Novel agents and approaches for stem cell mobilization in normal donors and patients

Spleen-targeted delivery systems and strategies for spleen-related diseases

The spleen, body's largest secondary lymphoid organ, is also a vital hematopoietic and immunological organ. It is regarded as one of the most significant organs in humans. As more researchers recognize the functions of the spleen, clinical methods for treating splenic diseases and spleen-targeted drug delivery systems to improve the efficacy of spleen-related therapies have gradually developed. Many modification strategies (size, charge, ligand, protein corona) and hitchhiking strategies (erythrocytes, neutrophils) of nanoparticles (NPs) have shown a significant increase in spleen targeting efficiency. However, most of the targeted drug therapy strategies for the spleen are to enhance or inhibit the immune function of the spleen to achieve therapeutic effects, and there are few studies on spleen-related diseases. In this review, we not only provide a detailed summary of the design rules for spleen-targeted drug delivery systems in recent years, but also introduce common spleen diseases (splenic tumors, splenic injuries, and splenomegaly) with the hopes of generating more ideas for future spleen research.

StemRegenin 1 Mitigates Radiation-Mediated Hematopoietic Injury by Modulating Radioresponse of Hematopoietic Stem/Progenitor Cells

Hematopoietic injury resulting from the damage of hematopoietic stem/progenitor cells (HSPCs) can be induced by either nuclear accident or radiotherapy. Radiomitigation of HSPCs is critical for the development of medical countermeasure agents. StemRegenin 1 (SR1) modulates the maintenance and function of HSPCs under non-stress conditions. However, the impact of SR1 in radiation-induced hematopoietic injury both in vivo and in vitro remains unknown. In this study, we found that treatment with SR1 after irradiation of C57BL/6 mice significantly mitigates TBI-induced death (80% of SR1-treated mice survival vs. 30% of saline-treated mice survival) with enhanced recovery of peripheral blood cell counts, with the density and cell proliferation of bone marrow components as observed by Hematoxylin and Eosin (H&E) and Ki-67 staining. Interestingly, in vitro analysis of human HSPCs showed that SR1 enhanced the population of human HSPCs (CD34+) under both non-irradiating and irradiating conditions, and reduced radiation-induced DNA damage and apoptosis. Furthermore, SR1 attenuated the radiation-induced expression of a member of the pro-apoptotic BCL-2 family and activity of caspase-3. Overall, these results suggested that SR1 modulates the radioresponse of HSPCs and might provide a potential radiomitigator of hematopoietic injury, which contributes to increase the survival of patients upon irradiation.

Stem Cell Mobilization with Ixazomib and G-CSF in Patients with Multiple Myeloma

(1) Background: High-dose chemotherapy (HDCT) followed by autologous stem cell transplantation (ASCT) is the standard consolidation strategy for patients with newly diagnosed multiple myeloma (MM) and for a subset of patients with relapsed/refractory disease. For stem cell mobilization, G-CSF alone or in combination with chemotherapy mobilizing agents and/or plerixafor are commonly used. Ixazomib is an oral proteasome inhibitor with less neurotoxic potential, which previously showed the ability to mobilize stem cells in preclinical studies. (2) Methods: Prospective single-center phase 1 study assessing the efficacy and safety of stem cell mobilization with ixazomib and G-CSF in patients with newly diagnosed or relapsed/refractory MM undergoing HDCT and ASCT. Primary endpoint was percentage of patients achieving a yield of at least 6.0 × 10⁶/kg CD34+ cells within the first apheresis. G-CSF (filgrastim) 10 μg/kg/day was administered subcutaneously (s.c.) from day 1 to day 5 (planned apheresis) and ixazomib 4 mg orally at day 4. Plerixafor 24 mg s.c. was administered if the stem cell mobilization with ixazomib and G-CSF was not sufficient. (3) Results: 19 patients were treated within the study between 06/2020 and 02/2021. The primary endpoint was reached in 17 (89%) patients, with a median of 7.1 × 10⁶/kg CD34+ cells collected within the first apheresis, comparable to previously published results, and only 2 (11%) patients required a second apheresis. Median number of circulating CD34+ cells was 14.0 × 10⁶/L (2.0-95.2) before the administration of ixazomib, and 33.0 × 10⁶/L (4.2-177.0) pre-apheresis. However, 9 (47%) patients required the addition of plerixafor to ensure optimal stem cell collection. (4) Conclusions: The combination of ixazomib and G-CSF showed promising stem cell mobilizing activity in patients with MM prior to HDCT and ASCT. Future larger studies might further investigate the role of ixazomib in stem cell mobilization regimens for MM.

