Hematopoietic stem and progenitor cell harvesting: technical advances and clinical utility

Electrical Stimulation of Mesenchymal Stem Cells as a Tool for Proliferation and Differentiation in Cartilage Tissue Engineering: A Scaffold-Based Approach

Electrical stimulation (ES) is a widely discussed topic in the field of cartilage tissue engineering due to its ability to induce chondrogenic differentiation (CD) and proliferation. It shows promise as a potential therapy for osteoarthritis (OA). In this study, we stimulated mesenchymal stem cells (MSCs) incorporated into collagen hydrogel (CH) scaffolds, consisting of approximately 500,000 cells each, for 1 h per day using a 2.5 Vpp (119 mV/mm) 8 Hz sinusoidal signal. We compared the cell count, morphology, and CD on days 4, 7, and 10. The results indicate proliferation, with an increase ranging from 1.86 to 9.5-fold, particularly on day 7. Additionally, signs of CD were observed. The stimulated cells had a higher volume, while the stimulated scaffolds showed shrinkage. In the ES groups, up-regulation of collagen type 2 and aggrecan was found. In contrast, SOX9 was up-regulated in the control group, and MMP13 showed a strong up-regulation, indicating cell stress. In addition to lower stress levels, the control groups also showed a more spheroidic shape. Overall, scaffold-based ES has the potential to achieve multiple outcomes. However, finding the appropriate stimulation pattern is crucial for achieving successful chondrogenesis.

Progresses in overcoming the limitations of in vitro erythropoiesis using human induced pluripotent stem cells

Researchers have attempted to generate transfusable oxygen carriers to mitigate RBC supply shortages. In vitro generation of RBCs using stem cells such as hematopoietic stem and progenitor cells (HSPCs), embryonic stem cells (ESCs), and induced pluripotent stem cells (iPSCs) has shown promise. Specifically, the limited supplies of HSPCs and ethical issues with ESCs make iPSCs the most promising candidate for in vitro RBC generation. However, researchers have encountered some major challenges when using iPSCs to produce transfusable RBC products, such as enucleation and RBC maturation. In addition, it has proven difficult to manufacture these products on a large scale. In this review, we provide a brief overview of erythropoiesis and examine endeavors to recapitulate erythropoiesis in vitro using various cell sources. Furthermore, we explore the current obstacles and potential solutions aimed at enabling the large-scale production of transfusable RBCs in vitro.

Efficient expansion of rare human circulating hematopoietic stem/progenitor cells in steady-state blood using a polypeptide-forming 3D culture

Although widely applied in treating hematopoietic malignancies, transplantation of hematopoietic stem/progenitor cells (HSPCs) is impeded by HSPC shortage. Whether circulating HSPCs (cHSPCs) in steady-state blood could be used as an alternative source remains largely elusive. Here we develop a three-dimensional culture system (3DCS) including arginine, glycine, aspartate, and a series of factors. Fourteen-day culture of peripheral blood mononuclear cells (PBMNCs) in 3DCS led to 125- and 70-fold increase of the frequency and number of CD34⁺ cells. Further, 3DCS-expanded cHSPCs exhibited the similar reconstitution rate compared to CD34⁺ HSPCs in bone marrow. Mechanistically, 3DCS fabricated an immunomodulatory niche, secreting cytokines as TNF to support cHSPC survival and proliferation. Finally, 3DCS could also promote the expansion of cHSPCs in patients who failed in HSPC mobilization. Our 3DCS successfully expands rare cHSPCs, providing an alternative source for the HSPC therapy, particularly for the patients/donors who have failed in HSPC mobilization.

