Allogeneic transplantation: peripheral blood vs. bone marrow

Toxicities associated with tyrosine kinase inhibitor maintenance following allogeneic hematopoietic cell transplantation in Philadelphia chromosome-positive acute lymphoblastic leukemia

Allogeneic hematopoietic cell transplantation (HCT) offers a potential cure in Philadelphia chromosome-positive (Ph+) acute lymphoblastic leukemia (ALL); nonetheless, relapses are common and the major cause of mortality. One strategy to prevent relapse is tyrosine kinase inhibitor (TKI) maintenance post-HCT, but published clinical experience is primarily with the first-generation TKI imatinib while data with newer generation TKIs are limited. We conducted a retrospective analysis of 185 Ph+ ALL patients who underwent HCT followed by TKI maintenance from 2003 to 2021 at City of Hope. Initially, 50 (27.0%) received imatinib, 118 (63.8%) received a second-generation TKI (2G-TKI), and 17 (9.2%) received ponatinib. A total of 77 patients (41.6%) required a dose reduction of their initial TKI due to toxicity. Sixty-six patients (35.7%) did not complete maintenance due to toxicity; 69 patients (37.3%) discontinued 1 TKI, and 11 (5.9%) discontinued 2 TKIs due to toxicity. Initial imatinib versus 2G-TKI versus ponatinib maintenance was discontinued in 19 (38.0%) versus 68 (57.6%) versus 3 (17.6%) patients due to toxicity (p = .003), respectively. Patients on ponatinib as their initial TKI had a longer duration of TKI maintenance versus 2G-TKI: 576.0 days (range, 72-921) versus 254.5 days (range, 3-2740; p = .02). The most common reasons for initial TKI discontinuation include gastrointestinal (GI) intolerance (15.1%), cytopenia (8.6%), and fluid retention (3.8%). The 5-year overall survival and progression-free survival for the total population were 78% and 71%, respectively. Our findings demonstrate the challenges of delivering post-HCT TKI maintenance in a large real-world cohort as toxicities leading to TKI interruptions, discontinuation, and dose reduction were common.

Management of classical Philadelphia chromosome-negative myeloproliferative neoplasms in Asia: consensus of the Asian Myeloid Working Group

Myeloproliferative neoplasms (MPN) are a heterogeneous group of clonal hematopoietic stem cell disorders characterized clinically by the proliferation of one or more hematopoietic lineage(s). The classical Philadelphia-chromosome (Ph)-negative MPNs include polycythemia vera (PV), essential thrombocythemia (ET) and primary myelofibrosis (PMF). The Asian Myeloid Working Group (AMWG) comprises representatives from fifteen Asian centers experienced in the management of MPN. This consensus from the AMWG aims to review the current evidence in the risk stratification and treatment of Ph-negative MPN, to identify management gaps for future improvement, and to offer pragmatic approaches for treatment commensurate with different levels of resources, drug availabilities and reimbursement policies in its constituent regions. The management of MPN should be patient-specific and based on accurate diagnostic and prognostic tools. In patients with PV, ET and early/prefibrotic PMF, symptoms and risk stratification will guide the need for early cytoreduction. In younger patients requiring cytoreduction and in those experiencing resistance or intolerance to hydroxyurea, recombinant interferon-α preparations (pegylated interferon-α 2A or ropeginterferon-α 2b) should be considered. In myelofibrosis, continuous risk assessment and symptom burden assessment are essential in guiding treatment selection. Allogeneic hematopoietic stem cell transplantation (allo-HSCT) in MF should always be based on accurate risk stratification for disease-risk and post-HSCT outcome. Management of classical Ph-negative MPN entails accurate diagnosis, cytogenetic and molecular evaluation, risk stratification, and treatment strategies that are outcome-oriented (curative, disease modification, improvement of quality-of-life).

Hematopoietic stem cell transplantation from HLA-matched sibling donors in children with acute lymphoblastic leukemia: A report from the Children’s Cancer Hospital Egypt

Introduction

Allogeneic hematopoietic stem cell transplantation (HSCT) is widely used for high-risk acute lymphoblastic leukemia (ALL) patients in their first complete remission (CR1), and for relapsed patients in second complete remission (CR2).

Patients and methods

We retrospectively analyzed data for 67 children with ALL, from a cancer center in a low/middle income country, who had undergone HSCT from human leukocyte antigen (HLA)-matched sibling donors (MSDs) using myeloablative conditioning (MAC) regimens, between 2007 and 2020, describing the survival outcome and relapse probability after achieving CR1 and CR2 and determining outcome differences in relation to indications for HSCT in patients transplanted in CR1. All patients had achieved a negative minimal residual disease prior to transplant (<0.01%).

