Reduced dose of lenograstim is as efficacious as standard dose of filgrastim for peripheral blood stem cell mobilization and transplantation: a randomized study in patients undergoing autologous peripheral stem cell transplantation

In vitro studies have demonstrated a 27% increased efficacy of lenograstim over filgrastim. However, equal doses of 10 microg/kg/day of filgrastim and lenograstim have been recommended for mobilization of CD34+ cells without associated chemotherapy. In this study, we investigated whether a 25% reduced dose of lenograstim at 7.5 microg/kg/day is equavalent to 10 microg/kg/day filgrastim for autologous peripheral blood stem cell (PBSC) mobilization and transplantation. A total of 40 consecutive patients were randomized to either filgrastim (n = 20) or lenograstim (n = 20). The two cohorts were similar in regard to disease, sex, body weight, body surface area, conditioning regimens, previous chemotherapy cycles and radiotherapy. Each growth factor was administered for 4 consecutive days. The first PBSC apheresis was done on the 5th day. In the posttransplant period, the same G-CSF was given at 5 microg/kg/day until leukocyte engraftment. Successful mobilization was achieved in 95% of patients. Successful mobilization with the first apheresis, was achieved in 10/20 (50%) patients in the filgrastim group versus 9/20 (46%) patients in the lenograstim group. No significant difference was seen in the median number of CD34+cells mobilized, as well as the median number of apheresis, median volume of apheresis, percentage of CD34+ cells, and CD34+ cell number. Leukocyte and platelet engraftments, the number of days requiring G-CSF and parenteral antibiotics, the number of transfusions were similar in both groups in the posttransplant period. Lenograstim 7.5 microg/kg/day is as efficious as filgrastim 10 microg/kg/day for autologous PBSC mobilization and transplantation.     

Pharmacokinetics and adverse events following 5-day repeated administration of lenograstim, a recombinant human granulocyte colony-stimulating factor, in healthy subjects

Recombinant human granulocyte colony-stimulating factor (rhG-CSF) (lenograstim) was administered to healthy subjects at doses of 2, 5 and 10 micrograms/kg/day for 5 days (twice a day subcutaneously) to examine the optimal dose and schedule of lenograstim in mobilizing peripheral blood progenitor cells (PBSC) for allogeneic transplantation. Lenograstim administration significantly increased CD34+ cells in a dose-related manner. A significant correlation was observed between the maximal post-dosing counts and the pre-dosing baseline counts of CD34+ cells. Peripheral neutrophils increased markedly by seven to 13 times from the baseline to a peak of approximately 40,000/microliter on day 5 for the 5 and 10 micrograms/kg/day doses. After peak serum concentration (Cmax) was attained 4 h following administration, serum G-CSF declined with time in a log-linear fashion. The Cmax and 12 h area-under-the-curve increased dose dependently, but minimum drug level increased up to day 2 and then decreased until day 5. Clearance decreased with increasing dosage at the first dose, and increased significantly at the last dose. We found a highly significant correlation between absolute neutrophil counts and clearance for each dose. Adverse events most frequently occurred on day 6, with increases of alkaline phosphatase and lactate dehydrogenase and onset of bone pain. Increases of aspartate aminotransferase and alanine aminotransferase occurred as delayed events. Platelet count gradually decreased after the end of drug administration to 57% of the pre-dosing count on day 10, but was still within the normal range. These preliminary results suggest that repeated doses of lenograstim induce mobilization of PBSC in a dose-dependent manner and the pre-dosing baseline count of PBSC may predict the post-dosing maximal mobilization. The drug treatment may cause delayed-onset moderate thrombocytopenia and increased transaminase, and the drug clearance changes in a complex manner during repeated dosing.     