Characterisation of canine CD34+/CD45 diminished cells by colony-forming unit assay and transcriptome analysis

Haematopoietic stem and progenitor cells (HSPCs) are used for transplantation to reconstruct the haematopoietic pathways in humans receiving severe chemotherapy. However, the characteristics of canine HSPCs, such as specific surface antigens and gene expression profiles, are still unclear. This study aimed to characterise the haematopoietic ability and gene expression profiles of canine bone marrow HSPCs in healthy dogs. In this study, the CD34 positive (CD34+) cells were defined as classical HSPCs, CD34+/CD45 diminished (CD45^dim) cells as more enriched HSPCs, and whole viable cells as controls. Haematopoietic abilities and gene expression profiles were evaluated using a colony-forming unit assay and RNA-sequencing analysis. Canine CD34+/CD45^dim cells exhibited a significantly higher haematopoietic colony formation ability and expressed more similarity in the gene expression profiles to human and mouse HSPCs than those of the other cell fractions. Furthermore, the canine CD34+/CD45^dim cells expressed candidate cell surface antigens necessary to define the canine haematopoietic hierarchy roadmap. These results indicate that the canine CD34+/CD45^dim cells express the HSPC characteristics more than the other cell fractions, thereby suggesting that these cells have the potential to be used for studying haematopoietic stem cells in dogs.

Impact of Cryopreservation and Freeze-Thawing on Therapeutic Properties of Mesenchymal Stromal/Stem Cells and Other Common Cellular Therapeutics

Purpose of Review

Cryopreservation and its associated freezing and thawing procedures–short “freeze-thawing”–are among the final steps in economically viable manufacturing and clinical application of diverse cellular therapeutics. Translation from preclinical proof-of-concept studies to larger clinical trials has indicated that these processes may potentially present an Achilles heel to optimal cell product safety and particularly efficacy in clinical trials and routine use.

Recent Findings

We review the current state of the literature on how cryopreservation of cellular therapies has evolved and how the application of this technique to different cell types is interlinked with their ability to engraft and function upon transfer in vivo, in particular for hematopoietic stem and progenitor cells (HSPCs), their progeny, and therapeutic cell products derived thereof. We also discuss pros and cons how this may differ for non-hematopoietic mesenchymal stromal/stem cell (MSC) therapeutics. We present different avenues that may be crucial for cell therapy optimization, both, for hematopoietic (e.g., effector, regulatory, and chimeric antigen receptor (CAR)-modified T and NK cell based products) and for non-hematopoietic products, such as MSCs and induced pluripotent stem cells (iPSCs), to achieve optimal viability, recovery, effective cell dose, and functionality of the cryorecovered cells.

Summary

Targeted research into optimizing the cryopreservation and freeze-thawing routines and the adjunct manufacturing process design may provide crucial advantages to increase both the safety and efficacy of cellular therapeutics in clinical use and to enable effective market deployment strategies to become economically viable and sustainable medicines.

Ex vivo expansion and functional activity preservation of adult hematopoietic stem cells by a diarylheptanoid from Curcuma comosa

Hematopoietic stem cells (HSCs, CD34+ cells) have shown therapeutic efficacy for transplantation in various hematological disorders. However, a large quantity of HSCs is required for transplantation. Therefore, strategies to increase HSC numbers and preserve HSC functions through ex vivo culture are critically required. Here, we report that expansion medium supplemented with ASPP 049, a diarylheptanoid isolated from Curcuma comosa, and a cocktail of cytokines markedly increased numbers of adult CD34+ cells. Interestingly, phenotypically defined primitive HSCs (CD34+CD38-CD90+) were significantly increased under ASPP 049 treatment relative to control. ASPP 049 treatment also improved two functional properties of HSCs, as evidenced by an increased number of CD34+CD38- cells in secondary culture (self-renewal) and the growth of colony-forming units as assessed by colony formation assay (multilineage differentiation). Transplantation of cultured CD34+ cells into immunodeficient mice demonstrated the long-term reconstitution and differentiation ability of ASPP 049-expanded cells. RNA sequencing and KEGG analysis revealed that Hippo signaling was the most likely pathway involved in the effects of ASPP 049. These results suggest that ASPP 049 improved ex vivo expansion and functional preservation of expanded HSCs. Our findings provide a rationale for the use of ASPP 049 to grow HSCs prior to hematological disease treatment.

