the concentration range 4.88-625 pg/mL. The LLOQ was established at 4.88 pg/mL. The inter- and intra-day precisions in the measurement of quality control (QC) samples, 15, 250 and 500 pg/mL, were in the range 3.00-8.66% relative standard deviation (RSD) and 1.03-4.69% RSD, respectively. Accuracy in the measurement of QC samples was in the range 87.28-110.79% of the nominal values. The assay shows dilutional linearity and specificity. Stability of G-CSF was established for 30 days at -80 degrees C and through three freeze-thaw cycles. The validated assay was successfully employed for the assessment of pharmacokinetic disposition of G-CSF in rats.

Converging pathways in leukemogenesis and stem cell self-renewal

Studies over the last 40 years have led to an understanding of the hierarchical organization of the hematopoietic system and the role of the pluripotential hematopoietic stem cell. Earlier recognition of the importance of bone marrow hematopoietic microenvironments has evolved into the recognition of specific niches that regulate stem cell pool size, proliferative status, mobilization, and differentiation. The discovery of the role of multiple hematopoietic growth factors and their receptors in the orchestration of stem cell self-renewal and differentiation has been followed by recognition of the importance of the Notch and Wnt pathways. The homeobox family of transcription factors serve as master regulators of development and are increasingly found to be critical regulators of hematopoiesis. In parallel with this understanding of normal hematopoiesis has come a recognition that stem cell dysregulation at various levels is involved in leukemogenesis. Furthermore, the progression from chronic leukemia or myelodysplasia to acute leukemia involves accumulation of at least two mutational events that lead to enhancement of stem cell proliferation, or acquisition of stem cell behavior by a progenitor cell, coupled with maturation inhibition. Translocations resulting in development of oncogenic fusion genes are found in AML and the transforming potential of two of these, AML1-ETO and NUP98-HOXA9, will be discussed. Secondary, constitutively activating mutations of the Flt3 and c-kit receptors and of K- and N-ras are found with high frequency in AML, and the transforming potential of mutated FLT3 and the role of STAT5A activation in human stem cell transformation will be reviewed.

Granulocyte colony-stimulating factor and leukemogenesis

The granulocyte colony-stimulating factor (G-CSF) plays an important role in normal granulopoiesis. Its functions are mediated by specific receptors on the surface of responsive cells and, upon ligand binding, several cytoplasmic tyrosine kinases are activated. The cytoplasmic region proximal to the membrane of the G-CSF receptor (G-CSF-R) transduces proliferative and survival signals, whereas the distal carboxy-terminal region transduces maturation signals and suppresses the receptor's proliferative signals. Mutations in the G-CSF-R gene resulting in truncation of the carboxy-terminal region have been detected in a subset of patients with severe congenital neutropenia who developed acute myelogenous leukemia (AML). In addition, the AML1-ETO fusion protein, expressed in leukemic cells harboring the t(8;21), disrupt the physiological function of transcription factors such as C/EBPalpha and C/EBPepsilon, which in turn deregulate G-CSF-R expression. The resulting high levels of G-CSF-R and G-CSF-dependent cell proliferation may be associated with pathogenesis of AML with t(8;21). Moreover, in vitro and in vivo studies demonstrated that G-CSF may act as a co-stimulus augmenting the response of PML-RARalpha acute promyelocytic leukemia cells to all-trans-retinoic acid treatment. Finally, in the PLZF-RARalpha acute promyelocytic leukemia transgenic model, G-CSF deficiency suppressed leukemia development. Altogether, these data suggest that the G-CSF signaling pathway may play a role in leukemogenesis.

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: 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.

Growth advantage of chronic myeloid leukemia CFU-GM in vitro: survival to growth factor deprivation, possibly related to autocrine stimulation, is a more common feature than hypersensitivity to GM-CSF/IL3 and is efficiently counteracted by retinoids +- alpha-interferon

Bcr/abl fusion gene, in experimental models, induces survival to growth factor deprivation and hypersensitivity to IL3. However, conflicting data were reported about chronic myeloid leukemia (CML) progenitors. We investigated the responsiveness of purified CML CFU-GM to GM-CSF/IL3 and their survival to growth factor deprivation. CFU-GM hypersensitivity to IL3 and/or GM-CSF was found in 3/11 CML cases only. CML CFU-GM survived well in stroma-free 'mass' culture (5 x 10(4) cells/ml) without cytokine addition, up to day 11, average recovery being around 95% in medium + 10% fetal bovine serum and 67-81% in serum-free medium. Conversely, normal progenitors declined steadily, particularly after extensive purification (18 +/- 10% recovery at the 7th day), and in serum-free medium (4 +/- 6% recovery). By contrast, normal and CML CFU-GM declined in a similar way in limiting dilution cultures (1-10 cells/50 microl). We also investigated the effects of retinoic acid and alpha-interferon on CFU-GM survival. Both all-trans- and 13-cis retinoic acid, particularly in combination with alpha-interferon, reduced CML CFU-GM recovery down to normal progenitors' values. In conclusion, hypersensitivity to CSFs is rare in CML, whereas resistance to growth factor deprivation has been confirmed in mass, but not in limiting, dilution cultures. Both stereoisomers of retinoic acid, at therapeutic concentrations and in combination with alpha-interferon, can overcome the survival advantage of CML progenitors.

