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

Role of leucocyte integrins in phagocyte responses to granulocyte-macrophage colony stimulating factor (GM-CSF): in vitro and in vivo studies on leucocyte adhesion deficiency neutrophils

The role of leucocyte integrins in phagocyte function has been studied by comparing normal neutrophils with those from a patient with partial leucocyte adhesion deficiency (LAD), in whom the levels of CD11b and CD11c were 10% of controls, whereas CD11a levels were normal. Unstimulated LAD neutrophils exhibited defective adhesion to plastic (4.4 +/- 1.5% cf. 14.4 +/- 3.8% in controls), but not to human umbilical vein endothelial cells (HUVECs). The adhesion to HUVECs could be further upregulated by granulocyte-macrophage colony stimulating factor (GM-CSF), but not by 12-O-tetradecanoylphorbol 13-acetate (TPA) which, in normal cells, is a more potent 'pro-adhesive agonist'. The normal neutrophil-endothelial interaction induced by GM-CSF in LAD neutrophils was confirmed in vivo when administration of GM-CSF resulted in rapid phagocyte margination. Neutrophil migration and phagocytosis/killing were defective in LAD neutrophils, and some improvement in phagocytosis/killing was seen following in vivo administration of GM-CSF. These studies illustrate that the degree to which the leucocyte integrins mediate adherence-related phagocyte functions varies not only with the particular function, but also with the conditions of stimulation. High levels of CD11b and CD11c expression appear not to be required for unstimulated or GM-CSF-stimulated neutrophil-endothelial interactions, either in vitro or in vivo. Other neutrophil functions, on the other hand, such as migration and phagocytosis/killing are much more dependent on the leucocyte integrins.

Chronic neutropenia. A new canine model induced by human granulocyte colony-stimulating factor

Normal dogs were treated with recombinant human granulocyte colony-stimulating factor (rhG-CSF) at 10 micrograms/kg/day for 30 d, which caused an initial neutrophilia, followed by a prolonged period of chronic neutropenia. A control dog treated with recombinant canine G-CSF (rcG-CSF) showed persistent neutrophilia over 3 mo. Serum from dogs during neutropenia contained an antibody to rhG-CSF, which neutralized the stimulatory effects of both rhG-CSF and rcG-CSF on dog marrow neutrophilic progenitor cell growth and on NFS-60 cell proliferation. 4 mo after discontinuation of rhG-CSF, the dogs' neutrophil counts returned to the normal range. Rechallenge with the rhG-CSF re-induced severe neutropenia in 1 wk. Neutropenia was transferred by plasma infusion from a neutropenic dog to a previously normal dog. These data suggest that human rhG-CSF immunizes normal dogs and thereby induces neutralization of endogenous canine G-CSF and neutropenia. This model system should allow more precise definition of the in vivo role of G-CSF.

Refractory myelomatosis treated with mitoxantrone in combination with vincristine and prednisone (NOP-regimen): a phase II study. The Nordic Myeloma Study Group (NMSG)

In a phase II study, patients with refractory myelomatosis were treated with a combination chemotherapy (NOP regimen): mitoxantrone (bolus injection of 4 mg/m2 on days 1-4), vincristine (continuous infusion of 0.4 mg/24 h on days 1-4) and prednisone (250 mg/d on days 1-4 and 17-20). The treatment was repeated every 4 weeks. Ninety-two patients were treated after they were found refractory to treatment with melphalan and prednisone (and occasionally vincristine) (n = 50) or more intensive treatment regimens (n = 42) including anthracyclines (n = 18). Response (greater than or equal to 50% reduction of M protein) was obtained in 23 patients and minor response (clinical improvement but less than 50% reduction in M protein) in 22 patients. The median duration of the response was 7.5 months. Equal response rates were observed irrespective of the type of previous treatment. The major toxicity was myelosuppression with severe granulocytopenia and infections. However, the frequency decreased throughout the cycles. The NOP treatment is recommended in refractory myelomatosis, especially in patients refractory to other intensive regimens. Patients in a poor clinical condition or with thrombocytopenia before treatment should have a reduced mitoxantrone dose in the first treatment cycles.