The Future of Gene Therapy for Transfusion-Dependent Beta-Thalassemia: The Power of the Lentiviral Vector for Genetically Modified Hematopoietic Stem Cells

β-thalassemia, a disease that results from defects in β-globin synthesis, leads to an imbalance of β- and α-globin chains and an excess of α chains. Defective erythroid maturation, ineffective erythropoiesis, and shortened red blood cell survival are commonly observed in most β-thalassemia patients. In severe cases, blood transfusion is considered as a mainstay therapy; however, regular blood transfusions result in chronic iron overload with life-threatening complications, e.g., endocrine dysfunction, cardiomyopathy, liver disease, and ultimately premature death. Therefore, transplantation of healthy hematopoietic stem cells (HSCs) is considered an alternative treatment. Patients with a compatible human leukocyte antigen (HLA) matched donor can be cured by allogeneic HSC transplantation. However, some recipients faced a high risk of morbidity/mortality due to graft versus host disease or graft failure, while a majority of patients do not have such HLA match-related donors. Currently, the infusion of autologous HSCs modified with a lentiviral vector expressing the β-globin gene into the erythroid progenitors of the patient is a promising approach to completely cure β-thalassemia. Here, we discuss a history of β-thalassemia treatments and limitations, in particular the development of β-globin lentiviral vectors, with emphasis on clinical applications and future perspectives in a new era of medicine.

Comparison of CD34+ cell mobilization, blood graft cellular composition, and post-transplant outcome in myeloma patients mobilized with filgrastim or pegfilgrastim added to low-dose cyclophosphamide: A prospective multicenter study

BACKGROUND

Scarce data exist on the impact of granulocyte-colony stimulating factor (G-CSF) type on the mobilizing capacity of CD34⁺ cells, graft cellular composition, and outcome in myeloma (MM) patients.

PATIENTS AND METHODS

In this prospective multicenter study, 70 patients with MM received filgrastim (FIL) and 20 patients received pegfilgrastim (PEG) as a G-CSF after low-dose cyclophosphamide. Flow cytometry was used to analyze the mobilization of CD34⁺ cells and cellular composition of blood grafts, hematologic recovery, and survival after auto-SCT according to the G-CSF choice.

RESULTS

The CD34⁺ cell yield of the first apheresis was higher in the FIL group (5.3 vs. 4.2 × 10⁶ /kg, p = .025). The better mobilizing capacity was observed in the FIL group especially after bortezomib-based induction based on the higher first apheresis yield of CD34⁺ cells (7.5 vs. 4.4 × 10⁶ /kg, p = .001). The median CD19⁺ cell count (1.0 vs. 0.4 × 10⁶ /kg, p = .010) and the number of CD3⁺ T lymphocytes (43.1 vs. 31.8 × 10⁶ /kg, p = .122) in the infused graft were higher in the patients mobilized with FIL. Both early (day +15) (56 vs. 108 × 10⁹ /L, p = .002) and later platelet recovery at 6 months (191 vs. 226 × 10⁹ /L, p = .026) were faster in the PEG group.

CONCLUSION

G-CSF type seems to impact on the mobilization capacity and cellular composition of infused graft and also platelet recovery post-transplant. A randomized study might be warranted to verify the effects of G-CSF choice in the mobilization field.

Donor characteristics and intraoperative total nucleated cell count influence hematopoietic progenitor cell yield of healthy donor bone marrow grafts

BACKGROUND

Bone marrow graft cell content impacts engraftment potential after allogeneic hematopoietic cell transplantation (alloHCT). Surrogates, such as intraoperative total nucleated cell count (ioTNC), are of unclear utility in predicting final graft characteristics. In addition, demographic and clinical factors may influence graft cellular profile and recipient engraftment.

PROCEDURE

We retrospectively reviewed marrow harvests at our institution performed between 2009 and 2019. During this time, an ioTNC was measured after 50% of the projected final graft volume was collected. Regression models were used to assess associations between ioTNC (cells/µL) and final graft CD34+ (cells/mL), and between graft and donor characteristics and final graft CD34+ (cells/mL).

