Peripheral Blood Progenitor Cell Collection during Hematopoietic Recovery following Autologous Blood Progenitor Cell Transplantation

Background and objectives: Peripheral blood progenitor cells (PBPC) are increasingly used for autologous transplantation after high-dose radio/chemotherapy in patients suffering from cancer. PBPC are usually collected after mobilization with conventional-dose chemotherapy plus growth factor. However, it is conceivable to perform leukapheresis for the second autograft during recovery of hematopoiesis after the first course of HDCT/ABPCT. Materials and methods: We treated two patients this way. In the first, with germ cell cancer, six 12-liter leukaphereses yielded 1.8×10⁶ CD34+ cells/kg after mobilization with cis-platinum, etoposide and ifosfamide (PEI) plus granulocyte colony-stimulating factor (G-CSF). The second patient, with relapsed Hodgkin's disease, underwent PBPC collection after treatment with dexamethasone, carmustine, etoposide, cytarabine and melphalan (DexaBEAM) plus G-CSF. Due to excellent mobilization, 8.5×10⁶ CD34+ cells/kg were collected by one 12-liter leukapheresis. Both patients then underwent PBPC collection during hematopoietic recovery following HDCT and ABPCT. Results: In patient 1, following HDCT and ABPCT, three 12-liter aphereses resulted in 0.7×10⁶ CD34+ cells/kg. In patient 2, also after HDCT and ABPCT, a second autograft with 3.2×10⁶ CD34+ cells/kg was harvested by a single 10-liter apheresis. No adverse effects were seen in either patient during apheresis following ABPCT. To our knowledge this is the first report dealing with PBCT collection during hematopoietic recovery following HDCT and ABPCT. Conclusions: (1) PBPC harvesting is feasible and well tolerated in this setting. (2) In appropriate patients with efficient PBPC mobilization after conventional-dose chemotherapy, a further PBPC autograft can be collected during recovery of hematopoiesis after ABPCT, serving as a rescue for a second course of HDCT.     

Autografting with blood progenitor cells: predictive value of preapheresis blood cell counts on progenitor cell harvest and correlation of the reinfused cell dose with hematopoietic reconstitution

One hundred and nine patients suffering from various malignancies underwent 285 apheresis procedures for PBPC collection. A median of two leukaphereses (range: 2–5) resulted in median numbers of 4.6×10 ⁸ MNC/kg, 14.1×10 ⁴ CFU-GM/kg, and 6.0×10 ⁶ CD34+ cells/kg. Preleukapheresis peripheral blood CD34+ cells correlated significantly with collected CD34+ cells/kg ( r=0.94; p<0.0001) and with CFU-GM/kg ( r=0.52; p<0.0001). A value >4×10 ⁴ CD34+ cells/ml was highly predictive for a collection yield >2.5×10 ⁶ CD34+ cells/kg harvested by a single leukapheresis. Sixty patients were evaluated for hematologic reconstitution and engrafted in a median time of 10 days for WBC >1.0×10 ⁹/l (range: 7–21 days), 10 days for ANC >0.5×10 ⁹/l (7–20) and 11 days for PLT >20×10 ⁹/l (7–62). Reinfused CD34+ cells/kg correlated significantly with hematologic engraftment ( r=0.44–0.52 and p<0.006–0.001) as well as CFU-GM/kg ( r=0.36–0.44 and p<0.007–0.001). A progenitor cell dose >2.5×10 ⁶ CD34+ cells/kg or >8.0×10 ⁴ CFUGM/kg led to a significantly faster recovery for WBC, ANC, and PLT when compared with patients receiving <2.5×10 ⁶ CD34+ cells/kg or <8.0×10 ⁴ CFU-GM/kg. We conclude that rapid hematopoietic engraftment after high-dose therapy and PBPC reinfusion correlates well with a progenitor cell dose >2.5×10 ⁶ CD34+ cells/kg or >8.0×10 ⁴ CFU-GM/kg, and that above a preleukapheresis threshold of 4×10 ⁴ CD34+ cells/ml a PBPC autograft containing >2.5×10 ⁶ CD34+ cells/kg can be collected by a single leukapheresis. We suggest that patients recovering from myelosuppression should be monitored for CD34+ cells in serial blood samples to determine the course of circulating hematopoietic progenitor cells. This issue will help to define the optimal time point to start apheresis and to predict a PBPC autograft harvested by a single leukapheresis, which will lead to rapid and stable hematopoietic reconstitution following transplantation.     