Early tooth loss due to cyclic neutropenia: long-term follow-up of one patient

In young patients with abnormal loosening of teeth and periodontal breakdown, dental professionals should consider a wide range of etiological factors/diseases, analyze differential diagnoses, and make appropriate referrals. The long-term oral and dental follow-up of a female patient diagnosed in early infancy with cyclic neutropenia is reviewed, and recommendations for care are discussed.

Granulocyte-colony stimulating factor levels in bronchoalveolar lavage fluid from patients with idiopathic pulmonary fibrosis

BACKGROUND

Granulocyte-colony stimulating factor (G-CSF) is known as a potent neutrophil chemotactic glycoprotein in vitro but its contribution to chemotactic activity in neutrophil mediated lung diseases is not yet known. The aims of this study were to determine whether G-CSF is present in high concentrations in bronchoalveolar lavage (BAL) fluid of patients with idiopathic pulmonary fibrosis (IPF, also called cryptogenic fibrosing alveolitis), a neutrophil mediated lung disease, and to what extent G-CSF in BAL fluid contributes to neutrophil accumulation in the lung of patients with IPF.

METHODS

G-CSF concentrations in BAL fluid samples from 16 healthy volunteers, 24 patients with IPF, and 73 patients with non-IPF lung disease were measured by enzyme linked immunosorbent assay. The relationship between G-CSF concentrations and neutrophil count in BAL fluid was also examined. Neutrophil chemotactic activity (NCA) was measured in BAL fluid in healthy volunteers and patients with IPF. The contribution of G-CSF to overall NCA in lungs with IPF was assessed by repeating the measurement of NCA after a complete neutralisation of G-CSF bioactivity by anti-human G-CSF antiserum.

RESULTS

Detectable levels of G-CSF were found in BAL fluid of 83% of patients with IPF while the levels in all healthy volunteers were below the detection limit. In patients with IPF a significant correlation was observed between the BAL fluid neutrophil count and the concentration of G-CSF in the BAL fluid. The neutrophil count also correlated significantly with percentage forced vital capacity. In BAL fluid samples from patients with IPF the mean NCA value was reduced by 35% after neutralisation with an anti-human G-CSF antiserum.

CONCLUSIONS

G-CSF may be involved in enhancing neutrophil accumulation in the lungs of patients with IPF.

A sandwich enzyme-linked immunoabsorbent assay for measurement of picogram quantities of murine granulocyte colony-stimulating factor

Granulocyte colony-stimulating factor (G-CSF) stimulates the proliferation and differentiation of hematopoietic progenitor cells of the neutrophil lineage. Measurement of murine G-CSF levels will allow examination of its role in host defense using murine models. Therefore, we developed a sensitive sandwich enzyme-linked immunoabsorbent assay (ELISA) for murine G-CSF. A polyclonal antibody to recombinant murine G-CSF was produced in rabbits and isolated using a protein A column. This purified native IgG served as the capture antibody and a portion of the IgG was biotinylated to serve as the developing antibody. Specificity was verified by lack of reactivity to GM-CSF, IL-6, IL-3, prolactin, and growth hormone. The lower limit of sensitivity routinely extended to 16 pg/ml in multiple ELISAs. Intra-assay coefficient of variation (CV) ranged from 3.4 to 21.5% across the detection limits of the assay, with the greatest variance occurring near the standard curve maximum. Interassay CV ranged from 11.5 to 23.3%. The ability of the ELISA to detect G-CSF in different sample preparations was examined in RPMI 1640 with 10% FCS, Hanks balanced salt solution, PBS/Tween-20/2% FCS, and the dilution media for ELISA (10% BLOTTO/PBS/0.05% Tween-20). Average recovery in these media ranged from 98 to 107%. Heparin anti-coagulated normal mouse plasma had a suppressive effect on the ELISA that varied between individual mice. Recovery was also determined from liver, spleen, and lung homogenate suspensions at dilutions of 1:5, 1:10, and 1:20 in dilution buffer. Recovery from liver was optimal at the 1:10 and 1:20 dilutions at 105%, with that of the 1:5 dilution at 135%. Recovery from spleen ranged from 94 to 96%. Lung homogenate displayed enhanced recovery (139% or greater) across all dilutions. The ability of the assay to detect G-CSF was explored by measurement of G-CSF levels in peritoneal lavage following polymicrobial intra-abdominal infection. Peak levels of G-CSF production occurred at 16 h after cecal ligation and puncture surgery with 18- and 21-guage needles (75.7 ng/ml and 111.4 ng/ml, respectively) as compared to the sham animals (0.61 ng/ml). The assay was found to be specific, sensitive, and accurate for measurement of murine G-CSF in a variety of sample types.

