Outcomes after related and unrelated umbilical cord blood transplantation for hereditary bone marrow failure syndromes other than Fanconi anemia

Outcomes of allogeneic hematopoietic stem cell transplantation in Shwachman-Diamond syndrome: a systematic review and meta-analysis

We conducted a systematic review and meta-analysis to evaluate the outcomes of Allogeneic hematopoietic stem cell transplantation (Allo-HSCT) in the treatment of Shwachman-Diamond syndrome (SDS). A literature search was performed on PubMed, Embase, and Web of Science. After screening 397 articles, 10 studies were included. Data was extracted in accordance with the PRISMA guidelines and analyzed using the R 'meta' package. The pooled median 3 (1-5)-year overall survival (OS) after Allo-HSCT were 63.7% (95% CI 56.9-70.2%), 80.3% (95% CI 68.% 5-92.1%), 41.1% (95% CI 21.7-60.4%), 48.9% (95% CI 29.0-68.9%), and 8.7% (95% CI 0.0-60.8%) in SDS patients, SDS patients with bone marrow failure (BMF), SDS patients with myeloid neoplasms (MN), SDS patients with myelodysplastic syndrome (MDS), and SDS patients with acute myeloid leukemia (AML), respectively. Allo-HSCT is an efficacious approach for treating SDS patients with severe hematologic complications. However, poor outcomes were revealed in SDS patients with MN with a pooled 3 (1-5)-year relapse rate (RR) after Allo-HSCT of 25.8% (95% CI 12.5-39.0%), and a pooled 3-year non-relapse mortality (NRM) was 52.6% (95% CI 34.2-70.9%). These findings were consistent with the clinical findings that transplant-related complications are the main cause of the poor transplantation prognosis of SDS patients with MN. Efficacious bone marrow conditioning regimens, graft-versus-host disease (GVHD) prevention, and bridging treatment regimens are potential means to improve the transplantation prognosis of SDS patients.

A phase 2 pilot study of umbilical cord blood infusion as an adjuvant consolidation therapy in elderly patients with acute myeloid leukemia

Acute myeloid leukemia (AML) is an aging-related malignancy, with patients aged ≥60 years old facing significantly poorer prognosis. Umbilical cord blood (UCB) has emerged as a promising source with effective anti-aging roles. Here, we conducted a prospective, phase 2, single-arm trial of UCB infusion as an adjuvant consolidation therapy in elderly AML patients (ChiCTR-OPC-15006492). A total of 51 patients were enrolled (median age 66 years; range, 60-75) and received two cycles of consolidation chemotherapy combined with UCB infusion. At a median follow-up of 27.3 months (range, 9.3-100), the median overall survival (OS) was not yet reached and the median event-free survival (EFS) was 72.2 months (range, 5.4-100). The 2-year OS and EFS rates were 76.9% and 62.8%, respectively. No acute graft-versus-host disease (aGVHD) or toxicity-related death occurred in any patient. The median times to platelet and neutrophil recovery were 11.5 days (range, 6-17) and 12.2 days (range, 0-21), respectively. Single-cell RNA sequencing (scRNA-seq) identified enhanced anti-tumor and anti-aging properties of UCB, manifested through activation of immune responses and telomere synthesis/maintenance. These findings suggest that UCB infusion is an effective and safe post-remission adjuvant therapy for elderly AML patients. This study provides evidence that anti-aging therapy may serve as a new and promising dimension in combined cancer treatment.

Allogeneic Hematopoietic Cell Transplant For Bone Marrow Failure or Myelodysplastic Syndrome in Dyskeratosis Congenita/Telomere Biology Disorders: Single-Center, Single-Arm, Open-Label Trial of Reduced-Intensity Conditioning Without Radiation

BACKGROUND

Dyskeratosis congenita/telomere biology disorders (DC/TBD) often manifest as bone marrow failure (BMF) or myelodysplastic syndrome (MDS). Allogeneic hematopoietic cell transplant (alloHCT) rescues hematologic complications, but radiation and alkylator-based conditioning regimens cause diffuse whole-body toxicity and may expedite DC/TBD-specific non-hematopoietic complications. Optimization of conditioning intensity in DC/TBD to allow for donor hematopoietic cell engraftment with the least amount of toxicity remains a critical goal of the alloHCT field.

