2-Hydroxyisonicotinate dehydrogenase isolated from Mycobacterium sp. INA1

The objective of this study was to identify factors associated with poor mobilization of peripheral blood progenitor cells (PBPCs) or delayed platelet engraftment after high-dose therapy and autologous stem cell transplantation in patients with lymphoma. Fifty-eight patients with Hodgkin's disease or non-Hodgkin's lymphoma underwent PBPC transplantation as the "best available therapy" at Memorial Sloan-Kettering Cancer Center (New York, NY) between 1993 and 1995. PBPCs were mobilized with either granulocyte colony-stimulating factor (G-CSF) alone (n = 19) or G-CSF following combination chemotherapy (n = 39). Forty-eight of these patients underwent a PBPC transplant, receiving a conditioning regimen containing cyclophosphamide, etoposide, and either total body irradiation, total lymphoid irradiation, or carmustine. A median number of 4.6 x 10(6) CD34+ cells/kg were obtained with a median of three leukapheresis procedures. Mobilization of PBPCs using chemotherapy plus G-CSF was superior to G-CSF alone (6.7 x 10(6) versus 1.5 x 10(6) CD34+ cells/kg; P = 0.0002). Poorer mobilization of progenitor cells was observed in patients who had previously received stem cell-toxic chemotherapy, including (a) nitrogen mustard, procarbazine, melphalan, carmustine or > 7.5 g of cytarabine chemotherapy premobilization (2.0 x 10(6) versus 6.0 x 10(6) CD34+ cells/kg; P = 0.005), or (b) > or = 11 cycles of any previous chemotherapy (2.6 x 10(6) versus 6.7 x 10(6) CD34+ cells/kg; P = 0.02). Platelet recovery to > 20,000/microliter was delayed in patients who received < 2.0 x 10(6) CD34+ cells (median, 13 versus 22 days; P = 0.06). Patients who received > or = 11 cycles of chemotherapy prior to PBPC mobilization tended to have delayed platelet recovery to > 20,000/microliter and to require more platelet transfusions than less extensively pretreated patients (median, 13.5 versus 23.5 days; P = 0.15; median number of platelet transfusion episodes, 13 versus 9; P = 0.17). These data suggest that current strategies to mobilize PBPCs may be suboptimal in patients who have received either stem cell-toxic chemotherapy or > or = 11 cycles of chemotherapy prior to PBPC mobilization. Alternative approaches, such as ex vivo expansion or the use of other growth factors in addition to G-CSF, may improve mobilization of progenitor cells for PBPC transplantation.     

Combination chemotherapy with mitoguazon, ifosfamide, MTX, etoposide (MIME) and G-CSF can efficiently mobilize PBPC in patients with Hodgkin's and non-Hodgkin's lymphoma

Many centers use CY and G-CSF to mobilize PBPC. In this study we explored whether a standard chemotherapy regimen consisting of mitoguazon, ifosfamide, MTX and etoposide (MIME) combined with G-CSF was capable of mobilizing PBPC in lymphoma patients. Twelve patients with Hodgkin's disease (HD) and 38 patients with non-Hodgkin's lymphoma (NHL) were mobilized with MIME/G-CSF. Most patients were heavily treated with different chemotherapy regimens receiving a median of 11 cycles (range 3 to 20) of chemotherapy prior to mobilization. It was found that the optimal time of PBPC harvest was at days 12 and 13 after initiating the mobilization regimen. The median number of collected CD34+ cells per kg body weight was 7.1 x 10(6) (range 0.5-26.2). More than 2.0 x 10(6) CD34+ cells/kg were achieved in 69% of the patients after one apheresis. When additional cycles of apheresis were done, only 6% failed to harvest this number of CD34+ cells. There was a statistically significant inverse correlation between the number of prior chemotherapy cycles and CD34+ cell yield (P = 0.003). No such association was found between CD34+ cell yield and prior radiotherapy. When MIME/G-CSF was compared with Dexa-BEAM/G-CSF, it was found that MIME/G-CSF tended to be more efficient in mobilizing PBPC in spite of being less myelotoxic. All patients transplanted with MIME/G-CSF mobilized PBPC had fast and sustained engraftment. These results demonstrate that an ordinary salvage chemotherapy regimen, such as MIME combined with G-CSF can be successfully used to mobilize PBPC.     

