Mobilization of peripheral blood stem cells

The effect of serum lipid levels on peripheral blood hematopoietic stem cell levels

INTRODUCTION

There are limited numbers of available retrospective studies on various hematological diseases treated with stem cell mobilization therapy. In the present study, we aimed to demonstrate the effects of serum lipid levels on peripheral blood CD34+ (PBCD34+) cell counts as well as the changes in serum lipid levels during stem cell mobilization process.

METHOD

PBCD34+ cell counts were compared between hypercholesterolemic patients and healthy individuals. Additionally, total cholesterol (TChol), LDL-cholesterol (LDL-C), HDL-cholesterol (HDL-C), and triglyceride (TG) levels were measured from healthy donors who underwent stem cell mobilization, at different time points (prior to filgrastim [phase 1], prior to apheresis [phase II], and the first week following apheresis [phase III].

RESULTS

In the hypercholesterolemia group, the PBCD34+ cell count was found to be higher among patients with elevated LDL-C (2.6 ± 0.35/μL vs. 1.7 ± 0.17/μL, p = 0.003) and TChol (2.6 ± 0.34/μL vs. 1.7 ± 0.14/μL, p = 0.006) in comparison to the healthy controls. In the mobilization group, phase II HDL-C levels (35.3 ± 2.8 mg/dL) were found to be lower than both phase I (45.6 ± 2.1 mg/dL) and phase III (44.5 ± 2.6 mg/dL) (p = 0.007). Phase II TChol levels (183.5 ± 10.0 mg/dL) were lower than both phase I (216.8 ± 8.5 mg/dL) and phase III (212.2 ± 8.4 mg/dL) (p = 0.02). At phase II, there was an inverse correlation between PBCD34+ cell count and HDL-C (r = - 0.57, p = 0.003).

DISCUSSION

Our results indicate that, while increased LDL-C level is the determinant of baseline PBCD34+ cell count, reduced HDL-C is the determinant of PBCD34+ cell count during mobilization process.

Is It Better to Mobilize Hematopoietic Stem Cells With Pegfilgrastim in Healthy Donors During Allogeneic Hematopoietic Stem Cell Transplantation?

The mobilization of hematopoietic stem cells (HSCs) using granulocyte colony-stimulating factor is a classic method. Recently, a single injection of pegfilgrastim was used to mobilize CD34+ cells in some small-sample studies. To confirm the efficacy and safety of pegfilgrastim in the mobilization of CD34+ cells from healthy donors, we conducted a retrospective multicenter study. A total of 146 healthy donors who all received subcutaneous pegfilgrastim (12 mg) on day 1 were enrolled in our study. Donor HSC apheresis was conducted on day 5. The primary endpoint was the percentage of donors from whom ≥4 × 10⁶ CD34+ cells/kg were collected in a single apheresis session. The median number of CD34+ cells in donors was significantly higher on day 5 than that on day 4 (82.26 μL vs. 51.65 μL, P ¡ 0.001). In 111 of the 146 donors, an optimal number of CD34+ cells (≥4 × 10⁶ kg) were collected in a single apheresis procedure. Bone pain and headache were the main adverse events, but the side effects did not require treatment. The number of white blood cells in most donors dropped to normal levels within 1 week after apheresis. Nearly 97% of patients achieved neutrophil and platelet engraftment. Pegfilgrastim for mobilization could be used to obtain an optimal number of CD34+ cells in a single session. Pegfilgrastim-induced mobilization not only was effective and safe but also avoided the pain of multiple injections and apheresis procedures in donors. However, prospective randomized controlled trials should be conducted in the future.

Expression of adhesion molecules on CD34+ cells from steady-state bone marrow before and after mobilization and their association with the yield of CD34+ cells

Background

Cell adhesion molecules (CAMs) expressed on hematopoietic progenitor cells (HPCs), endothelial cells, and stromal cells play a pivotal role in the mobilization of CD34+ cells. Herein, we conducted a non-randomized peripheral blood stem cell (PBSC) mobilization study aimed to compare the potential differences in the expressions of several CAMs and chemokines on CD34+ cells obtained from bone marrow aspirate before and after HPC mobilization from patients with hematologic malignancies and healthy donors.