OBJECTIVES/STUDY DESIGN

We report prospectively collected standard alloHCT outcomes from a single-center, single-arm, open-label clinical trial of bone marrow or peripheral blood stem cell alloHCT for DC/TBD-associated BMF or MDS. Conditioning was reduced intensity (RIC), including alemtuzumab 1 mg/kg, fludarabine 200 mg/m2, and cyclophosphamide 50 mg/kg. A previous single-arm, open-label phase II clinical trial for the same patient population conducted at the same center, differing only by inclusion of 200 cGy of total body irradiation (TBI), served as a control cohort.

RESULTS

The non-TBI cohort included 10 patients (ages 1.7-65.9 years, median follow-up of 3.9 years) compared with the control TBI cohort, which included 12 patients (ages 2.2-52.2 years, median follow-up of 10.5 years). Baseline characteristics differed only in total CD34+ cells received, with a median of 5.6 (non-TBI) compared with 2.6 (TBI) x 106/kg (P = .02; no difference in total nucleated cells). The cumulative incidence of day +100 grade II-IV acute and 4-year chronic graft-versus-host disease (GvHD) were low at 0% and 10% (non-TBI) and 8% and 17% (TBI), respectively (acute, P = .36; chronic, P = .72). Primary graft failure was absent. Secondary non-neutropenic graft failure occurred in one (non-TBI cohort). The non-TBI cohort demonstrated delayed achievement of full donor chimerism but superior lymphocyte recovery. There was no difference in 4-year overall survival at 80% (non-TBI) and 75% (TBI; P = .78). MDS as an indication for alloHCT was uncommon but overall associated with poor outcomes. There were 3 MDS patients in the non-TBI cohort: 1 relapsed and died at day +387; 1 relapsed at day +500 and is alive 5.5 years later following salvage with a second alloHCT; 1 relapsed at day +1093 and is alive at day +100 after a second alloHCT. There was 1 MDS patient in the TBI cohort who achieved 100% donor myeloid engraftment without relapse but died at day +827 from a bacterial infection in the setting of immune-mediated cytopenia.

CONCLUSION

Elimination of TBI from the RIC regimen for DC/TBD was not associated with significant changes in rates of graft failure, GvHD, and overall survival but was associated with delayed achievement of full donor chimerism and improved lymphocyte reconstitution. For DC/TBD-associated BMF, TBI appears to be dispensable. Optimal approaches to DC/TBD-associated MDS remain unclear. Larger cohorts are needed to better assess the unique contribution of TBI and donor CD34+ cell dose. Longer follow-up is required to assess differences in DC/TBD complications and late effects.

Pediatric Bone Marrow Failure: A Broad Landscape in Need of Personalized Management

Irreversible severe bone marrow failure (BMF) is a life-threatening condition in pediatric patients. Most important causes are inherited bone marrow failure syndromes (IBMFSs) and (pre)malignant diseases, such as myelodysplastic syndrome (MDS) and (idiopathic) aplastic anemia (AA). Timely treatment is essential to prevent infections and bleeding complications and increase overall survival (OS). Allogeneic hematopoietic stem cell transplantation (HSCT) provides a cure for most types of BMF but cannot restore non-hematological defects. When using a matched sibling donor (MSD) or a matched unrelated donor (MUD), the OS after HSCT ranges between 60 and 90%. Due to the introduction of post-transplantation cyclophosphamide (PT-Cy) to prevent graft versus host disease (GVHD), alternative donor HSCT can reach similar survival rates. Although HSCT can restore ineffective hematopoiesis, it is not always used as a first-line therapy due to the severe risks associated with HSCT. Therefore, depending on the underlying cause, other treatment options might be preferred. Finally, for IBMFSs with an identified genetic etiology, gene therapy might provide a novel treatment strategy as it could bypass certain limitations of HSCT. However, gene therapy for most IBMFSs is still in its infancy. This review summarizes current clinical practices for pediatric BMF, including HSCT as well as other disease-specific treatment options.