Three to six year follow-up of normal donors who received recombinant human granulocyte colony-stimulating factor

One hundred and one donors who had received filgrastim (rhG-CSF) for the purpose of donating either granulocytes or peripheral blood stem cells (PBSC) for their relatives more than 3 years ago were contacted. All donors had received daily rhG-CSF at a median dose of 16 microg/kg/day (range 3-16) for a median of 6 days (range 3-15 days). All collection procedures were completed and short-term side-effects of rhG-CSF were mild in the majority of the donors. At a median time interval of 43.13 months (range 35-73), the donors were contacted to assess whether adverse effects related to rhG-CSF administration had occurred. Prior to rhG-CSF two donors had cancer, one had a myocardial infarction, one was hepatitis C virus positive, one had a history of sinusitis, one had Graves' disease and two had arterial hypertension. None worsened with the rhG-CSF administration but the donor with a history of infarction had an episode of angina following apheresis, and the donor with Graves' disease had a stroke 15 months after rhG-CSF. Two pregnancies occurred after the rhG-CSF administration and one donor was 2-3 weeks pregnant during rhG-CSF treatment. Three pregnancies resulted in two normal births and one in a spontaneous abortion of a pregnancy which occurred more than 2 years following rhG-CSF. In the time following rhG-CSF administration two donors developed cancer (breast and prostate cancer) at a follow-up of 70 and 11 months, respectively. One donor developed lymphadenopathy 38 months after the rhG-CSF, which spontaneously resolved. Blood counts were obtained in 70 donors at a median follow up of 40.4 months (range 16.8-70.8). Hematocrit was 43% (median, range 36.8-48), white blood cells were 5.7 x 109/l (median, range 3-14), granulocytes 3.71 x 109/l (median, range 1. 47-10.36), lymphocytes 1.67 x 109/l (median, range 0.90-3.96), monocytes 0.46 x 109/l (median, range 0.07-0.87) and platelet counts were 193.0 x 109/l (median, range 175.0-240.0). This study indicates that short-term administration of rhG-CSF to normal donors for the purpose of mobilizing the PBSC or granulocytes appears safe and without any obvious adverse effects more than 3 years after the donation. Bone Marrow Transplantation (2000) 25, 85-89.     

Tetraploid myeloid cells in donors of peripheral blood stem cells treated with rhG-CSF

Recombinant human granulocyte colony-stimulating factor (rhG-CSF) is frequently used to mobilize CD34+ cells in healthy donors and patient with malignant diseases prior to peripheral blood stem cell (PBSC) harvest. To analyze the effects of rhG-CSF on morphology and genotype of white blood cells, a novel multiparametric cell scanning system that combines morphologic, immune and genotypic analyses of the same cells was used. We report here that tetraploid myeloid cells are present in the peripheral blood of donors treated with rhG-CSF. The tetraploidy was detected in up to 0.6% of differentiated myeloid cells and all observed CD34+ cells were diploid. Thus, short treatment with rhG-CSF of PBSC donors induces numerfical chromosomal alterations in a small subset of mature myeloid cells.     

Biosimilar G-CSF versus filgrastim and lenograstim in healthy unrelated volunteer hematopoietic stem cell donors

The World Marrow Donor Organization recommends original granulocyte-colony stimulating factor (G-CSF) for the mobilization of stem cells in healthy unrelated hematopoietic stem cell donors. We report the comparison of a biosimilar G-CSF (Zarzio) with two original G-CSFs (filgrastim and lenograstim) in mobilization in unrelated donors. We included data of 313 consecutive donors who were mobilized during the period from October 2014 to March 2016 at the Medical University of Warsaw. The primary endpoints of this study were the efficiency of CD34+ cell mobilization to the circulation and results of the first apheresis. The mean daily dose of G-CSF was 9.1 μg/kg for lenograstim, 9.8 μg/kg for biosimilar filgrastim, and 9.3 μg/kg for filgrastim (p < 0.001). The mean CD34+ cell number per microliter in the blood before the first apheresis was 111 for lenograstim, 119 for biosimilar filgrastim, and 124 for filgrastim (p = 0.354); the mean difference was even less significant when comparing CD34+ number per dose of G-CSF per kilogram (p = 0.787). Target doses of CD34+ cells were reached with one apheresis in 87% donors mobilized with lenograstim and in 93% donors mobilized with original and biosimilar filgrastim (p = 0.005). The mobilized apheresis outcomes (mean number of CD34+ cells/kg of donor collected during the first apheresis) was similar with lenograstim, biosimilar filgrastim, and filgrastim: 6.2 × 10⁶, 7.6 × 10⁶, and 7.3 × 10⁶, respectively, p = 0.06. There was no mobilization failure in any of the donors. Biosimilar G-CSF is as effective in the mobilization of hematopoietic stem cells in unrelated donors as original G-CSFs. Small and clinically irrelevant differences seen in the study can be attributed to differences in G-CSF dose and collection-related factors. Active safety surveillance concurrent to clinical use and reporting to donor outcome registry (e.g., EBMT donor outcome registry or WMDA SEAR/SPEAR) might help to evaluate the possible short- and long-term complications of biosimilar G-CSF.     