Methods

Three-color cytofluorometric analysis was used to compare the expressions of CAMs and chemokines in the bone marrow before and after mobilization.

Results

For all studied groups, CAM expression among those with good and poor yields of CD34+ cells was significantly correlated with VCAM-1 (P=0.007), CD44 (P=0.027), and VLA-4 (P=0.014) expressions. VCAM-1 (P=0.001), FLT-3 (P=0.001), CD44 (P=0.011), VLA-4 (P=0.001), and LFA-1 (P=0.001) expressions were higher before HPC mobilization than after HPC mobilization. By contrast, the expression of CXCR4 significantly varied before and after mobilization only among those with successful PBSC mobilization (P=0.002).

Conclusion

We attempted to identify particular aspects of CAMs involved in CD34+ cell mobilization, which is a highly complex mechanism that involves adhesion molecules and matrix metalloproteases. The mechanism by which CD34+ cell mobilization is activated through proteolytic enzymes is not fully understood. We believe that CXCR4, VLA-4, CD44, and VCAM-1 are the most important molecules implicated in HPC mobilization, particularly because they show a correlation with the yield of CD34+ cells collected via large volume leukapheresis.

Angiopoietins in haematopoietic stem cell mobilisation in patients with haematological malignancies

BACKGROUND

The bone marrow niche contains different types of cells including osteoblasts and endothelial progenitors, all of which interact and take part in the process of mobilisation. The aim of our study was to evaluate the levels of cytokines (osteopontin and angiopoietins 1 and 2) active in the bone marrow niche during the mobilisation of haematopoietic stem cells for autologous transplantation.

MATERIALS AND METHODS

Forty-eight patients (24 females, 24 males), median age 56.5 years, entered the study. The group consisted of patients with multiple myeloma (n=34), lymphoma (n=13) and acute myeloid leukaemia (n=1). Blood samples were collected before chemotherapy and on the day of the first apheresis. Cytokines were evaluated by enzyme-linked immunosorbent assays. Additionally, circulating endothelial cells were assessed by flow cytometry.

RESULTS

The median concentration of angiopoietin 1 at the time of apheresis was lower than that at baseline (2.7 vs 7.8 ng/mL, p<0.001). In contrast, the median level of angiopoietin 2 increased during the mobilisation procedure (3.6 vs 2.8 ng/mL, p=0.001). The patients were divided according to the number of days of granulocyte colony-stimulating factor treatment before the first apheresis into "early" (<median=11 days) and "late" (>median) mobilisers. The group of "early mobilisers" had higher baseline angiopoietin 1 levels (median=11.6 ng/mL) than those of the "late mobilisers" (median=6.0 ng/mL, p=0.05). An adverse correlation was observed between duration of granulocyte colony-stimulating factor treatment and baseline angiopoietin 1 level. Baseline angiopoietin 1 levels correlated with numbers of circulating endothelial cells. Low angiopoietin 2 level increased the chance of poor mobilisation.

CONCLUSIONS

The angiogenic processes can influence the timing of mobilisation. Angiopoietins 1 and 2 need further evaluation in the context of mobilisation.

Analysis of the feasibility of early hospital discharge after autologous hematopoietic stem cell transplantation and the implications to nursing care

Introduction

Autologous hematopoietic stem cell transplantation is a conduct used to treat some hematologic diseases and to consolidate the treatment of others. In the field of nursing, the few published scientific studies on nursing care and early hospital discharge of transplant patients are deficient. Knowledge about the diseases treated using hematopoietic stem cell transplantation, providing guidance to patients and caregivers and patient monitoring are important nursing activities in this process. Guidance may contribute to long-term goals through patients’ short-term needs.