Hematopoietic cell transplantation and gene therapy for Diamond-Blackfan anemia: state of the art and science

Diamond-Blackfan anemia (DBA) is one of the most common inherited causes of bone marrow failure in children. DBA typically presents with isolated erythroid hypoplasia and anemia in infants. Congenital anomalies are seen in 50% of the patients. Over time, many patients experience panhematopoietic defects resulting in immunodeficiency and multilineage hematopoietic cytopenias. Additionally, DBA is associated with increased risk of myelodysplastic syndrome, acute myeloid leukemia and solid organ cancers. As a prototypical ribosomopathy, DBA is caused by heterozygous loss-of-function mutations or deletions in over 20 ribosomal protein genes, with RPS19 being involved in 25% of patients. Corticosteroids are the only effective initial pharmacotherapy offered to transfusion-dependent patients aged 1 year or older. However, despite good initial response, only ~20-30% remain steroid-responsive while the majority of the remaining patients will require life-long red blood cell transfusions. Despite continuous chelation, iron overload and related toxicities pose a significant morbidity problem. Allogeneic hematopoietic cell transplantation (HCT) performed to completely replace the dysfunctional hematopoietic stem and progenitor cells is a curative option associated with potentially uncontrollable risks. Advances in HLA-typing, conditioning regimens, infection management, and graft-versus-host-disease prophylaxis have led to improved transplant outcomes in DBA patients, though survival is suboptimal for adolescents and adults with long transfusion-history and patients lacking well-matched donors. Additionally, many patients lack a suitable donor. To address this gap and to mitigate the risk of graft-versus-host disease, several groups are working towards developing autologous genetic therapies to provide another curative option for DBA patients across the whole age spectrum. In this review, we summarize the results of HCT studies and review advances and potential future directions in hematopoietic stem cell-based therapies for DBA.

Stem Cell Transplantation in Patients Affected by Shwachman-Diamond Syndrome: Expert Consensus and Recommendations From the EBMT Severe Aplastic Anaemia Working Party

Shwachman-Diamond syndrome is a rare disorder that can develop malignant and nonmalignant hematological complications. Overall, 10% to 20% of Shwachman-Diamond patients need hematopoietic stem cell transplantation (HSCT), but most centers have a limited experience and different approaches. The European Society for Blood and Marrow Transplantation-Severe Aplastic Anaemia Working Party promoted an expert consensus to propose recommendations regarding key issues in the management of Shwachman-Diamond patients with hematological complications. The main items identified as relevant for improving survival were: the importance of regular and structured hematologic follow-up, the potential reduction of transplant-related mortality by using reduced-intensity conditioning regimens, the limitation of total body irradiation, particularly for non-malignant severe cytopenia/bone marrow failure, the early diagnosis of clonal malignant evolution and early recognition of an indication for HSCT. Finally, the poor results of HSCT in patients with acute myeloid leukemia, irrespective of cytoreductive chemotherapy treatment received prior to transplantation, highlights the need for innovative approaches. © 2023 American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.

Recent advances in hematopoietic cell transplantation for inherited bone marrow failure syndromes

Inherited bone marrow failure syndromes (IBMFSs) are a group of rare genetic disorders characterized by bone marrow failure with unique phenotypes and predisposition to cancer. Classical IBMFSs primarily include Fanconi anemia with impaired DNA damage repair, dyskeratosis congenita with telomere maintenance dysfunction, and Diamond-Blackfan anemia with aberrant ribosomal protein biosynthesis. Recently, comprehensive genetic analyses have been implemented for the definitive diagnosis of classic IBMFSs, and advances in molecular genetics have led to the identification of novel disorders such as AMeD and MIRAGE syndromes. Allogeneic hematopoietic cell transplantation (HCT), a promising option to overcome impaired hematopoiesis in patients with IBMFSs, does not correct nonhematological defects and may enhance the risk of secondary malignancies. Disease-specific management is necessary because IBMFSs differ in underlying defects and are associated with varying degrees of risk for clonal evolution and early or late complications after HCT. In addition, long-term follow-up is essential to detect complications related to the IBMFS or HCT. This review provides a summary of current clinical practices along with the latest data on HCT in IBMFSs.

Non-myeloablative umbilical cord blood transplantation for atypical dyskeratosis congenita

BACKGROUND

Short telomere syndrome (STS) in children may result in phenotypically heterogenous clinical spectrum ranging from completely asymptomatic to typical dyskeratosis congenita (DC). Patients with this cancer predisposition syndrome may have multiple organ dysfunctions including pulmonary fibrosis, liver cirrhosis, and bone marrow failure. Not all mutations in telomerase or telomere genes have been identified, and STS may pose a diagnostic and management challenge.

METHODS

A retrospective chart review and literature search were done for this report.