Recombinant human GM-CSF in small cell lung cancer: a phase I/II study

Seventeen patients with small cell lung cancer were entered into a dose ranging phase I-II study using rhGM-CSF (Glaxo). In the phase I study patients received 50, 150, 300 or 500 micrograms/m2 GM-CSF for 10 days by daily subcutaneous injection. Full blood counts were performed thrice weekly. After 4 days off all therapy patients then received chemotherapy with doxorubicin 50 mg/m2 i.v. bolus, day 1, ifosfamide 5 g/m2 with mesna 5 g/m2 over 24 h by continuous infusion followed by mesna 3 g/m2, and etoposide 120 mg/m2 i.v. on days 1-3. A total of six courses of chemotherapy were given. In the phase II study patients received the same dose of GM-CSF as in the phase I. GM-CSF was given 24 h after the last dose of chemotherapy for 14 days. Full blood counts were checked thrice weekly and the incidence of infections noted. Patients were randomised to receive GM-CSF with either odd or even courses of chemotherapy. The leucocyte count rose from a mean of 8.7 to 21.6 x 10(9)/l at the 50 micrograms/m2 GM-CSF dosage and from 11.4 to 39.4 x 10(9)/l at the 500 micrograms/m2 dosage during the phase I study. Phase I toxicity was: bone pain in 65% of patients, rash in 47%, fever in 24%, lethargy in 12% and diarrhoea in 12%. In the phase II study the duration of neutropenia was less during the chemotherapy courses with GM-CSF (p = 0.04) but the number of infections was similar.(ABSTRACT TRUNCATED AT 250 WORDS)

Growth inhibitory effects of transforming growth factor-beta 1 in vivo

Transforming growth factor-beta (TGF-beta) can reversibly inhibit the in vitro proliferation of murine and human haemopoietic progenitors and some of their more developmentally restricted progeny. Using an assay for measuring day 8 and day 11 CFU-S, TGF-beta caused a gradual decline in the number of CFU-S undergoing DNA synthesis so that after 5 days of daily treatment only quiescent cells were found. Release of this growth inhibition was seen within 24 hours post-treatment with recovery of all progenitors to normal levels. Similar inhibitory effects of TGF-beta were seen on the cells of the intestinal epithelium, indicating that TGF-beta is a general stem cell growth inhibitor. These results suggest that TGF-beta can be used as a cytostatic agent to protect normal stem cells in patients being treated with cell cycle-specific cytotoxic agents.

Effect of recombinant granulocyte colony-stimulating factor (rG-CSF) on chemotherapy-induced neutropenia in patients with urogenital cancer

The effects of recombinant granulocyte colony-stimulating factor (rG-CSF) on the myelosuppression, especially neutropenia, induced by cancer chemotherapy in patients with urogenital cancer were investigated in a randomized, controlled clinical study. In this study, rG-CSF was given subcutaneously at a dose of 2 micrograms/kg per day for 14 consecutive days. Changes in neutrophil counts were compared between the first (no rG-CSF) and second cycles (rG-CSF treatment period) of chemotherapy. rG-CSF administration was found to be effective in reducing the duration of neutropenia, in elevating the neutrophil nadir, and in reducing recovery time. Based on comparisons between the randomized rG-CSF treatment group (with rG-CSF) and the control group, treatment with rG-CSF resulted in the moderation or prevention of neutropenia and the acceleration of recovery. These results demonstrate that in chemotherapy of patients with urogenital cancer, in which neutropenia is a dose- or schedule-limiting factor, the concomitant use of rG-CSF may enable an increase in the dose (higher single dose or increased dose per unit of time) or shorten the chemotherapy period.

G-CSF enhanced granulocyte production in a child with severe neutropenia in the setting of fatal virus-associated hemophagocytic syndrome

A 14-year-old boy with fatal varicella zoster virus-associated hemophagocytic syndrome (VAHS) was treated with recombinant human granulocyte colony-stimulating factor (G-CSF) based on the finding that the patient had severe neutropenia and possible bacterial superinfection. Support for the G-CSF therapy in VAHS is provided by the recent reports that G-CSF is relatively specific for the granulocyte lineage; it would not activate mature monocyte/macrophage/histiocyte lineage in VAHS, where the most striking morphologic feature is histiocytic hyperplasia with hemophagocytosis. He responded well to G-CSF with an elevation of neutrophil counts. There were no effects on other blood cells. The result indicates that G-CSF is useful to increase granulocyte production in severe neutropenia, even in the setting of fatal VAHS.