Addition of plerixafor in poorly mobilized allogeneic stem cell donors

Background

Peripheral blood stem cells (PBSCs) are the predominant graft source for adult allogeneic hematopoietic stem cell transplantation (HSCT). In poorly mobilized autologous donors, plerixafor improves collection outcomes. We examine plerixafor use in allogeneic donors who mobilize poorly with granulocyte colony‐stimulating factor (G‐CSF) in those who are healthy and those with pre‐existing medical conditions, and determine the optimal threshold to add plerixafor.

Study Design/Methods

We retrospectively examined all allogeneic PBSC collections from January 2013 to October 2020 at our center. Donors received G‐CSF 10 mcg/kg daily for 4 days before undergoing apheresis collection on day 5. Plerixafor was added based on poor CD34+ cell collection yield after the first or second collection day.

Results

Of the 1008 allogeneic donors, 41 (4.1%) received one dose of plerixafor in addition to G‐CSF due to poor collection yield. After starting plerixafor there was a 0.75‐ to 7.74‐fold (median 2.94) increase in CD34+ yield from the previous day. No donors with G‐CSF‐only mobilization who collected <2.0 × 10⁶ CD34+ cells/kg recipient weight on day one achieved the goal of ≥4.0 × 10⁶ CD34+ cells/kg recipient weight total over 2 days but 59.2% of donors who used rescue plerixafor did.

Conclusion

Donors both healthy and those with pre‐existing disease responded well to plerixafor with minimal side effects. If the first‐day collection yield is less than ~63% of the collection goal, addition of plerixafor may be necessary to reach the collection goal and limit the number of collection days in allogeneic donors.

Cyclophosphamide plus etoposide is a safe and effective mobilization regimen in patients with multiple myeloma

High-dose chemotherapy followed by autologous stem cell transplantation is a major component in the treatment of patients with multiple myeloma. As a prerequisite, the successful collection of a sufficient number of viable peripheral blood hematopoietic CD34+ cells is critical. A common standard protocol for mobilization is currently not defined and critically discussed especially in German-speaking Europe. In times of the Covid-19 pandemic, safe and effective strategies have to be chosen to minimize hospitalization times and severe courses. In this single-center retrospective analysis, safety and efficacy of cyclophosphamide plus etoposide (CE) and growth-factor support (n = 33) was compared to cyclophosphamide mono treatment and growth-factor support (n = 49) in 82 patients with multiple myeloma at first diagnosis. CE was superior to cyclophosphamide mono with a significantly higher number of collected CD34+ cells (15.46 × 10⁶ CD34⁺ cells/kg vs. 9.92 × 10⁶ CD34⁺ cells/kg), significantly faster engraftment of granulocytes after stem cell transplantation (day 10.5 vs. day 11.6), shorter duration of the inpatient stay (17.47 days vs. 19.16 days) and significantly less transfusions (8.82 % vs. 30.61 % patients receiving transfusions). The safety profile was comparable in both groups and in line with published data. We conclude that CE is a safe and highly effective mobilization protocol in patients with multiple myeloma at first diagnosis and appears to be superior to the commonly used cyclophosphamide mono regimen.

Coordinated Regulation of Mesenchymal Stem Cell Migration by Various Chemotactic Stimuli