Aim

To analyze the results of early hospital discharge on the treatment of patients submitted to autologous transplantation and the influence of nursing care on this conduct.

Methods

A retrospective, quantitative, descriptive and transversal study was conducted. The hospital records of 112 consecutive patients submitted to autologous transplantation in the period from January to December 2009 were revisited. Of these, 12 patients, who remained in hospital for more than ten days after transplantation, were excluded from the study.

Results

The medical records of 100 patients with a median age of 48.5 years (19–69 years) were analyzed. All patients were mobilized and hematopoietic stem cells were collected by leukapheresis. The most common conditioning regimes were BU12Mel100 and BEAM 400. Toxicity during conditioning was easily managed in the outpatient clinic. Gastrointestinal toxicity, mostly Grades I and II, was seen in 69% of the patients, 62% of patients had diarrhea, 61% of the patients had nausea and vomiting and 58% had Grade I and II mucositis. Ten patients required hospitalization due to the conditioning regimen. Febrile neutropenia was seen in 58% of patients. Two patients died before Day +60 due to infections, one with aplasia. The median times to granulocyte and platelet engraftment were 12 days and 15 days, respectively, with median red blood cell and platelet transfusions until discharge of three and four units, respectively. Twenty-three patients required rehospitalization before being discharged from the outpatient clinic.

Conclusion

The median time to granulocyte engraftment was 12 days and during the aplasia phase few patients were hospitalized or suffered infections. The toxicity of the conditioning was the leading cause of rehospitalization. The nursing staff participated by providing guidance to patients and during the mobilization, transplant and outpatient follow-up phases, thus helping to successfully manage toxicity.

Risk factors for a poor hematopoietic stem cell mobilization

Poor mobilization is an important problem in autologous stem cell transplantation. We retrospectively reviewed the data of 165 mobilized patients to identify possible risk factors for a poor stem cell mobilization. 27 patients (16.4%) were categorized as poorly mobilized. The poor mobilization ratio differed according to diagnosis (lymphoma: 25.4%, acute leukemia: 15.4%, amyloidosis: 14.3%, and multiple myeloma: 9.6%). Being diagnosed as lymphoma (odds ratio [OR]=6.02, p=0.001), advanced age (OR=1.05, p=0.007) and increased weight (OR=1.03, p=0.03) were found as possible risk factors. Being diagnosed as lymphoma was shown to be the most important risk factor for a poor mobilization. Leukapheresis staff should be aware of the increased risk of a poor mobilization in lymphoma patients and remobilization methods should be considered from the beginning.

The effect of granulocyte colony stimulating factor receptor gene missense single nucleotide polymorphisms on peripheral blood stem cell enrichment

Granulocyte-colony stimulating factor (G-CSF) has become the most effective agent supporting hematopoietic stem cell transplantation (HSCT). The cognate interaction between G-CSF and its specific receptor, G-CSFR, induces the mobilization of HSCs and increases their pool in the peripheral blood. G-CSFR has a highly conserved structure which may be functionally modulated by the presence of missense single nucleotide polymorphisms (SNPs). In this study, we asked whether the missense SNPs in G-CSFR could affect the response to G-CSF in HSCT patients and donors. Here, for the first time, G-CSFR missense SNPs were screened and minor allele frequencies were determined in a specific population with Turkish racial background. Five (rs3917991, rs3918001, rs3918018, rs3918019, and rs146617729) out of 16 missense SNPs screened were determined with minor allele frequencies lower than 0.04. Subsequent association analyses indicated potential impact of rs3918001, rs3918018, and rs3918019 minor alleles on peripheral blood CD34(+) cell enrichment. Although their frequency is rather low, certain missense SNPs, especially which are placed in the conserved regions of G-CSFR may possess the capacity to influence the response to G-CSF treatment.

