The effect of recombinant human granulocyte colony-stimulating factor (rG-CSF) on childhood neutropenias]

The clinical effect of recombinant human granulocyte colony-stimulating factor (rG-CSF), produced by Chinese hamster ovary cells, was studied in 27 patients with childhood neutropenias. The sample consisted of 8 patients with congenital neutropenia (Kostmann type), 9 with neutropenia with miscellaneous causes (5 chronic benign, 2 associated with hypogammaglobulinemia, 1 drug-induced, and 1 hypoplastic type), 3 with cyclic neutropenia, and 7 with severe aplastic anemia. The rG-CSF was given subcutaneously (or in a few cases intravenously) at a dose of 2 micrograms/kg/day for 7 days and 5 micrograms/kg/day for additional 7 to 28 days in cases with poor response. The rG-CSF was effective in 18 of 27 cases (67%). Patients with congenital neutropenia and aplastic anemia responded less frequently and poorly. The mean level of absolute neutrophil counts of 8 congenital neutropenia cases increased from 88/microliters to 2,718/microliters. That of 9 miscellaneous cases changed from 189/microliters to 7,224/microliters at a dose of 2 micrograms/kg/day. In 7 aplastic anemia cases pretreatment level of 220/microliters rose to 851/microliters, usually after increasing the dose up to 5 micrograms/kg/day. The rG-CSF was apparently effective in 3 cases of cyclic neutropenia. In any type of neutropenia, the effect was largely transient; after the discontinuation of rG-CSF, the absolute neutrophil counts tended to decrease to pretreatment levels within 1 to 2 weeks. The G-CSF was well tolerated, and only one case with mild lumbago and another with minimal elevation of transaminases were observed. We conclude that the rG-CSF can be effective for treating various types of childhood neutropenia.(ABSTRACT TRUNCATED AT 250 WORDS)     

Clinical evaluation of recombinant human G-CSF in children with cancer]

Recombinant human granulocyte colony-stimulating factor (rG-CSF), produced by Chinese hamster ovary cells, was administered in 69 chemotherapy-induced neutropenic pediatric patients (pts) with malignant tumors. Each pt received two cycles of the same chemotherapy and had neutropenia with absolute neutrophil counts (ANC) less than 500/microliter in the first cycle. Initiating 72 hours after termination of chemotherapy in the second cycle, rG-CSF (2 micrograms/kg/day) was given subcutaneously or intravenously to each pt for 10 days. rG-CSF significantly increased ANC at nadir; 72 +/- 14 vs. 206 +/- 40/microliter (data in the first cycle vs. data in the second cycle, respectively), and reduced the period of neutropenia with ANC less than 500/microliter; 9.7 +/- 0.6 vs. 5.1 +/- 0.6 days, and the period for restoration to ANC greater than or equal to 1,000/microliter after initiation of chemotherapy; 25.5 +/- 0.6 vs 17.5 +/- 0.9 days. rG-CSF did not affect other components of peripheral blood. The number of days with fever greater than or equal to 38 degrees C was significantly reduced by rG-CSF treatment. Neck pain and lumbago were observed in one pt, pollakisuria in one pt, and elevation of the serum levels of LDH and uric acid in one pt, however these were mild to moderate, transient, and resolved without any specific treatment. We concluded that rG-CSF was effective in neutropenia induced by intensive chemotherapy for malignant tumors without any serious side effects.     