Endogenous bone marrow-derived mesenchymal stem cells are mobilized to peripheral blood and injured tissues in response to changes in the expression of various growth factors and cytokines in the injured tissues, including substance P (SP), transforming growth factor-beta (TGF-β), and stromal cell-derived factor-1 (SDF-1). SP, TGF-β, and SDF-1 are all known to induce the migration of bone marrow-derived mesenchymal stem cells (BM-MSCs). However, it is not yet clear how these stimuli influence or interact with each other during BM-MSC mobilization. This study used mouse bone marrow-derived mesenchymal stem cell-like ST2 cells and human BM-MSCs to evaluate whether SP, TGF-β, and SDF-1 mutually regulate their respective effects on the mobilization of BM-MSCs. SP pretreatment of ST2 and BM-MSCs impaired their response to TGF-β while the introduction of SP receptor antagonist restored the mobilization of ST2 and BM-MSCs in response to TGF-β. TGF-β pretreatment did not affect the migration of ST2 and BM-MSCs in response to SP, but downregulated their migration in response to SDF-1. SP pretreatment modulated the activation of TGF-β noncanonical pathways in ST2 cells and BM-MSCs, but not canonical pathways. These results suggest that the migration of mesenchymal stem cells is regulated by complex functional interactions between SP, TGF-β, and SDF-1. Thus, understanding the complex functional interactions of these chemotactic stimuli would contribute to ensuring the development of safe and effective combination treatments for the mobilization of BM-MSCs.

Graft-versus-cancereffect and innovative approaches in thetreatment of refractory solid tumors

Background/aim

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) has been used for the treatment of various refractory solid tumors during the last two decades. After the demonstration of graft-versus-leukemia (GvL) effect in a leukemic murine model following allo-HSCT from other strains of mice, graft-versus-tumor (GvT) effect in a solid tumor after allo-HSCT has also been reported in a murine model in 1984. Several trials have reported the presence of a GvT effect in patients with various refractory solid tumors, including renal, ovarian and colon cancers, as well as soft tissue sarcomas [1]. The growing data on haploidentical transplants also indicate GvT effect in some pediatric refractory solid tumors. Novel immunotherapy-based treatment modalities aim at inducing an allo-reactivity against the metastatic solid tumor via a GvT effect. Recipient derived immune effector cells (RDICs) in the antitumor reactivity following allo-HSCT have also been considered as an emerging therapy for advanced refractory solid tumors.

Conclusion

This review summarizes the background, rationale, and clinical results of immune-based strategies using GvT effect for the treatment of various metastatic and refractory solid tumors, as well as innovative approaches such as haploidentical HSCT, CAR-T cell therapies and tumor infiltrating lymphocytes (TIL).

Salvage treatment with plerixafor in poor mobilizing allogeneic stem cell donors: results of a prospective phase II-trial

We conducted a prospective clinical trial to investigate the safety and efficacy of plerixafor (P) in allogeneic peripheral blood stem cells (PBSC) donors with poor mobilization response to standard-dose granulocyte colony-stimulating factor (G-CSF), defined by <2 × 10⁶ CD34 + cells/kg recipient body-weight (CD34+/kg RBW) after 1st apheresis. A single dose of 240 µg/kg P was injected subcutaneously at 10 p.m. on the day of the 1st apheresis. Thirty-seven allogeneic PBSC donors underwent study treatment. The median CD34+ count in peripheral blood was 15/µl on Day 1 after G-CSF alone, versus 44/µl on Day 2 after G-CSF plus P (p < 0.001). The median yield of CD34+ cells was 1.1 × 10⁸ on Day 1 and 2.8 × 10⁸ on Day 2. In contrast to a median yield of only 1.31 × 10⁶ CD CD34+/kg RBW on Day 1, triggering study inclusion, a median of 3.74 × 10⁶ CD CD34+/kg RBW were collected with G-CSF plus P on Day 2. Of 37 donors, 21 reached the target cell count of >4.5 × 10⁶ CD34+/kg RBW (57%, 95%CI 40-73%). No donor experienced a severe adverse event requiring treatment. In conclusion, P might be considered on a case-by-case basis for healthy allogeneic donors with very poor stem cell mobilization success after G-CSF.