Effects of hyperthermia and granulocyte-macrophage colony-stimulating factor on the differentiation of human leukemic cell line U937

We have studied the effects of granulocyte-macrophage colony-stimulating factor (GM-CSF) and hyperthermia individually and in combination on the cell growth and differentiation of human monoblastic leukemia cell line U937. Several criteria were used to evaluate the differentiation of these cells, including the reduction in the plating efficiency and cell growth, the ability to phagocytize latex particles, the reduction of nitro blue tetrazolium (NBT), and development of surface antigenic markers. Hyperthermia alone was able to inhibit cell proliferation, reduce cell viability, and induce differentiation. In the range of 41-43 degrees C, the major effect of hyperthermia was cell differentiation induction as judged by above criteria. On average, hyperthermia induced differentiation in 32% of cells. GM-CSF was able to induce differentiation in 37% of U937 cells as judged by similar criteria. The combined treatment with GM-CSF and hyperthermia resulted in the differentiation of 60% of U937 cells. The extent of differentiation obtained is comparable or better than other combinatorial treatments using various cytokines or cytokines and chemical reagents reported before.

Effect of escalating doses of recombinant human granulocyte colony-stimulating factor (filgrastim) on circulating neutrophils in healthy subjects

The safety profile, tolerability, pharmacodynamics, and pharmacokinetics of four doses of recombinant human granulocyte colony-stimulating factor (filgrastim) were assessed in healthy volunteers in a double-masked, placebo-controlled, parallel-group trial. Healthy subjects received subcutaneous injections of filgrastim 75 microg (n = 8), 150 microg (n = 4), 300 microg (n = 4), 600 microg (n = 8), or placebo (n = 6) daily for 10 consecutive days. Blood samples were drawn daily immediately before the injection and on days 1 and 10 serially throughout the day. Increased absolute neutrophil counts (ANCs) were seen within 90 minutes of drug administration in subjects in all dose groups, peaking approximately 12 hours after administration. This increase was dose related in subjects in the three lower dose groups. The time to peak ANC on day 10 was approximately 9 hours, with a daily ANC profile in all four dose groups that was similar to the profile on day 1. In all dose groups, ANCs were near baseline within 48 hours of discontinuation of filgrastim. Mild, reversible thrombocytopenia was reported in 4 of 10 subjects in the highest dose group. Two subjects in the filgrastim 600-microg group were withdrawn for adverse events. Filgrastim had a good safety profile and caused dose-related increases in ANC when administered to healthy volunteers for up to 10 days.

Hematopoietic growth factors in autologous transplantation

Hematopoietic growth factors (HGFs) sustain the survival, proliferation and differentiation of hematopoietic stem cells and some functions of mature blood cells. In man several HGFs have been characterised and cloned so far, and this has allowed investigators to confer the rationale for the clinical application of these molecules in hematology and oncology. In particular G-CSF and GM-CSF are currently utilised to abrogate the hematological toxicity of chemotherapy for standard and dose-intensified therapy, neutropenia following bone marrow and peripheral blood stem cell transplantation. Moreover there has recently been great interest in the ex vivo expansion of hematopoietic stem and progenitor cells for a variety of applications, such as in vitro tumor cell purging or for reducing the volume of blood processed by the leukapheresis. Several combinations of HGFs have been described to sustain the ex vivo survival and proliferation of these cells disclosing new opportunities in the field of stem cells transplants.

IL-3 in the clinic

Since the cloning of human interleukin 3 (IL-3) in 1986 [1] and the demonstration of its proliferative effects on multiple hematopoietic progenitor cells, IL-3 has been widely studied to treat different states of bone marrow failure or hematologic malignancies, to mobilize or expand hematopoietic progenitor cells for transplantation, and to support engraftment after bone marrow transplantation. However, no condition for the clinical use of IL-3 has been established so far despite its theoretical advantages as an early-acting cytokine and in contrast to erythropoietin (EPO), G-CSF, or GM-CSF all of which have already been approved for several clinical modalities. Here we shortly review our current knowledge about the effects of IL-3 on the molecular and cellular level, summarize recent clinical studies with IL-3, and discuss further perspectives for the use of this cytokine.

Amniotic fluid granulocyte colony stimulating factor levels in chorioamnionitis do not predict neonatal sepsis

PROBLEM

To assess the usefulness of amniotic fluid (AF) granulocyte colony-stimulating factor levels (G-CSF) in chorioamnionitis (CAM) to predict neonatal sepsis.

METHOD OF STUDY

AF samples were obtained from term and preterm patients with (Group I) and without (Group II) CAM and were assayed for G-CSF levels. Patients with other infections were excluded. All AF samples were also tested for gram stain and cultures. The sensitivity, specificity, and predictive values of these parameters for diagnosing neonatal sepsis were assessed.