Treatment of canine cyclic neutropenia by lentivirus-mediated G-CSF delivery

Cyclic neutropenia is a rare disease that occurs both in humans and gray collie dogs and is characterized by recurrent severe neutropenia leading to bacterial infections and shortened life expectancy. Daily injections of recombinant granulocyte colony-stimulating factor (rG-CSF) are effective in shortening the period of severe neutropenia and reducing infections. After demonstrating that rG-CSF induced elevated neutrophil production in an affected dog, cytokine administration was stopped and 109 infectious units (IUs) of a lentivirus pseudotyped with vesicular stomatitis virus G protein (VSV-G) encoding canine G-CSF cDNA was administered intramuscularly. Serial blood cell counts showed elevated neutrophil production for longer than 17 months. Although neutrophil counts continued to cycle, the range at nadirs was from 3710 to 5300 cells/microL, well above the nadirs before lentivirus administration. After the injection of lentivirus, mean neutrophil counts +/- SD were 12 460 +/- 4240 cells/microL, significantly increased over both pretreatment values of 3040 +/- 2540 cells/microL(P <.0001) and neutrophil counts during G-CSF administration of 10 290 +/- 4860 cells/microL(P <.007). The changes in blood counts from lentivirus injection were associated with absence of clinical signs of infection and fever. The gray collie continued to gain weight and was no longer housed in a pathogen-free environment. Genomic DNA from muscle at injection sites was positive for provirus, whereas gonad, lung, spleen, heart, liver, kidney, leukocytes, and noninjected muscle samples were all negative for provirus. Thus, intramuscular administration of lentivirus encoding G-CSF provided sustained therapeutic levels of neutrophils, suggesting this approach may be applied for long-term treatment of patients with cyclic and other neutropenias.     

Clinical significance of recombinant human granulocyte colony-stimulating factor (rG-CSF) in the chemotherapy of patients with malignant lymphoma]

We examined the effects of recombinant human granulocyte colony-stimulating factor (rG-CSF) on neutropenia induced by chemotherapy in 10 patients with non-Hodgkin's lymphoma (NHL). The numbers of peripheral blood hematopoietic progenitors were also evaluated before and after administration of rG-CSF. Six patients received an administration of 2 micrograms/kg/body weight of rG-CSF subcutaneously for 14 days after 2nd chemotherapy. Four patients received intravenous infusion of rG-CSF (300 micrograms/body/day) for 4 days from nadir state after chemotherapy. Administration of rG-CSF from the termination of chemotherapy, markedly shortend the period of bone marrow hypoplasia induced by chemotherapy. On the other hand, administration of rhG-CSF from nadir state after chemotherapy have accelerated the recovery of neutrophil counts. In addition, this type of therapy induced 26 to 60 folds increase of peripheral blood hematopoietic progenitors. These results demonstrate the validity of administration of rhG-CSF not only in the chemotherapy of NHL, but also in peripheral blood stem cell transplantation (PBSCT).     

A phase II trial of recombinant human granulocyte colony-stimulating factor in the myelodysplastic syndromes

We conducted a phase II study of the intravenous administration of a glycosylated recombinant human granulocyte colony-stimulating factor (rhG-CSF) for 7-14 d in 41 patients with the myelodysplastic syndromes (MDS). Administration of rhG-CSF elicited striking rises in both leucocyte and neutrophil counts in the majority of the patients irrespective of the FAB subtypes of MDS. The rises in neutrophil counts were dose dependent and 5 micrograms/kg/d of rhG-CSF yielded approximately an 8-fold increase in neutrophil counts. Leucocytes and neutrophil counts started to increase shortly after the first injection of 5 micrograms/kg, was maintained at significantly elevated levels during 14 d of treatment, and returned to the pretreatment levels within several days following discontinuation of rhG-CSF. The action of rhG-CSF was specific for neutrophils since leucocytosis was due exclusively to neutrophilic increase associated with an increased marrow myeloid maturation. There were no consistent changes in the monocyte, eosinophil, lymphocyte, platelet or reticulocyte counts. After treatment, the percentage of marrow blast cells was reduced in eight of 13 evaluable patients with refractory anaemia with an excess of blasts (RAEB) or RAEB in transformation (RAEB-t). No patients developed acute leukaemia during the treatment or in the immediate follow-up period. The treatment was well tolerated with only minimal toxicity. The results suggest that rhG-CSF is a safe and effective way to promptly improve neutropenia in MDS patients.     

Effects of recombinant human granulocyte colony-stimulating factor on the mice receiving bone marrow transplantation following lethal irradiation: acceleration of recovery of the peripheral blood neutrophils and potentiation of anti-Pseudomonas resistance.