Giant cell tumor of bone with selective metastases to mediastinal lymph nodes

We examined the efficiency of disease-specific "standard" chemotherapies epirubicin, cyclophosphamide (EC); cyclophosphamide, vincristine, doxorubicin, etoposide, prednisolone (CHOEP); epirubicin, ifosfamide (EPI/IFOS) for peripheral blood progenitor cell (PBPC) mobilization in comparison to well-characterized mobilization protocols, i.e. etoposide, ifosfamide, cisplatin, epirubicin (VIPE) and dexamethasone, carmustine, etoposide, cytarabine, melphalan (DexaBEAM). Twenty-seven patients with various malignancies underwent 75 apheresis procedures for PBPC collection. Median cell yields from all 75 aphereses were 1.18 x 10(5) mononuclear cells/kg [range (0.28-3.7) x 10)8)], 1.4 x 10(5) granulocyte/macrophage-colony-forming units (CFU-GM)/kg [range (0.2-11) x 10(5)] and 3.3 x 10(6) CD34+cells/kg [range (0.35-17.7) x 10(6). CD34+/ CD90+ cells could be mobilized by all mobilization regimens used. The difference observed in the mobilization of CD34+ cells was only of low significance when the mobilization regimens were compared, whereas the mobilizations of MNC and CFU-GM were significantly different between the groups. Breast cancer patients treated with the VIPE regimen (including pretreated women) had a significantly higher CFU-GM rate than patients treated with EC (P=0.0005). Mobilized CD34+ PBPC were correlated with CFU-GM in all apheresis products. The linear correlation coefficients differed for the various mobilization groups: DexaBEAM (r=0.9, P < 0.0001), VIPE (r=0.68, P=0.0024), CHOEP (r=0.52, P=0.022), EPI/ IFOS (r=0.34, P=0.11) and EC (r=0.23, P=0.2). We conclude that clonogenic assays can provide additional information about the autotransplant quality, particularly when alternative or new mobilization regimens are being investigated.     

Hyperleukocytosis and retinal hemorrhages after chemotherapy and Filgrastim administration for peripheral blood progenitor cell mobilization

A 49-year-old man with mantle cell lymphoma received 2.5 g/m2 of cyclophosphamide and 900 mg/m2 of etoposide followed by 10 microg/kg/day of Filgrastim for PBPC mobilization. This was complicated by marked hyperleukocytosis and retinal hemorrhages. The patient's symptoms improved gradually following leukopheresis. To the best of our knowledge, this is the first report describing this complication in patients undergoing PBPC mobilization. Early recognition of symptoms is important in order to stop Filgrastim and initiate immediate leukapheresis.     

Characterization of peripheral blood steady-state progenitor cells preserved in liquid culture conditions with or without GM-CSF and IL2

The cellular characteristics of steady-state peripheral blood progenitor cell (PBPC) apheresis, including total number of lymphomononuclear cells, CD34 and CFUs, was evaluated in a group of 26 chemo-radiotherapy patients as well as in a group of 23 surgically resected cancer patients. Three-to seven-day incubation in standard liquid culture conditions with growth factors (IL2, GM-CSF or both) correlated with a statistically significant increase in CD34+ and CD56+ cell populations compared with incubation without growth factors, especially when both GM-CSF and IL2 were used. In addition, an increase in CD33+, CD13+ and HLA-DR+ cell populations was observed after 3-7 days incubation with GM-CSF. The basal culture control exhibited a decrease in CD33+ and CD13+ cell populations while CD34+ and CD56+ cell populations were maintained. These results were similar in the treated and untreated groups of patients. The infusion of GM-CSF and IL2 preincubated PBPC after intensive chemotherapy was associated with a rapid hematological recovery with a median time duration for WBC < 500/uL, WBC < 1.000/uL and platelets < 20.000/uL of 7.9 days, 14.9 days and 10.7 days respectively. We conclude that a short GM-CSF and IL2 preincubation of steady-state PBPC is associated with an increase in cell populations exhibiting the immune and progenitor cell phenotypes and correlates with an early hematological recovery after intensive chemotherapy.     

Randomized comparison of progenitor-cell mobilization using chemotherapy, stem-cell factor, and filgrastim or chemotherapy plus filgrastim alone in patients with ovarian cancer

PURPOSE: This was the first randomized study to investigate the efficacy of peripheral-blood progenitor cell (PBPC) mobilization using stem-cell factor (SCF) in combination with filgrastim (G-CSF) following chemotherapy compared with filgrastim alone following chemotherapy. PATIENTS AND METHODS: Forty-eight patients with ovarian cancer were treated with cyclophosphamide and randomized to receive filgrastim 5 microg/kg alone or filgrastim 5 microg/kg plus SCF. The dose of SCF was cohort-dependent (5, 10, 15, and 20 microg/kg), with 12 patients in each cohort, nine of whom received SCF plus filgrastim and the remaining three patients who received filgrastim alone. On recovery from the WBC nadir, patients underwent a single apheresis. RESULTS: SCF in combination with filgrastim following chemotherapy enhanced the mobilization of progenitor cells compared with that produced by filgrastim alone following chemotherapy. This enhancement was dose-dependent for colony-forming unit-granulocyte-macrophage (CFU-GM), burst-forming unit-erythrocyte (BFU-E), and CD34+ cells in both the peripheral blood and apheresis product. In the apheresis product, threefold to fivefold increases in median CD34+ and progenitor cell yields were obtained in patients treated with SCF 20 microg/kg plus filgrastim compared with yields obtained in patients treated with filgrastim alone. Peripheral blood values of CFU-GM, BFU-E, and CD34+ cells per milliliter remained above defined threshold levels longer with higher doses of SCF. The higher doses of SCF offer a greater window of opportunity in which to perform the apheresis to achieve high yields. CONCLUSION: SCF (15 or 20 microg/kg) in combination with filgrastim following chemotherapy is an effective way of increasing progenitor cell yields compared with filgrastim alone following chemotherapy.     