Double-blind test of human urinary macrophage colony-stimulating factor for allogeneic and syngeneic bone marrow transplantation: effectiveness of treatment and 2-year follow-up for relapse of leukaemia

A randomized, double-blind placebo-controlled phase III clinical trial was performed to study the effects of human urinary macrophage colony-stimulating factor (hM-CSF) after allogeneic and syngeneic bone marrow transplantation (BMT) in 60 hM-CSF treated and 59 placebo control patients. HM-CSF was administered at a daily dose of 2 x 10(5) units/kg from day 1 to day 14 after BMT. Significant differences between hM-CSF and control patient were found in the recovery time to greater than 0.5 x 10(9) granulocytes/l and the survival rate during the initial 120 d without retransplantation. There was no difference in the incidence or grade of graft-versus-host disease (GVHD). There was no difference in the rate of leukaemic relapse at 24-36 months after BMT in patients with acute lymphocytic, acute nonlymphocytic, or monocytic leukaemia. The results of this trial show that human M-CSF improves the outcome of BMT without any influence on the occurrence of leukaemic relapse or GVHD.

Expression of the M-CSF receptor is controlled posttranscriptionally by the dominant actions of GM-CSF or multi-CSF

We have isolated a murine myeloid precursor cell line (FDC-P1/MAC) that simultaneously expresses receptors for multi-CSF, GM-CSF, and M-CSF (c-fms protooncogene). FDC-P1/MAC cells express high levels of c-fms mRNA and protein when grown in M-CSF, whereas growth in multi-CSF or GM-CSF caused a dramatic reduction of c-fms glycoprotein and mRNA. Nuclear run-off assays demonstrated that c-fms transcription was not growth factor dependent and the regulation occurred posttranscriptionally. Factor switching experiments have shown that both multi-CSF and GM-CSF act dominantly and in a factor concentration dependent manner to suppress c-fms expression. In vitro agar assays of bone marrow cells grown in the presence of GM-CSF and M-CSF, individually and in combination, support the concept that GM-CSF can act dominantly to prevent monocyte/macrophage development. These results suggest that GM-CSF and multi-CSF can suppress development along the monocyte/macrophage lineage and offer a simple stochastic mechanism governing myeloid lineage restriction.

Hematopoietic growth factors: overview and clinical applications, Part III

The growth and differentiation of blood cells is regulated by a group of at least 12 glycoproteins, collectively known as hematopoietic growth factors. Advances in protein biochemistry and molecular genetics have provided the tools for the bulk production of these hormones for clinical application. Clinical trials of macrophage colony-stimulating factor, granulocyte macrophage colony-stimulating factor, granulocyte colony-stimulating factor, and interleukin-3 have all demonstrated significant effects on the peripheral blood counts of the recipients. The clinical usefulness of at least two of these agents in ameliorating post-chemotherapy myelosuppression, in the treatment of other cytopenias, and in enhancing engraftment after bone marrow transplantation has already been demonstrated. Potential applications to the therapy and diagnosis of other clinical disorders is under study. The history of the elucidation of these growth factors, our current understanding of their properties, interactions, and clinical effects, and the potential prospects for their future use in the manipulation of human blood cell production are the subject of this review.

Colony-stimulating factors

Recombinant hematopoietic colony-stimulating factors have profound effects on developing and mature granulocytes, macrophages, and lymphocytes. Use of these agents for treatment of disease may result in a variety of adverse cutaneous reactions. The recent discovery of colony-stimulating factor production by keratinocytes and dermal cells suggests that these agents may also be significant in cutaneous homeostasis and in the pathogenesis of cutaneous diseases.

Effect of granulocyte colony-stimulating factor on neutropenia due to chemotherapy for non-Hodgkin's lymphoma

The authors administered recombinant human granulocyte colony-stimulating factor (rhG-CSF) to 16 patients with advanced non-Hodgkin's lymphoma treated with combination chemotherapy. Groups of three to five patients were treated with 50, 100, 200, and 400 micrograms/m2 per day of rhG-CSF by intravenous infusion for 14 days, beginning 3 days after chemotherapy. There was a strong linear relationship between the dose and the area under the curve over this dose range. The rhG-CSF was rapidly cleared from serum, with a mean half-life of 5.97 hours for the second phase (t1/2). In patients treated with a dose of more than 100 micrograms/m2 per day, the duration of neutropenia (P less than 0.01) and the duration of fever (P less than 0.05) were significantly decreased. The rhG-CSF was well tolerated and the only clinical observation that appeared relating to rhG-CSF administration was slight bone pain. This study strongly suggests that an optimum dose of rhG-CSF in patients after chemotherapy is 100 to 200 micrograms/m2. Our study shows that rhG-CSF is a clinically useful drug for patients treated with myelosuppressive chemotherapy.