Pulmonary and systemic effects of mononuclear leukapheresis

Background and Objectives There is increasing evidence that monocytes play a key role in the pathogenesis of acute lung inflammation. Mononuclear cell (MNC) leukapheresis can be used to remove large numbers of monocytes from circulating blood; however, the detailed characteristics of monocyte subpopulations removed by MNC leukapheresis, and the biological effects on the lung, remain incompletely defined. Material and Methods Six healthy male volunteers underwent MNC leukapheresis of four total blood volumes. Blood was collected at 0, 2, 4, 6, 8 and 24 h; bronchoscopy with bronchoalveolar lavage (BAL) was performed at 8–9 h. Multiparameter flow cytometry was used to identify subpopulations of monocytes in blood and monocyte‐like cells in BAL fluid. Results A median of 5·57 × 10⁹ monocytes were retrieved. Blood monocyte counts indicated that the circulating blood monocyte pool was actively replenished during leukapheresis and subsequently contained a greater proportion of classical (CD14⁺⁺ CD16^?) monocytes. A particular subpopulation of monocyte‐like cells, reminiscent of classical monocytes, was also prominent in BAL fluid after leukapheresis. Conclusion Mononuclear cell leukapheresis was safe. The greater proportion of classical monocytes present in blood after MNC leukapheresis may be clinically significant. MNC leukapheresis also appears to affect the proportion of monocyte‐like cells in the lung; however, we found no evidence that leukapheresis has a clinically important pro‐inflammatory effect in the human lung.     

Chemomobilization with high‐dose etoposide and G‐CSF results in effective and safe stem cell collection in heavily pretreated lymphoma patients: report from a single institution study and review

The optimal mobilization strategy prior to autologous stem cell transplantation (auto‐SCT) for patients with lymphoma is yet to be determined. We reviewed our institutional experience using chemomobilization with high‐dose (HD) etoposide (1.6 g/m²) and G‐CSF (300 μg/day) in 79 patients with lymphoma. The majority (76%) had received at least two prior regimens of chemotherapy, and 12 (15.2%) patients had previously failed to mobilize following HD cyclophosphamide or DHAP or ICE with G‐CSF. HD etoposide and G‐CSF chemomobilization resulted in successful collection (>2 × 10⁶ CD34+ cells/kg) in 82.3% of patients within a median 2 (1–6) apheresis days. Patients had stem cells collected between days +8 and +15, with a median +12 day. Median total CD34+ cells/kg collected was 5.95 × 10⁶ (0.1–36.8). Seventy‐one percent of patients yielded >2 × 10⁶ CD34+ cells/kg in ≤2 d of apheresis and were defined as good mobilizers. While median CD34+ cells/kg collected for good mobilizers was 7.6 × 10⁶, it was 2.6 × 10⁶ for poor mobilizers (P < 0.001). This regimen was safe with a low rate of febrile neutropenia (7.6%) and acceptable rates of RBC (40.5%) and platelet transfusions (22.8%). Hematopoietic recovery after auto‐SCT was achieved on expected time. Therapy‐related myelodysplastic syndrome/acute myeloid leukemia occurred in only one patient (1.3%) with in a median follow‐up of 16 months after chemomobilization. We conclude that HD etoposide and G‐CSF chemomobilization appear to result in effective, tolerable, and safe stem cell collection in the majority of heavily pretreated lymphoma patients.     

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/μl; median 20.0/μl). To reach the target quantity of 2.5 × 10⁶ CD34⁺ cells/kg, between one and six (median two) leukaphereses (LP) were performed. The LP products contained between 0.2 × 10⁶ and 18.9 × 10⁶ CD34⁺cells/kg (median 1.2 × 10⁶/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 × 10⁹/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.     

Pediatric apheresis: Special emphasis on peripheral blood progenitor cell harvest in children