RESULTS

Fifty-three marrow harvests and donor-recipient pairs were analyzed. Median (range) donor and recipient ages were 13 (0.7-28) years and 9 (0.2-21) years, respectively. The median ratio of donor/recipient weight was 1.225 kg (range 0.31-7.13). Median total volume of harvested marrow was 15.3 mL/kg (range 4.3-20.4) of donor weight and 19.4 mL/kg (range 4.7-87.4) of recipient weight. Median ioTNC was 20 930/µL (range 6600-44310) or 2.1 × 10⁹ /mL, corresponding to median predicted final graft TNC of 3.59 × 10⁸ /kg recipient weight (range 1.28-19.42 × 10⁸ ). Simple linear regression between ioTNC and CD34+ cells/mL resulted in an R² of 0.42. Least absolute shrinkage and selection operator (LASSO) regression produced a moderately predictive model consisting of ioTNC, donor age, and donor weight (adjusted R²  = 0.7) of final graft CD34+ cells/mL.

CONCLUSIONS

ioTNC and certain donor characteristics correlate moderately well with marrow product CD34+ cells/mL, potentially informing donor selection and marrow procurement strategies.

Retrospective comparison between COBE SPECTRA and SPECTRA OPTIA apheresis systems for hematopoietic progenitor cells collection for autologous and allogeneic transplantation in a single center

INTRODUCTION

COBE SPECTRA [COBE] (Terumo, BCT Lakewood CO) apheresis system has been the most used device for hematopoietic progenitor cells (HPC) collection. Recently, it has been replaced by the SPECTRA OPTIA [OPTIA] (Terumo, BCT Lakewood CO) apheresis system. The aim of our study is to compare both methods for HPC collection.

MATERIAL AND METHODS

We retrospectively compared 302 HPC collection apheresis procedures (115 allogeneic donors and 187 autologous). The study cohort was divided according to the apheresis system used to analyze the differences between COBE and OPTIA, specifically efficacy of apheresis procedure and product characteristics.

RESULTS

OPTIA collections result in a higher CD34⁺ collection efficiency in both groups (autologous 45.3% vs 41%, P < .006; allogeneic 54.9% vs 45%, P < .0001). The total of CD34⁺ cells ×10⁶ /kg recipient collected in the product were comparable in both groups (autologous 2.9 in OPTIA group vs 2.8 in COBE group, P = .344; allogeneic 6.2 in OPTIA group vs 5.8 in COBE group, P = .186). The percentage of platelet loss in autologous donors was significantly lower (35.7% vs 40.8%, P < .01). Regarding quality of the product, we observed a significantly lower hematocrit in products collected with OPTIA in both groups (1.8% vs 4%, P < .0001) as well as significantly lower amount of leukocytes (median 153.4 vs 237.2 × 10⁹ /L in autologous, P < .0001; 239.5 vs 340.2 × 10⁹ /L in allogeneic P < .0001).

CONCLUSION

Both apheresis systems are comparable in collection of hematopoietic progenitor cells, with significantly higher collection efficiency with the OPTIA system. Collection products obtained with OPTIA contain significantly lower hematocrit and leukocytes.

Peripheral Blood Stem Cell Harvest HPC Count Is an Effective Surrogate Marker for CD34+ Cell Count in Allogeneic Stem Cell Transplant Setting

OBJECTIVE: We assessed the predictive potential of XN-HPC for CD34+ cell count as obtained through Sysmex automated hematology analyzers (XN-1000). METHODS: This study was conducted at the National Institute of Blood Diseases and Bone Marrow Transplantation in 84 donors between December 2012 and December 2017 in the first phase and later validated in 112 donors between December 2017 and December 2018. Sysmex XN-1000 and BD FACS Calibur estimated XN-HPC and CD34+ cells of peripheral blood apheresis product, respectively. Spearman's correlation was assessed between XN-HPC and CD34+ cell count followed by receiver operating characteristic curve calculation to determine the XN-HPC cutoff for a CD34+ count of ≥2 million cells/kg of recipient's body weight RESULTS: There is a moderately positive correlation (P value = .003) between XN-HPC and CD34+ count. Receiver operating characteristic curve analyses demonstrated that a cutoff value for XN-HPC of ≥1·845×10⁶cells/kg of recipient's body weight has a specificity and sensitivity of 100% and 78·2%, respectively, for predicting the CD34+ count of ≥2 million cells/kg of recipient's body weight. This cutoff value of XN-HPC was prospectively validated in 112 donors. The positive predictive value was found to be 100%, while negative predictive value was 17%. CONCLUSION: XN-HPC has a highly promising potential to serve as a cost-effective and time-saving surrogate for CD34+ cell count.