Mobilization of peripheral blood progenitor cells by disease-specific chemotherapy in patients with soft tissue sarcoma

We investigated peripheral blood progenitor cell (PBPC) mobilization by disease-specific chemotherapy in patients with metastatic soft tissue sarcoma (STS). Nine patients, five females and four males, aged 12-51 years, pretreated by one to nine courses of cytotoxic chemotherapy, underwent STS-specific mobilization followed by G-CSF at 5 microg/kg/day. PBPC were collected by 19 conventional-volume aphereses (8-12 l) with one to four procedures in individual patients. Leukaphereses started on median day 15 (range 13-18) from the first day of mobilization chemotherapy at medians of 25.8 x 10(3) WBC/microl (6.8-46.9), 3.5 x 10(3) MNC/microl (1.1-8.8), 122 x 10(3) platelets/microl (72-293) and 30.7 CD34+ cells/microl (6.7-207.8). Cumulative harvests resulted in medians of 4.6 x 10(8) MNC/kg (3.0-6.4), 2.9 x 10(6) CD34+ cells/kg (1.1-11.1) and 12.0 x 10(4) CFU-GM/kg (2.0-37.8). Eight patients underwent high-dose chemotherapy (HDCT) followed by PBPC rescue. Seven patients recovered hematopoiesis at medians of 12 days (8-15) for ANC >0.5 x 10(3)/microl and 14 days (8-27) for platelets >20 x 10(3)/microl. One patient, who received 1.6 x 10(6) CD34+ cells/kg, exhibited delayed ANC recovery on day +37 and failed to recover platelets until hospital discharge on day +55. We conclude that in patients with metastatic STS, who are pretreated by standard chemotherapy, PBPC can be mobilized by a further course of STS-specific chemotherapy plus G-CSF. One to four conventional-volume aphereses result in PBPC autografts that can serve as hematopoietic rescue for patients scheduled for HDCT.     

Peripheral blood progenitor cell mobilization using stem cell factor in combination with filgrastim in breast cancer patients

The safety and optimal dose and schedule of stem cell factor (SCF) administered in combination with filgrastim for the mobilization of peripheral blood progenitor cells (PBPCs) was determined in 215 patients with high-risk breast cancer. Patients received either filgrastim alone (10 microg/kg/d for 7 days) or the combination of 10 microg/kg/d filgrastim and 5 to 30 microg/kg/d SCF for either 7, 10, or 13 days. SCF patients were premedicated with antiallergy prophylaxis. Leukapheresis was performed on the final 3 days of cytokine therapy and, after high-dose chemotherapy and infusion of PBPCs, patients received 10 microg/kg/d filgrastim until absolute neutrophil count recovery. The median number of CD34+ cells collected was greater for patients receiving the combination of filgrastim and SCF, at doses greater than 10 microg/kg/d, than for those receiving filgrastim alone (7.7 v 3.2 x 10(6)/kg, P < .05). There were significantly (P < .05) more CD34+ cells harvested for the 20 microg/kg/d SCF (median, 7.9 x 10(6)/kg) and 25 microg/kg/d SCF (median, 13.6 x 10(6)/kg) 7-day combination groups than for the filgrastim alone patients (median, 3.2 x 10(6)/kg). The duration of administration of SCF and filgrastim (7, 10, or 13 days) did not significantly affect CD34+ cell yield. Treatment groups mobilized with filgrastim alone or with the cytokine combination had similar hematopoietic engraftment and overall survival after PBPC infusion. In conclusion, the results of this study indicate that SCF therapy enhances CD34+ cell yield and is associated with manageable levels of toxicity when combined with filgrastim for PBPC mobilization. The combination of 20 microg/kg/d SCF and 10 microg/kg/d filgrastim with daily apheresis beginning on day 5 was selected as the optimal dose and schedule for the mobilization of PBPCs.     