The effect of apheresis can be powerful when selectively applied, since it has the ability to directly remove or harvest target substance(s) or cells in circulating blood. In addition, direct removal may have potential immunomodulatory effects, which can further enhance therapeutic efficacy. Apheresis has been widely utilized in both donor and therapeutic procedures in adults. However, its use in pediatric patients remains limited primarily for two reasons. The first is a lack of generally accepted indications and treatment schedules. Even in illnesses in which the efficacy in adults has been proven, there has been reluctance to apply therapeutic apheresis guidelines formulated for adult patients to children without supporting data derived from controlled studies or clinical trials in children. The second reason is technical difficulty. Apheresis equipment is designed for adults and it is not possible for operators to perform safe procedures in infants and small children without modifying procedures. In addition, difficulty in securing adequate vascular access may discourage or even prohibit a trial of apheresis in children. Nevertheless, therapeutic apheresis has a definite role in the treatment of certain disorders in pediatric patients as a standard therapy or as a first-line adjunct to primary therapy. The objective of this talk is to provide practical guidelines for pediatric apheresis. During the first half, primarily three areas will be covered: 1) special considerations unique to pediatric apheresis, 2) guidelines for the modification of standard operating procedures, and 3) rather new applications of apheresis in children. The latter half will be dedicated to peripheral blood progenitor cell (PBPC) transplantation in children. PBPC transplantation has been used primarily as an adjunctive therapy to achieve hematopoietic reconstitution following myeloablative therapy in patients with malignant diseases. In this situation, nearly all transplantations have been performed using autologous PBPCs. However, the use of PBPCs from related allogeneic donors has gradually increased and other trials are exploring utilization of PBPCs for unrelated allogeneic transplantation. Currently, the minimum CD34+ cell dose needed for successful engraftment is ～1×10⁶/kg body weight. In general, one procedure is sufficient, provided that PBPCs have been mobilized. For newer treatment protocols that require tandem PBPC transplantations or CD34⁺ cell and/or tumor cell-selection, at least 5?10×10⁶ CD34+ cells /kg body weight are needed. The success of a PBPC harvest largely depends upon the number of circulating PBPCs. With various mobilization regimens, the number of circulating progenitor cells can be significantly increased. It is also important to determine the optimal timing for PBPC harvest, which coincides with the time of leukocyte recovery after chemotherapy compared with the pretherapy steady state. Studies indicate that preharvest assessment of CD34+ cells in the peripheral blood of the patient can predict the optimal timing of leukapheresis. To enhance the PBPC collection, several strategies have been employed: 1) increasing the number of leukapheresis procedures, 2) increasing the volume of blood processed per procedure, 3) increasing the efficiency of the MNC collection by technical improvements in cell separators, or 4) expanding the PBPC pool by the use of cytokines or other agents. Currently, combined strategies would allow collecting sufficient numbers of PBPCs for transplant with fewer leukapheresis procedures. To harvest such a large number of PBPCs successfully from a child, specific procedural issues unique to PBPC collection will be discussed: 1) intravascular fluid and red cell volume shifts, 2) citrate toxicity, and 3) removal of circulating platelets. In this presentation, PBPC harvest in children using the Spectra system will be discussed. The principles used for the Spectra can be applied to other equipment. In addition, various mobilization regimens, quality assurance, and clinical experience of PBPC transplantation in children will be presented.     

Stimulation of adrenergic activity by desipramine enhances hematopoietic stem and progenitor cell mobilization along with G‐CSF in multiple myeloma: A pilot study

Hematopoietic stem cell (HSC) release is positively regulated by the sympathetic nervous system through the β3 adrenergic receptor. Preclinical studies have demonstrated that the combination of desipramine and G‐CSF resulted in improved HSC mobilization. Here, we present the results of an open‐label single‐arm pilot study in patients with multiple myeloma undergoing autologous stem cell transplantation (ASCT) to assess the safety and efficacy of desipramine combined with G‐SCF to induce HSC mobilization. The primary endpoint was safety of the combination including engraftment kinetics. The secondary endpoint was the proportion of patients who collected ≥5 × 10⁶ CD34⁺ cells/kg. Outcomes were compared with historical matched controls during the same time period with multiple myeloma mobilized with G‐CSF. All study patients received desipramine 100 mg daily for 7 days, starting 4 days prior to G‐CSF administration (D‐3) and continued taking it along with G‐CSF for a total of 7 days. Six of ten patients enrolled completed the protocol with minimal side effects. All of them achieved the target collection of 5 × 10⁶ CD34 cells/kg in a median of 1.5 apheresis session with two patients needing additional plerixafor (16%), while 11 out of 13 patients (85%) achieved the target of 5 × 10⁶ CD34 cells/kg in the historical control group in a median of 2 apheresis procedures and seven patients needed plerixafor (54%). The combination of desipramine and G‐CSF is safe and signals improved mobilization over G‐CSF alone, providing a possible alternative means of mobilization that needs further investigation.     