Involvement of GTP-binding proteins in actin polymerization in human neutrophils.

The motility of human neutrophils, which is of vital importance for the role of these cells in host defense, is based on rapid and dynamic changes of the filamentous actin F-actin) network. Consequently, to understand how neutrophils move and ingest particles, we need to know how polymerization and depolymerization of actin are regulated. Previous studies by several investigators have, based on indirect evidence obtained with pertussis toxin, suggested a role for GTP-binding protein(s) (G protein) in chemotaxis-induced, but not phagocytosis-induced, reorganization of the F-actin network. The aim of the present investigation was to study the effects of directly activated G proteins (i.e., without prior ligand-receptor complex formation) on the F-actin content in human neutrophils. AlF4- induced a pronounced and sustained increase in F-actin in intact neutrophils. This effect coincided with an increase in cytosolic free Ca2+, indicating that phospholipase C and the subsequent transduction mechanism were also activated. Inhibition of phospholipase C activity by extensive depression of the cytosolic free Ca2+ level (less than 20 nM) only marginally affected the AlF4(-)-induced rise in F-actin content. The major part of the AlF4(-)-induced rise in F-actin content was also resistant to pertussis toxin, suggesting that pertussis toxin-insensitive G proteins in neutrophils are also able to trigger actin polymerization. The specificity of AlF4- in activating G proteins was also tested in permeabilized cells. In this case the effect was more rapid and could be totally abolished by guanosine 5'-[beta-thio]diphosphate. In analogy, in permeabilized cells guanosine 5'-[gamma-thio]triphosphate mimicked the effect of AlF4- on actin polymerization, and the effect induced by this nonhydrolyzable GTP analogue could also be totally abolished by guanosine 5'-[beta-thio]diphosphate. In summary, the present data support our previous hypothesis that G proteins are intimately linked to actin polymerization in human neutrophils.     

Experiences of donors enrolled in a randomized study of allogeneic bone marrow or peripheral blood stem cell transplantation

The experiences of 69 (38 marrow and 31 peripheral blood stem cell [PBSC]) donors participating in a randomized trial comparing allogeneic bone marrow with PBSC transplantation were studied. Marrow was collected by means of standard harvest techniques and general or regional anesthesia. PBSC donors were treated with 5 to 7 days of filgrastim at a dose of 16 microg/kg/d and underwent 1 to 3 days of apheresis to obtain 5 x 10(6) CD34(+) cells per kilogram recipient weight. Donors completed questionnaires describing their health experiences before, during, and then weekly after donation until return to baseline status. Both marrow and PBSC donors reported minimal fluctuation in symptoms measuring emotional status. In contrast, both groups of donors reported deterioration in physical status starting with administration of filgrastim (PBSC donors) or after the marrow collection procedure. The symptom burden reported was similar, with pain a prominent symptom for both groups. Equivalent mean levels of maximal pain, average pain, and pain duration through the day were reported, although toxicity peaks occurred at different time points during the harvest procedures. All PBSC donors but only 79% of marrow donors reported good physical status by 14 days after the harvest procedures. These data demonstrate similar levels of physical discomfort for hematopoietic stem cell donors regardless of the collection procedure used, but a quicker resolution of symptoms for PBSC donors.     

Acute Ethanol Administration Modulates Leukocyte Actin Polymerization in Endotoxic Rats

The effects of acute ethanol intoxication with or without endotoxemia were studied on chemoattractant-initiated actin polymerization in circulating and liver-recruited neutrophils [polymorphonuclear leukocytes (PMNs)] and Kupffer cells of age-matched male and female rats. In female rats, F-actin content in response to f-Met-Leu-Phe in circulating PMNs was significantly upregulated by ethanol + endotoxin (ET) treatment relative to saline + ET-treated animals. Male rats did not show this upregulated response. In liver-recruited PMNs, the F-actin response did not change significantly due to ethanol + ET treatment in cells of either gender. The actin polymerization response in Kupffer cells was smaller than in liver sequestered PMNs and also exhibited a gender difference. In Kupffer cells of female rats, only ethanol + ET treatment elicited an F-actin response to f-Met-Leu-Phe, whereas in cells of male rats similar increases in F-actin content were observed in both saline + ET and ethanol + ET groups. We conclude that ethanol-enhanced actin polymerization in rats is associated with gender differences. This may be one of the underlying mechanisms resulting in upregulated leukocyte activation in acutely ethanol-intoxicated endotoxic animals.     