RESULTS

Positive AF cultures were the best predictors of neonatal sepsis in CAM, with a sensitivity of 67% and a positive predictive value (PPV) of 80%. Elevated AF G-CSF levels (> 1,000 pg/ml) were poor predictors of neonatal sepsis with a sensitivity of 29% and PPV of 39%.

CONCLUSION

Even though AF G-CSF levels were markedly elevated in patients with CAM, they were poor predictors of subsequent neonatal sepsis.

Maternal serum granulocyte-colony stimulating factor in preterm birth with subclinical chorioamnionitis

Preterm birth has been linked with intrauterine infection and inflammation. Serum and amniotic fluid markers of inflammation, such as interleukin-1 (IL-1), IL-6, and granulocyte-colony stimulating factor (G-CSF), have been associated with clinical chorioamnionitis and preterm delivery. As G-CSF regulates the production and maturation of neutrophils, we sought to determine if maternal serum G-CSF levels are elevated in patients with preterm birth with subclinical histologic chorioamnionitis. Maternal serum G-CSF levels were significantly different among five groups of women studied (P < .001, Kruskall-Wallis test), and were highest in subjects with preterm labor who delivered preterm (P < .05, Mann-Whitney U test). Among women with preterm labor who delivered preterm, maternal serum G-CSF levels were significantly higher if histologic chorioamnionitis was present than when histologic evidence of infection was not present (P = 0.04, Mann-Whitney U test). Intrauterine infection may cause a local inflammatory process and initiate preterm labor. This inflammatory response may include production of G-CSF, which would enter the circulation and stimulate the migration of neutrophils to the site of infection. Our data support this concept, as maternal serum G-CSF is elevated with subclinical infection in association with preterm birth.

[G-CSF in radiochemotherapy]

BACKGROUND

G-CSF enhances the division, maturation and release of granulocyte precursor cells. The shortening of chemotherapy-induced leukopenia via G-CSF is well documented in literature, with fractionated radiotherapy alone one finds a distinct increase of the granulocyte level. There are only few results for combined simultaneous radiochemotherapy.

PATIENTS AND METHODS

In the Department of Radiotherapy of the University of Erlangen 102 patients were treated with G-CSF since 1992. Twenty-eight patients (31 applications) undergoing radiotherapy only (n = 4) or combined simultaneous radiochemotherapy (n = 27) received G-CSF interventional daily. These results are presented and discussed. Indications for the application of G-CSF were severe leukopenia below 1000/mm3 (level IV according to WHO) or rapid decreasing leukocytes during therapy. G-CSF was not applied during chemotherapy and terminated at least 24 h before the next chemotherapy cycle. r-metHuG-CSF (Filgrastim, Neupogen) was used subcutaneously. Documented were the duration until the leukocyte increase, neutrophil granulocytes, thrombocytes, interruption of radiotherapy, febrile episodes and side effects.

RESULTS

In case of severe leukopenia (< 1000/mm3 n = 16) the leukocytes increased after 3 days of G-CSF application, the radiotherapy was interrupted in 2 cases, terminated in 1 case. Four patients had lever before during G-CSF 4 additional febrile episodes occurred. If G-CSF application was started between leukocyte levels of 1000 and 1500/mm3 after 1 day the leukocytes increased in 9 of 10 cases beyond the starting level. Interruption of radiotherapy was not necessary. Only 1 febrile episode occurred (1/11). There were no relevant side effects of G-CSF.

CONCLUSIONS

Rapidly developing or severe leukopenia during radio(chemo)therapy are indications for an interventional application of G-CSF. The leukocyte level for the start of G-CSF should be chosen so that without G-CSF an interruption of therapy or a level IV leukopenia seems to be unavoidable.

Recombinant cytokines and hematopoietic growth factors in allogeneic and autologous bone marrow transplantation

Use of recombinant hematopoietic growth factors in the course of bone marrow transplantation has revolutionized this modality by significantly improving the safety of the procedure. It is anticipated that use of cytokines in combination and the introduction of newer agents will further reduce costs and improve antitumor responses as well.

Biology and therapeutic uses of myeloid hematopoietic growth factors and interferons

Recent advances in basic science and clinical trials have demonstrated that IFNs and myeloid hematopoietins play crucial roles in host defense against pathogens and immune surveillance. Here we have reviewed the biologic functions of GM-CSF, G-CSF, IFN-alpha and IFN-gamma. For patients with neutropenia resulting from cytotoxic chemotherapy, bone marrow transplantation, congenital agranulocytosis and cyclic neutropenia, therapeutic uses of GM-CSF and G-CSF were reviewed. Application of these growth factors to patient management represents a major contribution of biotechnology to a difficult area of therapeutics in febrile, neutropenic patients. Because IFN-alpha plays crucial roles in antiviral responses, its clinical applications in hepatitis B and C, human papilloma virus, HIV infection and malignancy were discussed. The use of IFN-gamma in bacterial prophylaxis in patients with chronic granulomatous disease was also presented. Advances in clinical applications of IFNs and hematopoietic growth factors serve as a paradigm for further development to investigate the use of other important cytokines in modern therapeutics.