Peripheral blood progenitor cell transplantation in lymphoma and leukemia using a single apheresis

Myeloablative treatment and peripheral blood progenitor cell (PBPC) transplantation are increasingly used for lymphomas and leukemias. We have sought to optimize conditions for priming, collection, and engraftment of the leukapheresis product. Fifty-four consecutive adult patients were eligible, 31 with high-grade non-Hodgkin's lymphoma of poor prognosis, 12 with Hodgkin's disease in chemosensitive relapse, and 11 with poor prognosis acute lymphoblastic leukemia. Filgrastim was administered after routine chemotherapy with VAPEC-B or HiCCOM to mobilize PBPC. A rapidly increasing white blood cell count was used to predict the time of peak PBPC release and plan leukapheresis. Forty- five patients underwent leukapheresis. A median of 14 L of blood was processed at a single apheresis. A median of 2.4 x 10(8)/kg mononuclear cells (MNCs), 1.04 x 10(6)/kg granulocyte-macrophage colony-forming cells (GM-CFCs), and 10.6 x 10(6)/kg CD34+ cells were obtained. Slightly fewer MNCs were obtained from the heavily pretreated Hodgkin's disease group. There were no other significant differences in the size or composition of the leukapheresis harvest in the three patient groups. Forty patients underwent high-dose therapy and PBPC transplantation. Filgrastim was administered by daily subcutaneous injection until the absolute neutrophil count was > or = 1 x 10(9)/L for 2 consecutive days. Rapid and sustained hematopoietic engraftment occurred in all patients. The median time to achieve a neutrophil count > or = 0.5 x 10(9)/L was 9 days (range, 8 to 16 days); to achieve a platelet count > or = 20 x 10(9)/L was 10 days (range, 6 to 88 days); and to achieve a platelet count > or = 50 x 10(9)/L was 15.5 days (range, 10 to 100 days). Neutrophil recovery was faster than that of a historical control group treated with autologous bone marrow transplantation and filgrastim, but platelet recovery times were halved in the PBPC group. There was no secondary engraftment failure. Requirements for blood and platelet transfusions, antibiotic use, and parenteral nutrition were similar in the three patient groups. The median number of days in the hospital was 13 (range, 10 to 55) in the PBPC patients, compared with 19 (range, 14 to 51) in the historical controls. Leukapheresis yields (MNC, GM-CFC, and CD34+ cell numbers) were not useful for predicting the times to engraftment. We have shown that sufficient PBPC for transplantation can be obtained at a single leukapheresis after mobilization with routine chemotherapy and filgrastim in patients with non-Hodgkin's lymphoma, Hodgkin's disease, and acute lymphoblastic leukemia, even those heavily pretreated.(ABSTRACT TRUNCATED AT 400 WORDS)     

Peripheral blood progenitor cells mobilized by chemotherapy plus granulocyte-colony stimulating factor accelerate both neutrophil and platelet recovery after high-dose VP16, ifosfamide and cisplatin

Summary. We report on the chemotherapy plus granulocyte colony-stimulating factor (G-CSF) induced mobilization of peripheral blood progenitor cells (PBPCs) and their impact on haematopoietic recovery following high-dose chemotherapy. Twenty-four patients with advanced solid tumours or lymphomas received standard-dose chemotherapy with VP16, ifosfamide and cisplatin (VIP) followed by filgrastim (G-CSF; 5 μg/kg s.c. daily for 14 d) for the prevention of chemotherapy induced neutropenia and for the simultaneous mobilization of PBPCs. Maximal numbers of progenitors of different lineages were reached at day 11 (range 9–14) after VIP chemotherapy. A median of 0·415 × 10⁹/1 CD34⁺ cells (range 0·11–1·98), 9000 CFU-GM/ml (range 2800–17700). 3500 BFU-E/ml (range 400–10800) and 200 CFU-GEMM/ml (range 0–4400) were recruited. One single apheresis yielded a median of 1·6 × 10⁸ mononuclear cells/kg (range 0·2–5·4) or 5·4 × 10⁶ CD34⁺ cells/kg body weight (range 0·2–24·2). Fourteen patients who showed at least a partial remission after two cycles of the standard-dose chemotherapy regimen were subjected to high-dose VIP chemotherapy (cumulative doses of 1500 mg/m² VP16, 12 g/m² ifosfamide and 150 mg/m² cisplatin) with or without PBPC support. The first six patients were treated with growth factors only (IL-3/GM-CSF) and did not receive PBPCs, whereas the following eight patients were supported with PBPCs in addition to IL-3 and GM-CSF. Neutrophil recovery as well as platelet recovery were significantly faster in patients receiving PBPCs with a median of 6·5 d below 0·1 × 10⁹ neutrophils/1 and 3 d below 20 × 10⁹ platelets/1 as compared to 10·5 d and 8 d in control patients receiving growth factors only. The accelerated platelet recovery in patients supported with PBPCs might be explained—in the absence of detectable colony-forming units megakaryocyte—by the presence of glycoprotein IIb/IIIa⁺, non-proliferating endomitotic megakaryocytic precursor cells within G-CSF mobilized PBPCs. Our data demonstrate that chemotherapy plus G-CSF mobilized PBPCs accelerate both neutrophil and platelet recovery after high-dose VIP chemotherapy in patients with solid tumours or lymphomas.     