Effects of the protein tyrosine phosphatase CD45 on FcgammaRIIa signaling and neutrophil function

OBJECTIVE: Neutrophil receptors for the Fc portion of IgG (FcgammaR) trigger immune responses following cross-linking by IgG-coated foreign particles or immune complexes. Membrane-associated CD45, a protein tyrosine phosphatase termed leukocyte common antigen, has been shown to be essential for antigen receptor kinase mediated signaling in lymphocytes, and we hypothesized that CD45 may play a similar role in FcgammaR-mediated signaling and immune function in human neutrophils. METHODS: The experimental approach was that of cell surface molecule ligation via cross-linking with specific antibodies. Antibody dependent cellular cytotoxicity (ADCC) was assessed using a single-cell plaque assay and IL-6 production measured using ELISA. Tyrosine phosphorylation levels were assessed with anti-phospho-tyrosine blots and F-actin polymerization by flow cytometry and confocal microscopy. RESULTS: Neutrophils pretreated with anti-CD45 had a reduced ability to perform ADCC compared to untreated neutrophils. FcgammaRIIa cross-linking resulted in significantly increased concentrations of secreted IL-6 compared to untreated neutrophils, and IL-6 production was further enhanced by cocross-linking CD45 with FcgammaRIIa. Cross-linking CD45 alone also induced IL-6 production. FcgammaRIIa cross-linking resulted in increased protein tyrosine phosphorylation and F-actin polymerization in neutrophils. Cocross-linking CD45 with FcgammaRIIa resulted in abrogation of FcgammaRIIa mediated tyrosine phosphorylation and F-actin polymerization. CONCLUSIONS: These data provide evidence that CD45 can regulate or enhance the stimulation and function of human neutrophils mediated through FcgammaR(s). In addition, CD45 ligation may play an essential role in cytokine induction pathways that lead to inflammatory reactions in vivo.     

Superior mobilisation of haematopoietic progenitor cells with glycosylated G-CSF in male but not female unrelated stem cell donors

Granulocyte colony-stimulating factor (G-CSF) effectively mobilises haematopoietic stem cells to the peripheral blood. It is unclear whether the mobilisation of stem cells with lenograstim (glycosylated G-CSF) or filgrastim (non-glycosylated G-CSF) leads to a higher cell number of collected engraft able progenitor cells. Thus, we investigated harvesting efficiency of the licensed G-CSF preparations in mobilising peripheral stem cells in a randomised study. A total of 501 healthy unrelated donors, including 339 males and 162 females received either lenograstim (n = 261) or filgrastim (n = 240) at 10 microg/kg body weight (BW) per day. Aphaeresis was performed on day 5 and, if necessary, on day 6 of mobilisation. The number of CD34+ cells collected was 11.5% higher in the lenograstim group (7.19 x 10(6) vs. 6.44 x 10(6)/kg BW donor; P < 0.03). Univariate variance analysis revealed that this effect was caused by male donors: more progenitors cells per kg BW of the donor (7.73 x 10(6) vs. 6.88 x 10(6); P < 0.017) and of the recipient (10.1 x 10(6) vs. 8.88 x 10(6), P < 0.029) could be harvested. There was no significant difference in the percentage of donors in whom a second aphaeresis was required (9.6% vs. 11.6%). Lenograstim mobilises progenitor cells into the peripheral blood more effectively in males than filgrastim.     