Successful collection of peripheral blood progenitor cells in patients with acute myeloid leukaemia following early consolidation therapy with granulocyte colony-stimulating factor-supported high-dose cytarabine and mitoxantrone

We evaluated the feasibility of collecting peripheral blood progenitor cells (PBPC) in patients with acute myeloid leukaemia (AML) following two cycles of induction chemotherapy with idarubicin, cytarabine and etoposide (ICE), and one cycle of consolidation therapy with high-dose cytarabine and mitoxantrone (HAM). Thirty-six patients of the multicentre treatment trial AML HD93 were enrolled in this study, and a sufficient number of PBPC was harvested in 30 (83%). Individual peak concentrations of CD34+ cells in the blood varied (range 13.1-291.5/microl; median 20.0/microl). To reach the target quantity of 2.5 x 10(6) CD34+ cells/kg, between one and six (median two) leukaphereses (LP) were performed. The LP products contained between 0.2 x 10(6) and 18.9 x 10(6) CD34+ cells/kg (median 1.2 x 10(6)/kg). Multivariate analysis showed that the white blood cell count prior to HAM and the time interval from the start of HAM therapy to reach an unsupported platelet count > 20 x 10(9)/l were predictive for the peak value of CD34+ cells in the blood during the G-CSF stimulated haematological recovery. In 16 patients an intraindividual comparison was made between bone marrow (BM) and PBPC grafts. Compared to BM grafts, PBPC grafts contained 14-fold more MNC, 5-fold more CD34+ cells and 36-fold more CFU-GM. A CD34+ subset analysis showed that blood-derived CD34+ cells had a more immature phenotype as indicated by a lower mean fluorescence intensity for HLA-DR and CD38. In addition, the proportion of CD34+/Thy-1+ cells tended to be greater in the PBPC grafts. The data indicate that sufficient PBPC can be collected in the majority of patients with AML following intensive double induction and first consolidation therapy with high-dose cytarabine and mitoxantrone.     

Concomitant mobilization of plasma cells and hematopoietic progenitors into peripheral blood of multiple myeloma patients: positive selection and transplantation of enriched CD34+ cells to remove circulating tumor cells

One advantage of the use of peripheral blood stem cells (PBSCs) over autologous bone marrow would be a reduced risk of tumor cell contamination. However, the level of neoplastic cells in the PB of multiple myeloma (MM) patients after mobilization protocols is poorly investigated. In this study, we evaluated PB samples from 27 pretreated MM patients after the administration of high dose cyclophosphamide (7 g/m2 or 4 g/m2) and granulocyte-colony stimulating factor for the detection of myeloma cells as well as hematopoietic progenitors. Plasma cells containing intracytoplasmic lg were counted by microscope immunofluorescence after incubation with appropriate antisera directed against light- and heavy-chain lg. Moreover, flow cytometry studies were performed to determine the presence of malignant B-lineage elements by using monoclonal antibodies against the CD19 antigen and the monotypic light chain. Before initiation of PBSC mobilization, circulating plasma cells were detected in all MM patients in a percentage ranging from 0.1% to 1.8% of the mononuclear cell fraction (mean value, 0.7% +/- 0.4% SD). In these patients, a higher absolute number of PB neoplastic cells was detected after chemotherapy and granulocyte colony-stimulating factor. Kinetic analysis showed a pattern of tumor cell mobilization similar to that of normal hematopoietic progenitors with a maximum peak falling within the optimal time period for the collection of PBSCs. The absolute number of plasma cells showed a 10 to 50-fold increase as compared with the baseline value. Apheresis products contained 0.7% +/- 0.2% SD of myeloma cells (range, 0.2% to 2.7%). Twenty-three MM patients were submitted to PBSC collection. In 10 patients, circulating hematopoietic CD34+ cells were highly enriched by avidin-biotin immunoabsorption, were cryopreserved, and used to reconstitute bone marrow function after myeloablative therapy. The median purity of the enriched CD34+ cell population was 89.5% (range, 51% to 94%), with a 75-fold increase as compared with the pretreatment samples. The median overall recovery of CD34+ cells and colony-forming unit-granulocyte-macrophage was 58% (range, 33% to 95%) and 45% (range, 7% to 100%), respectively. Positive selection of CD34+ cells resulted in 2.5- to 3-log depletion of plasma cells and CD19+ B-lineage cells as determined by immunofluorescence studies, although DNA analysis of CDR III region of IgH gene showed the persistence of minimal residual disease in 5 of 6 patient samples studied. Myeloma patients were reinfused with enriched CD34+ cells after myeloablative therapy consisting of total body irradiation (1,000 cGy) and highdose melphalan (140 mg/m2). They received a median of 4 x 10(6) CD34+ cells/kg and showed a rapid reconstitution of hematopoiesis; the median time to 0.5 x 10(9) neutrophils and to 20 and 50 x 10(9) platelets per liter of PB was 10, 11, and 12 days, respectively. These results, as well as other clinically significant parameters, did not significantly differ from those of patients (n = 13) receiving unmanipulated PBSCs after the same pretransplant conditioning regimen. In summary, our data show the concomitant mobilization of tumor cells and hematopoietic progenitors in the PB of MM patients. Positive selection of CD34+ cells reduces the contamination of myeloma cells from the apheresis products up to 3-log and provides a cell suspension capable of restoring a normal hematopoiesis after a total body irradiation-containing conditioning regimen.     