Impact of pre-induction therapy leukapheresis on treatment outcome in adult acute myelogenous leukemia presenting with hyperleukocytosis

9 /l were scheduled to undergo leukapheresis. This represented 53 patients (median age 59 years, range 16–78 years) who underwent from 1 to 4 sets of leukapheresis (median 1). The median initial WBC count was 160×10⁹/l (range 100–480×10⁹/l). Morphologic subtypes, according to the French–American–British classification, showed 3 M0, 16 M1, 6 M2, 10 M4, 16 M5, and 2 unclassified cases of AML. In 21 patients (40%), leukapheresis did not reduce their WBC counts significantly, while 32 patients (60%) achieved a WBC count of less than 100×10⁹/l (median 71×10⁹/l) after leukapheresis. Analysis of cell cycle was performed on bone marrow (BM) and peripheral blood leukemic cells before and after leukapheresis in three cases. In two of those cases, a recruitment of BM leukemic cells in the S phase was observed after leukapheresis. The median WBC count at the time of starting chemotherapy was 85×10⁹/l (range 23–264×10⁹/l). Complete remission was achieved in 55% (95% confidence interval 40–68%). Early death occurred in two cases. Median disease-free survival was 10 months, while median overall survival was 8 months. In this study, early death rate is lower than data previously published in the literature and almost all patients could receive chemotherapy. This might suggest a benefit of initial leukapheresis in the treatment of AML presenting with hyperleukocytosis. Received: 23 November 1999 / Accepted: 8 March 2000     

Harvesting of Peripheral Blood Progenitor Cells with Different Programmes of Discontinuous Flow Systems

Background and Objectives: From a technical point of view two problems arise during the collection of peripheral blood progenitor cells (PBPC): first, the volume of the apheresis product is often large, requiring volume reduction prior to cryopreservation. Second, the platelet (PLT) Ioss due to the harvesting of the buffy coat is an unwanted side effect. With respect to these problems, the present study was designed to compare programs for PBPC collection with discontinous-flow cell separators. Materials and Methods: Three different protocols for PBPC harvesting were investigated in 32 patients with malignancies. In the first protocol, the blood cell separator Haemonetics MCS 3p was used. In the second protocol using the same machine, the opening and closure of the stem cell valve was modified in combination with a centri surge to reduce the PLT loss. The MCS+ device with another configuration of the valves was used in the third protocol. PBPC were mobilised by chemotherapy plus cytokine administration or application of growth factor alone. Blood counts and CD34 antigen-expressing cells were determined before apheresis and in the PBPC product. Colony-forming unit granulocyte/macrophage (CFU-GM) were determined in the apheresis product. Results: 55 PBPC collections were carried out with a median end product volume of 105 ml. The median counts for CD34+ antigen-expressing cells and CFU-GM were 1.5 × 10⁶ and 2.5 × 10⁴/kg body weight, respectivel. PLT loss was significantly lower in protocol III. Conclusion: The study reported here revealed that PBPC could be easily collected in a reduced product volume by the intermittent-flow cell separators. No additional centrifugation prior to cryopreservation was necessary to remove the plasma from the apheresis product. Patient's PLT loss was reduced by the centrisurge technique but this still has to be improved.     

Sequential peripheral blood progenitor cell transplantation after mobilization with salvage chemotherapy and G-CSF in patients with resistant lymphoma

We enrolled 18 patients affected by refractory or relapsed lymphoma (HD, NHL) in a two-step protocol that included salvage chemotherapy with mitoxantrone, carboplatinum, methylprednisolone, and cytosine arabinoside (MICMA) plus G-CSF (5 μg/kg/day), peripheral blood progenitor cell (PBPC) collection, and subsequent transplantation after BUCY2 regimen. After MiCMA chemotherapy, four patients (22%) achieved complete response, eight patients (44%) obtained a partial response, and six showed progression of disease (PD). Fourteen out of 18 patients (78%) were considered eligible for PBPC transplantation. Three patients with complete response refused PBPCT; they are currently in continuous complete remission (CCR) at 15, 13, and 15 months, respectively. One patient has been recently transplanted but is too early to be evaluated. Ten patients so far completed the study, eight of whom are currently alive in CR, with a median follow-up of 7.5 months (range 2–13). Hematologic reconstitution was very rapid with a median time to achieve WBC > 1 × 10⁹/L, PMN > 0.5 × 10⁹/L, platelets > 50 × 10⁹ /L and > 100 × 10⁹/L of 13 (range 9–15), 12(range 9–14), 10(range 0–22), and 14 (range 5–49) days, respectively. Our protocol is highly effective as a salvage treatment, while permitting PBPC collection after G-CSF administration. Hemopoietic reconstitution after transplantation of PBPCs collected with this procedure is complete, rapid, and sustained. © 1994 Wiley-Liss, Inc.     