Use of hematopoietic growth factors in radiation accidents

Molecularly cloned hematopoietic growth factors are likely to be useful in treating radiation victims with bone marrow suppression. Some effects, such as increased granulocytes, are clearly beneficial. Other effects, such as altering the probability of survival of hematopoietic stem cells, may also be important. Interesting questions remain to be studied including which molecularly cloned hematopoietic growth factor(s) to use, optimal dose, timing, combinations of growth factors, and other issues. Some can be studied in vitro or in animal models. Others require clinical trials. Molecularly cloned hematopoietic growth factors clearly herald a new era in treating radiation accidents.

Subcutaneous administration of recombinant human granulocyte colony-stimulating factor (KRN8601) in intensive chemotherapy for patients with advanced lung cancer

The efficacy and toxicity of recombinant human granulocyte colony-stimulating factor (rh G-CSF, KRN8601) given subcutaneously was evaluated in patients with advanced lung cancer undergoing intensive chemotherapy. Twenty-nine and 30 patients with or without prior therapy were enrolled in this study. At dose levels of 50, 90 and 130 micrograms/m2 of rh G-CSF for 14 consecutive days after chemotherapy, the mean neutrophil nadir counts, the mean neutrophil nadir ratios and the duration of neutropenia (days of less than 1000/mm3) were significantly improved. No significant differences were seen in frequency and duration of febrile episodes (greater than 38 degrees C). When rh G-CSF is given subcutaneously, the dose required for an equal effect in alleviating neutropenia is 50% of that required when it is given intravenously. The monocyte counts in the peripheral blood were also significantly increased after chemotherapy cycles with rh G-CSF. The cumulative plasma concentration of rh G-CSF showed a decrement after 7-9 days despite maintenance of the same dose of rh G-CSF for the entire 14 days. In conclusion, 50-130 micrograms/m2 of sc rh G-CSF increased the neutrophil nadir count and shortened the duration of neutropenia in patients undergoing intensive chemotherapy for lung cancer without intolerable side effects.

Effect of recombinant human granulocyte colony-stimulating factor on human neutrophil adherence in vitro

We measured the effects of recombinant human granulocyte-colony stimulating factor (rhG-CSF) on the adherence of human neutrophils by using a dacron fiber system to assay the adhesive ability of neutrophils. rhG-CSF enhanced neutrophil adherence to dacron fibers. N-formyl-methionyl-leucyl-phenylalanine (fMLP) induced neutrophil-neutrophil interaction (neutrophil aggregation) in addition to neutrophil-dacron interaction, whereas rhG-CSF did not cause neutrophil aggregation. These results indicated that rhG-CSF increases the adhesive ability of neutrophils without neutrophil-neutrophil interaction, and the action of rhG-CSF in neutrophil activation is different from the neutrophil activation caused by fMLP.

Differential effects of recombinant human colony stimulating factor (rh G-CSF) on stem cells in marrow, spleen and peripheral blood in mice

Previously it has been hypothesized that the granulopoietic and erythropoietic lineages may compete for differentiating stem cells. According to this hypothesis one would expect that a stimulation of granulopoiesis by G-CSF administration would lead to a reduction of the stem cell pool and be followed by a decline of erythropoietic progenitor numbers. In addition one would expect an enhanced response of granulopoiesis if G-CSF administration were combined with suppression of erythropoiesis by red cell transfusion. To evaluate whether this hypothesis holds true C57bl mice were injected subcutaneously for 6 d with 3.75 micrograms rh G-CSF/mouse/d (150 micrograms G-CSF/kg body weight/d). Marrow CFU-S numbers showed an increase to 160% on day 2, followed by a decrease to 50% of control on day 6. Splenic and peripheral blood CFU-S increased 20-fold and 10-fold, respectively. Marrow CFU-E declined to 40% of the control value. Splenic CFU-E increased 10-fold. The increase in marrow CFU-GM numbers ranged between 140% and 180%. CFU-GM obtained from the spleen and the peripheral blood increased 60-fold and 15-fold, respectively. Regarding the CFU-S and CFU-GM a similar pattern of response was found in an experiment where rh G-CSF administration was combined with an additional red cell transfusion. These data do not provide convincing evidence for an exhaustion of haemopoietic stem cells during treatment with G-CSF. They rather suggest that an important side effect of G-CSF treatment is a release of CFU-S and progenitors from the marrow to the peripheral blood and a reseeding in the spleen.