Granulocyte colony-stimulating factor as a marker for bacterial infection in neonates

OBJECTIVE

To evaluate granulocyte colony-stimulating factor (G-CSF) as an early marker of bacterial or fungal infection in neonates.

STUDY DESIGN

We measured G-CSF levels in infants of varying gestational and postnatal ages. We separated the infants into three groups: group 1, positive bacterial or fungal blood culture result; group 2, negative blood culture result but evidence of clinical sepsis; and group 3, negative blood culture result and no or weak evidence of sepsis. Comparison of mean G-CSF levels by group was accomplished by an analysis of variance.

RESULTS

One hundred seventy-six evaluations for sepsis were done for 156 infants with gestational ages ranging from 24 to 43 weeks; 50% of these infants were less than 35 weeks of gestational age. The mean G-CSF levels of groups 1 and 2 were significantly higher than those of group 3. The mean G-CSF level of each group was 2278 pg/ml (group 1), 1873 pg/ml (group 2), and 280 pg/ml (group 3) (p < 0.001). On the basis of a cutoff level of 200 pg/ml, the sensitivity of the test was 95%, specificity 73%, positive predictive value 40%, and negative predictive value 99%.

CONCLUSION

G-CSF levels represent a sensitive marker of infection in neonates of all gestational ages.

Recombinant human granulocyte colony-stimulating factor treatment improves macrophage suppression of granulocyte and macrophage growth after burn and burn wound infection

Granulocyte and macrophage production after burn injury or burn wound infection is significantly reduced and further compromised by endotoxin (ET). Moreover, the macrophage seems to be the major source of this bone marrow suppression. We sought to determine if recombinant human granulocyte colony-stimulating factor (rhG-CSF), a hematopoietic growth factor that is capable of improving survival after experimental burn wound sepsis, altered postburn macrophage-mediated marrow suppression. Groups of male BDF1 mice (n = 6 to 10) receiving a 15% total body surface area burn +/- infection (B or B + I) with Pseudomonas aeruginosa were injected with 100 ng rhG-CSF twice daily. On day 3, peritoneal-elicited macrophages (5 x 10(6) cells/mL) from either rhG-CSF-treated or control (5% dextrose in water) mice were incubated +/- ET (300 ng/mL). The resultant macrophage supernatant was added to cultures of target marrow granulocyte-macrophage progenitor cells (GM-CFC) at a volume of 1:10. The GM-CFC growth as a percentage of cultures not containing macrophage supernatant were compared and reductions in the number of GM-CFC taken as an index of marrow suppression. Macrophages obtained from B and B + I animals reduced target GM-CFC growth, compared with macrophages from normal animals (B vs. normal animals p < 0.05). In addition, ET-stimulated macrophages induced further bone marrow suppression for all three groups (p < 0.01). Macrophages from granulocyte colony-stimulating factor-treated animals caused significantly less bone marrow suppression, compared with untreated animals for all groups (p < 0.05 to 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Short-term rhG-CSF priming before chemotherapy does mobilize blood progenitors but does not prevent chemotherapy induced myelotoxicity: a randomized study of patients with non-Hodgkin's lymphomas

The aim of this study was to evaluate the efficacy, safety and toxicity of short-term priming with recombinant human granulocyte colony-stimulating factor (rhG-CSF) immediately after diagnosis but before combination chemotherapy (CHOP) for non-Hodgkin's lymphomas. Of fourteen patients entering the study, seven received five days subcutaneous injection of rhG-CSF (5 micrograms/kg/day) before CHOP (CSF-group), and seven were treated with CHOP alone (control group). Blood samples were studied before and on days 1-5 during rhG-CSF priming as well as twice weekly after treatment. The number of blood and bone marrow progenitors was identified by clonogenic growth day 7, 14 and 21 of GM-CFU in semisolid medium. Blood absolute neutrophil counts increased in all rhG-CSF primed patients. The expansion of marrow myelopoiesis resulted in increased myeloid:erythroid ratios, increased bone marrow cellularity and increased numbers of myeloid progenitors both in the blood as well as the marrow. Chemotherapy induced neutropenia developed on day 9-12 in all patients independent of myeloid growth factor priming. However, neutropenia appeared earlier in the cytokine primed group (P = .0038). Five patients in the CSF-group and three patients in the control group were hospitalized with neutropenic fever, and septicemia was documented in three patients in the CSF-group. RhG-CSF induced expansion of myelopoiesis immediately before combination chemotherapy mobilized sufficient number of blood progenitors for apheresis but did not result in reduction of duration and degree of neutropenia in patients with newly diagnosed non-Hodgkin's lymphoma. Although the small number of patients prevents drawing definite conclusions, this time schedule for priming should be used with caution in the future due to an increased risk of hematologic toxicity.

