Peripheral blood stem cell mobilization by cytokines

Hematopoietic stem cells circulate in the peripheral blood. These cells can be collected by apheresis techniques either in the unperturbed state, after mobilization following the administration of cytokines like G-CSF or GM-CSF, or during the phase of early blood count recovery following chemotherapy-induced myelosuppression. The number of cells collected following mobilization is greater than that obtained after apheresis in the unperturbed state. There are, however, qualitative differences between unperturbed and mobilized cells. Chemotherapy related mobilization can be potentially dangerous in that severe myelosuppression necessary to achieve mobilization can have serious consequences. There are no controlled studies that evaluate the relative merits of each method of collection. Regardless of the techniques employed peripheral blood stem cells can reliably accelerate hematologic recovery after potentially myeloblative therapy and provide an alternative to bone marrow support. © 1992 Wiley-Liss, Inc.     

Peripheral blood stem cell mobilization by chemotherapy with and without recombinant human granulocyte colony-stimulating factor.

Chemotherapy can serve as a stimulus for mobilizing hematopoietic progenitor cells to the peripheral blood for harvest via leukapheresis. Mobilized peripheral blood stem cells (PBSC) support rapid hematologic reconstitution after bone marrow aplasia induced by intensive myelosuppressive treatments. Our purpose was to develop effective mobilization regimens allowing collection of large quantities of PBSC. We administered high-dose cyclophosphamide (HDC, 4 gm/m2) or cyclophosphamide (4 gm/m2) plus etoposide (600 mg/m2) (HDCE) in a nonrandomized, sequential fashion to 94 patients with breast cancer, lymphoma, and other malignancies with collection of PBSC via leukapheresis during white blood cell (WBC) recovery from nadir counts. Each apheresis product was analyzed for total nucleated cell number, granulocyte-macrophage colony-forming units (CFU-GM) and CD34+ cells. Twenty-four additional patients with comparable pretreatment characteristics received HDCE plus recombinant human granulocyte colony-stimulating factor (HDCE+G) after chemotherapy through the end of apheresis. Patients receiving HDC were matched for age, sex, and disease but were more heavily pretreated. HDCE was superior to HDC in mean daily CFU-GM and CD34+ yield (p < 0.05), even when groups were adjusted for performance status and amount of prior therapy. HDCE+G led to 3.7 times more CFU-GM and 4.7 times more CD34+ cells than HDCE. Target PBSC yield, defined as > 20 x 10(4) CFU-GM/kg and >4 x 10(8) cells/kg, was achieved by 92% of HDCE+G patients after a median of three aphereses, 56% of HDCE patients after five aphereses, and 16% of HDC patients after six apheresis (p < 0.0001). Prior chemotherapy inversely correlated with the quantity of PBSC harvested regardless of regimen utilized. Our results demonstrate effective chemotherapy regimens for harvesting hematopoietic progenitors in a diverse patient population. HDCE+G produced the highest number of progenitors, suggesting that increasing dose intensity and adding rhG-CSF enhances mobilization. Correlation between cumulative CD34+ and CFU-GM allows real-time flow cytometric analysis of the number of aphereses required to harvest target numbers of PBSC.     

Peripheral blood cell repopulation following high-dose cyclophosphamide.

High-dose cyclophosphamide can be used to obtain haematological stem cells from the peripheral blood. In this paper we analyse the dynamics of appearance of cells with these characteristics, together with the impact of this drug on the immunological system. Cyclophosphamide seems to possess immunomodulating effects even at high doses.     

Management strategies for poor peripheral blood stem cell mobilization.

Peripheral blood stem cells (PBSC) have nearly replaced bone marrow (BM) as the preferred source of hematopoietic rescue for patients undergoing high-dose chemotherapy. However, some patients fail to mobilize sufficient numbers of PBSC into the peripheral blood thereby putting high-dose chemotherapy at risk. The present article reviews mobilization of PBSC with a special focus on poor mobilizers. Under steady-state conditions less than 0.05% of the white blood cells (WBC) are CD34+ cells. Chemotherapy results in a 5-15-fold increase of PBSC. Combining chemotherapy and growth factors increases CD34+ cells up to 6% of WBC. Several factors affect the mobilization of PBSC: age, gender, type of growth factor, dose of the growth factor and in the autologous setting patient's diagnosis, chemotherapy regimen and number of previous chemotherapy cycles or radiation. Poor mobilizers are defined as patients with less than 10 CD34+ cells/mul in the peripheral blood during mobilization. Promising approaches for those patients rely on remobilization, use of high doses of granulocyte-colony stimulating factor (G-CSF), or the combination of G-CSF and granulocyte macrophage (GM)-CSF, which successfully mobilized the majority of poor mobilizing patients. New agents such as long lasting variants of G-CSF and CXCR4 antagonists are at the horizon and studied in clinical trials as mobilizing agents. Muscle and bone pain are frequent adverse events in stem cell mobilization but are usually tolerated under the use of analgesics. Large volume apheresis (LVL) with a processed volume of more than 4-fold patient's blood volume is an approach to increase the CD34+ yield in patients with low CD34+ pre-counts resulting in higher yields of CD34+ cells for transplantation. Processing of more blood in LVL is achieved by an increase of the blood flow rate and an altered anticoagulation regimen with the occurrence of more citrate reactions.     