Mobilization and harvesting of peripheral blood stem cells in pediatric patients with solid tumors

Survival of patients with high‐risk pediatric solid tumors has improved with the introduction of a high‐dose chemotherapy regimen and autologous stem cell rescue. Here, we present our data regarding the evaluation of the efficacy and safety of hematopoietic stem cell mobilization and harvesting in children with solid tumors. From November 2002 to March 2010, 85 children underwent autologous peripheral blood stem cell collection; 35 (41.1%) of them weighed less than 20 kg and were diagnosed with neuroblastoma, Wilms' tumor, medulloblastoma, yolk sac sarcoma, or non‐Hodgkin's lymphoma. The mobilization regimens included disease‐specific chemotherapy plus granulocyte colony‐stimulating factor in most of the patients. The median age and weight at the time of apheresis was 36 months and 13.5 kg, respectively. Large‐volume leukapheresis was performed with the aim of reducing the psychological and financial impact of leukapheresis by reducing the number of procedures while collecting a large number of cells. The median number of mobilization and leukapheresis procedures per case was one. The pre‐apheresis CD34+ cell count ranged from 2 to 845 µL, with a median of 24 µL. A median of four patient blood volumes was processed per procedure, lasting 279 min (range, 113–420 min). A radial catheter was used for harvesting in 35 procedures (71.4%). The median yield of CD34+ cells was 6.6 × 10⁶/kg per patient. The targeted dose of 5 × 10⁶/kg CD34+ cells was realized in 80% of patients. The tolerance of peripheral blood stem cell collection in our patients was good. In conclusion, the collection of peripheral blood stem cells is an effective and safe procedure, even when conducted on the youngest children.     

Mobilization of peripheral blood progenitor cells in patients with breast cancer: a prospective randomized trial comparing rhG-CSF with the combination of rhG-CSF plus rhEpo after VIP-E chemotherapy.

Peripheral blood progenitor cells (PBPC) can be mobilized by chemotherapy, cytokines, or the combination of both. Recently, data from two non-randomized studies were published, showing an advantage for a combination of rhG-CSF plus rhEpo compared to rhG-CSF alone in mobilization of PBPC. To address this question we initiated a prospective, randomized trial in patients with breast cancer. Thirty (28 female, two male) of 32 randomized patients were evaluable. After primary surgery, therapy consisted of two cycles of VIP-E chemotherapy followed by high-dose (HD) chemotherapy with VIC. Mobilization and harvest of PBPC followed cycle 2. Group A received 5 microg rhG-CSF/kg body weight (bw) plus 150 IU rhEpo/kg bw. Group B was treated with 5 microg rhG-CSF/kg bw from dl until end of harvest. In the peripheral blood CD34+ cells as well as colony-forming units (CFU) started to rise on d8 with a peak on d10, followed by a decrease. No significant differences were observed between the groups. Furthermore, there was no significant difference with regard to MNC, CD34+ cells BFU-E and CFU-GM in apheresis products. Transplantation of > 1 x 10(6) CD34+ cells/kg bw after HD chemotherapy resulted in normal hematological recovery of all patients. No differences were observed in time to neutrophil or platelet recovery and need for blood product support. In this study addition of rhEpo to our standard mobilization chemotherapy did not result in improved mobilization of PBPC or in clinical benefits after HD chemotherapy.     

Efficacy of pre-emptively used plerixafor in patients mobilizing poorly after chemomobilization: a single centre experience