G-CSF-stimulated PMN in immunotherapy of breast cancer with a bispecific antibody to Fc gamma RI and to HER-2/neu (MDX-210)

Myeloid cells can mediate tumor cell cytotoxicity via certain receptors for immunoglobulins. Among the different Fc receptors, the high-affinity IgG receptor (Fc gamma RI, CD64) is a promising trigger molecule because it is selectively expressed on effector cells, including monocytes/macrophages and granulocyte colony-stimulating factor (G-CSF)-primed neutrophils. In vitro, a bispecific antibody (BsAb) (MDX-210, constructed by chemically cross-linking F(ab') fragments of monoclonal antibody (mAb) 520C9 to HER-2/neu and F(ab') fragments of mAb 22 to Fc gamma RI) mediated effective lysis of HER-2/neu overexpressing breast cancer cell lines. HER-2/neu (c-erbB2) is overexpressed in approximately 30% of breast and ovarian carcinomas and is a target for immunotherapy in clinical trials. In vitro assays showed Fc gamma RI-positive neutrophils to constitute a major effector cell population during G-CSF therapy. Based on these preclinical data and a preceding study at Dartmouth (New Hampshire) with a single dose of MDX-210 alone, a combination of G-CSF and MDX-210 is tested in a phase I study in breast cancer patients. In this study, patients receiving G-CSF are treated with escalating single doses of MDX-210. This therapy was generally well tolerated by the treated patients, some of whom reacted with fever and short periods of chills, which were temporally related to elevated plasma levels of IL-6 and TNF-alpha. After MDX-210 application, a transient decrease in the total white blood count and absolute neutrophil count (ANC) was observed. During G-CSF application, isolated neutrophils were highly cytotoxic in the presence of MDX-210 in vitro. These data indicate a potential role for G-CSF and BsAb in immunotherapy.

In vivo effects of interleukin 3 in HIV type 1-infected patients with cytopenia

OBJECTIVE

To determine the safety, tolerance, and hematological and virological effects of the recombinant hematopoietic growth factor interleukin 3 (IL-3) in HIV-1-infected individuals with cytopenia.

DESIGN AND METHODS

A phase I single-center trial was conducted with patients in cohorts of three receiving one of four dose levels of self-administered, subcutaneously injected IL-3 (0.5, 1.0, 2.5, or 5.0 micrograms/kg/day). Toxicities, hematological effects, and virological effects were recorded. Viral studies included serum HIV p24 antigen levels, quantitative plasma and peripheral blood mononuclear cell cultures, and quantitative, competitive polymerase chain reaction of patient plasma.

RESULTS

Increases in white blood cell counts (WBC) and absolute neutrophil counts (ANC) were noted at the higher dose levels while absolute eosinophil counts (AEC) increased in all patients. The percent changes in WBC from baseline ranged from 52 to 309 and in ANC from 20 to 262 in the 2.5- and 5.0-micrograms/kg/day groups. The mean AEC change was 17-fold (range, 2- to 59-fold). Hemoglobin, hematocrit, platelets, and CD4 and CD8 counts were generally unaffected although individual patients demonstrated increases in hemoglobin and platelet levels. Toxicities were generally mild, but one patient developed a transient local erythematous rash at the sites of IL-3 injection which pathologically demonstrated hypersensitivity vasculitis. Of note, viral studies did not demonstrate any consistent changes in HIV-1 activity.

CONCLUSION

These data demonstrate limited hematological effects of IL-3 monotherapy in HIV-1-infected patients with cytopenia. However, should IL-3 be incorporated into combination cytokine therapies for HIV disease, these data suggest that IL-3 does not enhance in vivo HIV-1 activity.

Modifying the host response to injury. The future of trauma care

It is beyond the scope of this article to describe all of the contributions of molecular biology to increasing our understanding of the pathophysiology of inflammation and the response to injury. This review focuses on those aspects that are clinically relevant. In addition to providing quantities of recombinant proteins, recent advances in molecular and cellular biology have provided other tools to help differentiate the pathophysiology of the host response to injury and infection. Hybridoma technology has facilitated the development of specific antibodies that are used to block the activity of a specific factor or toxin. Receptor and signal transduction biology has provided further insight into the activity and function of various factors and mediators. Studies at the level of the gene have shed light on the phylogenic relationship among various factors. Transgenic animals can be used to determine the effects of excess factor production; conversely, genetic "knockouts" are useful in determining the pathophysiology associated with the absence of a particular factor. It is clear that as our understanding of the complex interactions leading to inflammation increases, we will be able to take advantage of this knowledge to more effectively treat patients.