Pegfilgrastim improves the outcomes of mobilization and engraftment in autologous hematopoietic stem cell transplantation for the treatment of multiple myeloma

Autologous stem cell transplantation (ASCT) is the only curable therapy for multiple myeloma (MM), while its success primarily relies on mobilization to obtain sufficient hematopoietic stem/progenitor cells (HPC). Although the role of Pegfilgrastim (PEG), a novel PEGylated form of the recombinant G-CSF filgrastim (FIL), in mobilization has been demonstrated, it remains unclear whether this approach is cost-effective in MM treatment. Here, we performed a real-world analysis to evaluate the efficacy and cost of PEG for mobilization in a cohort of MM patients, of which 53% carried high-risk cytogenetic abnormalities. A total of 91 patients who received either a single dose of PEG (6 or 12 mg, n = 42) or multiple dosing of 10 μg/kg/day FIL (n = 49) after chemotherapy for HPC mobilization were included. The yield of MNCs and CD34⁺ cells per milliliter of blood collected via apheresis was significantly greater in the PEG group than that in the FIL group (P = 0.014 and P = 0.038). Mobilization with PEG yielded significantly higher median number of collected CD34⁺ cells than FIL (5.56 vs. 4.82 × 10⁶/kg; P = 0.038). Moreover, the average time-to-recovery of leukocytes and platelets after transplantation was markedly shorter in the PEG group than that in the FIL group (leukocyte, 11.59 ± 1.98 vs 12.93 ± 2.83 days, P = 0.019; platelet, 12.86 ± 2.62 vs 14.80 ± 5.47, P = 0.085). However, the total cost of mobilization and apheresis using PEG or FIL was comparable (P = 0.486). Of note, mobilization with 12 mg PEG further shortened time-to-recovery of leukocytes (10.64 ± 0.51 vs. 12.04 ± 2.26 days, P = 0.05) and platelets (10.60 ± 2.89 vs. 13.33 ± 2.35 days, P = 0.031) compared with 6 mg PEG. Our results support a notion that PEG (especially 12 mg) combined with chemotherapy is a cost-effective and convenient regimen of mobilization, which might improve the outcome of ASCT in MM.

Long-Acting IL-33 Mobilizes High-Quality Hematopoietic Stem and Progenitor Cells More Efficiently Than Granulocyte Colony-Stimulating Factor or AMD3100

Mobilization of hematopoietic stem and progenitor cells (HSPCs) has become increasingly important for hematopoietic cell transplantation. Current mobilization approaches are insufficient because they fail to mobilize sufficient numbers of cells in a significant fraction of patients and are biased toward myeloid immune reconstitution. A novel, single drug mobilization agent that allows a more balanced (myeloid and lymphoid) reconstitution would therefore be highly favorable to improve transplantation outcome. In this present study, we tested commercially available IL-33 molecules and engineered novel variants of IL-33. These molecules were tested in cell-based assays in vitro and in mobilization models in vivo. We observed for the first time that IL-33 treatment in mice mobilized HSPCs and common myeloid progenitors more efficiently than clinical mobilizing agents granulocyte colony-stimulating factor (G-CSF) or AMD3100. We engineered several oxidation-resistant IL-33 variants with equal or better in vitro activity. In vivo, these variants mobilized HSPCs and, interestingly, also hematopoietic stem cells, common lymphoid progenitor cells, and endothelial progenitor cells more efficiently than wild-type IL-33 or G-CSF. We then engineered an IL-33-Fc fusion molecule, a single dose of which was sufficient to significantly increase the mobilization of HSPCs after 4 days. In conclusion, our findings suggest that long-acting, oxidation-resistant IL-33 may be a novel approach for HSPC transplantation. IL-33-mobilized HSPCs differ from cells mobilized with G-CSF and AMD3100, and it is possible that these differences may result in better transplantation outcomes.

Current Approach to Non-Infectious Pulmonary Complications of Hematopoietic Stem Cell Transplantation

Hematopoietic stem cell transplantation is an established treatment for patients with a wide range of malignant and nonmalignant conditions. Noninfectious pulmonary complications still remain a leading cause of morbidity and mortality in these patients. Treating hematopoietic stem cell transplantation recipients with noninfectious pulmonary complications is still challenging, and the current treatment armamentarium and strategies are not adequate for patients receiving hematopoietic stem cell transplantation. Further trials are needed for a better description of the pathogenesis and the complete diagnostic criteria as well as for the development of effective therapeutic approaches for the management of noninfectious pulmonary complications of the hematopoietic stem cell transplantation. This review outlines the incidence, risk factors, pathogenesis, and clinical spectrum and discusses the current approaches to the management of noninfectious pulmonary complications of Hematopoietic stem cell transplantation.