High-dose etoposide with granulocyte colony-stimulating factor for mobilization of peripheral blood progenitor cells: efficacy and toxicity at three dose levels

High-dose etoposide (2.0-2.4 g m(-2)) with granulocyte colony-stimulating factor (G-CSF) is an effective strategy to mobilize peripheral blood progenitor cells (PBPCs), although in some patients this is associated with significant toxicity. Sixty-three patients with malignancy were enrolled into this non-randomized sequential study. The majority (55/63, 87%) had received at least two prior regimens of chemotherapy, and seven patients had previously failed to mobilize following high-dose cyclophosphamide with G-CSF. Consecutive patient groups received etoposide at three dose levels [2.0 g m(-2) (n = 22), 1.8 g m(-2) (n = 20) and 1.6 g m(-2) (n = 21)] followed by daily G-CSF. Subsequent leukaphereses were assayed for CD34+ cell content, with a target total collection of 2.0 x 10(6) CD34+ cells kg(-1). Toxicity was assessed by the development of significant mucositis, the requirement for parenteral antibiotics or blood component support and rehospitalization incidence. Ten patients (16%) had less than the minimum target yield collected. Median collections in the three groups were 4.7 (2 g m(-2)), 5.7 (1.8 g m(-2)) and 6.5 (1.6 g m(-2)) x 10(6) CD34+ cells kg(-1). Five of the seven patients who had previously failed cyclophosphamide mobilization achieved more than the target yield. Rehospitalization incidence was significantly lower in patients receiving 1.6 g m(-2) etoposide than in those receiving 2.0 g m(-2) (P = 0.03). These data suggest that high-dose etoposide with G-CSF is an efficient mobilization regimen in the majority of heavily pretreated patients, including those who have previously failed on high-dose cyclophosphamide with G-CSF. An etoposide dose of 1.6 g m(-2) appears to be as effective as higher doses but less toxic.     

Autologous transplantation of mobilized peripheral blood CD34+ cells selected by immunomagnetic procedures in patients with multiple myeloma

In the use of autologous PBPC transplantation in patients with multiple myeloma, contamination of PBPC with myeloma cells is commonly observed. Enrichment for CD34+ cells has been employed as a method of reducing this contamination. In this study the reduction of myeloma cells in PBPC was accomplished by the positive selection of CD34+ cells using immunomagnetic bead separation (Isolex 300 system). PBPC were mobilized from 18 patients using cyclophosphamide (4.5 g/m2) and G-CSF (10 microg/kg/day). A median of two leukaphereses and one selection was performed per patient. The median number of mononuclear cells processed was 3.50 x 10(10) with a recovery of 1.11 x 10(8) cells after selection. The median recovery of CD34+ cells was 48% (range 17-78) and purity was 90% (29-99). The median log depletion of CD19+ cells was 3.0. IgH rearrangement, assessed by PCR, was undetectable in 13 of 24 evaluable CD34+ enriched products. Patients received 200 mg/m2 of melphalan followed by the infusion of a median of 2.91 x 10(6)/kg CD34+ cells (1.00-16.30). The median time to absolute neutrophil count >0.5 x 10(9)/l was 11 days, and sustained platelet recovery of >20 x 10(9)/l was 14 days. We conclude that immunomagnetic-based enrichment of CD34+ cells results in a marked reduction in myeloma cells without affecting engraftment kinetics.     

Factors controlling haemopoiesis in ovine long-term bone marrow cultures

There is increasing interest in both standardization and simplification of methods for enumeration of CD34+ hematopoietic progenitor cells (HPC) to facilitate cellular therapies and to improve interinstitutional comparison of clinical and laboratory results. We evaluated a novel method for CD34+ cell enumeration based on microvolume fluorimetry (MVF) compared with our laboratory's routine flow cytometric method on samples of peripheral blood and leukapheresis products. The MVF method is semiautomated and uses a 633-nm light from a helium-neon laser to scan fluorochrome-labeled cells held in stasis in a capillary known volume. The performance of the MVF assay for enumeration of CD34+ cells was found to be comparable to our routine flow cytometric assay in linearity and accuracy in the range of 5-1500 cells per microliter. Precision of MVF for replicate assays on the same instrument was demonstrated by coefficient of variation (CV) values of 8.4% at a CD34+ cell concentration of 284/microliters for a sample volume of 0.8 microliters, and 15.7% at 12/microliters for a sample volume of 3.2 microliter. Precision among three different instruments was demonstrated, using sample volumes of 1.6 microliters, by CV values of 44% at 6 cells/microliters and 4.6% at 733 cells/microliters. In a field sample evaluation, precision of the entire assay system for paired measurements on 0.8-microliter sample volumes was demonstrated by CV values of 50%, 31%, and 15% for peripheral blood samples with concentrations of 0-10, 10-20, and 20-100 CD34+ cells/microliters, respectively, and 6.3%, 8.1% and 6.5% for leukapheresis samples with concentrations of 0-100, 100-1,000, and 1,000-2,500 CD34+ cells/microliters, respectively. The MVF assay was easy to perform, required minimal technical training time, and had a turnaround time of 40 min, of which less than 10 min was actual technical time. These observations suggest that the MVF method for CD34+ cell enumeration may prove useful to clinical laboratories providing support for HPC collection, processing, and transplantation services that require relatively simple, rapid assays for product quality control or to guide real-time clinical decisions.     