Absence of G-CSF receptors and absent response to G-CSF in childhood Burkitt's lymphoma and B-ALL cells

The expression of the granulocyte colony-stimulating factor (G-CSF) receptor in childhood Burkitt's lymphoma (BL) cells, and the mitogenic effect of G-CSF on these cells, was studied in a panel of 13 Epstein-Barr virus (EBV) positive and negative BL cell lines derived from nine children. G-CSF receptor mRNA expression was investigated by Northern blot analysis and reverse transcriptase polymerase chain reaction (RT-PCR). Binding of G-CSF to BL cell lines was measured by chemical crosslinking of 125I-G-CSF, and proliferation by thymidine incorporation. Inducibility of the G-CSF receptor was studied by stimulation with interleukin-1 beta, tumour necrosis factor-alpha, Staphylococcus aureus Cowan A, anti-human IgM, phorbol myristate acetate, calcium ionophore A23187, and by infection in vitro by immortalizing and non-immortalizing strains of EBV. BL cell lines, unstimulated or stimulated by biological reagents or EBV infection, did not bind radioionated G-CSF in crosslinking experiments. No stimulation by recombinant human G-CSF was observed in 3H-thymidine incorporation assays. No G-CSF receptor mRNA was detected by Northern blot analysis or RT-PCR in BL cell lines. It is concluded that G-CSF plays no direct stimulatory role in the growth of these malignant B-cells, making a deleterious influence of G-CSF in the clinical treatment situation unlikely.

Enhancement of neutrophil function by in vivo filgrastim treatment for prophylaxis of sepsis in surgical intensive care patients

PURPOSE

To determine the kinetics of leukocyte counts and of oxygen radical production of neutrophils from postoperative/posttraumatic patients with or without infusion of filgrastim (recombinant human granulocyte colony-stimulating factor, rhG-CSF) as prophylaxis against sepsis.

METHODS

Twenty postoperative/posttraumatic patients with a Therapeutic Intervention Scoring System (TISS) score greater than 30 were included in this study. In the 10 patients of the study group, filgrastim (1 microgram/kg/d) was infused continuously within the first 3 days and tapered to 0.5 microgram/kg/d on the following 4 days or until discharge from the surgical intensive care unit. Ten patients without administration of filgrastim served as controls. Oxygen radical production of isolated neutrophils of these patients was tested by N-formyl-methionyl-leucyl-phenylalanine (FMLP)- and zymosan-induced chemiluminescence from serial blood samples, taken until the 16th postoperative day.

RESULTS

Compared with the first postoperative day, in vitro FMLP-induced neutrophil chemiluminescence was significantly increased during the following 4 postoperative days in the patients with filgrastim infusion; however, only during the first 2 postoperative days in the control group. The increase in the FMLP-induced neutrophil chemiluminescence was significantly greater (P < .05) in the study group than in the control group on the third and on the fourth postoperative day. Tapering of filgrastim by 0.5 microgram/kg/d in the study group resulted in a reduction of FMLP-induced neutrophil oxygen radical production within 48 hours. In contrast, zymosan-induced neutrophil chemiluminescence was not measurably affected in both groups. Leukocyte count of the study group significantly (P < .05) exceeded the leukocyte count of the control group from the third up to the 10th postoperative day. None of the patients treated with filgrastim developed sepsis; however, three patients within the control group did.

CONCLUSIONS

Prolonged enhancement of neutrophil count and function induced by rhG-CSF may be useful in the prophylaxis of sepsis in posttraumatic/postoperative patients at high risk of sepsis.

Effect of granulocyte colony-stimulating factor (G-CSF) on chemotherapy-induced oral mucositis

In this study, the ability of granulocyte colony-stimulating factor (G-CSF) to treat or prevent chemotherapy-induced oral mucositis in patients with advanced breast cancer was evaluated. A total of 14 patients who received intraarterial (i.a.) adriamycin (ADM) preoperatively were divided into two groups according to whether or not G-CSF was given. Thus, group A (n = 7) was given G-CSF and group B (n = 7) was not. G-CSF therapy reduced both the incidence and duration of ADM-induced oral mucositis, and a positive correlation was also seen between the incidence of mucositis and ADM-induced leukopenia (< 2,000/mm3). Group A was further divided into two subgroups according to whether G-CSF was given after or before the leukopenia had dropped below 2,000/mm3: group A-1 (n = 3) and group A-2 (n = 4), respectively. ADM-induced mucositis was observed in two of the three patients in group A-1, but in none of the four patients in group A-2. These results strongly support the idea that G-CSF can effectively treat and prevent ADM-induced oral mucositis.