Infectious complications in patients receiving mobilization chemotherapy for autologous peripheral blood stem cell collection

The purpose of this retrospective study was to evaluate infectious complications in patients receiving mobilization chemotherapy for stem cell collection prior to autologous peripheral blood stem cell transplantation. An additional goal was to evaluate risk factors associated with the development of infectious complications. At the Medical College of Georgia BMT center, 54 patients were administered mobilization chemotherapy for the purpose of collecting stem cells between June, 1997, and May, 2002. All patients received Filgrastim in addition to chemotherapy, and 50 of 54 patients received prophylactic acyclovir, fluconazole, and ciprofloxacin until neutrophil recovery. The median duration to neutrophil recovery was 11 days. Fourteen of 54 (26%) patients developed fever/infections during the mobilization phase. One patient developed both a catheter-related infection and Clostridium difficile colitis, increasing the total number of infectious episodes to 15. Twelve patients had a documented site of infection whereas 2 patients had neutropenic fever with no identifiable source. Eight of the 15 (55%) infections were Gram-positive catheter infections. All the patients were treated successfully with antibiotics. No systemic fungal infections were identified and none of the patients died from complications related to mobilization chemotherapy. Logistic regression was applied for univariate and multivariate analysis and showed that age, sex, diagnosis, neutrophil recovery, disease status, use of salvage chemotherapy, and mobilization regimen used did not affect the infection rate. In our series of 54 patients, 14 patients developed fever/infections during mobilization. Although there is a substantial risk of infectious complications among patients who receive mobilization chemotherapy, it is not clear that prophylactic antibiotics decrease infectious complications. Because the vast majority of infections are Gram-positive catheter infections, it appears reasonable to employ Gram-positive prophylaxis. Controlled studies should be conducted to define the optimum mobilization regimens as well as the optimum combination of prophylactic antibiotics.     

Peripheral blood hematopoietic stem cell mobilization and collection efficacy is not an independent prognostic factor for autologous stem cell transplantation

BACKGROUND: The successful mobilization and collection of hematopoietic stem cells are dependent on a number of clinical factors such as previous chemotherapy and disease stage. The aim of this retrospective study was to determine whether the effectiveness of mobilization and collection is an independent prognostic factor for autologous stem cell transplantation outcome. STUDY DESIGN AND METHODS: A total of 358 patients who received transplants from January 2003 to December 2004 (201 male and 157 female patients, ages from 2.7 to 77.3 years with median of 53 years of age) underwent autologous hematopoietic stem cell collection after mobilization with granulocyte-colony-stimulating factor (G-CSF) or G-CSF plus chemotherapy priming. This retrospective study included patients with diagnoses of acute myelogenous leukemia, non-Hodgkin's lymphoma, Hodgkin's disease, multiple myeloma, and solid tumors. All patients underwent stem cell collection until a target or a minimum CD34+ cell dose was reached. Correlations were performed between stem cell mobilization and/or collection efficacy and transplantation outcomes. RESULTS: In general, both larger reinfused CD34+ cell dose and shorter number of days for the stem cell count to reach the minimum of 2 x 10(6) per kg CD34+ cells do not foster quicker engraftment. Reinfused CD34+ cell dose of less than 12 x 10(6) and number of days stem cell collection to reach this minimum CD34+ cell dose did not independently affect the overall survival (OS) or disease-free survival (DFS). CONCLUSION: The effectiveness of hematopoietic stem cell mobilization and collection as defined as number of days to reach a CD34+ cell dose of 2 x 10(6) per kg should not be used independently to forecast posttransplantation prognosis, engraftment, DFS, and OS.     