Expansion of Haematopoietic Stem and Progenitor Cells: Paving the Way for Next-Generation Haematopoietic Stem Cell Transplantation

Haematopoietic stem cell transplantation (HSCT) is now an established practice with over 70,000 transplants performed annually, and over 1.5 million around the world so far. The practice of HSCT has improved over the years due to advances in conditioning regiments, preparatory practices for patients leading up to the transplant, graft versus host disease (GVHD) and infection prophylaxis, as well as a better selection of patients. However, in many instances, the stem cells supplied to the patient may not be adequate for optimal transplantation outcomes. This may be seen in a few areas including umbilical cord blood transplantation, inadequate bone marrow, peripheral blood stem cell harvest, or gene therapy. Growing and expanding HSCs in culture would provide an increase in cell numbers prior to stem cell infusion and accelerate haematopoietic recovery, resulting in improved outcomes. Several new technologies have emerged in recent years, which have facilitated the expansion of haematopoietic stem and progenitor cells (HSPCs) in culture with good outcomes in vitro, in vivo, and in clinical trials. In this review, we will outline some of the reasons for the expansion of HSPCs as well as the new technologies facilitating the advances in HSCT.

Does Resetting the Immune System Fix Multiple Sclerosis?

Multiple sclerosis is the leading non-traumatic cause of disability in young adults, affecting up to 100,000 Canadians. This chronic inflammatory and neurodegenerative disease of the central nervous system leads to irreversible neurologic disability if inadequately controlled. Though many current medications are available that reduce inflammatory damage, most patients continue to show some evidence of disease activity and accrue disability. In this review, we discuss the role of immune ablation followed by autologous hematopoietic stem cell transplantation (AHSCT), a therapeutic option for select patients with a more aggressive disease course. By "resetting" the immune system with a variety of ablative conditioning regimens, followed by immune reconstitution, this therapy has shown a durable response in halting evidence of inflammatory activity in most patients, without the need for continued disease-modifying therapies (DMT). Since the introduction of this therapy, there have been advances in patient selection and supportive care, such that morbidity has significantly declined and treatment-related mortality is minimized. Recent phase-II trials have shown excellent results in efficacy and safety of AHSCT; however, challenges exist which require ongoing study. The future challenges include comparing the variety of AHSCT conditioning regimens with each other as well as with existing highly effective DMT; identifying patients with an aggressive disease course through novel biomarkers who may benefit the most from AHSCT; and surveillance of long-term outcomes of different treatment protocols. In select patients, replacing the immune system with AHSCT holds promise of fundamentally altering the trajectory of their aggressive disease course.

The impact of multiple myeloma induction therapy on hematopoietic stem cell mobilization and collection: 25-year experience

While first-line induction therapy for patients with multiple myeloma has changed over the years, autologous hematopoietic stem cell transplantation still plays a significant role, improving both depth of response and progression-free survival of myeloma patients. Our 25-year experience in mobilizing hematopoietic stem and progenitor cells for 472 transplant-eligible myeloma patients was retrospectively reviewed. Patients were stratified according to the remission induction therapy received, and the outcomes were compared among the cohorts that received vincristine, adriamycin and dexamethasone (VAD) (n = 232), bortezomib and dexamethasone (BD) (n = 86), cyclophosphamide, bortezomib and dexamethasone (CyBorD) (n = 82) and other regimens (n = 67). Cyclophosphamide plus granulocyte colony-stimulating factor was the predominant mobilization regimen given. A greater number of CD34⁺ cells (9.9 × 10E6/kg, p = 0.026) was collected with less hospital admissions in BD patients (13%, p = 0.001), when compared to those receiving VAD (7.5 × 10E6/kg, 29%), CyBorD (7.6 × 10E6/kg, 19%), or other regimens (7.9 × 10E6/kg, 36%). Induction therapy did not influence the overall rate of unscheduled visits or the length of hospitalization because of complications following mobilization. The myeloma response was not significantly deepened following the cyclophosphamide administered for mobilization. This analysis demonstrates the importance of monitoring the impact of initial treatment on downstream procedures such as stem cell mobilization and collection.