Impaired neutrophil actin assembly causes persistent CD11b expression and reduced primary granule exocytosis in Type II diabetes

AIMS/HYPOTHESIS: Neutrophil dysfunction has a role in the pathogenesis of complications in Type II (non-insulin-dependent) diabetes mellitus. Neutrophils adhere through expression of the beta(2)integrin CD11b/CD18 which closely associates with the actin cytoskeleton. The aim of this study was to investigate the effect of actin polymerisation on CD11b expression and exocytosis of the primary granule marker CD69 in neutrophils from patients with Type II diabetes. METHODS: Neutrophils were activated with fMLP or PMA, actin polymerisation was inhibited with cytochalasin D. Cells were stained for CD11b and CD69 expression and intracellular F-actin was measured with phalloidin-FITC. Cellular fluorescence was measured by flow cytometry. Actin content of Triton X-100 fractions of cells was measured by SDS-PAGE and Coomassie blue staining. RESULTS: PMA caused an increase in neutrophil F-actin that was greater in control subjects than in patients with Type II diabetes (50.8% vs 33.4%, p<0.001) and correlated with actin integrated optical density (IOD) by SDS-PAGE ( r=0.74, p=0.01). Loss of CD11b from cell surfaces only occurred in neutrophils with high F-actin. The proportion of cells losing CD11b was lower in patients than in control subjects (23.1% vs 37.5%, p<0.001) and lowest in patients with additional cardiovascular risk markers (20.1% vs 27.7%; p<0.05). Cytochalasin D prevented loss of CD11b ( p<0.001). CD69 expression was reduced in patients with Type II diabetes (22.6% vs 36.4%, p<0.001) and correlated with F-actin content ( r=0.78, p<0.0001). CONCLUSION/INTERPRETATION: In Type II diabetes impaired neutrophil actin polymerisation leads to persistent expression of CD11b and reduced exocytosis of primary granules and could contribute to the pathogenesis of diabetic complications.     

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

Purpose The aim of the study was to evaluate whether glycosylated granulocyte colony-stimulating factor (G-CSF) (lenograstim) offers a benefit over non-glycosylated G-CSF (filgrastim) in clinically relevant end points after high-dose chemotherapy (HDC) and autologous peripheral blood stem cell transplantation (PBSCT).Methods We retrospectively analyzed the outcome of 261 patients treated with either lenograstim (n=68) or filgrastim (n=193). Time to blood cell recovery, toxicities, and infectious complications were analyzed in a total of 469 G-CSF treatment cycles.Results Mean time to leukocyte recovery was 10.7 days (SD±0.9) (lenograstim) and 10.8 days (SD±0.6) (filgrastim), respectively. Likewise, time to thrombocyte engraftment, febrile days, duration of therapeutic antibiotic treatment, severity of non-hematological toxicities, duration of in-hospital stay, and duration of G-CSF treatment were similar in both groups. Owing to the physicochemical and pharmacokinetic properties of lenograstim, the required dose until leukocyte recovery was significantly smaller as compared to filgrastim (38.5 vs 54.0 µg/kg of body weight).Conclusions Collectively, our data indicate that both G-CSF preparations are equally effective in hastening leukocyte recovery in the setting of high-dose chemotherapy followed by autologous PBSCT.     

Thrombotic microangiopathy: a new dose-limiting toxicity of high-dose sequential chemotherapy

Ten patients with refractory (n = 8) or early relapsing (n = 2) aggressive non-Hodgkin's lymphoma were enrolled in a pilot study evaluating a high-dose sequential chemotherapy regimen with peripheral blood stem cell (PBSC) support. Five treatment phases were scheduled: phase I (cyclophosphamide + etoposide followed by lenograstim (G-CSF), and a PBSC harvest); phase II (cisplatinum + cytarabine + etoposide followed by lenograstim); phases III and IV (cyclophosphamide + cytarabine + etoposide followed by autologous PBSC infusion and lenograstim); and phase V (carmustine + cytarabine + etoposide + melphalan followed by autologous PBSC infusion and lenograstim). Ten, nine, eight, six and four of the 10 patients received one, two, three, four and five of the five scheduled phases of treatment, respectively. Four patients were withdrawn from the study due to progressive disease and two due to thrombotic microangiopathy (TM). Moreover, in the four patients who completed all treatment phases, an additional case of TM was seen. In all three patients with TM, laboratory studies showed evidence of Coombs negative hemolytic anemia, thrombocytopenia, renal dysfunction and in addition cardiac failure in two patients. TM may be a new dose-limiting toxicity of high-dose sequential chemotherapy followed by repeated PBSC transplantation.     