Mifepristone modulation of ACTH and CRH regulation of bovine adrenocorticosteroidogenesis in vitro

In this article, we review neoplastic contamination in the peripheral blood (PB) of patients with multiple myeloma (MM) upon stem cell mobilization. We first evaluated PB samples from pretreated MM patients following administration of high-dose cyclophosphamide (Cy, 7 g/m2 or 4 g/m2) and granulocyte colony-stimulating factor (G-CSF) for the presence of myeloma cells as well as hematopoietic progenitors. Plasma cells containing intracytoplasmic immunoglobulin (cIg) were counted by immunofluorescence microscopy after incubation with appropriate antisera against light and heavy chain Ig. Flow cytometry studies were performed to determine the presence of malignant B lineage elements, using monoclonal antibodies against the CD19 antigen and the monotypic light chain. Prior to PBSC mobilization, circulating plasma cells were detected in all MM patients at 0.1%-1.8% of the mononuclear cell (MNC) fraction (mean value 0.7 +/- 0.4% SD). In these patients, a higher absolute number of PB neoplastic cells was detected after administration of chemotherapy and G-CSF. Kinetic analysis showed a pattern of tumor cell mobilization similar to that of normal hematopoietic progenitors, with the peak coinciding with the optimal period for the collection of PBSC. The absolute number of plasma cells showed a 10-50-fold increase over the baseline value. Apheresis products contained 0.7 +/- 0.2% SD myeloma cells (range 0.2%-2.7%), which demonstrated the capacity of plasma cells to proliferate, differentiate, and mature in response to c-kit ligand (SCF), IL-3, IL-6, and a combination of IL-3 and IL-6. Subsequently, in an attempt to reduce tumor cell contamination prior to autologous transplantation, circulating hematopoietic CD34+ cells were highly enriched by avidin-biotin immunoabsorption, cryopreserved, and used to reconstitute bone marrow (BM) function after myeloablative therapy in 13 patients. The median purity of the enriched CD34+ cell population was 89.5% (range 51%-94%), with a 75-fold enrichment compared with the pretreatment samples. The median overall recovery of CD34+ cells and CFU-GM was 58% (range 33%-95%) and 45% (range 7%-100%), respectively. Positive selection of CD34+ cells resulted in 2.5-3 log depletion of plasma cells and CD 19+ B lineage cells as determined by immunofluorescence studies, although DNA analysis of the CDR III region of the IgH gene demonstrated the persistence of minimal residual disease (MRD) in 5 of 6 patient samples studied. Myeloma patients were reinfused with enriched CD34+ cells after myeloablative therapy consisting of total body irradiation (TBI, 1000 cGy) and high-dose melphalan (140 mg/m2) or melphalan (200 mg/m2) alone. They received a median of 5 x 10(6) CD34+ cells/kg and showed a rapid reconstitution of hematopoiesis. The median time to 0.5 x 10(9) neutrophils, 20 x 10(9) and 50 x 10(9) platelets/L of PB was 10, 11, and 12 days, respectively. These results, as well as other clinically significant parameters, did not significantly differ from those of patients (n = 13) receiving unmanipulated PBSC following the same pretransplant conditioning regimen. Our data demonstrate the concomitant mobilization of tumor cells and hematopoietic progenitors in the PB of MM patients. Positive selection of CD34+ cells reduces the contamination of myeloma cells from the apheresis products up to 3 log and provides a cell suspension capable of restoring normal hematopoiesis following a TBI-containing conditioning regimen.     

中剂量依托泊苷联合粒细胞集落刺激因子动员恶性淋巴瘤的外周血造血干/祖细胞

目的 观察中剂量依托泊苷(VP16)和粒细胞集落刺激因子(G-CSF)在恶性淋巴瘤患者动员采集自体外周血造血干/祖细胞的有效性和安全性.方法 31例恶性淋巴瘤患者(非霍奇金淋巴瘤30例,霍奇金淋巴瘤1例),VP16 1.2 g/m2分3 d静脉滴注,外周血白细胞降至最低点时给予G-CSF每天5μg/kg,分2次,皮下注射,直至采集结束.结果 VP16应用后12 d(10～15 d)开始采集外周血造血干/祖细胞,获得单个核细胞(MNC)7.8×108/kg[(5.2～11.3)×108/kg],CD+34细胞7.2×106/kg[(5.3～13.1)×106/kg] 18例患者采集1次,13例采集2次.所有患者移植后均恢复造血,外周血粒细胞＞0.5×109/L的中位时间为12 d(9～18 d),血小板＞20×109/L的中位时间为14d(10～21 d).患者无严重不良反应结论中剂量VP16和G-CSF动员恶性淋巴瘤患者外周血干/祖细胞有效、安全,可获得满意的动员采集效果.     