Comparison of filgrastim, pegfilgrastim, and lipegfilgrastim added to chemotherapy for mobilization of CD34+ cells in non-Hodgkin lymphoma patients

BACKGROUND

Data are limited on the long-acting granulocyte-colony stimulating factors (G-CSFs) pegfilgrastim (PEG) and lipegfilgrastim (LIPEG) compared with filgrastim (FIL) regarding the mobilization efficiency of CD34⁺ cells, graft cellular composition, and engraftment.

STUDY DESIGN AND METHODS

In this prospective nonrandomized study, 36 patients with non-Hodgkin lymphoma received FIL, 67 received PEG, and 16 patients received LIPEG as a cytokine after chemotherapy. We analyzed the mobilization and collection of CD34⁺ cells, cellular composition of blood grafts, and hematologic recovery after auto-SCT according to the type of G-CSF used.

RESULTS

Patients in the LIPEG group had fewer apheresis sessions (1 vs. 2, p = 0.021 for FIL and p = 0.111 for PEG) as well as higher median blood CD34⁺ cell counts at the start of the first apheresis (LIPEG 74 × 10⁶ /L vs. FIL 31 × 10⁶ /L, p = 0.084 or PEG 27 × 10⁶ /L, p = 0.021) and CD34⁺ yields of the first apheresis (FIL 5.1 × 10⁶ /kg vs. FIL 2.3 × 10⁶ /kg, p = 0.105 or PEG 1.8 × 10⁶ /kg, p = 0.012). Also, the costs associated with G-CSF mobilization and apheresis were lower in the LIPEG group. The graft composition was comparable except for the higher infused CD34⁺ cell counts in the LIPEG group. The engraftment kinetics were significantly slower in the FIL group.

CONCLUSION

LIPEG appears to be more efficient compared with PEG after chemotherapy to mobilize CD34⁺ cells for auto-SCT demonstrated as fewer sessions of aphereses needed as well as 2.8-fold CD34⁺ cell yields on the first apheresis day. Early hematologic recovery was more rapid in the LIPEG group. Thus further studies on LIPEG in the mobilization setting are warranted.

Mobilization, Isolation and Characterization of Stem Cells from Peripheral Blood: a Systematic Review

Objectives

The purpose of this article is to systematically review the methods of mobilization, isolation and characterization of stem cells from peripheral blood and to discuss their potential therapeutic applications for bone tissue regeneration.

Material and Methods

An electronic literature search was performed through MEDLINE (PubMed) electronic database. The search was restricted to English language articles published during the last 10 years, from January 2006 to November 2016.

Results

In total, 37 literature sources were reviewed, and 11 of the most relevant articles that are suitable to the criteria were selected. Articles were analysed with data on animals and humans for mobilization, isolation and characterization of stem cells from peripheral blood. From the examination of selected articles, the mobilization materials, side effects, alternatives and factors affecting the extracted amount of mesenchymal stem cells (MSC) from mobilized peripheral blood of healthy individuals, as well as characterization of mobilized MSC were reviewed in this article.

Conclusions

Bone tissue engineering is a potential alternative strategy in bone regeneration and bone defect repair, however, insufficiency data display in the literature on potential therapeutic applications of peripheral blood stem cells for bone tissue regeneration.