Results

Forty-six patients (68.7%) were in CR1; 25 had adverse cytogenetics, including 18 patients with Philadelphia chromosome-positive ALL (Ph-positive ALL), and 21 had poor induction response. The 5-year overall survival (OS), event-free survival (EFS) and cumulative incidence of relapse (CIR) for the whole cohort were 56.1% (95% CI, 42.8%-69.4%), 49% (95% CI, 35.7%-62.3%) and 33.5% (95% CI, 21.7%-45.8%), respectively with better EFS and CIR for CR1 transplants compared to CR2 transplants (P=0.02 and P=0.03, respectively). Patients with Ph-positive ALL had better 5-year OS, EFS and non-relapse mortality (NRM) compared with other CR1 transplants (P=0.015, P=0.009 and P=0.028, respectively).

Conclusion

Hematopoietic stem cell transplantation from MSD for ALL in CR1 group had superior outcomes compared to CR2 group and was apparently a curable option for Ph-positive ALL without an increased risk of non-relapse mortality. Poorer survival rates and higher relapse probabilities were associated with HSCT conducted to patients who had a poor response to induction therapy or suffered a relapse.

Early intestinal microbial features are associated with CD4 T-cell recovery after allogeneic hematopoietic transplant

Low intestinal microbial diversity is associated with poor outcomes after allogeneic hematopoietic cell transplantation (HCT). Using 16S rRNA sequencing of 2067 stool samples and flow cytometry data from 2370 peripheral blood samples drawn from 894 patients who underwent allogeneic HCT, we have linked features of the early post-HCT microbiome with subsequent immune cell recovery. We examined lymphocyte recovery and microbiota features in recipients of both unmodified and CD34-selected allografts. We observed that fecal microbial diversity was an independent predictor of CD4 T-cell count 3 months after HCT in recipients of a CD34-selected allograft, who are dependent on de novo lymphopoiesis for their immune recovery. In multivariate models using clinical factors and microbiota features, we consistently observed that increased fecal relative abundance of genus Staphylococcus during the early posttransplant period was associated with worse CD4 T-cell recovery. Our observations suggest that the intestinal bacteria, or the factors they produce, can affect early lymphopoiesis and the homeostasis of allograft-derived T cells after transplantation.

Stem Cell-Based Disease Models for Inborn Errors of Immunity

The intrinsic capacity of human hematopoietic stem cells (hHSCs) to reconstitute myeloid and lymphoid lineages combined with their self-renewal capacity hold enormous promises for gene therapy as a viable treatment option for a number of immune-mediated diseases, most prominently for inborn errors of immunity (IEI). The current development of such therapies relies on disease models, both in vitro and in vivo, which allow the study of human pathophysiology in great detail. Here, we discuss the current challenges with regards to developmental origin, heterogeneity and the subsequent implications for disease modeling. We review models based on induced pluripotent stem cell technology and those relaying on use of adult hHSCs. We critically review the advantages and limitations of current models for IEI both in vitro and in vivo. We conclude that existing and future stem cell-based models are necessary tools for developing next generation therapies for IEI.

Reproducible immortalization of erythroblasts from multiple stem cell sources provides approach for sustainable RBC therapeutics

Developing robust methodology for the sustainable production of red blood cells in vitro is essential for providing an alternative source of clinical-quality blood, particularly for individuals with rare blood group phenotypes. Immortalized erythroid progenitor cell lines are the most promising emergent technology for achieving this goal. We previously created the erythroid cell line BEL-A from bone marrow CD34⁺ cells that had improved differentiation and enucleation potential compared to other lines reported. In this study we show that our immortalization approach is reproducible for erythroid cells differentiated from bone marrow and also from far more accessible peripheral and cord blood CD34⁺ cells, consistently generating lines with similar improved erythroid performance. Extensive characterization of the lines shows them to accurately recapitulate their primary cell equivalents and provides a molecular signature for immortalization. In addition, we show that only cells at a specific stage of erythropoiesis, predominantly proerythroblasts, are amenable to immortalization. Our methodology provides a step forward in the drive for a sustainable supply of red cells for clinical use and for the generation of model cellular systems for the study of erythropoiesis in health and disease, with the added benefit of an indefinite expansion window for manipulation of molecular targets.

A bone substitute composed of polymethyl-methacrylate bone cement and Bio-Gene allogeneic bone promotes osteoblast viability, adhesion and differentiation

BACKGROUND

Increasing reports on new cement formulations that address the shortcomings of PMMA bone cements and various active components have been introduced to improve the biological activity of PMMA cement.

OBJECTIVE

Evaluating the biological properties of PMMA cements reinforced with Bio-Gene allogeneic bone.

METHODS

The MC3T3-E1 mouse osteoblast-like cells were utilized to determine the effects of Bio-Gene + PMMA on osteoblast viability, adhesion and differentiation.

RESULTS

The combination of allogeneic bone and PMMA increased the number of adherent live cells compared to both control group and PMMA or Bio-Gene group. Scanning electron microscopy observed that the number of cells adhered to Bio-Gene + PMMA was larger than Bio-Gene and PMMA group. Compared with the control and PMMA or Bio-Gene group, the level of ALP and the number of calcium nodules after osteoinduction was remarkably enhanced in Bio-Gene + PMMA group. Additionally, the combination of Bio-Gene and PMMA induced the protein expression of osteocalcin, osterix and collagen I.