The effects of recombinant human granulocyte colony-stimulating factor (rG-CSF) on the recovery of peripheral blood neutrophil counts and resistance to i.p. infection by Pseudomonas aeruginosa were studied using a mouse bone marrow transplantation (BMT) model. A severe neutropenic period continued in the BMT mice for greater than 9 days following BMT. In contrast, the number of peripheral blood neutrophils in the BMT mice that received a daily administration of 2.5 micrograms of rG-CSF following BMT returned to normal by day 9. Thus, rG-CSF accelerated the recovery of the peripheral blood neutrophil counts in BMT mice. Anti-Pseudomonas resistance of the control BMT mice examined on days 7, 9, and 11 following BMT was one fifteenth to one fiftieth of normal mice, as indicated by the LD50 value. The anti-Pseudomonas resistance was elevated six- to sevenfold by the rG-CSF treatment. A marked increase in the neutrophils exudating into the peritoneal cavity in response to casein injection was observed in the rG-CSF-treated BMT mice. In addition, the reduced superoxide generative and phagocytic activity of the peritoneal neutrophils of the BMT mice were restored to normal by the rG-CSF treatment. It is suggested that rG-CSF potentiated anti-Pseudomonas resistance of the BMT mice by increasing neutrophils migrating to the infection site and restoring their functions; this may result from a prompt recovery of the peripheral blood neutrophil level together with the effect on neutrophil functions. These results indicate the clinical usefulness of rG-CSF in applications for BMT.     

Clinical study of rhG-CSF (KRN8601) in patients with myelodysplastic syndrome]

A clinical study of rhG-CSF (KRN8601) in patients with myelodysplastic syndrome (MDS) was performed to investigate the hematopoietic effects and the increase of neutrophils. The rhG-CSF was administered daily by intravenous infusion over 30 min. to 21 patients with MDS (PARA = 11, RAEB = 4, RAEB in T = 6). The dose was escalated stepwise from 50 to 400 microgram/m2 every week. Within one week to 26 days after commencement of rhG-CSF administration, the increases of absolute neutrophil counts in peripheral blood were observed in all patients. Treatment with rhG-CSF enhanced normal marrow myeloid cell differentiation and maturation in 3 of 9 PARA patients and in 3 of 4 RAEB patients. None of patients changed to acute leukemia attributable to rhG-CSF, but one of RAEB patient and two of RAEB in T patients progressed to leukemic phase in 21 days or two months after treatment. Minor side effects or abnormal laboratory findings were observed in 3 patients (14.3%). These results suggested that treatment with rhG-CSF was well tolerated and effective for improving the neutropenia between 50 to 400 micrograms/m2 in patients with MDS.     

Effects of recombinant human granulocyte colony-stimulating factor on neutrophil function in normal rats.

We studied the effects of recombinant human granulocyte colony-stimulating factor (rG-CSF) on neutrophil functions in vitro using neutrophils isolated from the venous blood of normal rats. FMLP-induced superoxide anion (O2-) release, phagocytosis, and FMLP-induced chemotaxis were evaluated. These functions were significantly enhanced by rG-CSF treatment. In addition to performing neutrophil function assays, we evaluated FMLP binding to rat neutrophils after rG-CSF treatment. FMLP specific binding was not changed by rG-CSF treatment. In addition, we intravenously injected rG-CSF (10 micrograms/kg) or control vehicle into rats for 7 consecutive days, and evaluated the functions of neutrophils isolated from venous blood at 6 h after the final injection. The neutrophil count in the peripheral blood of rG-CSF-treated rats was increased significantly compared with that in control rats. FMLP-induced O2- release, phagocytosis, FMLP-induced chemotaxis and spontaneous migration of rG-CSF-treated neutrophils were significantly enhanced in comparison with those in control rats. These findings demonstrate that rG-CSF not only increases neutrophil counts in peripheral blood, but that it also enhances neutrophil functions, both in vitro and in vivo.     

Granulocyte-colony stimulating factor-induced proliferation of primary adult T-cell leukaemia cells