Efficient removal of platelets from peripheral blood progenitor cell products using a novel micro-chip based acoustophoretic platform

Background

Excessive collection of platelets is an unwanted side effect in current centrifugation-based peripheral blood progenitor cell (PBPC) apheresis. We investigated a novel microchip-based acoustophoresis technique, utilizing ultrasonic standing wave forces for the removal of platelets from PBPC products. By applying an acoustic standing wave field onto a continuously flowing cell suspension in a micro channel, cells can be separated from the surrounding media depending on their physical properties.

Study Design and Methods

PBPC samples were obtained from patients (n = 15) and healthy donors (n = 6) and sorted on an acoustophoresis-chip. The acoustic force was set to separate leukocytes from platelets into a target fraction and a waste fraction, respectively. The PBPC samples, the target and the waste fractions were analysed for cell recovery, purity and functionality.

Results

The median separation efficiency of leukocytes to the target fraction was 98% whereas platelets were effectively depleted by 89%. PBPC samples and corresponding target fractions were similar in the percentage of CD34+ hematopoetic progenitor/stem cells as well as leukocyte/lymphocyte subset distributions. Median viability was 98%, 98% and 97% in the PBPC samples, the target and the waste fractions, respectively. Results from hematopoietic progenitor cell assays indicated a preserved colony-forming ability post-sorting. Evaluation of platelet activation by P-selectin (CD62P) expression revealed a significant increase of CD62P+ platelets in the target (19%) and waste fractions (20%), respectively, compared to the PBPC input samples (9%). However, activation was lower when compared to stored blood bank platelet concentrates (48%).

Conclusion

Acoustophoresis can be utilized to efficiently deplete PBPC samples of platelets, whilst preserving the target stem/progenitor cell and leukocyte cell populations, cell viability and progenitor cell colony-forming ability. Acoustophoresis is, thus, an interesting technology to improve current cell processing methods.

Advances in mobilization for the optimization of autologous stem cell transplantation

In autologous stem cell transplantation, mobilized peripheral blood has replaced the bone marrow as the preferred source of hematopoietic stem cells (HSCs). Because HSCs normally exist in the blood in very low numbers, the use of agents to "mobilize" HSCs from the marrow niche to the peripheral blood is essential for successful transplantation. Until recently, granulocyte colony-stimulating factor (G-CSF) and granulocyte-macrophage colony-stimulating factor were the only approved agents by the US Food and Drug Administration for use as peripheral blood stem cell (PBSC)-mobilizing agents in the United States, but G-CSF has become the gold standard. Unfortunately, some patients fail to mobilize sufficient numbers of PBSCs for transplantation in response to G-CSF with or without chemotherapy. Recently, a new agent, plerixafor (AMD3100) added to G-CSF has been approved to enhance PBSC mobilization. This review will discuss the current methodologies to improve hematopoietic stem cell mobilization.

Increased haematopoietic progenitor cells are associated with poor outcome in patients with metastatic renal cancer treated with sunitinib

BACKGROUND

Haematopoietic progenitor cells (HPCs) are present in blood in metastatic renal cell cancer (mRCC). We investigate their expression in mRCC patients treated with sunitinib and correlate their expression with plasma growth factor levels [insulin-like growth factor (IGF)-1].

METHODS

Circulating HPCs (CD34(+)/CD45(+)) and plasma IGF-1 levels were measured at specific sequential time points (0, 6, 18 and 28 weeks) in 43 untreated mRCC patients receiving sunitinib (50 mg for 28 days followed by 14-day off treatment). Univariate and multivariate analysis assessed the prognostic significance of HPCs and IGF-1.

RESULTS

HPCs levels were raised in 40 of 43 (93%) of patients. IGF-1 levels were raised in 9 of 43 patients (21%). Univariate and multivariate analysis revealed that high HPCs before treatment were associated with a significantly shorter overall survival (hazard ratio 3.3, 95% confidence interval 1.23-8.8, P=0.01), which was not the case for IGF-1 levels. Both HPC and IGF-1 levels fell with sunitinib (61% and 14% fall, respectively, P <0.05 for both). A positive correlation between the falls in HPC and IGF-1 occurred (P<0.001).