CONCLUSION

The composition of PMMA and allogeneic bone could provide a more beneficial microenvironment for osteoblast proliferation, adhesion and differentiation. PMMA bone cement reinforced with Bio-Gene allogeneic bone may act as a novel bone substitute to improve the biological activity of PMMA cement.

National Marrow Donor Program-Sponsored Multicenter, Phase II Trial of HLA-Mismatched Unrelated Donor Bone Marrow Transplantation Using Post-Transplant Cyclophosphamide

PURPOSE

Hematopoietic cell transplantation (HCT) is curative for hematologic disorders, but outcomes are historically inferior when using HLA-mismatched donors. Despite unrelated donor registries listing > 38 million volunteers, 25%-80% of US patients lack an HLA-matched unrelated donor, with significant disparity across ethnic groups. We hypothesized that HCT with a mismatched unrelated donor (MMUD) using post-transplant cyclophosphamide (PTCy), a novel strategy successful in overcoming genetic disparity using mismatched related donors, would be feasible and increase access to HCT.

PATIENTS AND METHODS

We performed a prospective phase II study of MMUD bone marrow HCT with PTCy for patients with hematologic malignancies. The primary end point was 1-year overall survival (OS), hypothesized to be 65% or better. 80 patients enrolled at 11 US transplant centers (December 2016-March 2019). Following myeloablative or reduced-intensity conditioning-based HCT, patients received PTCy on days +3, +4, with sirolimus and mycophenolate mofetil starting on day +5. We compared outcomes to Center for International Blood and Marrow Transplant Research contemporary controls receiving PTCy.

RESULTS

Notably, 48% of patients enrolled were ethnic minorities. 39% of pairs were matched for 4-6 out of 8 HLA alleles. The primary end point was met, with 1-year OS of 76% (90% CI, 67.3 to 83.3) in the entire cohort, and 72% and 79% in the myeloablative and reduced-intensity conditioning strata, respectively. Secondary end points related to engraftment and graft-versus-host-disease were reached. Multivariate analysis comparing the study group with other mismatched HCT controls found no significant differences in OS.

CONCLUSION

Our prospective study demonstrates the feasibility and effectiveness of HCT with an MMUD in the setting of PTCy. Remarkably, nearly half of the study participants belonged to an ethnic minority population, suggesting this approach may significantly expand access to HCT.

Optimal treatment regimes for competing risk data using doubly robust outcome weighted learning with bi-level variable selection

The goal of the optimal treatment regime is maximizing treatment benefits via personalized treatment assignments based on the observed patient and treatment characteristics. Parametric regression-based outcome learning approaches require exploring complex interplay between the outcome and treatment assignments adjusting for the patient and treatment covariates, yet correctly specifying such relationships is challenging. Thus, a robust method against misspecified models is desirable in practice. Parsimonious models are also desired to pursue a concise interpretation and to avoid including spurious predictors of the outcome or treatment benefits. These issues have not been comprehensively addressed in the presence of competing risks. Recognizing that competing risks and group variables are frequently present, we propose a doubly robust estimation with adaptive L 1 penalties to select important variables at both group and within-group levels for competing risks data. The proposed method is applied to hematopoietic cell transplantation data to personalize the graft source choice for treatment-related mortality (TRM). While the existing medical literature attempts to find a uniform solution ignoring the heterogeneity of the graft source effects on TRM, the analysis results show the effect of the graft source on TRM could be different depending on the patient-specific characteristics.

Allogeneic Peripheral Blood Stem Cell Transplant: Correlation of Donor Factors with Yield, Engraftment, Chimerism, and Outcome: Retrospective Review of a Single Institute During a 3-Year Period

BACKGROUND

Donor factors have a variable correlation with cluster of differentiation (CD)34+ cell dose in allogeneic peripheral blood stem cell (PBSC) harvests. CD34+ cell dose affects the speed of hematopoietic recovery and percentage of donor chimerism in the recipient.

METHODS

A total of 25 allogeneic PBSC transplants performed during a 3-year period were included. All donors underwent mobilization with filgrastim. Leukapheresis, flowcytometric CD34+ cell enumeration, and chimerism analysis were performed and correlated with recipient outcome.

RESULTS

Besides age, all other donor parameters had a positive correlation with CD34+ cell count. Engraftment kinetics and chimerism had a positive correlation with the CD34+ yield of the PBSC product. Acute graft-vs-host disease (GVHD) was observed in patients with complete chimerism at day 30 after transplantation.

CONCLUSION

Adequate CD34+ cell yield happens in healthy donors, independent of donor demographic patterns with G-CSF only. A diverse population of donors can thus be approached for Matched Unrelated Donor (MUD) transplants. An accurate quantitative analysis of early donor chimerism in the recipient (at day 30) is an excellent tool for post-transplant monitoring for acute GvHD.