Granulocyte-colony stimulating factor (G-CSF) is known to induce proliferation and differentiation of granulocyte progenitors, and is widely used to treat neutropenia induced by intensive chemotherapy for malignant lymphoma or adult T-cell leukaemia/lymphoma (ATL). G-CSF is thought not to stimulate malignant lymphoid cells. In the present study we examined the ability of G-CSF to induce in vitro growth of primary ATL cells from 14 patients (nine acute-type, two chronic-type and three lymphoma-type), and we analysed the in vivo counts of ATL cells in patients who received G-CSF for neutropenia. FACS analysis using phycoerythrin-labelled recombinant G-CSF demonstrated that ATL cells from 11/14 patients express some G-CSF receptor (G-CSFR), with a range between 5.4% and 87.3%. Cells expressing G-CSFR also expressed CD4. Reverse polymerase chain reaction (PCR) analysis demonstrated expression of G-CSFR messenger RNA in G-CSFR expressing cells. Leukaemic cells derived from seven (four acute-type, one chronic-type and two lymphoma-type) of the 14 patients proliferated in vitro in response to G-CSF, as measured by [³H]thymidine incorporation; maximum responses were at G-CSF concentrations of 10–100 ng/ml. Nine of 14 patients receiving rG-CSF for neutropenia were analysed retrospectively for ATL cell numbers. Four patients whose primary tumour cells proliferated in response to rG-CSF in vitro showed a significant increase in ATL cell count after administration of rG-CSF ( P  =0.038), whereas five patients whose leukaemic cells did not proliferate in vitro showed no significant increase in ATL cell count. G-CSF can stimulate proliferation of ATL cells which may complicate therapy for this disease.     

Recombinant human granulocyte-macrophage colony-stimulating factor plus erythropoietin for the treatment of cytopenias in patients with myelodysplastic syndromes

In vitro studies have indicated that granulocyte-macrophage colony-stimulating factor (GM-CSF) synergizes with erythropoietin (EPO) for the production of erythroid precursors in patients with myelodysplastic syndrome (MDS). We performed a clinical trial to evaluate whether the combination of these growth factors was effective in relieving the cytopenias associated with MDS. 31 anaemic patients with low and intermediate-risk primary MDS were enrolled in a 12-week study. Therapy was initiated with GM-CSF at 1 microgram/kg/d.s.c., and then adjusted to either normalize or double the absolute neutrophil count. EPO was given subcutaneously on alternate days starting from day 2. The EPO dose was initiated at 150 U/kg and increased to 300 U/kg if after 6 weeks there was no or suboptimal erythroid response. 26 patients completed the study treatment. All evaluable cases had a neutrophil response. Clinically significant erythroid responses with increases of haemoglobin levels of at least 1 g/dl and/or reduction of transfusion needs were seen in 9/26 (34.6%), five patients improving their response after dose escalation of EPO. Treatment had no apparent effect on mean platelet counts, a single case displaying a trilineage response. An elevated bone marrow erythroid infiltration and low concentrations of circulating tumour necrosis factor-alpha were the only predictors of haemoglobin response both in univariate and in multivariate analysis. We conclude that the combination GM-CSF + EPO can abrogate neutropenia and substantially relieve transfusion requirements in a large proportion of patients with low and intermediate risk MDS. However, in vivo synergy between these growth factors for the production of erythroid precursors is not supported by our data.     

Increases in neutrophil counts by purified human urinary colony- stimulating factor in chronic neutropenia of childhood

Clinical effects of purified human urinary colony-stimulating factor (CSFHU) were studied in nine patients with chronic neutropenia of childhood who ranged in age from 1 to 18 years. The patients were given CSFHU at a dose of 6 x 10(6) U/m2/d for seven consecutive days, and their peripheral neutrophil counts were serially followed for 6 to 12 months. In addition, changes in bone marrow morphology and granulocyte- macrophage colony-forming cells (GM-CFUs) were studied. Transient increases in neutrophil counts occurred during the first 4 weeks in all patients except one. Repeated increases were seen in a cyclic fashion in five patients. Three of the patients recovered from the neutropenia after several cycles of fluctuation of neutrophil counts; the counts (per microliter) reached 5,880, 5,640, and 2,000 as compared with pretreatment levels (mean +/- 2 SD) of 80 +/- 164, 182 +/- 250, and 2 +/- 14, respectively. The percentage (mean +/- SE) of marrow neutrophilic cells increased from 30.4% +/- 7.0% to 34.9% +/- 6.9% (P less than .05) and the ratio of the later neutrophil precursors to the earlier ones from 1.02 +/- 0.27 to 1.42 +/- 0.36 (P less than .02) 2 weeks after CSFHU infusion. There were no changes in GM-CFU numbers. These results indicate that CSFHU can increase neutrophil counts by increasing the number and maturity of the marrow neutrophil precursors in some types of childhood chronic neutropenia.     