RESULTS

Here, we report a case of atypical DC with a heterozygous germline missense mutation in the postmeiotic segregation increased 2 (PMS2) gene, exon 5, (c.466A>G (p. Thr156Ala)). The PMS2 (a mismatch repair protein) gene is known to be an important mediator of telomere-induced aging. The patient was transfusion dependent and underwent successful umbilical cord blood transplant using a non-myeloablative regimen with alemtuzumab, fludarabine, cyclophosphamide, and total body irradiation.

CONCLUSION

In this case of atypical DC with a previously unreported germline missense mutation in PMS2, the patient was successfully treated with an umbilical cord blood transplant with a non-myeloablative regimen.

Clinical outcome of cord blood transplantation for nine children with juvenile myelomonocytic leukemia receiving fludarabine-busulfan-cyclophosphamide-based conditioning

BACKGROUND

Juvenile myelomonocytic leukemia (JMML) is a rare hematological malignancy in young children and can only be cured through the allogeneic stem cell transplantation.

PROCEDURE

We have retrospectively analyzed the outcomes of nine children with JMML after unrelated cord blood transplantation (UCBT).

RESULTS

Eight patients who have received a myeloablative conditioning regimen of fludarabine (FLU), busulfan (BU), and cyclophosphamide (CY) have gotten engraftment. None of the nine patients has relapsed following initial UCBT. Six patients are still alive and in complete remission after UCBT with a median observation time of 43 months (range: 10-80 months).

CONCLUSIONS

This study shows that UCBT with FLU-BU-CY conditioning regimen can represent a suitable option for children with JMML.

Individualized Dosage Optimization for Myeloablative Conditioning before Unrelated Cord Blood Transplantation in a Diamond–Blackfan Anemia Patient with Germline RPL11 Mutation: A Case Study

Unrelated cord blood transplantation (CBT) for Diamond–Blackfan anemia (DBA), a systemic ribosomopathy affecting the disposition of conditioning agents, has resulted in outcomes inferior to those by transplantations from matched donors. We report the experience of the pharmacokinetics-guided myeloablative unrelated CBT in a DBA patient with a germline RPL11 mutation. The conditioning consisted of individualized dosing of fludarabine (based on weight and renal function with a target area under the curve (AUC) of 17.5 mg·h/L) and busulfan (based on therapeutic drug monitoring with a target AUC of 90 mg·h/L), as well as dosing and timing of thymoglobulin (based on body weight and pre-dose lymphocyte count to target pre-CBT AUC of 30.7 AU·day/mL and post-CBT AUC of 4.3 AU·day/mL, respectively). The pharmacokinetic measures resulted in a 27.5% reduction in busulfan and a 35% increase in fludarabine, as well as an over three-fold increase in thymoglobulin dosage with the start time changed to day-9 instead of day-2 compared to regular regimens. The transplantation resulted in rapid, complete, and sustained hematopoietic engraftment. The patient is now healthy over 3 years after CBT. A pharmacokinetics-guided individualized dosing strategy for conditioning might be a feasible option to improve the outcomes of DBA patients receiving unrelated myeloablative CBT.

Hematopoietic stem cell transplantation for classical inherited bone marrow failure syndromes: an update

INTRODUCTION

Inherited bone marrow failure syndromes (IBMFS) feature complex molecular pathophysiology resulting in ineffective hematopoiesis and increased risk of progression to myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML). Allogenic hematopoietic stem cell transplantation (HSCT) is the only well-established cure for the hematological manifestations of these diseases.

AREAS COVERED

In recent years, analysis of large series from international databases (mainly from the European Bone Marrow Transplantation [EBMT] database) has improved knowledge about HSCT in IBMFS. This review, following a thorough Medline search of the pertinent published studies, reports the most recent data on HSCT in IBMFS.

EXPERT OPINION

Despite the common features, IBMFS are very different in their manifestations and in the occurrence and management of HSCT complications. Thus, a 'disease-specific' HSCT using an optimized conditioning regimen based on the characteristics of the disease is essential for achieving long-term survival. The phenotypical heterogeneity associated with extramedullary abnormalities has to be carefully evaluated before HSCT because transplantation may only correct impaired hematopoiesis. HSCT may be associated with the risk of treatment-related mortality and with significant early and late morbidity. For these reasons, the benefits should be carefully weighed against the risks.