BM is preferred over PBSCs in transplantation from an HLA-matched related female donor to a male recipient

The use of granulocyte colony-stimulating factor-mobilized peripheral blood stem cells (PBSCs) and sex-mismatched hematopoietic cell transplantation (HCT), especially with female donors and male recipients (FtoM), is known to be associated with an increased risk of chronic graft-versus-host disease (GVHD) compared with transplantation with bone marrow (BM). This raises the question of whether the use of PBSCs in FtoM HCT might affect allogeneic responses, resulting in fatal complications. Using a Japanese transplantation registry database, we analyzed 1132 patients (FtoM, n = 315; MtoF, n = 260; sex-matched, n = 557) with standard-risk diseases who underwent HCT with an HLA-matched related donor without in vivo T-cell depletion between 2013 and 2016. The impact of PBSC vs BM on transplantation outcomes was separately assessed in FtoM, MtoF, and sex-matched HCT. Overall survival (OS) and nonrelapse mortality (NRM) at 2 years post-HCT were significantly worse in patients with PBSCs vs those with BM in FtoM HCT (2-year OS, 76% vs 62%; P = .0084; 2-year NRM, 10% vs 21%; P = .0078); no differences were observed for MtoF or sex-matched HCT. Multivariate analyses confirmed the adverse impact of PBSCs in FtoM HCT (hazard ratio [HR] for OS, 1.91; P = .025; HR for NRM, 3.70; P = .0065). In FtoM HCT, patients with PBSCs frequently experienced fatal GVHD and organ failure. In conclusion, the use of PBSCs in FtoM HCT was associated with an increased risk of NRM in the early phase, resulting in inferior survival. This suggests that, when we use female-related donors for male patients in HCT, BM may result in better outcomes than PBSCs.

The Graft-Versus-Leukemia Effect in AML

Allogeneic hematopoietic stem cell transplantation (allo-SCT) is the most established and commonly used cellular immunotherapy in cancer care. It is the most potent anti-leukemic therapy in patients with acute myeloid leukemia (AML) and is routinely used with curative intent in patients with intermediate and poor risk disease. Donor T cells, and possibly other immune cells, eliminate residual leukemia cells after prior (radio)chemotherapy. This immune-mediated response is known as graft-versus-leukemia (GvL). Donor alloimmune responses can also be directed against healthy tissues, which is known as graft-versus-host disease (GvHD). GvHD and GvL often co-occur and, therefore, a major barrier to exploiting the full immunotherapeutic benefit of donor immune cells against patient leukemia is the immunosuppression required to treat GvHD. However, curative responses to allo-SCT and GvHD do not always occur together, suggesting that these two immune responses could be de-coupled in some patients. To make further progress in successfully promoting GvL without GvHD, we must transform our limited understanding of the cellular and molecular basis of GvL and GvHD. Specifically, in most patients we do not understand the antigenic basis of immune responses in GvL and GvHD. Identification of antigens important for GvL but not GvHD, and vice versa, could impact on donor selection, allow us to track GvL immune responses and begin to specifically harness and strengthen anti-leukemic immune responses against patient AML cells, whilst minimizing the toxicity of GvHD.

Peripheral Blood or Bone Marrow Stem Cells? Practical Considerations in Hematopoietic Stem Cell Transplantation

Although peripheral blood stem cells (PBSC) have worldwide become the predominant source of progenitor cells for hematopoietic stem cell transplantation (HSCT), debate about their role compared with bone marrow (BM) has recently intensified, in large part based on the results of a multicenter Clinical Trials Network study which showed lower incidence of chronic graft-versus-host disease (cGVHD) and improved quality of life in recipients of myeloablative HLA-matched unrelated BM compared with PBSC transplants. However, in certain patient populations, PBSC may lead to improved clinical outcomes due to faster hematologic recovery, a lower risk of graft failure, and possibly a lower probability of relapse. This review will provide a comprehensive summary of studies comparing PBSC with BM as the graft source in terms of acute and chronic GVHD incidence, time to engraftment, and disease-free and overall survival probabilities after HLA-matched related and unrelated donor transplantation and haploidentical donor transplantation. Recommendations based on these studies regarding the use of PBSC versus BM for HSCT are offered.

Homeostatic γδ T Cell Contents Are Preserved by Granulocyte Colony-Stimulating Factor Priming and Correlate with the Early Recovery of γδ T Cell Subsets after Haploidentical Hematopoietic Stem Cell Transplantation