Pilot study: effects of G-CSF on neutrophil ex-vivo function post bone marrow transplantation

Summary The effects of human recombinant granulocyte colony stimulating factor (G-CSF) on neutrophil recovery have been studied in patients undergoing bone marrow transplantation for haematological disease. Nine patients (five autografts and four allografts) were studied while receiving daily doses of G-CSF (range 2-20 μg/kg body weight) were compared to eight patients (four autografts and four allografts) who did not receive G-CSF as a control group. In both groups flow cytometry was used to determine neutrophil IgG Fc receptor (FcRII, FcRIII) expression. Phagocytosis and metabolic burst was assessed using IgG opsonized bacteria. The patients' neutrophils were studied prior to conditioning in autografts and donor cells were studied in allografts. Studies were repeated at neutrophil recovery (neutrophil count 1.0 ± 10⁹/1) and ten days post recovery. At recovery FcRII expression was slightly increased in all groups, whereas the number of cells expressing FcRIII was reduced. This reduction was significant in the patients receiving rG-CSF at recovery and post recovery compared to the pretreatment levels. The ability to phagocytose bacteria in cells from patients receiving G-CSF was also reduced. The associated metabolic burst was significantly reduced in the autograft group but not the allograft group receiving rG-CSF. The reduced function and reduced expression of FCRIII suggests the presence of immature neutrophils in patients receiving rG-CSF post BMT.     

Assessing the delivery of neutrophils to tissues in neutropenia

Studies of neutrophil kinetics in neutropenic individuals, as well as clinical observations of variability in the occurrence of infection among patients with neutropenia, have suggested that blood neutrophil counts may not uniformly reflect the effective delivery of neutrophils to extravascular tissues where the cells perform their principal host defense functions. To evaluate this possibility we developed a sensitive, reproducible method of measuring the extravascular delivery of neutrophils to a normal mucosal site of neutrophil turnover. This method is based upon the quantification of neutrophils recoverable from saline mouth wash specimens. Twenty-five mL specimens, obtained in a controlled manner from neutropenic patients and normal subjects, were centrifuged and the sediments resuspended in 1.0 mL Hank's buffer with 2 micrograms acridine orange, incubated at 37 degrees C for 15 minutes, and then examined in a hemocytometer chamber by fluorescence microscopy. Neutrophils could be clearly distinguished by their characteristic fluorescence and were counted. With this method as few as 1,500 neutrophils were detected reliably in mouth wash specimens. Mucosal neutrophil counts varied less than 10% with repeated sampling of individual subjects over 5-day periods and were consistently greater than 1.3 X 10(5)/specimen in non-neutropenic individuals. Although profound neutropenia was generally reflected by lower than normal oral mucosal neutrophil counts, these counts were significantly higher in individuals with chronic severe neutropenia (blood neutrophils less than 300/mm3) than in patients with acute neutropenia of comparable severity that had developed following chemotherapy. Also, in individuals recovering from profound neutropenia, neutrophils usually reappeared earlier in mouth wash specimens than in blood, and oral mucosal neutrophil counts attained recovery levels more rapidly than did blood counts. This phenomenon was particularly evident in an individual with cyclic neutropenia. Moreover, mucosal neutrophils could occasionally be detected in profoundly neutropenic patients when neutrophils were not present in blood samples. These findings indicate that mucosal neutrophil counts in individuals with neutropenia provide information about the delivery of neutrophils to tissues that may not be apparent from blood neutrophil counts alone.     

Contrasting effects of recombinant human granulocyte-macrophage colony- stimulating factor (CSF) and granulocyte CSF treatment on the cycling of blood elements in childhood-onset cyclic neutropenia