Transient apoptosis inhibition in donor stem cells improves hematopoietic stem cell transplantation

During hematopoietic stem cell transplantation, a substantial number of donor cells are lost because of apoptotic cell death. Transplantation-associated apoptosis is mediated mainly by the proapoptotic BCL-2 family proteins BIM and BMF, and their proapoptotic function is conserved between mouse and human stem and progenitor cells. Permanent inhibition of apoptosis in donor cells caused by the loss of these BH3-only proteins improves transplantation outcome, but recipients might be exposed to increased risk of lymphomagenesis or autoimmunity. Here, we address whether transient inhibition of apoptosis can serve as a safe but efficient alternative to improve the outcome of stem cell transplantation. We show that transient apoptosis inhibition by short-term overexpression of prosurvival BCL-XL, known to block BIM and BMF, is not only sufficient to increase the viability of hematopoietic stem and progenitor cells during engraftment but also improves transplantation outcome without signs of adverse pathologies. Hence, this strategy represents a promising and novel therapeutic approach, particularly under conditions of limited donor stem cell availability.

How to manage poor mobilizers for high dose chemotherapy and autologous stem cell transplantation?

Today, peripheral blood stem cells are the preferred source of stem cells over bone marrow. Therefore, mobilization plays a crutial role in successful autologous stem cell transplantation. Poor mobilization is generally defined as failure to achieve the target level of at least 2×10⁶ CD34⁺ cells/kg body weight. There are several strategies to overcome poor mobilization: 1) Larger volume Leukapheresis (LVL) 2) Re-mobilization 3) Plerixafor 4) CM+Plerixafor (P)+G-CSF and 5) Bone Marrow Harvest. In this review, the definitions of successful and poor mobilization are discussed. Management strategies for poor mobilization are defined. The recent research on new agents are included.

The effect of age on peripheral stem cell mobilization in healthy donors, single center experience

PURPOSE

Peripheral stem cell transplantation is used as a life-saving therapeutic option in hematological malignancies. As previously established, most hematological malignancies are seen in the elderly population. Therefore, possible HLA-identical sibling donors of elderly patients are generally of an advanced age. In this study, we aimed to evaluate the effect of old age on stem cell mobilization and quality in older adult healthy sibling donors.

MATERIALS AND METHODS

Between 2006 and 2014, we evaluated 38 healthy donors aged ≥55 years. The granulocyte-colony stimulating factor (G-CSF) analogs were used at a dose of 5 µg/kg/day and administered subcutaneously twice a day for five days. CD34+ cells were estimated in the peripheral blood before collection of the apheresis product. The National Marrow Donor Program selects healthy unrelated donors if they are younger than 60 years. Therefore, we compared the product quality in donors over the age of 60 to that in donors aged 60 years or less.

RESULTS

We collected sufficient products from all the donors with one to three apheresis procedures. No serious complication was detected in all donors. Reaching the target CD34+ cell count in one day were detected in 83% of younger and 79% of older donors (P = NS). Collected CD34+ cells x10e6/recipient body weight (kg) was same and 5.1 in the groups (P = NS). There were no correlation between the donor age and these parameters.

CONCLUSION

Healthy donor apheresis in older adults can be performed effectively and possible donors should be evaluated regardless of their age. J. Clin. Apheresis 32:16-20, 2017. © 2016 Wiley Periodicals, Inc.

Increased yield of endothelial cells from peripheral blood for cell therapies and tissue engineering

AIM

Peripheral blood-derived endothelial cells (pBD-ECs) are an attractive tool for cell therapies and tissue engineering, but have been limited by their low isolation yield. We increase pBD-EC yield via administration of the chemokine receptor type 4 antagonist AMD3100, as well as via a diluted whole blood incubation (DWBI).

MATERIALS & METHODS

Porcine pBD-ECs were isolated using AMD3100 and DWBI and tested for EC markers, acetylated LDL uptake, growth kinetics, metabolic activity, flow-mediated nitric oxide production and seeded onto titanium tubes implanted into vessels of pigs.

RESULTS

DWBI increased the yield of porcine pBD-ECs 6.6-fold, and AMD3100 increased the yield 4.5-fold. AMD3100-mobilized ECs were phenotypically indistinguishable from nonmobilized ECs. In porcine implants, the cells expressed endothelial nitric oxide synthase, reduced thrombin-antithrombin complex systemically and prevented thrombosis.