Management of psychiatric complications in unrelated donor before unrelated peripheral hematopoietic stem cell collections

Allogeneic hematopoietic stem cell transplantation can efficiently treat patients with severe hematological diseases. A human leukocyte antigen-compatible donor is required for performing transplantation. The occurrence of unexpected acute severe diseases in a donor can compromise the feasibility of allogeneic hematopoietic stem cell transplantation. However, when a severe health problem occurs in a donor while the recipient has already received a conditioning regimen, hematologists have to find the best solutions for the recipient, while the team in charge of the donor has to find the best medical solutions for the donor. We describe here the occurrence of psychiatric acute complications in an unrelated donor while the myeloablative conditioning regimen had already been given to the recipient. We report the successive decisions that were made in an emergency based upon the expertise of physicians specialized in hematology, apheresis, cell therapy, and psychiatry to preserve the donor's health and recipient's life.

Efficiency of autologous stem cell collection: Comparison of three different cell separators

Peripheral blood progenitor cells (PBPC) infusion allows rapid haematological recovery after high dose chemotherapy. Efficient PBPC collection is therefore essential as rescue therapy for transplantation. In order to validate a new equipment (ComTec^®, Fresenius Kabi), we compared the efficiency of three cell separators for PBPC collection in patients with haematological malignant diseases. From June 2014 to December 2015, 83 PBPC were collected in 48 patients. Three aphaeresis machines were used: Cobe Spectra^® (Terumo BCT, 11), Amicus^® (Fenwall, 30), and ComTec^® (Fresenius Kabi, 42). The median collection efficiency was similar between the three separators. The evaluation of cell contamination in the final product revealed a lower red cell contamination with Spectra^® and ComTec^®, whereas the platelet contamination was lower with Amicus^®. The new equipment has been validated and can be further used in routine, with a total running cost that turned out to be quite lower. Each separator has its own characteristics and advantages. Further study is needed to suggest that the choice of separator could be guided following the patient's blood characteristics.

Mobilization of hematopoietic stem cells with the novel CXCR4 antagonist POL6326 (balixafortide) in healthy volunteers-results of a dose escalation trial

BACKGROUND

Certain disadvantages of the standard hematopoietic stem and progenitor cell (HSPC) mobilizing agent G-CSF fuel the quest for alternatives. We herein report results of a Phase I dose escalation trial comparing mobilization with a peptidic CXCR4 antagonist POL6326 (balixafortide) vs. G-CSF.

METHODS

Healthy male volunteer donors with a documented average mobilization response to G-CSF received, following ≥6 weeks wash-out, a 1-2 h infusion of 500-2500 µg/kg of balixafortide. Safety, tolerability, pharmacokinetics and pharmacodynamics were assessed.

RESULTS

Balixafortide was well tolerated and rated favorably over G-CSF by subjects. At all doses tested balixafortide mobilized HSPC. In the dose range between 1500 and 2500 µg/kg mobilization was similar, reaching 38.2 ± 2.8 CD34 + cells/µL (mean ± SEM). Balixafortide caused mixed leukocytosis in the mid-20 K/µL range. B-lymphocytosis was more pronounced, whereas neutrophilia and monocytosis were markedly less accentuated with balixafortide compared to G-CSF. At the 24 h time point, leukocytes had largely normalized.

CONCLUSIONS

Balixafortide is safe, well tolerated, and induces efficient mobilization of HSPCs in healthy male volunteers. Based on experience with current apheresis technology, the observed mobilization at doses ≥1500 µg/kg of balixafortide is predicted to yield in a single apheresis a standard dose of 4× 10E6 CD34+ cells/kg from most individuals donating for an approximately weight-matched recipient. Exploration of alternative dosing regimens may provide even higher mobilization responses. Trial Registration European Medicines Agency (EudraCT-Nr. 2011-003316-23) and clinicaltrials.gov (NCT01841476).

Prospective randomized and crossover comparison of two apheresis machines for peripheral blood stem cell collection: a multicenter study

BACKGROUND

Improving apheresis technology may lead to an efficient and safe peripheral blood stem cell (PBSC) collection. Recently, the Spectra Optia (Optia, Terumo BCT) was introduced as an automated apheresis instrument, but comparisons with other instruments have been few. This is the first randomized multicenter and crossover comparison of the Optia with the automated program of the established apheresis instrument, the Spectra (Spectra-Auto, Terumo BCT).