Fas antigen (CD95) expression in peripheral blood progenitor cells from patients with leukaemia and lymphoma

Fas antigen (CD95) is a cell surface receptor belonging to the tumour necrosis factor/nerve growth factor superfamily and is able to induce apoptosis when triggered by its' natural ligand or an anti-Fas antibody. Fas expression is low on CD34+ bone marrow (BM) progenitor cells, but is increased by various cytokines in vitro. We investigated Fas expression on CD34+ cells from 39 peripheral blood progenitor cell (PBPC) harvests and from 5 normal BM harvests by dual colour flow cytometry to determine if Fas expression was altered during mobilisation. By including calibrated microbeads during flow cytometry, we quantified the number of Fas antigen molecules per cell. A low percentage of PBPC (22%) and normal BM (23%) CD34+ cells expressed Fas antigen. Fas expression varied on CD34+ cells from different diseases and the highest expression was found in ALL (52%). There was a significant three fold increase in the number of Fas molecules/cell expressed on CD34+ cells (PBPC 6,230 molecules/cell, BM 2,236; p = 0.0003). This level of expression was considerably less than that for CD3/CD19 lymphocytes (33,095 molecules/cell) and CD14 monocytes (47,467 molecules/cell) in the PBPC harvest. In conclusion, mobilisation including the use of growth of factors, has minimal effect on CD34 progenitor cell Fas expression.     

Pulsed field agarose gel electrophoresis in the study of morphogenesis: packaging of double-stranded DNA in the capsids of bacteriophages

Circulating hemopoietic progenitors were evaluated in 19 multiple myeloma patients at diagnosis. Eleven patients received either high-dose cyclophosphamide (7 g/m2, 8 patients) or etoposide (2 g/m2, 3 patients) followed by GM-CSF administration; the remaining 8 patients received intermediate-dose cyclophosphamide (1.2 g/m2 on days 1 and 3), 4 of them with GM-CSF support. The highest levels of circulating progenitor cells were observed among patients in the high-dose chemotherapy group (median CFU-GM peak value of 6432 per ml), while in patients receiving intermediate-dose, with or without GM-CSF, median peak values were 2588 and 462 per ml, respectively. In all groups a remarkable heterogeneity in the yield of circulating progenitors was observed; this was particularly pronounced in the high-dose group, where CFU-GM peak values ranged between 200 and 38,070 per ml. At variance with the effect observed in previously untreated patients with lymphoma or breast cancer, the degree of mobilization in myeloma patients was rather unpredictable. The only pre-treatment characteristic correlating to some extent with a poor expansion of the circulating progenitor pool was heavy BM infiltration with plasma cells. The mobilizing effect was not restricted to the myeloid lineage, as demonstrated by the rise of BFU-E; CD34+ cells were increased as well. Indeed, a simultaneous evaluation of CFU-GM and CD34+ cells was carried out and a highly significant correlation (r = 0.9) was observed.(ABSTRACT TRUNCATED AT 250 WORDS)     

Rapid engraftment without significant graft-versus-host disease after allogeneic transplantation of CD34+ selected cells from peripheral blood

We have prospectively evaluated the feasibility and results of the biotin-avidin immunoadsorption method (Ceprate SC system) for a phase I/II study of T-cell depletion of granulocyte colony-stimulating factor (G-CSF) mobilized peripheral blood progenitor cells (PBPC) for allogeneic transplantation. Twenty consecutive patients, median age, 40 years (21 to 54) and diagnoses of chronic myeloid leukemia in chronic phase (n = 5), acute myeloblastic leukemia (n = 7), acute lymphoblastic leukemia (n = 2), chronic myelomonocytic leukemia (n = 1), refractory anemia with excess of blasts in transformation (n = 3), histiocytosis X (n = 1), and chronic lymphocytic leukemia (n = 1), were conditioned with cyclophosphamide (120 mg/kg) and total body irradiation (13 Gy; 4 fractions). HLA identical sibling donors received G-CSF at 10 microg/kg/d subcutaneously (SC); on days 5 and 6 (19 cases) and days 5 to 8 (1 case) donors underwent 10 L leukapheresis. PBPC were purified by positive selection of CD34+ cells using immunoadsorption biotin-avidin method (Ceprate SC) and were infused in the patients as the sole source of progenitor cells. No growth factors were administered posttransplant. The median recovery of CD34+ cells after the procedure was of 65%. The median number of CD34+ cells infused in the patients was 2.9 (range, 1.5 to 8.6) x 10(6)/kg. The median number of CD3+ cells administered was 0.42 x 10(6)/kg (range, 0.1 to 2). All patients engrafted. Neutrophil counts >500 and >1,000/microL were achieved at a median of 14 days (range, 10 to 18) and 15 days (range, 11 to 27), respectively. Likewise, platelet counts >20,000 and >50,000/microL were observed at a median of 10 days (range, 6 to 23) and 17 days (range, 12 to 130), respectively. Graft-versus-host disease (GVHD) prophylaxis consisted of cyclosporine plus methylprednisolone. No patient developed either grade II to IV acute or extensive chronic GVHD. After a median follow-up of 7.5 months (range, 2 to 22) three patients have relapsed, and one of them is again in hematologic and cytogenetic remission after infusion of the donor lymphocytes. Two patients died in remission: one on day +109 of pulmonary aspergillosis and the other on day +251 of metastasic relapse of a previous breast cancer. Sixteen of the 20 patients are alive in remission after a median follow-up of 7.5 months (range, 2 to 22). In conclusion, despite the small number of patients and limited follow-up, it appears that this method allows a high CD34+ cell recovery from G-CSF mobilized PBPC and is associated with rapid engraftment without significant GVHD, and with low transplant related mortality.     