CONCLUSION

Administration of AMD3100 and the DWBI method both increase pBD-EC yield.

DHAP plus filgrastim as an effective peripheral stem cell mobilization regimen for autologous stem-cell transplantation in patients with relapsed/refractory lymphoma: A single center experience

This study aimed to evaluate the efficiency of DHAP regimen plus filgrastim for mobilization of stem cells in patients with recurrent and/or refractory lymphoma. Thirty-four patients who took DHAP as salvage therapy prior to autologous stem cell transplantation were included. After chemotherapies, 2 cycles of DHAP plus filgrastim were administered to the patients. Stem cells from 32 patients (94%) were collected on median 11th day (8-12), and the median collected CD34(+) cell dose was 9.7 × 10(6)/kg (range 3.8-41.6). DHAP plus filgrastim was found to be an effective chemotherapy regimen in mobilizing CD34(+) stem cells into the peripheral.

Sodium Caseinate (CasNa) Induces Mobilization of Hematopoietic Stem Cells in a BALB/c Mouse Model

BACKGROUND Hematopoietic stem cells transplantation has high clinical potential against a wide variety of hematologic, metabolic, and autoimmune diseases and solid tumors. Clinically, hematopoietic stem cells derived from peripheral blood are currently used more than those obtained from sources such as bone marrow. However, mobilizing agents used in the clinic tend to fail in high rates, making the number of mobilized cells insufficient for transplantation. We investigated whether sodium caseinate induces functional mobilization of hematopoietic stem cells into peripheral blood of Balb/c mice. MATERIAL AND METHODS Using a mouse model, we administrated sodium caseinate or Plerixafor, a commercial mobilizing agent, and analyzed counts of hematopoietic stem cells in peripheral blood, and then cells were transplanted into lethally irradiated mice to restore hematopoiesis. All assays were performed at least twice. RESULTS We found that sodium caseinate increases the number of mononuclear cells in peripheral blood with the immunophenotype of hematopoietic stem cells (0.2 to 0.5% LSK cells), allowing them to form colonies of various cell lineages in semisolid medium (p<0.05). This effect is similar to that of Plerixafor, and cells transplanted into lethally irradiated mice can restore hematopoiesis at higher percentages than mononuclear cells mobilized by Plerixafor (40% vs. 20%, respectively). Further, a secondary transplant rescued a separate group of irradiated mice from death, proving definitive evidence of hematopoietic reconstitution after hematopoietic stem cells transplantation. Data are presented as mean ± standard deviation. To determine significant differences between the data, one-way ANOVA and the Tukey test were used. CONCLUSIONS Collectively these results show the utility of sodium caseinate as a mobilizer of hematopoietic stem cells and its potential clinical application in transplantation settings.

Transcription factor-mediated reprogramming toward hematopoietic stem cells

De novo generation of human hematopoietic stem cells (HSCs) from renewable cell types has been a long sought-after but elusive goal in regenerative medicine. Paralleling efforts to guide pluripotent stem cell differentiation by manipulating developmental cues, substantial progress has been made recently toward HSC generation via combinatorial transcription factor (TF)-mediated fate conversion, a paradigm established by Yamanaka's induction of pluripotency in somatic cells by mere four TFs. This review will integrate the recently reported strategies to directly convert a variety of starting cell types toward HSCs in the context of hematopoietic transcriptional regulation and discuss how these findings could be further developed toward the ultimate generation of therapeutic human HSCs.

R-ESHAP plus pegfilgrastim as an effective peripheral stem cell mobilization regimen for autologous stem-cell transplantation in patients with relapsed/refractory diffuse large B-cell lymphoma

Stem cell (SC) mobilization is significantly influenced by the mobilization schedule in patients with lymphoma. We evaluated data from 30 patients with relapsed or refractory diffuse large B-cell lymphoma (DLBCL) undergoing SC mobilization. All received R-ESHAP plus a single dose of pegfilgrastim. All patients collected ⩾ 2 × 10(6) CD34+cells/kg, 80% of them at least 5 × 10(6) CD34+cells/kg. Adverse effects of the regimen included myelosuppression and neutropenic fever. Herein, our results suggest that R-ESHAP plus pegfilgrastim is a highly effective mobilization strategy in patients affected by DLBCL associated with a low incidence of adverse events.