In vitro bioassay with enhanced sensitivity for human granulocyte colony-stimulating factor

A method for the determination of human granulocyte colony-stimulating factor (hG-CSF) activity, based on stimulation of cellular proliferation, was developed using a subclone of the murine myeloid leukemia cell line NFS-60, with an improved sensitivity for hG-CSF, as indicator. The optimal range for quantitative analysis of hG-CSF was about 4-60 pg ml-1. The stimulatory effect was measured by a colorimetric microassay: the optical density of formazan, which is produced by viable cells from 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), was obtained by reading plates in a multi-channel photometer. The assay was designed as a five-dose parallel line test, employing three or four doses for potency determinations, which fulfil pharmacopoeial requirements for assay validity. Inter-assay relative standard deviation (RSD) varied between 5.2 and 12.0%. Most assay experiments revealed potencies within limits of error of 90-110% and the mean index of precision value was 0.057. The recently developed yeast cell-derived International Standard (88/502) served as a reference for activity of rhG-CSF. Specificity of the assay was demonstrated by absence of response upon exposure to a panel of biomolecules, including recombinant human interleukin-3, and by the suppression of growth stimulation in the presence of neutralizing anti hG-CSF antibodies. Potency readings of unglycosylated rhG-CSF were dependent on pH of assay medium with higher relative activities observed at pH 6.6 than at 7.4. Moreover, SDS-PAGE analysis of the carbohydrate-deficient preparation, following incubation at physiological pH, revealed several high molecular weight rhG-CSF bands and decreased monomeric form. The method described was found suitable for potency assessments of pharmaceutical formulations of hG-CSF.

Successful treatment of chronic wound infection in neutropenia and rheumatoid arthritis with filgrastim (rhG-GSF)

A 73-year-old woman was diagnosed with seropositive destructive rheumatoid arthritis in 1981. She was treated with cortisone, chloroquine, and cyclophosphamide (Sendoxan) in 1982 and 1984 and contracted severe neutropenia. After that she only received cortisone. During 1991, again low neutrophilic counts were registered, especially granulocytopenia. At first, B-cell lymphoma was suspected, but later Felty's syndrome was established. The patient was treated with high-dose cortisone with some success and had a few minor septic episodes. In May 1992 she contracted a traumatic wound on the back of the lower leg. Conservative treatment resulted in a worsening of the condition and an increased wound area, most likely related to the neutropenic condition. In mid July the patient was hospitalized. Bacterial isolates yielded mixed gram-negative enteric bacteria from the wound. Parenteral antibiotic treatment was started, followed by oral drugs, rhG-CSF (filgrastim) was given subcutaneously once a day, starting 3 days after admission. This resulted in increased numbers of peripheral granulocytes. The ulcer started to heal and by mid August the patient received a transplant with autologous skin grafting. In mid September the wound was completely healed. It is concluded that the combination of antibiotics, skin transplantation, and G-CSF was necessary for the successful result. Actually, the bacterial growth did not call for antibiotics, but it was considered necessary to cover for staphylococci. No worsening of the underlying arthritis was observed.

Differential effects of transferrin receptor antibodies on growth and receptor expression of human lymphocytic and myelocytic cell lines

J64, a monoclonal antibody against the human transferrin receptor, has been shown to induce interleukin-2 production by HUT78 cells. It also causes growth inhibition of several cell lines and stimulated lymphocytes. These effects were also present using transferrin-free culture conditions. In this paper, we dissect cell membrane and intracellular events after binding of J64 and other transferrin receptor antibodies. Incubation of HUT78 and several other cell lines with J64 resulted in an increased number of receptor molecules expressed on the cell surface in contrast to a downmodulation seen with other monoclonal antibodies to the transferrin receptor. This upregulation after treatment with J64 was not due to an increased concentration of transferrin receptor mRNA in these cells or a higher protein synthesis rate. We therefore suggest that J64 causes a redistribution of transferrin receptor molecules from intracellular pools to the cell surface. Additional experiments investigating signal transduction mechanisms revealed no influence of J64 on intracellular Ca2+ concentrations or translocation of protein kinase C. However, an increase of transferrin receptor phosphorylation was seen in HL60 cells after treatment with phorbolester or J64. This phosphorylation of the transferrin receptor might be a signal transduction pathway involved in activation and growth control.

Serum granulocyte colony-stimulating factor in patients with repeated infections

We have already reported significant elevation of serum granulocyte colony-stimulating factor (G-CSF) in the acute phase of infection. In this study, we compared the responses to infection between patients with frequently repeated infection (repeaters) and others (non-repeaters). We examined the clinical data and serum G-CSF levels in 48 patients with acute infections. Serum G-CSF levels were significantly lower in repeaters than in non-repeaters (197.7 +/- 370.0 vs. 1014.1 +/- 924.4 pg/ml. P less than 0.001). There were no significant differences in age, serum total protein, or cholinesterase between the groups, but serum albumin was significantly lower in repeaters than in non-repeaters (2.87 +/- 0.5 vs. 3.31 +/- 0.4 g/dl. P less than 0.005). It is suggested that administration of recombinant G-CSF may be useful for patients with repeated infections.