Influence of recombinant human granulocyte colony-stimulating factor (filgrastim) on hematopoietic recovery and outcome following allogeneic bone marrow transplantation (BMT) from volunteer unrelated donors.

Effects of recombinant human granulocyte colony-stimulating factor (rhG-CSF, filgrastim) on hematopoietic recovery and clinical outcome in patients undergoing allogeneic bone marrow transplantation (BMT) from volunteer unrelated donors (VUD) were analyzed retrospectively. Additionally, the influence of baseline patient and transplant characteristics on hematopoietic recovery was evaluated. From January 1994 to March 1996, 47 consecutive adult patients received VUD-BMT. GVHD prophylaxis was cyclosporin A/short course methotrexate/prednisolone, and in four patients additional ATG. Post-transplantation, cohorts of patients received rhG-CSF (5 microg/kg/day) (n = 22) or no rhG-CSF (n = 25) in a non-randomized manner. The patient groups with and without rhG-CSF were rather comparable with respect to baseline patient and transplant characteristics. Median time to neutrophil counts (ANC) >500/microl was 14 days with rhG-CSF vs 16 days without rhG-CSF (P = 0.048), to ANC >1000/microl was 15 vs 18 days (P = 0.084). Neutrophil recovery was accelerated in patients receiving more than the median MNC dose of 2.54 x 10(8)/kg with a median time to ANC >1000/microl of 13 days vs 19 days (P = 0.017). RhG-CSF did not influence platelet recovery and incidence of infectious complications. Incidence of acute GVHD II-IV was 50% with rhG-CSF and 28% without rhG-CSF (P = 0.144), but death before acute GVHD II-IV occurred in 9% of patients with and 20% of patients without rhG-CSF. The median follow-up time was 38 and 36 months in patients with and without rhG-CSF, respectively. Survival at 2 years post-transplant was 39% (95% confidence interval (18%, 60%)) in patients with rhG-CSF and 24% (95% confidence interval (7%, 41%)) in patients without rhG-CSF. Administration of rhG-CSF after VUD-BMT may lead to more rapid neutrophil recovery, but did not influence the incidence of infectious complications. Patients receiving rhG-CSF showed a slightly higher incidence of acute GVHD II-IV. Higher numbers of MNC in the marrow graft accelerated hematopoietic engraftment.     

Donating stimulated peripheral blood stem cells vs bone marrow: do donors experience the procedures differently?

As the demand for undifferentiated stem cells for the treatment of leukemia and other cancers has increased, new methods for their collection have been developed. One of these new methods, allogeneic peripheral blood stem cell (PBSC) donation, involves the administration of a granulocyte colony-stimulating factor (G-CSF, filgrastim), and a 1-2 day apheresis collection procedure. Our goal in the current study was to examine donors' psychosocial and physical experiences of PBSC vs marrow donation. Potential participants included 80 donors from the National Marrow Donor Program (NMDP) who donated a second time between 1991 and 1997. All of these donors had previously donated marrow. A final cohort of 70 donors (25 PBSC and 45 marrow) participated in a retrospective questionnaire study of their donation experiences. In general, all second-time donors reported low levels of concern about the physical consequences of donation. However, PBSC donors were more likely to have postponed the decision to donate a second time. Despite their reservations, PBSC donors reported fewer donation-related side-effects than did marrow donors. Finally, PBSC donors reported that marrow donation was more physically difficult, time-consuming, and inconvenient, and that they preferred PBSC to marrow donation.     

Signal transduction and the regulation of actin conformation during myeloid maturation: studies in HL60 cells