Peripheral blood stem cell collection with a blood cell separator

Forty-three patients with malignant nonmyeloid diseases underwent peripheral blood stem cell collections on an apheresis system (Spectra, COBE BCT, Lakewood, CO). Collections took place during the white cell (WBC) recovery phase following conditioning chemotherapy. One hundred two procedures were done after chemotherapy alone, and 72 procedures after chemotherapy plus granulocyte-colony-stimulating factor (G-CSF). Four centrifugal separation factors were tested. One and one-half patient blood volumes were processed in each procedure. The mean volume of the collected component was 158 +/− 16 mL. After chemotherapy alone, the procedures provided a mean of 0.8 × 10(8) WBCs per kg and 2.3 × 10(4) colony-forming units-granulocyte macrophage (CFU-GM) per kg of recipient body weight. The mononuclear cell percentage in the components increased with the centrifugal separation factor from 85 to 96 percent. In parallel, platelet contamination increased from 2.1 to 3.8 × 10(11). The collect hematocrit ranged from 1.0 to 2.5 percent (0.01-0.025). The collection efficiency for mononuclear cells and CFU- GM also increased with the centrifugal separation factors from 52 to 70 percent for mononuclear cells and from 55 to 68 percent for CFU-GM. Collections performed after G-CSF-stimulated mobilization were characterized by a higher neutrophil contamination independent of centrifugal separation factor, which gave a mean mononuclear cell percentage of 64 percent in the collected component. The average yield for these procedures was 2 × 10(8) WBCs per kg and 28 × 10(4) CFU-GM per kg.(ABSTRACT TRUNCATED AT 250 WORDS)     

Thrombotic microangiopathy during peripheral blood stem cell mobilization

Granulocyte colony‐stimulating factor (GCSF) is currently the most widely used cytokine for stem cell mobilization. There are few studies suggesting GCSF administration may induce activation of both coagulation and endothelial cells that could favor the developing of thrombotic events. We report a 58‐year‐old female with vasculitis and renal impairment. She was found to have an underlying monoclonal gammopathy of unknown significance (MGUS). The monoclonal protein was felt to play a role in her underlying renal disease and peripheral neuropathy. She was considered a candidate for peripheral blood stem cell transplantation to manage the monoclonal protein. During stem cell mobilization with GCSF, she developed worsening of anemia; thrombocytopenia and worsening of renal function. She was diagnosed with thrombotic microangiopathy (TMA) which was successfully treated with therapeutic plasma exchange and rituximab. It is possible that GCSF may have directly (activating endothelial cells) or indirectly (activation of underlying autoimmune disorder) contributed to TMA in this patient. J. Clin. Apheresis 2009. © 2009 Wiley‐Liss, Inc.     

儿童外周血造血干细胞采集

目的　探索儿童外周血干细胞 (PBSC)的采集 ,特别是体重 <2 0kg的小儿外周血干细胞采集方法。方法　 18例儿童 ,共 31次采集PBSC。①年龄小 ,血管细和不能很好地配合的儿童患者 ,在PBSC采集的前 1d ,根据患者的情况 ,选择性行锁骨下静脉、股静脉或颈内静脉穿刺 ,插入一儿童型双腔管 (18～ 36cm) ;②采集儿童PBSC时 ,使用SVSC分离槽和SVCC收集槽 ,体重 <2 0kg的小儿 ,在初始化完成后 ,使用经射线照射过的血液预先运转分离机 ,使儿童体内的血液保持平衡 ;③在分离过程中 ,ACD/全血的比例保持在 1∶11～ 1∶13之间 ;④成人的PBSC采集一般循环量为 10 0 0 0～ 15 0 0 0ml,儿童为全身血容量的 2～ 3倍 ,每次处理血液总量为 4 80 0～ 10 0 0 0ml。结果　除 2例采集 3次外 ,其余的经 1～ 2次PBSC采集 ,均收集到足够的MNC和CD3 4 细胞 ,达到外周血干细胞移植的阈值要求。结论　使用本方法能很好地采集儿童外周血造血干细胞。     

Predictive parameters for granulocyte colony-stimulating factor-induced peripheral blood stem cell mobilization