A significant proportion of patients with lymphoid malignancies are hard‐to‐mobilize with a combination of chemotherapy plus granulocyte colony‐stimulating factor (G‐CSF) (chemomobilization). Plerixafor is a novel drug used to improve mobilization of blood stem cells. However, it has been studied mainly in association with G‐CSF mobilization. We evaluated the efficacy of ‘pre‐emptive’ use of plerixafor after chemomobilization in patients who seem to mobilize poorly. During a 15 month period, altogether 63 patients with lymphoid malignancies were admitted to our department for blood stem cell collection. Sixteen patients (25%) received plerixafor after the first mobilization due to the low blood (B) CD34⁺ cell counts (n = 12) or poor yield of the first collection (n = 4). The median number of plerixafor injections was 1 (1–3). The median B‐CD34⁺ count after the first plerixafor dose was 39 × 10⁶/L (<1–81) with the median increase of fivefold. Stem cell aphaereses were performed in 14/16 patients (88%) receiving plerixafor and a median of 2.9 × 10⁶/kg (1.6–6.1) CD34⁺ cells were collected with a median of one aphaeresis (1–3). Altogether 13/16 patients mobilized with a combination of chemomobilization and plerixafor received high‐dose therapy with stem cell support and all engrafted. Pre‐emptive use of plerixafor after chemomobilization is efficient and safe and should be considered in poor mobilizers to avoid collection failure. In patients with low but rising B‐CD34⁺ counts, the use of plerixafor might be delayed as late mobilization may occur. Further studies are needed to optimize patient selection and timing of plerixafor.     

G-CSF-mobilized peripheral blood progenitor cells for allogeneic transplantation: safety,kinetics of mobilization,and composition of the graft

Allogeneic transplantation of peripheral blood progenitor cells (PBPC) markes the general anaesthesia of the donor unnecessary and may result in more rapid engraftment and faster recovery of the immune system. We have studied G-CSF-mediated PBPC mobilization in healthy donors and analysed the cellular composition of the resulting PBPC grafts. PBPC grafts were obtained from nine healthy donors (18-67 years old) for allogeneic or syngeneic transplantation. Six donors received 10 μg/kg G-CSF per day, the others 5-6 μg/kg. Mobilization and harvesting were well tolerated except for moderate bone pain which occurred in all donors primed with 10 μg/kg. With 10 μg/kg, a 31-fold (9-62) enrichment of circulating CD34⁺ cells was observed with peak values constantly occurring on day 5 after the start of G-CSF administration. Starting harvest on day 5, one to three collections on consecutive days yielded 5.5 x 10⁶/kg (0.9-10.7) CD34⁺ cells, 219 x 10⁶/kg (106–314) T cells, and 34 x 10⁶/kg (23–67) NK cells per 10 litres leukapheresis volume. Altogether, PBPC grafts contained 3 times more CD34⁺ cells, 7 times more T cells, and 20 times more NK cells than five allogeneic marrow grafts that were analysed for comparison. The yield of CD34⁺ cells per 10 litres apheresis volume as well as the height of the CD34⁺ peak in peripheral blood were inversely correlated to the age of the donor. In the donors primed with 5–6μg/kg G-CSF the increase of circulating CD34⁺ cells (4–7-fold enrichment) and the CD34⁺ cell yield per 10 litres leukapheresis volume (1 x 10⁶/kg [0.8-2-2]) was much smaller compared with the 10μg/kg group. In conclusion, sufficient amounts of PBPC capable of restoring haemopoiesis in allogeneic recipients can be mobilized safely by administration of G-CSF (10 μg/kg s.c. for 5 d) in healthy donors, and harvested with one or two leukapheresis procedures. Whether the large numbers of T-cells and NK cells that are contained in the collection products may influence graft-versus-host and graft-versus-leukaemia reactivities of PBPC grafts remains to be determined.     

Correlation between granulocyte/macrophage-colony-forming units and CD34+ cells in apheresis products from patients treated with different chemotherapy regimens and granulocyte-colony-stimulating factor to mobilize peripheral blood progenitor cells

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 × 10⁵ mononuclear cells/kg [range (0.28–3.7) × 10⁸], 1.4 × 10⁵ granulocyte/macrophage-colony-forming units (CFU-GM)/kg [range (0.2–11) × 10⁵] and 3.3 × 10⁶ CD34⁺cells/kg [range (0.35–17.7) × 10⁶. 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. Received: 7 January 1998 / Accepted: 24 February 1998     

Large-volume leukapheresis in pediatric patients: pre-apheresis peripheral blood CD34+ cell count predicts progenitor cell yield

BACKGROUND AND OBJECTIVE: In children it is very important to optimize PBPC harvesting and to reduce the number of leukaphereses per patient. The value of pre-apheresis peripheral blood CD34+ cell concentration as a predictor of PBPC yield was studied in 23 pediatric patients with hematologic and non-hematologic malignancies in order to optimize duration of PBPC collection. DESIGN AND METHODS: The patients underwent 25 stem-cell mobilization episodes with G-CSF alone and 40 large-volume leukapheresis procedures. Peripheral blood and harvested CD34+ cell concentrations were analyzed by means of flow cytometry. RESULTS: Using linear regression analysis, a highly significant correlation was found between the peripheral blood CD34+ cell count and the CD34+ cells/kg patient body weight collected on the apheresis day (r = 0.826, p = 0.0001). The results indicate that at least 1 x 10(6)/kg CD34+ cells can be harvested during one leukapheresis procedure in all patients if the pre-apheresis blood CD34+ cell count is > or = 30/microL and a CD34+ cell target of > or = 5 x 10(6)/kg is achieved in at least 80% of patients if this value is > or = 50 CD34+ cells/microL processing a median blood volume of 438.7 mL/kg (range, 207-560) over a median time of 232.5 minutes (range, 182-376). INTERPRETATION AND CONCLUSIONS: Our results suggest that the number of CD34+ cells harvested in a single large-volume leukapheresis can be predicted from the measurement of peripheral blood CD34+ cell concentration on the collection day.     