Maturation of human myeloid cells is associated with quantitative and qualitative changes in protein kinase C (PKC) and increases in N-formyl- L-methionyl-L-leucyl-L-phenylalanine (FMLP) receptors, actin, and actin regulatory proteins. We have studied the actin responses and cell shape changes caused by FMLP and its second messenger pathways in HL60 cells undergoing neutrophilic maturation. In uninduced cells, the PKC activators 12-O-tetradecanoyl phorbol-13-acetate (TPA), bryostatin, and 1-oleyl-2-acetylglycerol (OAG) resulted in 15% to 30% decreases in F- actin, whereas FMLP had no effect. Ionomycin had no effect on actin but did cause a 10-fold increase in intracellular calcium. Cells grown for 24 hours in 1% dimethyl sulfoxide (DMSO) acquired the ability to polymerize actin in response to FMLP and ionomycin. TPA continued to cause a decrease in F-actin at 24 hours, but caused an increase in F- actin at 48 to 72 hours of maturation. The PKC inhibitor 1-5- isoquinolinesulfonyl 2-methylpiperazine (H7) partially blocked the F- actin increase caused by TPA in induced cells, but had no effect on the decrease in F-actin caused by TPA in uninduced cells or the increase in F-actin seen in FMLP-treated neutrophils. F-actin rich pseudopods developed following TPA or FMLP stimulation of induced HL60 cells; in uninduced cells neither agent caused pseudopod formation but TPA caused a dramatic loss of surface ruffles. The ability of FMLP and ionomycin to elicit a neutrophil-like actin response in HL60 cells within 24 hours after DMSO treatment shows that the actin regulatory mechanism is mature by that time. The inability of ionomycin to increase F-actin in uninduced cells supports the view that calcium increases alone are insufficient for actin polymerization. The longer maturation time required for HL60 cells to develop an actin polymerization response to TPA compared with FMLP, coupled with the inability of H7 to block the FMLP-mediated F-actin increase in neutrophils, suggests that the F- actin increase caused by FMLP is not mediated solely by PKC. Lastly, the TPA-induced F-actin decrease and shape changes in uninduced HL60 cells, and the longer time required for a "mature" response to TPA, may reflect immaturity in the PKC isoenzyme pattern rather than immaturity of the actin regulatory mechanism.     

Efficacy and safety of two different rG-CSF preparations in the treatment of patients with severe congenital neutropenia

In patients with severe congenital neutropenia (SCN), the absolute neutrophil count (ANC) is raised during treatment with granulocyte colony-stimulating factor (G-CSF), resulting in a marked reduction of bacterial infection. Some patients, however, still have recurrent but less severe bacterial infections and severe periodontal infections. As it has been suggested that the biological activity of glycosylated recombinant human G-CSF (rHuG-CSF, i.e. lenograstim) is higher than the non-glycosylated form (i.e. filgrastim), we compared the two given in equimolar doses. Seven SCN patients participated in an open, randomized, double crossover study comprising 60 weeks, with four 12-week periods when the two drugs alternated after a 12-week run-in-period. The mean ANC values, sampled every second week, were 5.1 x 10(9)/l during filgrastim treatment and 4.2 x 10(9)/l during lenograstim treatment (P = 0.042). The ANC levels were also significantly higher during filgrastim treatment, when comparing each complementary pair of ANC measurements (P = 0.011) as well as the mean ANC values during each 12-week treatment period (P = 0.033). There were no differences regarding the frequency of infection, antibiotic treatment, gingival bleeding and the number of hospital admissions between the groups. We conclude that filgrastim and lenograstim displayed equal clinical efficacy, but that ANC levels were higher during filgrastim treatment, when administered in equimolar doses.     

Neutrophils express the high affinity receptor for IgG (Fc gamma RI, CD64) after in vivo application of recombinant human granulocyte colony-stimulating factor.

Fc receptors are important effector molecules of neutrophilic granulocytes (polymorphonuclear neutrophils [PMN]), connecting phagocytic cells and the specific immune response. Neutrophils from healthy donors express the low-affinity receptors for IgG Fc gamma RII (CD32) and Fc gamma RIII (CD16), but not the high-affinity receptor Fc gamma RI (CD64). The latter has been found on neutrophils from patients with certain bacterial infections and can be induced in vitro after incubation with interferon-gamma. We show here that neutrophils strongly express Fc gamma RI after in vivo application of recombinant human granulocyte colony-stimulating factor (rhG-CSF). PMN from patients receiving rhG-CSF displayed higher cytotoxicity against Daudi lymphoma cells in vitro compared with control patients and with healthy donors. Fab fragments against Fc gamma RII (monoclonal antibody [MoAb] IV.3) inhibited neutrophil-mediated cytotoxicity of healthy donors but not of patients during rhG-CSF therapy. Therefore, expression of Fc receptors by PMN was investigated by flow cytometry and the mean fluorescence intensity (MFI) was compared. After staining with MoAb 32.2 against Fc gamma RL, the median MFI of neutrophils from G-CSF patients (median, 4.78; range, 2.40 to 8.50; n = 5) was significantly higher (P = .002 and P = .001, respectively) than the median MFI of patients not receiving G-CSF (median, 1.23; range, 1.01 to 1.58; n = 6) and the median MFI of healthy donors (median, 1.04; range, 0.67 to 1.12; n = 6). Fc gamma RI disappeared after the discontinuing of the G-CSF injections, but was reinduced during the next treatment cycle with rhG-CSF. The high expression of Fc gamma RI during rhG-CSF therapy correlated with enhanced cytotoxicity. In vitro incubation with rhG-CSF also enhances cytotoxicity, but only minor increments in Fc gamma RI expression were observed. Thus, during in vivo application of rhG-CSF neutrophils acquire an additional potent receptor for mediating tumor cell killing in vitro by induction of the high-affinity receptor for IgG (Fc gamma RI, CD64).     