CONCLUSIONS

HPCs are over expressed in the peripheral blood in the majority of patients with mRCC. Higher levels are associated with poor prognosis. A concurrent fall in HPCs and growth factor expression (IGF-1) with sunitinib occurs.

Plerixafor: a peripheral blood stem cell mobilizer

Autologous hematopoietic stem cell (HSC) transplantation is a treatment strategy for restoring normal hematopoietic function in patients with select hematologic malignancies. The number of CD34(+) cells available for transplantation has been reported to be the strongest predictor of transplantation success, as measured by rapid and durable hematopoietic recovery. Currently, granulocyte colony-stimulating factor (G-CSF) alone or G-CSF plus chemotherapy are the most commonly used methods for stem cell mobilization. Unfortunately, 5-30% of patients do not respond to these agents. Plerixafor is a new HSC mobilizing drug that antagonizes the binding of chemokine stromal-cell-derived factor-1alpha (SDF-1alpha) to CXC chemokine receptor 4 (CXCR4). It is indicated in combination with G-CSF to mobilize HSC to the peripheral blood for collection and subsequent autologous transplantation in patients with non-Hodgkin's lymphoma (NHL) and multiple myeloma (MM). Results of clinical trials have shown that plerixafor plus G-CSF allow for the collection of a high yield of HSC with fewer apheresis sessions in patients with NHL and MM. Plerixafor has also shown promising results in small studies enrolling patients with Hodgkin's lymphoma. Moreover, for patients who fail G-CSF mobilization alone, plerixafor with G-CSF may be useful as a salvage mobilization strategy. Overall, plerixafor has been generally well tolerated with adverse effects classified as mild to moderate. The most common adverse effects reported in randomized clinical trials were injection site reactions and diarrhea, with approximately 33% of patients experiencing these effects. To our knowledge, clinical trials comparing G-CSF plus plerixafor with G-CSF plus chemotherapy and cost-effectiveness analyses have not been published; therefore, questions remain regarding the optimal role of plerixafor in the clinical practice setting.

Plasma levels of FL and SDF-1 and expression of FLT-3 and CXCR4 on CD34+ cells assessed pre and post hematopoietic stem cell mobilization in patients with hematologic malignancies and in healthy donors

Peripheral blood stem cells (PBSC) became the main source of cells for autologous transplantation. Alterations in the expression of adhesion molecules are essential in the CD34+ cells mobilization process. These molecules are involved in the interaction between hematopoietic and stromal cells and they have been disclosed as a considerable factor to the trafficking and homing of the CD34+ progenitor cells. This is a non-randomized PBSC mobilization study designed to evaluate the influence and behavior of FL and SDF-1 and their receptors in two different moments, prior and after HPCs mobilization, with the yield of CD34+ cells collected by apheresis. There was higher concentration of FL and lower of SDF-1 plasma level at post than pre PBSC mobilization (p=0.001 and p=0.012, respectively) regarding all individuals searched, but without any correlation with a good yield of CD34+ cells. However, CXCR4 expressions on the CD34+ cells from bone marrow aspirates (BMA), at pre and post mobilization showed a difference statistical significant for those individuals with good yield of CD34+ cells (p=0,036), but not achieved for poor yield (p=0,156). There was a higher expression of CXCR4 in steady-state for the successfully individuals than for those unsuccessfully (529.84+/-54.68 and 496.31+/-97.51, respectively). In conclusion, we confirmed the important role of CXCR4/SDF-1 axis in the process of PBSC mobilization.

Mobilization, collection, and transplantation of peripheral blood hematopoietic progenitor cells in a patient with multiple myeloma and hemoglobin SC disease

BACKGROUND

The use of granulocyte-colony-stimulating factor (G-CSF) for mobilization, collection, and transplantation of autologous hematopoietic progenitor cells (HPCs) in patients with hemoglobinopathies can be complicated by severe vasoocclusive crises. Erythrocytapheresis before G-CSF administration may help prevent these complications. To date, no cases regarding the safety and outcome of erythrocytapheresis followed by autologous high-dose G-CSF mobilization in hemoglobinopathy populations have been reported.