The addition of allogeneic peripheral blood-derived progenitor cells to bone marrow for transplantation: results of a randomised clinical trial

Background: The use of cytokine-mobilised peripheral-blood-derived progenitor cells (PBPC) has resulted in a significant improvement in the safety of autologous transplantation. Collections of PBPC contain large numbers of haemopoietic progenitors and T-lymphocytes when compared with bone marrow (BM). Aims: To assess the clinical effects and safety of filgrastim-mobilised allogeneic PBPC, in particular whether PBPC would alter the kinetics of engraftment or the incidence and severity of graft-versus-host disease (GVHD). Methods: Twenty-seven patients undergoing allogeneic transplantation were randomised to receive BM or BM supplemented by PBPC. Patients were conditioned with busulphan 16 mg/kg and cyclophosphamide 120 mg/kg. GVHD prophylaxis was with methotrexate and cyclosporin. Ganciclovir prophylaxis was administered to all cytomegalovirus seropositive patients. No haemopoietic growth factor was used after BMT. Donors of PBPC underwent a single, seven litre apheresis after four days of filgrastim, 10 μg/kg/day by subcutaneous injection. Results: Donor toxicity was mild, with the most frequently reported being bone pain in the cytokine-treated donors. The patients transplanted with BM+PBPC received an eight-fold increase in CD3+ T-lymphocytes (1.65X10⁸kg vs 0.22×10⁸/kg, p=0.04) and the cytokine product contained a median of 5×10⁶ CD34+ cells/kg. BM+PBPC patients had more rapid engraftment of neutrophils to 0.5×10⁹/L (17 days vs 19 days, p=0.02) and platelets to 50×10⁹/L (22 days vs 35 days, p=0.04). BM megakaryocyte numbers were significantly enhanced at days 14 and 28 after BMT (both p=0.04), however platelet transfusions were not significantly different. The incidence, organ distribution, severity and time to onset of acute and chronic GVHD were not different between the treatment groups and there was no difference in overall survival or event-free survival. Conclusions: Allogeneic PBPC from HLA-identical siblings may speed engraftment of neutrophils and platelets without detrimental effects on GVHD or survival.     

High-dose ara-C with autologous peripheral blood progenitor cell support induces a marked progenitor cell mobilization: an indication for patients at risk for low mobilization

A high-dose (HD) chemotherapy scheme was designed for the collection of large numbers of peripheral blood progenitor cells (PBPC) in lymphoma patients who were candidates for myeloablative therapy with autograft. The scheme included the sequential administration of HD cyclophosphamide (CY) (7 g/m(2)) and HD ara-C (2 g/m(2) twice a day for 6 consecutive days), followed by final consolidation with PBPC autograft. PBPC harvests were scheduled following both HD CY and HD ara-C. To minimize hematologic toxicity, small aliquots of PBPC (20 circulating CD34(+) cells/microl, whereas the remaining 19 'low-mobilizer' patients did not reach this cut-off value. In spite of poor mobilization after HD CY, 16 out of 19 low mobilizers provided good harvests following HD ara-C; overall, median collected CD34(+) cells x 10(6)/kg were 1.4 (0-3.1) and 10.2 (0-37) after HD CY and HD ara-C, respectively (P = 0.00007). Similar patterns were observed when PBPC were evaluated by CFU-GM/kg. Complete and durable hemopoietic reconstitution followed autograft with post HD ara-C PBPC. Within the high-mobilizer group, 88 patients received HD ara-C and 79 (90%) still showed high mobilization; overall, median collected CD34(+)cells x 10(6)/kg were 17.8 (range 3-94) and 19 (range 0-107) after HD CY and HD ara-C respectively (P = NS). Thus, the scheme allowed sufficient PBPC collections for autografting in low mobilizer patients; in addition, the scheme could be considered whenever extensive chemotherapy debulking is needed prior to PBPC collection.