Emerging evidence from graft manipulations and immunotherapeutic treatments has highlighted a favorable effect of γδ T cells in the setting of allogeneic hematopoietic stem cell transplantation (alloHSCT). However, γδ T cell subsets and their distinct features in the allograft have not been characterized. Additionally, whether homeostatic γδ T cell fractions are influenced by treatment with granulocyte colony-stimulating factor (G-CSF) remains elusive. We initially compared the phenotypes of γδ T cell subsets, including CD27⁺, CD27^-, Vδ1⁺, Vδ2⁺, Vδ1⁺CD27⁺, Vδ1⁺CD27^-, Vδ2⁺CD27⁺, and Vδ2⁺CD27^- cells, in the peripheral blood of 20 healthy donors before and after G-CSF mobilization. The effects of G-CSF on the cytokine production capacities of γδ T cell subsets were also detected. Moreover, the correlation between donor homeostatic γδ T cell content and the early recoveries of γδ T cell subgroups after haploidentical HSCT was investigated in 40 pairs of donors and recipients. We found that both the proportions and IFN-γ secretion capacities of peripheral γδ T cell subsets were preserved in G-CSF-primed grafts. Homeostatic Vδ1 and Vδ2 proportions of donors significantly correlated with the early recoveries of Vδ1 and Vδ2 cells after haploidentical HSCT. Interestingly, a higher day 30 Vδ1 concentration was associated with a lower incidence of cytomegalovirus reactivation in recipients. These results not only clarify the preservation of γδ T cell phenotypes and functional features by G-CSF mobilization but also suggest the importance of homeostatic γδ T cell content for immune recovery after alloHSCT.

Risk Factors for Graft-Versus-Host Disease After Transplantation of Hematopoietic Stem Cells from Unrelated Donors in the China Marrow Donor Program

Background

We identified risk factors for acute and chronic graft-versus-host disease (aGVHD and cGVHD, respectively) in recipients after hematopoietic stem cell transplantation (HSCT) from unrelated donors in the China Marrow Donor Program (CMDP).

Material/Methods

We analyzed follow-up clinical information from 1824 patients who underwent HSCT between 2001 and 2010.

Results

The incidence of aGVHD and cGVHD after transplantation was 49.29% and 27.3%, respectively. aGVHD incidence decreased as HLA matching increased (p<0.001). Incidence of aGVHD and cGVHD was higher in 2 HLA-A locus donor/recipient groups (02: 01/02: 06 and 02: 01/02: 07; p≤0.022). aGVHD incidence was associated with patient age, absence of rabbit anti-thymocyte globulin (ATG) pretreatment, and disease status (p≤0.040). aGVHD appeared to be a risk factor for cGVHD, and total body irradiation (TBI) was also associated with cGVHD. Patients with cGVHD after transplantation had a higher survival rate than patients without cGVHD (p<0.001), which may be due to reduced relapse rates. Survival was also associated with ATG prophylaxis and disease status.

Conclusions

The incidence of GVHD after HSCT from unrelated donors in the Chinese population is similar to the results reported from other countries. A high degree of HLA matching, a conditioning regimen without TBI, and the use of ATG may reduce the incidence of aGVHD.

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).

Subsequent vitiligo after hematopoietic stem cell transplantation: A nationwide population-based cohort study from Korea

BACKGROUND

Subsequent vitiligo after hematopoietic stem cell transplantation (HSCT) has been described sporadically in case series.

OBJECTIVE

To investigate the incidence and risk factors of subsequent vitiligo after HSCT.

METHODS

A nationwide, population-based cohort study was performed using the Korean National Health Insurance Claims Database from 2009 to 2013. All HSCT recipients who had undergone HSCT between 2010 and 2011 and not treatment for vitiligo in 2009 (to exclude preexisting active vitiligo) were included in the HSCT recipient group, and an age- and sex-matched control group without HSCT was also established.

RESULTS

A total of 2747 HSCT recipients and 8241 controls were enrolled. Newly acquired vitiligo occurred in 1.06% of HSCT recipients between 2010 and 2013, and there was a significant increase (OR 3.130, 95% CI 1.859-5.271) in cases of vitiligo in HSCT recipients compared with controls (0.34%). Allogeneic HSCT (OR 5.593, 95% CI 1.628-19.213) and bone marrow-sourced stem cells (as compared with peripheral blood-sourced stem cells; OR 2.492, 95% CI 1.114-5.576) were independently associated with the development of vitiligo after HSCT.

LIMITATIONS

Medical record review was not available.

CONCLUSION

Vitiligo developed at a significantly increased rate after HSCT compared with controls. Allogeneic HSCT and bone marrow-sourced stem cells were independent risk factors.

Granulocyte colony-stimulating factor impairs CD8(+) T cell functionality by interfering with central activation elements

Besides mobilizing stem cells into the periphery, granulocyte colony-stimulating factor (G-CSF) has been shown to influence various types of innate and adaptive immune cells. For example, it impairs the effector function of cytotoxic T lymphocytes (CTLs). It is assumed that this effect is mediated indirectly by monocytes, regulatory T cells and immunomodulatory cytokines influenced by G-CSF. In this study, isolated G-CSF-treated CD8(+) T cells were stimulated antigen-dependently with peptide-major histocompatibility complex (pMHC)-coupled artificial antigen-presenting cells (aAPCs) or stimulated antigen-independently with anti-CD3/CD28 stimulator beads. By measuring the changes in interferon (IFN)-γ and granzyme B expression at the mRNA and protein level, we showed for the first time that G-CSF has a direct effect on CD8(+) CTLs, which was confirmed based on the reduced production of IFN-γ and granzyme B by the cytotoxic T cell line TALL-104 after G-CSF treatment. By investigating further elements affected by G-CSF in CTLs from stem cell donors and untreated controls, we found a decreased phosphorylation of extracellular-regulated kinase (ERK)1/2, lymphocyte-specific protein tyrosine kinase (Lck) and CD3ζ after G-CSF treatment. Additionally, miRNA-155 and activation marker expression levels were reduced. In summary, our results show that G-CSF directly influences the effector function of cytotoxic CD8(+) T cells and affects various elements of T cell activation.