Recombinant human granulocyte colony-stimulating factor (G-CSF) treatment has been shown to increase average neutrophil counts substantially in patients with childhood-onset cyclic neutropenia (or "cyclic hematopoiesis"), but not to eliminate the cyclic oscillations of neutrophil counts or those of other blood elements (monocytes, platelets, eosinophils, and reticulocytes) that are characteristic of this hematopoietic disorder. Indeed, oscillations of neutrophil counts are amplified during G-CSF treatment. We have compared the effects of recombinant granulocyte-macrophage-CSF (GM-CSF) with those of G-CSF in three patients with this disease (2 men and 1 woman, 17, 30, and 32 years of age). These patients were treated with GM-CSF (2.1 micrograms/kg/day, subcutaneously) for 6 weeks, preceded and followed by 6 to 13 weeks of detailed observation to document changes in the cyclic oscillations of blood neutrophils and other blood elements; two of the patients were subsequently treated with G-CSF (5.0 micrograms/kg/d, subcutaneously) and observed for comparable periods of time. Unlike G-CSF treatment, which increased average neutrophil counts more than 20-fold, GM-CSF increased neutrophil counts only modestly, from 1.6- to 3.9-fold, although eosinophilia of varying prominence was induced in each patient. However, at the same time, GM-CSF treatment dampened or eliminated the multilineage oscillations of circulating blood elements (neutrophils, monocytes, platelets, and/or reticulocytes) in each of the patients. In contrast, G-CSF treatment of the same patients markedly amplified the oscillations of neutrophil counts and caused the cycling of other blood elements (monocytes in particular) to become more distinct. These findings support the conclusion that the distinctive cycling of blood cell production in childhood-onset cyclic neutropenia results from abnormalities in the coordinate regulation of both GM-CSF-responsive, multipotential progenitor cells and G-CSF-responsive, lineage-restricted, neutrophil progenitors.     

Clinical evaluation of recombinant human granulocyte colony-stimulating factor (rhG-CSF) in autologous bone marrow transplantation]

We administered recombinant human granulocyte colony-stimulating factor (rhG-CSF) at 5 micrograms/kg/day by intravenous drip infusion for 21 consecutive days in autologous bone marrow transplanted patients. The period of posttransplant neutropenia was markedly shortened by the rhG-CSF treatment; mean days required for neutrophil recovery (greater than 500/mm3) of 14.3 days in the rhG-CSF group (n = 21) versus 27.8 days in the historical control group (n = 11). More importantly, the numbers of febrile days between day 15 and day 28 were found to be fewer in the rG-CSF group than in control group. These effects were obtained without delay in the recovery of other blood cell series and without any side effect. We conclude that the posttransplant use of the rhG-CSF is beneficial for prevention and treatment of infectious complications after autologous bone marrow transplantation.     

Granulocyte colony-stimulating factor dosing in pegylated interferon alpha-induced neutropenia and its impact on outcome of anti-HCV therapy

Many patients with chronic hepatitis C (HCV) infection undergoing treatment with pegylated interferon-alpha (PEG-IFN-alpha) and ribavirin develop neutropenia requiring dose reduction or granulocyte colony-stimulating factor (G-CSF) supplement. We analysed the database of patients who completed treatment for chronic HCV infection between 2003 and 2006. Patients with absolute neutrophil counts below 1000 cells/microL were initiated on G-CSF (G-CSF group) while a matching group of patients who received anti-HCV treatment without developing neutropenia were used as a control group (non-G-CSF group). Patients on the G-CSF arm were divided into two subgroups based on the timing of G-CSF administration relative to PEG-IFN-alpha administration. Of the 163 patients with HCV infection, 30 patients received G-CSF, most of who were maintained on 300 microg of G-CSF once a week. Administration of G-CSF 2 days before or after each dose of PEG-IFN-alpha did not make a significant difference in the neutrophil counts. In the G-CSF arm, 23 of 30 patients (77%) had undetectable end-of-treatment viral response which was comparable with 27 of 30 in the control group (90%; P = 0.17). There was no statistically significant difference in the sustained viral response between the two groups (61%vs 76%, P = 0.18). In most patients PEG-IFN-alpha induced neutropenia improved with a once-a-week dose of G-CSF with a comparable virological outcome. Timing of G-CSF administration did not make any significant impact on the patient's neutrophil counts but was better tolerated when given 2 days apart from PEG-IFN-alpha.     