Safety and tolerability of intrathecal delivery of autologous bone marrow nucleated cells in children with cerebral palsy: an open-label phase I trial

BACKGROUND AIMS

Cerebral palsy (CP) is related to severe perinatal hypoxia with permanent brain damage in nearly 50% of surviving preterm infants. Cell therapy is a potential therapeutic option for CP by several mechanisms, including immunomodulation through cytokine and growth factor secretion.

METHODS

In this phase I open-label clinical trial, 18 pediatric patients with CP were included to assess the safety of autologous bone marrow-derived total nucleated cell (TNC) intrathecal and intravenous injection after stimulation with granulocyte colony-stimulating factor. Motor, cognitive, communication, personal-social and adaptive areas were evaluated at baseline and 1 and 6 months after the procedure through the use of the Battelle Developmental Inventory. Magnetic resonance imaging was performed at baseline and 6 months after therapy. This study was registered in ClinicaTrials.gov (NCT01019733).

RESULTS

A median of 13.12 × 10(8) TNCs (range, 4.83-53.87) including 10.02 × 10(6) CD34+ cells (range, 1.02-29.9) in a volume of 7 mL (range, 4-10.5) was infused intrathecally. The remaining cells from the bone marrow aspirate were administered intravenously; 6.01 × 10(8) TNCs (range, 1.36-17.85), with 3.39 × 10(6) cells being CD34+. Early adverse effects included headache, vomiting, fever and stiff neck occurred in three patients. No serious complications were documented. An overall 4.7-month increase in developmental age according to the Battelle Developmental Inventory, including all areas of evaluation, was observed (±SD 2.63). No MRI changes at 6 months of follow-up were found.

CONCLUSIONS

Subarachnoid placement of autologous bone marrow-derived TNC in children with CP is a safe procedure. The results suggest a possible increase in neurological function.

Optimizing autologous stem cell mobilization strategies to improve patient outcomes: consensus guidelines and recommendations

Autologous hematopoietic stem cell transplantation (aHSCT) is a well-established treatment for malignancies such as multiple myeloma (MM) and lymphomas. Various changes in the field over the past decade, including the frequent use of tandem aHSCT in MM, the advent of novel therapies for the treatment of MM and lymphoma, and the addition of new stem cell mobilization techniques, have led to the need to reassess current stem cell mobilization strategies. Mobilization failures with traditional strategies are common and result in delays in treatment and increased cost and resource utilization. Recently, plerixafor-containing strategies have been shown to significantly reduce mobilization failure rates, but the ideal method to maximize stem cell yields and minimize costs associated with collection has not yet been determined. A panel of experts convened to discuss the currently available data on autologous hematopoietic stem cell mobilization and transplantation and to devise guidelines to optimize mobilization strategies. Herein is a summary of their discussion and consensus.

Toward a universal treatment for cancer: cell inflation assisted chemotherapy

Cancers show considerable genetic and functional heterogeneity, preventing the development of a universal anticancer drug. Here, I argue that it is nevertheless possible to elaborate a therapeutic strategy that can be used in almost every cancer, exploiting the negative feedback effect of normal cells on the proliferation of their precursors. This method, termed cell inflation assisted chemotherapy, is aimed at blocking normal cell division prior to high-dose antimitotic chemotherapy. Evidence for a negative feedback effect on granulocyte production suggests that it is possible to prevent neutropenia by transfusion of autologous granulocytes. In a first step, this protocol will be devised to protect neutrophils and to prevent granulopenia in patients treated with intensive chemotherapy. In its simplest form, it will consist of a leukapheresis–storage–reinjection sequence just prior to drug administration. Then, if the proof of concept is established, a more systematic use of intensive cell cycle-specific chemotherapy, together with protection of other lineages through temporary mitotic blockade might be a treatment applicable for most cancers.

Negative feedback effect of normal cells on the proliferation of their precursors may be used to protect them from high-dose antimitotic chemotherapy, preventing myelosuppression. In its simplest form, cell inflation assisted chemotherapy will consist of a leukapheresis-storage-reinjection sequence just prior to drug administration.

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.