Transplantations from HLA-identical siblings versus 10/10 HLA-matched unrelated donors

The clinical outcome after allogeneic stem cell transplantation from a human leukocyte antigen (HLA)-matched sibling donor as well as an HLA-matched unrelated donor has clearly improved due in part to the progress made in the domains of HLA-typing techniques. Although HLA-matched sibling transplantation is still held as the "gold standard," transplantation from HLA-A, -B, -C, -DRB1, and -DQB1-matched unrelated donors (so called 10/10) represent the first choice for patients without a suitable related donor. Several studies have shown that unmanipulated marrow transplantation from an HLA allele-matched unrelated donor resulted in similar outcomes to those observed following sibling transplantation. However, incorporating anti-thymocyte globulin (ATG) within graft-versus-host disease (GVHD) prophylaxis should be considered for peripheral blood stem cell grafts in order to decrease the risk of developing chronic GVHD.

[Changes of angiopoietin 1 expression in G-CSF induced hematopoietic stem progenitor cells mobilization]

目的

探讨G-CSF诱导的造血干／祖细胞（HSPC）动员过程中血管生成素1(Ang1)在小鼠骨髓的表达变化及导致其变化的机制。

方法

采用流式细胞术检测小鼠动员前及动员后外周血Lin⁻Sca1⁺cKit⁺(LSK)细胞比例变化，并应用ELISA、免疫组化、RQ-PCR等方法检测G-CSF动员不同时间点小鼠外周血和骨髓标本，观察Ang1、骨钙素（OCN）基因及蛋白水平变化，显微镜下计数骨髓标本成骨细胞数量。

结果

G-CSF动员5 d小鼠外周血LSK细胞比例为（0.61±0.05)%，相对于对照组的(0.04±0.01)%显著增高(P<0.05)；稳态小鼠OCN及Ang1 mRNA在骨内膜细胞表达高于骨髓有核细胞；动员后骨内膜细胞OCN及Ang1 mRNA相对表达量对照组（28.64±8.61及2.84±0.95)、G-CSF动员3 d组（12.55±7.06及0.93±0.30）及动员5 d组（4.75±1.62及0.92±0.22）均下降；动员后骨内膜成骨细胞数量显著减少，骨髓组织Ang1蛋白表达下降；对照组、动员3 d及5 d组外周血OCN及Ang1浓度分别为（24.11±3.17）及（2.24±0.52)ng/ml、(9.96±2.16）及（1.21±0.38)ng/ml和（8.43±2.62）及(0.90±0.24) ng/ml，动员3 d及5 d组均明显低于对照组，差异均有统计学意义(P值均<0.05)。

结论

在G-CSF介导的HSPC动员过程中，骨髓微环境中成骨细胞数量下降、功能减低，进而导致骨髓Ang1表达下降，导致骨髓对HSPC的趋化和黏附能力下降，有利于HSPC动员的发生。

Plerixafor as a salvage mobilization strategy for haploidentical peripheral blood allogeneic stem cell transplantation

In allogeneic stem cell mobilization, peripheral blood stem cell mobilization with filgrastim can be considered standard of care. Poor mobilizers may be at risk for inadequate stem cell collection during apheresis. He we present a successful case of salvage plerixafor use with filgrastim in a haploidentical identical transplant patient.

New clinical advances in immunotherapy for the treatment of solid tumours

Advances in understanding the mechanisms of cancer cells for evading the immune system surveillance, including how the immune system modulates the phenotype of tumours, have allowed the development of new therapies that benefit from this complex cellular network to specifically target and destroy cancer cells. Immunotherapy researchers have mainly focused on the discovery of tumour antigens that could confer specificity to immune cells to detect and destroy cancer cells, as well as on the mechanisms leading to an improved activation of effector immune cells. The Food and Drug Administration approval in 2010 of ipilumumab for melanoma treatment and of pembrolizumab in 2014, monoclonal antibodies against T-lymphocyte-associated antigen 4 and programmed cell death 1, respectively, are encouraging examples of how research in this area can successfully translate into clinical use with promising results. Currently, several ongoing clinical trials are in progress testing new anti-cancer therapies based on the enhancement of immune cell activity against tumour antigens. Here we discuss the general concepts related to immunotherapy and the recent application to the treatment of cancer with positive results that support their consideration of clinical application to patients.