STUDY DESIGN AND METHODS

A total of 233 apheresis procedures performed in 46 autologous patients and 108 allogeneic donors were investigated. Apheresis performed in the first day for all subjects using the Spectra-Auto (n = 79) and the Optia (n = 75) were evaluated as first-day analysis. Seventy-nine subjects, who required another session on the second day, underwent apheresis using the other instrument than the first-day instrument and were compared with each other in a paired crossover analysis.

RESULTS

The two instruments processed similar volumes with comparable run times and volumes of acid-citrate-dextrose used. The volumes of collected products were greater in the Optia. Yields of mononuclear cells and CD34+ cells were not different, but collection efficiencies were higher in the Optia (p = 0.008 in CE1 of crossover analysis). Spectra-Auto-collected products contained more contaminating red blood cells (RBCs), whereas there was a trend of more contaminating platelets (PLTs) in the Optia-collected products. Slight reductions were noted in the RBC or PLT counts of subjects who underwent apheresis with the Spectra-Auto or the Optia, respectively.

CONCLUSION

The Optia is safe and more efficient in the PBSC collection compared with the Spectra-Auto.

Hematopoietic stem cell transplantation activity worldwide in 2012 and a SWOT analysis of the Worldwide Network for Blood and Marrow Transplantation Group including the global survey

Data on 68 146 hematopoietic stem cell transplants (HSCTs) (53% autologous and 47% allogeneic) gathered by 1566 teams from 77 countries and reported through their regional transplant organizations were analyzed by main indication, donor type and stem cell source for the year 2012. With transplant rates ranging from 0.1 to 1001 per 10 million inhabitants, more HSCTs were registered from unrelated 16 433 donors than related 15 493 donors. Grafts were collected from peripheral blood (66%), bone marrow (24%; mainly non-malignant disorders) and cord blood (10%). Compared with 2006, an increase of 46% total (57% allogeneic and 38% autologous) was observed. Growth was due to an increase in reporting teams (18%) and median transplant activity/team (from 38 to 48 HSCTs/team). An increase of 167% was noted in mismatched/haploidentical family HSCT. A Strengths, Weaknesses, Opportunities, Threats (SWOT) analysis revealed the global perspective of WBMT to be its major strength and identified potential to be the key professional body for patients and authorities. The limited data collection remains its major weakness and threat. In conclusion, global HSCT grows over the years without plateauing (allogeneic>autologous) and at different rates in the four World Health Organization regions. Major increases were observed in allogeneic, haploidentical HSCT and, to a lesser extent, in cord blood transplantation.

Simultaneous measurement of human hematopoietic stem and progenitor cells in blood using multicolor flow cytometry

Hematopoietic stem cells are the source of all inflammatory cell types. Discovery of specific cell surface markers unique to human hematopoietic stem (HSC) and progenitor (HSPC) cell populations has facilitated studies of their development from stem cells to mature cells. The specific marker profiles of HSCs and HSPCs can be used to understand their role in human inflammatory diseases. The goal of this study is to simultaneously measure HSCs and HSPCs in normal human venous blood using multicolor flow cytometry. Our secondary aim is to determine how G-CSF mobilization alters the quantity of each HSC and HSPC population. Here we show that cells within the CD34+ fraction of human venous blood contains cells with the same cell surface markers found in human bone marrow samples. Mobilization with G-CSF significantly increases the quantity of total CD34+ cells, blood borne HSCs, multipotent progenitors, common myeloid progenitors, and megakaryocyte erythroid progenitors as a percentage of total MNCs analyzed. The increase in blood borne common lymphoid and granulocyte macrophage progenitors with G-CSF treatment did not reach significance. G-CSF treatment predominantly increased the numbers of HSCs and multipotent progenitors in the total CD34+ cell population; common myeloid progenitors and megakaryocyte erythroid progenitors were enriched relative to total MNCs analyzed, but not relative to total CD34+ cells. Our findings illustrate the utility of multicolor flow cytometry to quantify circulating HSCs and HSPCs in venous blood samples from human subjects. © 2016 International Clinical Cytometry Society.