Proliferation and differentiation of myelodysplastic CD34+ cells in serum-free medium: II. Response to combined colony-stimulating factors

Abstract: To investigate the role of colony stimulating factors (CSFs) in the proliferation and differentiation of progenitor cells from myelodysplastic syndromes (MDS), marrow progenitor cells from 18 MDS patients were highly purified using CD34 monoclonal antibody and immunomagnetic microspheres (MDS CD34+ cells). These cells were cultured in serum-free medium with various combinations of five colony stimulating factors (CSFs): recombinant human interleukin-3 (rIL-3), granulocyte/macrophage-CSF (rGM-CSF), granulocyte-CSF (rG-CSF), macrophage-CSF (rM-CSF), and erythropoietin (rEP). Among the tested CSFs, such as rM-CSF, rG-CSF, rGM-CSF and rIL-3, a combination of the first three CSFs was the most effective stimulus for the proliferation of non-erythroid MDS progenitor cells. An increase of undifferentiated “blast” cell colonies in 5/18 MDS patients occurred and these 5 patients belonged to the high-risk group. In the presence of these three CSFs, rIL-3 had no effect on the proliferation and differentiation of MDS CD34+ cells; however, IL-3 was efficient for the proliferation of MDS CD34+ cells to the erythroid lineage. rGM-CSF or rIL-3 alone did not efficiently support proliferation and differentiation of CD34+ cells. M-CSF is present in normal human serum at a concentration of 550 ±110 U/ml, a concentration exceeding that used in this study (100 U/ml). Therefore, in vivo administration of G-CSF combined with GM-CSF to MDS patients may be one of the most effective CSF combinations for proliferation of MDS progenitor cells to the non-erythroid lineage. However, the effect on the capacity for differentiation was minimal, especially in patients belonging to the high-risk group.     

Chronic idiopathic neutropenia improved by recombinant granulocyte colony stimulating factor]

A 55-year-old man was admitted to our hospital for the evaluation of neutropenia. On physical examination, he had apthae and splenomegaly. CBC showed 1,000/microliter WBC with 5% neutrophils, and microcytic anemia consistent with iron deficiency. Bone marrow examination revealed a marked decrease of mature neutrophils, but normal percentage of immature myeloid cells. There was no morphological abnormality in the hemopoietic cells. He had no drug or family history responsible for the neutropenia. Anti-neutrophil auto-antibody was negative. Hence, a diagnosis of chronic idiopathic neutropenia (CIN) was made. He developed frequent episodes of infection such as balanitis, peri-anal infection, gingivitis, and pharyngitis. He was treated with steroid pulse therapy, anabolic hormone, and high dose gamma-globulin infusion, but no significant improvement occurred. Then, recombinant granulocyte-colony stimulating factor (rG-CSF) was started. The neutrophil count was normalized by the 7th day of 5 micrograms/kg/day rG-CSF administration. The administration of G-CSF was discontinued after a 14-day course. Thereafter, the neutrophil count remained at near normal level (approximately 1,500/microliter) and there have been no episodes of infection in the last 5 months. However this cannot be explained simply by the direct effect of rG-CSF on the myeloid precursors; rather, it suggests some unknown effect of G-CSF on the bone marrow microenvironment regulating myeloid hemopoiesis. We consider this to be a rare case of CIN with frequent episodes of infection, which was successfully treated with G-CSF.     

Neutropenia during combination therapy of interferon alfa and ribavirin for chronic hepatitis C

Interferon therapy of hepatitis C causes a decrease in neutrophil counts, and neutropenia is a common reason for dose adjustment or early discontinuation. However, it is unclear whether neutropenia caused by interferon is associated with an increased rate of infection. In this study, we assessed factors associated and clinical consequences of neutropenia before and during interferon therapy of chronic hepatitis C. A total of 119 patients with chronic hepatitis C treated with the combination of interferon alfa and ribavirin were analyzed. In these studies, neutropenia was not used as an exclusion or dose modification criterion. In multivariate analysis, only black race was associated with baseline neutropenia. During treatment, neutrophil counts decreased by an average of 34%. Among 3 blacks with baseline neutropenia without cirrhosis or splenomegaly, there was little or no decrease in neutrophil counts (despite typical decreases in platelet and lymphocyte counts). Documented or suspected bacterial infections developed in 22 patients (18%), but in no patient with neutropenia. United States population estimates suggest that 76,000 blacks with hepatitis C have neutrophil counts below 1,500 cells/microL and might be denied therapy if this exclusion criterion was generally applied. In conclusion, neutropenia is frequent during treatment of hepatitis C with interferon and ribavirin, but it is not usually associated with infection. Constitutional neutropenia, which is common among blacks, should not exclude patients from therapy with interferon as these patients usually have minimal further decreases in neutrophil counts on therapy and are not excessively prone to bacterial infections.