Mitoxantrone/high-dose Ara-C and recombinant human GM-CSF in the treatment of refractory non-Hodgkin's lymphoma. A pilot study

Previous study has shown that the combination of mitoxantrone (Novantrone, NO) and Ara-C (AC) (NOAC) was active in refractory non-Hodgkin's lymphoma (NHL) but myelosuppression was dose-limiting. In a pilot study, we investigated the effects of recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) after NOAC chemotherapy in patients with refractory NHL. NO was applied at a dosage of 10 mg/m2/day on days 2 and 3 and AC at 3 g/m2/12h on days 1 and 2. RhGM-CSF was administered at 250 ug/m2/day as a continuous i.v. infusion from day 6 until the neutrophils were greater than 3.0/nl for 3 consecutive days. Twenty-three patients from five of the nine participating centers were treated with NOAC chemotherapy plus rhGM-CSF, whereas 14 patients from the other four centers received chemotherapy alone. With rhGM-CSF, the median duration of severe neutropenia (less than 0.5/nl) after NOAC was 8 days versus a median of 13 days without rhGM-CSF (P = 0.0058), and that of thrombocytopenia (less than 20.0/nl), 3 days versus 7 days (P greater than 0.4, NS). The rates of infections and stomatitis were 25% and 17%, respectively, for patients treated with rhGM-CSF as compared to 53% (P = 0.0547, NS) and 60% (P = 0.0078), respectively, without rhGM-CSF. The following side effects were associated with the administration of rhGM-CSF: pleural and/or pericardial effusions in five patients, thrombosis in two patients, bone pain in two patients, and respiratory distress syndrome in one patient. A complete remission was achieved in nine of the 23 patients treated with NOAC plus rhGM-CSF, and in two of the 14 patients treated with chemotherapy alone. The median survival of patients treated with rhGM-CSF was not reached at 400 days and seemed to be longer than that of patients treated with chemotherapy alone (median, 109 days; P = 0.036). RhGM-CSF after chemotherapy can be applied safely to patients with NHL, shorten the period of severe cytopenia, reduce the rates of stomatitis, and did not seem to cause adverse effects on response.

Therapeutic efficacy of granulocyte colony-stimulating factor alone and in combination with antibiotics against Pseudomonas aeruginosa infections in mice

The therapeutic efficacy of granulocyte colony-stimulating factor (G-CSF) against an experimental intramuscular infection induced by Pseudomonas aeruginosa in mice was confirmed. Bacterial growth in the infected thigh muscle was suppressed by G-CSF treatment. The change in the number of peripheral blood polymorphonuclear leukocytes (PMN) after bacterial challenge was investigated. The results showed that G-CSF could stimulate stronger defense mechanisms after stimulation by bacterial challenge. In the G-CSF-treated group, more clusters of matured PMN were observed in the infected thigh muscle 6 h after bacterial challenge. Next, the correlation between the number of PMN in the blood at the time of infection and the therapeutic efficacy of antibiotics was investigated. The therapeutic efficacy of ceftazidime, a beta-lactam antibiotic, was affected by the number of blood PMN at the time of infection. In particular, a decrease of peripheral blood PMN at the time of infection resulted in a dramatic decrease in the efficacy of ceftazidime. The reduction in leukopenia by G-CSF remarkably strengthened the therapeutic effect of antibiotics in mice.

Colony stimulating activity in the serum of patients with multiple myeloma is enhanced by interleukin 3: a possible role for interleukin 3 after high dose melphalan and autologous bone marrow transplantation for multiple myeloma

Sera from 36/37 multiple myeloma patients and 19/21 sera from patients with other solid or liquid tumours had granulocyte-macrophage colony stimulating activity (CSA) towards normal human donor bone marrow whereas 1/16 sera from normal donors had this activity. Unlike human rhGM-CSF and GM-CSF from 5637 (human bladder cell line) conditioned medium which is heat stable, CSA from serum is heat labile (56 degrees C/30 min). In multiple myeloma patients, CSA was detectable more than 2 years after treatment with 'high dose melphalan. Although multiple myeloma patients, at relapse, have sufficient CSA in their serum to produce maximal stimulation of GM-CFUc from normal donor bone marrow in vitro, their own GM population responds poorly. The results suggest that the failure of patients own bone marrow to respond to endogenous CSA may be due to damage to the stem cells of the marrow or the failure of precursor cells to respond to CSA. Addition of rhIL-3 to myelomatous serum increased the number of GM-CFUc from both normal and myelomatous bone marrow but did not stimulate the growth of MY-CFUc significantly. The results suggest that rhIL-3 may assist bone marrow recovery in multiple myeloma patients after intensive chemotherapy.