Challenges posed by health care restructuring in Ontario

Gene therapy is becoming one of the most promising modalities for the treatment of acquired immunodeficiency syndrome. The purpose of this study was to investigate the mobilization and collection of peripheral blood progenitor cells from human immunodeficiency virus (HIV)-infected individuals using granulocyte colony-stimulating factor (G-CSF). A total of 10 patients (9 male, 1 female; median age 36.5 years) with varying circulating CD4+ cell counts (13.9-1467/microL) were administered 10 microg/kg G-CSF daily for 6 days. Peripheral white blood cells (WBCs), CD34+ cell counts, lymphocyte subsets, and plasma viremia were monitored before each G-CSF injection. An average sixfold increase in WBCs was observed, which stabilized on day 4 or thereafter. The level of CD34+ cells was increased by 20-fold, and did not differ between days 5 and 6. Smaller increases in CD4+, CD8+, and CD4+CD8+ cells were observed. HIV viral load, as measured by RNA copy number in plasma, was not significantly altered by G-CSF administration. The leukapheresis product (LP), collected on day 7, contained an average of 6.25+/-4.52 (mean +/- standard deviation) x 10(10) WBCs and 3.08+/-2.98 x 10(6) CD34+ cells/kg. The levels of different CD34+ cell subsets were similar to those in the LPs of G-CSF-mobilized healthy individuals from an earlier study. Primitive hematopoietic cells (CD38- and CD38-HLA-DR+ cells) were detected in LPs (1.19+/-0.46% and 0.87+/-0.23%, respectively, of CD34+ cells). All parameters (WBC counts, lymphocyte populations, CD34+ cells, and HIV-1 RNA copies) measured 3 weeks after leukapheresis returned to baseline values. The administration of G-CSF was well tolerated by the HIV patients; side effects included bone pain, headache, flulike symptoms, and fatigue. There were no correlations between baseline CD4+ cell count and the WBCs, mononuclear cells, or CD34+ cells collected in the LP. Similarly, no correlation existed between baseline CD4+ and CD34+ cells, peak CD34+ cells, or days to achieve peak CD34+ cell counts after G-CSF mobilization. Our results showed that: (1) maximal mobilization can be achieved after 4 days of G-CSF administration; (2) therapeutic quantities of hematopoietic cells can be collected and used for gene therapy; and (3) G-CSF administration is well tolerated and does not cause a clinically significant increase in viremia.     

Cyclophosphamide/granulocyte colony-stimulating factor induces hematopoietic stem cells to proliferate prior to mobilization

We isolated hematopoietic stem cells (HSC) from mice treated with cyclophosphamide (CY) and granulocyte colony-stimulating factor (G-CSF). All mobilized multipotent progenitor activity was contained in two populations: Thy-1(lo) Sca-1+ Lin- Mac-1- CD4- c-kit+ long-term reconstituting progenitors and Thy-1(lo) Sca-1+ Lin- Mac-1(lo) CD4- transiently reconstituting progenitors. CY/G-CSF treatment drove both long-term and transient multipotent progenitors into cycle, leading to a more than 12-fold expansion in the number of long-term self-renewing HSC prior to mobilization. After CY and 2 days of G-CSF treatment the number of bone marrow HSC began to decline and the number of blood and splenic HSC increased. HSC continued to proliferate in the bone marrow and spleen through 8 days of G-CSF treatment, but HSC released into the blood tended to be in G0/G1 phase. Mobilized multipotent progenitors isolated from the spleen were less efficient than normal bone marrow multipotent progenitors in engrafting irradiated mice but did not differ in colony forming unit-spleen (CFU-S) activity or single cell in vitro assays of primitive progenitor activity. The data suggest that mobilized HSC isolated from the spleen are less efficient at homing to and engrafting the bone marrow of irradiated recipient mice.