Comparison of marrow and blood cell yields from the same donors in a double-blind, randomized study of allogeneic marrow vs blood stem cell transplantation

Forty healthy adult donors underwent marrow (BM) as well as peripheral blood (PBSC) stem cell collections for their HLA-identical adult siblings with hematologic malignancies. BM was harvested on day 1 (target 3 x 108 nucleated cells/kg, 10 microg/kg lenograstim (glycosylated G-CSF) administered on days 2-6, and a single leukapheresis performed on day 6. The blood volume processed was the higher of 200% donor blood volume or 10 liters. The total nucleated cell (TNC) yields from PBSC were 1.1- to 4.3-fold higher than BM (median 7.0 vs 3.1 x 10(8)/kg, P < 0.0001). Although BM contained a higher proportion of CD34+cells (1.3% vs 0.7%, P < 0. 0001) and a comparable proportion of CD3+ cells (median 29% vs 26%, P = 0.4), the absolute numbers of CD34+ and CD3+ cells and their subsets were several times higher in PBSC. There was a poor correlation between BM and PBSC CD34 and TNC numbers, but a significant correlation between BM and PBSC CD3 numbers. Only five of 40 BM harvests contained >/=2 x 10(6) CD34+ cells/kg compared with 35 of 40 PBSC harvests (P < 0.0001). We conclude that the numbers of progenitor and immunocompetent cells in PBSC are several times higher than in BM. It is possible to collect adequate numbers of progenitor cells from blood after lenograstim stimulation more frequently than from marrow, and donors yielding low quantities of progenitor cells from BM usually deliver better quantities from PBSC. Bone Marrow Transplantation (2000) 25, 501-505.     

Mobilization, collection, and processing of peripheral blood stem cells in individuals with sickle cell trait.

Mobilized peripheral blood is increasingly used as the source of hematopoietic stem cells for allogeneic transplantation, currently the only curative approach for sickle cell anemia. However, the safety and feasibility of stem cell mobilization in individuals with sickle cell trait (SCT) has not been documented. This study is a prospective controlled trial to evaluate the safety and feasibility of peripheral blood stem cell (PBSC) mobilization in 8 SCT subjects and 8 control subjects matched for age and race. Mobilization with filgrastim 10 microg/kg subcutaneous daily for 5 days was followed by 12-L apheresis on the fifth day. Filgrastim administration was accompanied by similar symptoms in all subjects; no untoward adverse events occurred in either group, including sickle cell crises. CD34+ cell mobilization response was not significantly different between SCT and control subjects. Median CD34+ cell content was also similar in PBSCs collected from SCT versus control subjects, 6.8 versus 3.9 x 10(6) CD34+ cells/70 kg, P =.165. Red cell depletion from SCT products was not possible by using hydroxyethyl starch sedimentation but was achievable with ammonium chloride lysis. There was no evidence of gelling of SCT products after thaw, and no difference in cell recovery was seen among red cell-depleted versus nondepleted products. Cryopreservation in 5% dimethyl sulfoxide/6% pentastarch was associated with superior cell recovery (both SCT and control subjects) compared with 10% dimethyl sulfoxide (P =.001). The study concluded that filgrastim mobilization, large volume apheresis, processing, and cryopreservation appears to be safe in donors with SCT, allowing PBSC use for transplantation in patients with sickle cell anemia.