To improve the selection of donors for allogeneic stem cell transplantation, it is important to identify reliable parameters that predict CD34+-cell yields after granulocyte-colony stimulating factor (G-CSF)-induced peripheral blood stem cell (PBSC) mobilization. We retrospectively investigated the peripheral blood (PB) kinetics of white blood cells (WBCs), CD34+ cells, matrix metalloproteinases (MMP)-9 and -2, and tissue inhibitors of metalloproteinases (TIMP)-1 and -2 in 15 healthy donors during their treatment with G-CSF. All donors received 10 microg/kg of recombinant human G-CSF once a day subcutaneously. Leukapheresis was initiated after 4 days of G-CSF treatment, and G-CSF treatment continued until the last day of leukapheresis. WBC and CD34+ cell numbers in the PB rose after 2 and 3 or 4 days of G-CSF treatment, respectively. The PB CD34+ cell numbers on day 4 correlated weakly with the increase in WBC counts from day 1 to day 2 (R(2) = 0.254, P = 0.056). There were also positive correlations between the CD34+ cell numbers in the PBSC products on day 4 and the CD34+ cells in the PB on days 1 and 4 (R(2) = 0.768, P < 0.0001 and R(2) = 0.816, P < 0.0005, respectively). The MMP-9 plasma levels on days 1 and 4 also correlated positively with the day 4 circulating CD34+ cell numbers (R(2) = 0.393, P < 0.05 and R(2) = 0.406, P = 0.01, respectively). In conclusion, the CD34+ cell numbers in the PB steady state may be a useful parameter selecting allogeneic PBSC donors.     

外周血干细胞动员研究现状

外周血干细胞(PBSC)因其获取便利,已广泛应用于临床造血干细胞移植.迄今已有大量研究阐明造血干细胞(HSC)骨髓定植机制,以及如何通过扰乱这种机制促使HSC释放于外周血中,并已发现用于PBSC动员的新一代药物--普乐沙福(Plerixafer)与甲状旁腺素(PTH)等联合G-CSF用于PBSC动员,大大提高了动员效率,其中Plerixafer已被FDA批准用于临床.     

短程大剂量粒细胞集落刺激因子动员外周血造血干细胞的研究

研究短程大剂量粒细胞集落刺激因子对外周血造血干细胞的动员作用。方法采用短程大剂量Ｇ－ＣＳＦ对１１例患者进行外周血造血干细胞动员，Ｇ－ＣＳＦ５μｇ／ｋｇ皮下注射，每日２次，共３天，动员当天及第４天，分别取骨髓及外周血增生明显活跃，外周血白细胞计数明显升高。     

Cyclophosphamide mobilization of peripheral blood stem cells for use in autologous transplantation after high-dose chemotherapy: clinical results in patients with contaminated or hypocellular bone marrow.

Peripheral blood stem cells (PBSC) can be used for hematopoietic reconstitution in patients who have received high-dose chemotherapy (HDC). Previously, we reported 18 such patients who had nonmobilized PBSC harvested in steady state. We have now performed PBSC reinfusion in 24 patients with hypocellular or tumor-involved marrow who received cyclophosphamide (Cy) mobilization (4 grams/m2) prior to PBSC collection. The PBSC were collected upon rebound hematopoietic recovery by continuous-flow leukapheresis and subsequently cryoproserved. A median of 3.17 x 10(8) mononuclear cells/kg (range 1.47-3.95 x 10(8)) were collected. Patients underwent a median of 6 apheresis procedures (range 5-12). To date all 24 patients have undergone PBSC reinfusion after HDC. Fourteen patients received post-reinfusion granulocyte/macrophage colony-stimulating factor. Granulocyte recovery (> 500 x 10(6)/ml) has occurred at a median of 13.5 days (range 7-39) and platelet recovery (> 50 x 10(9)/ml without transfusion support) has occurred in 20 patients at a median of 33 days (range 7-121 days). Four other patients have platelet counts of greater than 20K and are transfusion independent, but have still not achieved counts of 50K. PBSC collection after Cy mobilization is feasible and effective for hematopoietic reconstitution after HDC and reinfusion. All 24 patients demonstrated trilineage engraftment. Although neutrophil recovery was not significantly hastened (as compared with our nonmobilized or steady-state data), time to platelet engraftment was foreshortened.     

Novel strategies for blood stem cell mobilization: special focus on plerixafor

Introduction: More than 98% of autologous stem cell transplants are now performed with the support of mobilized blood stem cells, and the proportion of allogeneic blood stem cell transplants has risen to more than 70%. Blood stem cell mobilization strategies are therefore important components of all transplant programs.

Areas covered: Stem cell mobilization strategies are evaluated based on current literature, with special focus on the use of plerixafor, a CXCR4 chemokine receptor antagonist. Mobilization methods in autologous settings include the use of G-CSF alone or following chemotherapy (chemomobilization), and the use of G-CSF alone in allogeneic transplants. A combination of G-CSF + plerixafor has been shown to be effective in patients who have failed a previous mobilization. This combination has also been found to be superior to G-CSF alone in Phase III studies in myeloma and non-Hodgkin lymphoma patients as the first-line mobilization.