Bone marrow versus peripheral blood allogeneic haematopoietic stem cell transplantation for haematological malignancies in adults

BACKGROUND

Allogeneic haematopoietic stem cell transplantation (allo-HSCT) is an established treatment option for many malignant and non-malignant disorders. In the past two decades, peripheral blood stem cells replaced bone marrow as stem cell source due to faster engraftment and practicability. Previous meta-analyses analysed patients treated from 1990 to 2002 and demonstrated no impact of the stem cell source on overall survival, but a greater risk for graft-versus-host disease (GvHD) in peripheral blood transplants. As transplant indications and conditioning regimens continue to change, whether the choice of the stem cell source has an impact on transplant outcomes remains to be determined.

OBJECTIVES

To assess the effect of bone marrow versus peripheral blood stem cell transplantation in adult patients with haematological malignancies with regard to overall survival, incidence of relapse and non-relapse mortality, disease-free survival, transplant-related mortality, incidence of GvHD and time to engraftment.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2014, Issue 1), MEDLINE (from 1948 to February 2014), trial registries and conference proceedings. The search was conducted in October 2011 and was last updated in February 2014. We did not apply any language restrictions.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing bone marrow and peripheral blood allogeneic stem cell transplantation in adults with haematological malignancies.

DATA COLLECTION AND ANALYSIS

Two review authors screened abstracts and extracted and analysed data independently. We contacted study authors for additional information. We used the standard methodological procedures expected by The Cochrane Collaboration.

MAIN RESULTS

We included nine RCTs that met the pre-defined selection criteria, involving a total of 1521 participants. Quality of data reporting was heterogeneous among the studies. Overall, the risk of bias in the included studies was low.For the primary outcome overall survival, our analysis demonstrated comparable results between bone marrow transplantation (BMT) and peripheral blood stem cell transplantation (PBSCT) (six studies, 1330 participants; hazard ratio (HR) 1.07; 95% CI 0.91 to 1.25; P value = 0.43; high-quality evidence).Disease-free survival (six studies, 1225 participants; HR 1.04; 95% CI 0.89 to 1.21; P value = 0.6; moderate-quality of evidence) and non-relapse or transplant-related mortality (three studies, 758 participants; HR 0.98; 95% CI 0.76 to 1.28; P = 0.91; high-quality evidence) were also comparable between transplantation arms.In the related-donor setting, data from two of eight studies with 211 participants (21%) indicated a higher relapse incidence in participants transplanted with bone marrow stem cells rather than peripheral blood stem cells (HR 2.73; 95% CI 1.47 to 5.08; P value = 0.001). There was no clear evidence of a difference in relapse incidence between transplantation groups in unrelated donors (HR 1.07; 95% CI 0.78 to 1.47; P value = 0.66). The difference between the donor-related and -unrelated subgroups (P-value = 0.008) was considered to be statistically significant.BMT was associated with lower rates of overall and extensive chronic GvHD than PBSCT (overall chronic GvHD: four studies, 1121 participants; HR 0.72; 95% CI 0.61 to 0.85; P value = 0.0001, extensive chronic GvHD: four studies, 765 participants; HR 0.69; 95% CI 0.54 to 0.9; P value = 0.006; moderate-quality evidence for both outcomes). The incidence of acute GvHD grades II to IV was not lower (six studies, 1330 participants; HR 1.03; 95% CI 0.89 to 1.21; P value = 0.67; moderate-quality evidence), but there was a trend for a lower incidence of grades III and IV acute GvHD with BMT than with PBSCT (three studies, 925 participants; HR 0.75; 95% CI 0.55 to 1.02; P value = 0.07; moderate-quality evidence).Times to neutrophil and platelet engraftment were longer with BMT than with PBSCT (neutrophil: five studies, 662 participants; HR 1.96; 95% CI 1.64 to 2.35; P value < 0.00001; platelet: four studies, 333 participants; HR 2.17; 95% CI 1.69 to 2.78; P value < 0.00001).

AUTHORS' CONCLUSIONS

This systematic review  found high-quality evidence that overall survival following allo-HSCT using the current clinical standard stem cell source - peripheral blood stem cells - was similar to that following allo-HSCT using bone marrow stem cells in adults with haematological malignancies. We found moderate-quality evidence that PBSCT was associated with faster engraftment of neutrophils and platelets, but a higher risk of GvHD (in terms of more overall and extensive chronic GvHD). There was an imprecise effect on relapse and on severe (grades III to IV) acute GvHD. Quality of life, which is severely affected by GvHD, was not evaluated.Against the background of transplantation practices that have clearly changed over the past 10 to 15 years, our aim was to provide current data on the best stem cell source for allo-HSCT, by including the results of recently conducted trials. Our review includes participants recruited up to 2009, a proportion of whom were older, had received reduced-intensity conditioning regimens or had been transplanted with stem cells from unrelated donors. However, only one, large, study included relatively recently treated participants. Nevertheless, our findings are comparable to those of previous meta-analyses suggesting that our results hold true for today's practice.