Rapid Therapeutic and Biotechnological Advances: Effects on Practice

As practices have rapidly evolved over the past 20 years into various areas of specialization, pharmacy managers have recognized different needs of specialists. Accelerated development of antineoplastic and biotechnological agents has propelled oncology practitioners and educators to keep with the pace of these developments. The rapid growth of biotechnology will play the most important role in shaping the direction of oncology pharmacy in the next decade. The development of recombinant growth factors, such as erythropoietin and granulocyte-macrophage colony-stimulating factor as well as interleukins, interferons, and monoclonal antibodies, heralds a new era in the treatment and diagnosis of cancers. Pharmacy managers can assist this process by supporting clinicians and educators with excellent distributive services, readily accessible drug information resources, and the capability of attending continuing educational programs in the areas of biotechnology and new drug delivery systems.

Granulocyte-macrophage colony stimulating factor (GM-CSF) after high-dose melphalan in patients with advanced colon cancer

Nine patients with progressive, metastatic disease from primary carcinoma of the colon were entered into a phase I/II study using continuous intravenous infusions of granulocyte-macrophage colony-stimulating factor (GM-CSF) and high dose melphalan (120 mg m-2). GM-CSF was given alone to six patients during the first part of the study to determine a dose that would produce a peripheral leucocyte count (WCC) greater than or equal to 50 X 10(9) 1(-1) and was initially given at 3 micrograms kg-1 day-1 and escalated to 10 micrograms kg-1 day-1 after 10 days. The infusion was discontinued when the WCC exceeded 50 X 10(9) 1(-1) and after a gap of one week, melphalan was given over 30 min. GM-CSF was recommenced 8 h later and was continued until the neutrophil count had exceeded 0.5 X 10(9) 1(-1) for greater than 1 week. One patient achieved a WCC greater than 50 X 10(9) 1(-1) with GM-CSF 3 micrograms kg-1 day-1, but the other five who entered this phase of the study required dose escalation to 10 micrograms kg-1. No toxicity attributed to GM-CSF was seen. After melphalan, the median times to severe neutropenia (less than 0.5 X 10(9) 1(-1] and thrombocytopenia (greater than 20 X 10(9) 1(-1] were 6 and 9 days respectively. The median durations of neutropenia and thrombocytopenia were 14 and 10 days respectively. All patients required intensive support with a median duration of inpatient stay of 24 days. There was one treatment related death due to renal failure. One complete and two partial remissions (33% response rate) were seen but these were of short duration (median of 10 weeks). This study demonstrates that GM-CSF given by continuous intravenous infusion produces significant increments of peripheral granulocyte counts at 3 and 10 micrograms kg-1 day-1 and is not associated with any toxicity. The duration of neutropenia and thrombocytopenia induced by high-dose melphalan appears to be reduced by the subsequent administration of GM-CSF to times which are at least as short as have been reported in historical series which have used autologous bone marrow rescue.

Therapeutic administration of recombinant human granulocyte colony-stimulating factor accelerates hemopoietic regeneration and enhances survival in a murine model of radiation-induced myelosuppression

The primary cause of death after radiation exposure is infection resulting from myelosuppression. Because granulocytes play a critical role in host defense against infection and because granulocyte proliferation and differentiation are enhanced by granulocyte colony-stimulating factor (G-CSF), this agent was evaluated for the ability to accelerate hemopoietic regeneration and to enhance survival in irradiated mice. C3H/HeN mice were irradiated and G-CSF (2.5 micrograms/day, s.c.) or saline was administered on days 3-12, 1-12 or 0-12 post-irradiation. Bone marrow, splenic and peripheral blood cellularity, and bone marrow and splenic granulocyte-macrophage progenitor cell recoveries were evaluated in mice exposed to 6.5 Gy. Mice exposed to 8 Gy were evaluated for multipotent hemopoietic stem cell recovery (using endogenous spleen colony-forming units) and enhanced survival. Results demonstrated that therapeutic G-CSF 1) accelerates hemopoietic regeneration after radiation-induced myelosuppression, 2) enhances survival after potentially lethal irradiation and 3) is most effective when initiated 1 h following exposure.