Expert opinion: Addition of plerixafor to chemomobilization or G-CSF mobilization may be more cost-effective than its routine use, and it is worth considering in predicted or proven poor mobilizers. Novel mobilization strategies have allowed more successful stem cell collection in autologous setting, although the effect of plerixafor on graft content and long-term patient outcomes needs further investigation.     

Novel strategies for blood stem cell mobilization: special focus on plerixafor

INTRODUCTION: More than 98% of autologous stem cell transplants are now performed with the support of mobilized blood stem cells, and the proportion of allogeneic blood stem cell transplants has risen to more than 70%. Blood stem cell mobilization strategies are therefore important components of all transplant programs. AREAS COVERED: Stem cell mobilization strategies are evaluated based on current literature, with special focus on the use of plerixafor, a CXCR4 chemokine receptor antagonist. Mobilization methods in autologous settings include the use of G-CSF alone or following chemotherapy (chemomobilization), and the use of G-CSF alone in allogeneic transplants. A combination of G-CSF + plerixafor has been shown to be effective in patients who have failed a previous mobilization. This combination has also been found to be superior to G-CSF alone in Phase III studies in myeloma and non-Hodgkin lymphoma patients as the first-line mobilization. EXPERT OPINION: Addition of plerixafor to chemomobilization or G-CSF mobilization may be more cost-effective than its routine use, and it is worth considering in predicted or proven poor mobilizers. Novel mobilization strategies have allowed more successful stem cell collection in autologous setting, although the effect of plerixafor on graft content and long-term patient outcomes needs further investigation.     

Antiemetic therapy for multiple-day chemotherapy and high-dose chemotherapy with stem cell transplant: review and consensus statement

The objective of this paper is to evaluate the efficacy of modern antiemetic therapy for chemotherapy-induced nausea and vomiting for patients receiving multiple-day or high-dose chemotherapy. Published phase II and phase III studies as well as their personal experiences were evaluated by the authors to develop this consensus statement. The largest published experience with multiple-day chemotherapy is with 5-day cisplatin combination chemotherapy. The introduction of 5-HT3 antagonists greatly improved emetic control. However, day 4–5 nausea as well as delayed nausea and vomiting remains a clinical problem despite the inclusion of dexamethasone. A 5-HT3 antagonist plus dexamethasone is the preferred current option for patients receiving high-dose chemotherapy with stem cell transplant. However, the results do not appear as successful as for highly emetic standard-dose chemotherapy.     

Peripheral blood stem cell collection from healthy donors for allogeneic transplantation

There is great interest in the use of peripheral blood stem cells (PBSC) for allogeneic transplantation, based on the good results seen with autologous PBSC infusion. Reasonable caution exists regarding the use of allogeneic PBSC for transplantation because of donor toxicities due to rhG-CSF administration and the risk of graft-versus-host-disease (GVHD) in the recipient because of the large number of T-cell infused. We present preliminary data on allogeneic PBSC collections and transplantation in ten patients affected by advanced leukemia (eight patients), severe aplastic anemia (one patient) and sickle cell anemia (one patient). Seven donors were HLA-identical siblings, while the other three were mismatched for three, two and one locus, respectively. All donors received rhG-CSF at a dose of 12 micrograms/kg for a mean of 5 days. Leukaphereses were performed with the aim of collecting a minimum of 5 x 10(6)/kg (recipient's weight) CD 34+ cells. Collection timing was determined by monitoring CD 34+ cells in the donor's peripheral blood from the second day of rhG-CSF therapy. The PBSC collections yielded a mean of 10.05 x 10(8) MNCs/kg and of 10.48 x 10(6) CD 34+ cells/kg (recipient's weight). PBSC were immediately infused after collection in patients given myeloablative therapy. Engraftment was observed in each patient at a mean of 13.2 days for an absolute neutrophil count (ANC) more than 0.5 x 10(9)/L and of 26.5 days for a platelet count of more than 20 x 10(9)/L. Eight patients experienced no or moderate acute GVHD, whereas two patients died of grade 4 GVHD, notwithstanding GVHD prophylaxis with cyclosporine and prednisone. Two other patients died of viral and fungal infections, respectively, despite prophylaxis. The remaining six patients are alive between 58 and 430 days after transplant. Our results document that allogeneic PBSC are capable of engraftment after a myeloablative regimen. Controlled trials are necessary to compare the potential benefits of this approach with the results obtained in allogeneic bone marrow transplantation.