STUDY DESIGN AND METHODS

A patient with hemoglobin (Hb) SC disease and multiple myeloma underwent erythrocytapheresis followed by high-dose (16 microg/kg) G-CSF in preparation for HPC mobilization and collection.

RESULTS

Erythrocytapheresis reduced the patient's combined Hb S and C levels to less than 20 percent. Subsequent HPC mobilization and peripheral blood harvesting using high-dose G-CSF yielded approximately 9 x 10(6) CD34+ HPCs per kg over 3 days of collection. Mobilization and leukapheresis were completed without vasoocclusive complications. Two weeks after collection, and after myeloablative chemotherapy, 5.33 x 10(6) CD34+ HPCs per kg were infused to the patient; platelet and white cell engraftment occurred, respectively, on Days +9 and +10 posttransplant. The patient experienced no vasoocclusive complications in the posttransplant period.

CONCLUSIONS

The results of this case demonstrate that erythrocytapheresis before high-dose G-CSF HPC mobilization and collection appears to be an effective means for prevention of vasoocclusive crisis in patients with hemoglobinopathies undergoing autologous stem cell transplantation.

Stem cell harvesting protocol research in autologous transplantation setting: Large volume vs. conventional cytapheresis

Background/Aim. The use of peripheral blood as a source of hematopoietic stem cells (SCs) is progressively increasing and has nearly supplanted bone marrow transplantation. Interpatient variability in the degree and kinetics of SC mobilization into peripheral blood is an expected event after conventional chemotherapy-based treatment, followed by sequential administration of recombinant granulocyte-colony- stimulating factor (rHu-CSF). In this study, specific factors associated with the application of two different SC-harvesting approaches, including the use of large volume leukapheresis (LVL) vs. repetitive conventional apheresis (RCA), were analyzed. The basic goal of the study was to evaluate the influence of apheresis protocol (collection timing, processed blood volume and cell yield) upon the clinical outcome of transplantation. Methods. Results obtained by LVL (76 pts) and RCA (20 pts - control group) were compared. The SC mobilizing regimen used was cyclophosphamide (4-7 g/m2) or polychemotherapy and rHuG-CSF 10-16 ?g/kg of body mess (bm) per day. Cell harvesting was performed using COBE-Spectra (Caridian-BCT, USA). The volume of processed blood in LVL setting was ? 3.5 - fold of the patient's circulating blood quantity (ranged from 12.7 to 37.8 l). All patients tolerated well the use of intensive treatment, without any side or adverse effects. Our original controlled-rate cryopreservation was carried out with 10% dimethyl sulfoxide (DMSO) using Planer R203/200R or Planer 560-16 equipments (Planer Products Ltd, UK). Total nucleated cell (NC) and mononuclear cell (MNC) counts were examined by flow cytometry (Advia-2120 Bayer, Germany; Technicon H-3 System, USA). The CD34+ cell surface antigen was investigated by the EPICS XL-MCL device (Coulter, Germany). Results. Performing LVL-apheresis, high-level MNC and CD34+ cell yields (7.6?4.6 ? 108/kg bm and 11.8?6.5 ? 106/kg bm, respectively) were obtained. As a result, rapid hematopoietic reconstitution ("graft-healing") - on the 9.4th and 12.4th day for granulocytes and platelets, respectively was achieved. Using repetitive conventional apheresis (2-3 procedures), the total MNC count was high (8.2?7.0 ? 108/kg bm), but the total CD34+ yield was lower 10.8?9.9 due to inferior CD34+ vs. MNC ratio. Conclusion. The results obtained suggest that well-timed LVL-apheresis increased SC-yield in cell harvest, resulting in faster bone marrow repopulation and hematological reconstitution, as well as better overall clinical outcome of transplantation. These results necessitate additional examinations of CD34+ subsets ratio in cell harvest.