Hematopoietic growth factors in cancer

The family of colony stimulating factors and interleukins influence all aspects of hematopoietic cell proliferation and differentiation. In most instances these hematopoietic growth factors have overlapping, pleiotropic effects and frequently regulate early progenitor cell proliferation and mature cell function. Currently, seven of these factors are in clinical trial: erythropoietin for treatment of anephric anemia, IL-2 in conjunction with LAC therapy, and IL-1, IL-3, G-CSF, GM-CSF, and M-CSF for stimulation of myelopoiesis and granulocyte-macrophage function after chemotherapy, irradiation, or bone marrow transplantation in patients with cancer. G-CSF and GM-CSF have also proved effective in treatment of congenital and idiopathic neutropenias and have had some efficacy in treatment of myeloid leukemias, myelodysplastic disorders, aplastic anemia, and acquired immunodeficiency syndrome (AIDS).

Effect of recombinant human granulocyte colony-stimulating factor on granulocytopenia in mice induced by irradiation

We report the effect of human granulocyte colony-stimulating factor (hG-CSF) on the recovery from granulocytopenia induced by irradiation. Female 9-week old C3H/He mice were used. The irradiation schedule was as follows: Group 1 and 2 received whole-body irradiation of 1 Gy and 5 Gy, respectively, on day 0; Group 3 and 4 received whole-body irradiation of 0.5 and 1.0 Gy, respectively, for 5 consecutive days; Group 5 received upper hemibody irradiation of 3 Gy for 5 consecutive days. Daily subcutaneous injections of G-CSF (3 x 10(5) Unit/mouse) or 0.3 ml of saline to each group were started from the day after the first irradiation and continued for 18 days. Mice were sampled randomly from each group, and the total number of leukocytes, erythrocytes of peripheral blood, nucleated cells in femur, and spleen weight were counted and measured, respectively, on day 0, 3, 5, 7, 9, 12, and 18. The leukocyte counts decreased with an increase in radiation doses. In Group 1 and 2 mice, G-CSF enhanced the leukocyte count more than saline. In Group 3 mice, the recovery of leukocytopenia was facilitated by G-CSF, but in Group 4 mice, G-CSF had no effect on the leukocyte count decrease or on leukocytopenia recovery. In Group 5 mice, G-CSF greatly affected leukocytopenia recovery. Increase in spleen weight paralleled the peripheral leukocyte count. Daily administration of recombinant hG-CSF accelerated the granulocytopenia recovery which was induced by irradiation, and it may be a useful therapeutic agent for treating myelosuppressive cases.

Disease states induced by hemopoietic growth factor excess: their implications in medicine

Sustained excess levels of hemopoietic regulators can induce a variety of disease states in mice in addition to the anticipated hyperplasia of the responding hemopoietic lineages. In all the models examined so far, there is a complicating problem that at least some responding cells are also producing the excess regulator concerned. The development of the various disease states may therefore not necessarily be the simple consequence of overstimulation by excess regulator levels. The various disease states develop rapidly in a high proportion of animals and should serve as useful models for a variety of disease states in man.

Neutrophil kinetics of recombinant human granulocyte colony-stimulating factor-induced neutropenia in rats

Single injection of recombinant human granulocyte colony-stimulating factor (rhG-CSF) immediately induced a decrease in the number of circulating neutrophils in rats. This neutropenia occurred 10 minutes after the injection but disappeared 40 minutes after injection. This transient neutropenia was dose-dependently induced by rhG-CSF and also induced by repeated injections. We studied the kinetics of circulating neutrophils in transient neutropenia. rhG-CSF markedly decreased the number of 3H-diisopropylfluorophosphate (3H-DFP) labeled neutrophils in the circulation 10 minutes after injection but the labeled neutrophils recovered to near the control level 40 minutes after the injection. These results indicate that the neutrophil margination accounts for the neutropenia and the marginated neutrophils return to the circulation.

Effect of granulocyte-macrophage colony-stimulating factor on neutropenia and related morbidity induced by myelotoxic chemotherapy

A phase Ib/II clinical study was undertaken to assess the efficacy of recombinant human granulocyte-macrophage colony-stimulating factor (GM-CSF) to attenuate neutropenia and associated morbidity caused by high-dose anticancer chemotherapy administered in the presence or absence of autologous bone marrow support. We treated 22 patients with various solid tumors and lymphoid neoplasias with a single daily subcutaneous dose of GM-CSF (250 micrograms/m2) 48 h after a second cycle of highly myelotoxic chemotherapy for a period of 10 days and compared intraindividually neutropenia-related clinical and laboratory variables with data obtained from the same patients having previously received a first neutropenia-inducing cycle of identical chemotherapy in the absence of GM-CSF. We show that GM-CSF is active in neutropenic patients by significantly increasing the neutrophil nadir, reducing the time of relevant neutropenia, and reducing the duration of the patient's hospital stay and necessity for parenteral antibiotics. No significant toxicity was encountered with subcutaneous GM-CSF treatment.