Impaired functionality of antiviral T cells in G-CSF mobilized stem cell donors: implications for the selection of CTL donor

Adoptive transfer of antiviral T cells enhances immune reconstitution and decreases infectious complications after stem cell transplantation. Information on number and function of antiviral T cells in stem cell grafts is scarce. We investigated (1) immunomodulatory effects of G-CSF on antiviral T cells, (2) the influence of apheresis, and (3) the optimal time point to collect antiviral cells. CMV-, EBV- and ADV-specific T cells were enumerated in 170 G-CSF-mobilized stem cell and 24 non-mobilized platelet donors using 14 HLA-matched multimers. T-cell function was evaluated by IFN-γ ELISpot and granzyme B secretion. Immunophenotyping was performed by multicolor flow cytometry. G-CSF treatment did not significantly influence frequency of antiviral T cells nor their in vitro expansion rate upon antigen restimulation. However, T-cell function was significantly impaired, as expressed by a mean reduction in secretion of IFN-γ (75% in vivo, 40% in vitro) and granzyme B (32% target-independent, 76% target-dependent) as well as CD107a expression (27%). Clinical follow up data indicate that the first CMV-reactivation in patients and with it the need for T-cell transfer occurs while the donor is still under the influence of G-CSF. To overcome these limitations, T-cell banking before mobilization or recruitment of third party donors might be an option to optimize T-cell production.

Granulocyte Transfusion Therapy

Bacterial and fungal infections continue to be a major cause of morbidity and mortality in severely neutropenic patients undergoing aggressive chemotherapy regimens or hematopoietic stem cell transplantation. Traditional granulocyte transfusion therapy, a logical approach in treating these infections, has been available for many years, and several controlled studies have shown this therapy to be useful. However, granulocyte transfusion therapy fell out of favor because the results were not clinically impressive, and adverse results were reported. These disappointing results were felt to be, in part, because of the low doses of granulocytes provided. More recent studies have attempted to increase the numbers of transfused cells by stimulating normal granulocyte donors with G-CSF (+/-corticosteroids). With these techniques, the number of granulocytes transfused can be increased 3-4 fold. The cells have been shown to circulate in recipients, and daily transfusions are capable of maintaining normal or near-normal blood neutrophil counts in previously severely neutropenic patients. The cells appear to function normally by a variety of in vitro and in vivo tests. Clinical benefit, as defined by survival or clearance of infection, has not been definitively determined. Results of an ongoing randomized controlled clinical trial should be available in the near future.

Donor body mass index is an important factor that affects peripheral blood progenitor cell yield in healthy donors after mobilization with granulocyte-colony-stimulating factor

BACKGROUND

The use of hematopoietic progenitor cell (HPC) transplantation has rapidly expanded in recent years. Currently, several sources of HPCs are available for transplantation including peripheral blood HPCs (PBPCs), cord blood cells, and marrow cells. Of these, PBPC collection has become the major source of HPCs. An important variable in PBPC collection is the response to PBPC mobilization, which varies significantly and sometime causes mobilization failure.

STUDY DESIGN AND METHODS

A retrospective study of 69 healthy donors who underwent PBPC donation by leukapheresis was performed. All of these donors received 10 μg/kg/day or more granulocyte-colony-stimulating factor (G-CSF) for 5 days before PBPC harvest. Donor factors were evaluated and correlated with mobilization responses, as indicated by the precollection CD34 count (pre-CD34).

RESULTS

Donors with a pre-CD34 of more than 100 × 10(6) /L had higher body mass index (BMI) compared with donors whose pre-CD34 was 38 × 10(6) to 99 × 10(6) /L or less than 38 × 10(6) /L (32.0 ± 1.04 kg/m(2) vs. 28.7 ± 0.93 kg/m(2) vs. 25.9 ± 1.27 kg/m(2) , respectively; p < 0.05). In addition, donors with high BMIs had higher pre-CD34 on a per-kilogram-of-body-weight basis compared with donors with low BMIs.

CONCLUSION

BMI is an important factor that affects donor's response to mobilization and consequently the HPC yield. This effect may be due to a relatively high dose of G-CSF administered to donors with higher BMI or due to the presence of unknown intrinsic factors affecting mobilization that correlate with the amount of adipose tissue in each donor.

The expanding frontier of hematopoietic cell transplantation

Over the past several decades there has been a tremendous expansion of the indications for hematopoietic cell transplantation. This growth has been possible because of advances in supportive care, more effective graft versus host disease prophylaxis and the advent of reduced intensity conditioning regimens which have greatly reduced transplant related morbidity and allowed for the transplantation of older patients and patients with significant co-morbid disease. The role of flow cytometry in transplantation is crucial to both clinical care, for accuracy of diagnosis and monitoring of disease, and research. In this review, we highlight some of the important advances that have been made in the field, including the use of alternative donors for transplantation, novel therapies for the myeloid malignancies, which remain the prototype diseases for transplantation, and advances in diagnosis and treatment of graft versus host disease, which is the principal complication of allogeneic hematopoietic cell transplantation. Future directions in hematopoietic cell transplantation, particularly those that attempt to modulate the post-transplant cellular environment to favor separation of graft versus host disease from the graft versus tumor effects of the transplant are discussed.