In vitro growth response to G-CSF and GM-CSF by bone marrow cells of patients with acute myeloid leukemia

The in vitro growth response of bone marrow and blood cells to granulocyte/macrophage colony-stimulating factor (GM-CSF) and granulocyte colony-stimulating factor (G-CSF) was studied in 18 acute myeloid leukemia (AML) patients using semisolid and suspension cultures. In 80% of the cases growth of leukemic progenitor cells was stimulated by GM-CSF and/or G-CSF, as judged by colony or cluster formation. In acute promyelocytic leukemia [t(15;17)], G-CSF stimulated and maintained the leukemic progenitors only transiently but fully stimulated the residual normal granulocyte/macrophage colony-forming units (CFU-GM). In some cases of M2 and M4 leukemia, G-CSF enhanced markedly the production of mature but cytochemically abnormal neutrophils. In some cases of M1 leukemia, neither CSF stimulated leukemic progenitors but instead stimulated only residual normal granulopoiesis. Spontaneous colony formation was observed in 20% of cases and was correlated with high-grade leukemic growth in vivo and a poor response to chemotherapy. The differing effects of the CSFs upon leukemic cells and residual normal granulopoiesis may have some implications for the clinical use of GM-CSF and G-CSF to overcome infectious complications.

Partial purification and characterization of human megakaryocyte colony-stimulating factor (Meg-CSF)

Megakaryocyte colony-stimulating factor (Meg-CSF) in urinary extracts from patients with aplastic anemia was partially characterized and purified. Using Meg-CSF-enriched fractions, we established that the moiety has the following characteristics: 1) portions of the molecules having Meg-CSF activity have sialic acid, probably with a biantennary structure, and beta-galactose residues as the terminal and penultimate sugars; 2) disulfide residues are an essential chemical group of the molecule and are located on its surface; and 3) Meg-CSF activity is stable in n-propanol, but not in acetonitrile with trifluoroacetic acid. Partial purification of Meg-CSF by a four-step procedure of ethanol precipitation, CM Affi-Gel Blue chromatography, wheat germ agglutinin-sepharose chromatography, and high-resolution hydroxyapatite chromatography, yielded a concentrate with a 430- to 630-fold increase in specific activity. The partially purified Meg-CSF fractions stimulated both human and murine megakaryocytopoiesis in vitro (CFU-meg). When analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis under nonreduced conditions, Meg-CSF activity was recovered in the 29-34 kDa molecular weight fractions. We have also shown that Meg-CSF, purified from the urine of aplastic anemia patients, stimulated murine megakaryocytopoiesis and platelet production in vivo. Final purification of human urinary Meg-CSF is currently in progress.

The role of hemopoietic growth factors in self-renewal and differentiation of IL-3-dependent multipotential stem cells

A multipotent hemopoietic cell line has been employed to assess the influence of the hemopoietic growth factors, IL-3, GM-CSF, G-CSF, and CSF-1 on the processes of self-renewal, the generation of lineage restricted progenitor cells and the production of mature neutrophils and macrophages. At a high concentration of IL-3, the cells undergo self-renewal and demonstrate little or no ability to undergo differentiation in the presence of the other growth factors. In the absence of IL-3, the cells show minimal (GM-CSF) or no (G-CSF or CSF-1) ability to respond to these other growth factors. When combined with a low concentration of IL-3, the ability of the cells to respond to GM-CSF, G-CSF, and CSF-1 is enhanced and a selective preference for the neutrophil or macrophage lineage is seen depending on the combination used, i.e., the presence of CSF-1 preferentially promotes macrophage development and G-CSF preferentially promotes neutrophil development. Conditions optimal for neutrophil development were seen using a combination of low IL-3 concentrations plus GM-CSF plus G-CSF. In such conditions, the cells undergo extensive proliferation and progressively lose their clonogenic potential (i.e., differentiation much greater than self-renewal) and acquire the biochemical markers characteristic of fully mature phagocytes.