Recommendations on hematopoietic stem cell transplantation for patients with Diamond-Blackfan anemia. On behalf of the Pediatric Diseases and Severe Aplastic Anemia Working Parties of the EBMT

Diamond Blackfan anemia (DBA) is a rare congenital syndrome presenting primarily as pure red cell aplasia with constitutional abnormalities and cancer predisposition. Established treatment options are corticosteroids, regular erythrocyte transfusions with iron chelation therapy, and hematopoietic stem cell transplantation (HSCT). To date, HSCT is the only definitive curative treatment for the hematological phenotype of DBA, but there is little experience with its use. Given the rarity of the disease and its unique features, an expert panel agreed to draw up a set of recommendations on the use of HSCT in DBA to guide clinical decision-making and practice. The recommendations address indications, pretransplant patient evaluation, donor selection, stem cell sources, conditioning regimens, prophylaxis of rejection and graft versus host disease, and post-transplant follow-up.

Favorable outcomes of hematopoietic stem cell transplantation in children and adolescents with Diamond-Blackfan anemia

Diamond-Blackfan anemia (DBA) is a congenital pure red cell aplasia associated with congenital abnormalities and cancer predisposition. Allogeneic hematopoietic stem cell transplantation (HSCT) can correct the hematological phenotype and is indicated in transfusion-dependent patients. In 70 children reported to the German DBA and French HSCT registries, HSCT was performed from 1985 to 2017. Median age at HSCT was 5.5 years (range, 0.9-17.3 years). Two-thirds of patients (64%) were transplanted from a matched sibling donor (MSD), and most procedures were performed after the year 1999 (73%). Primary engraftment was achieved in all patients. One patient developed secondary graft failure. Cumulative incidence of acute graft-versus-host disease (GVHD) was 24% for °II-IV (95% confidence interval [CI], 16% to 37%) and 7% for °III-IV (95% CI, 3% to 17%); cumulative incidence of chronic GVHD was 11% (95% CI, 5% to 22%). The probability of chronic GVHD-free survival (cGFS) was 87% (95% CI, 79% to 95%) and significantly improved over time (<2000: 68% [95% CI, 47% to 89%] vs ≥2000: 94% [95% CI, 87% to 100%], P < .01). cGFS was comparable following HSCT from a MSD and an unrelated donor (UD). Of note, no severe chronic GVHD or deaths were reported following MSD-HSCT after 1999. The difference of cGFS in children transplanted <10 years of age compared with older patients did not reach statistical significance (<10 years: 90% [95% CI, 81% to 99%] vs 10-18 years 78% [95% CI, 58% to 98%]). In summary, these data indicate that HSCT is efficient and safe in young DBA patients and should be considered if a MSD or matched UD is available. HSCT for transfusion dependency only must be critically discussed in older patients.

Special pre- and posttransplant considerations in inherited bone marrow failure and hematopoietic malignancy predisposition syndromes

Advances in the diagnosis and treatment of inherited bone marrow failure syndromes (IBMFS) have provided insight into the complexity of these diseases. The diseases are heterogeneous and characterized by developmental abnormalities, progressive marrow failure, and predisposition to cancer. A correct diagnosis allows for appropriate treatment, genetic counseling, and cancer surveillance. The common IBMFSs are Fanconi anemia, dyskeratosis congenita, and Diamond-Blackfan anemia. Hematopoietic cell transplantation (HCT) offers curative treatment of the hematologic complications of IBMFS. Because of the systemic nature of these diseases, transplant strategies are modified to decrease immediate and late toxicities. HCT from HLA-matched related or unrelated donors offers excellent survival for young patients in aplasia. Challenges include the treatment of adults with marrow aplasia, presentation with myeloid malignancy regardless of age, and early detection or treatment of cancer. In this article, I will describe our approach and evaluation of patients transplanted with IBMFS and review most frequent complications before and after transplant.

Hematopoietic cell transplantation for Diamond Blackfan anemia: A report from the Pediatric Group of the Brazilian Bone Marrow Transplantation Society

OBJECTIVES

The aim of this study was to analyze the outcomes of children with Diamond-Blackfan anemia (DBA) treated in Brazil with hematopoietic cell transplantation (HCT).

METHODS

We performed a retrospective analysis of 44 pediatrics patients transplanted between 1990 and 2018. The median age of patients was 5 years, and 57% were male. Twenty-five received their first HCT from an HLA-matched sibling donor (MSD), 12 from a HLA matched unrelated bone marrow donor (MUD 10/10, n = 12) and 7 other HLA mismatched donors (MMD).

RESULTS

After a median follow-up of 4 years, estimate 5-year overall survival (OS) for the entire cohort was 70%, 80% for MSD group, 73% for MUD, and 29% for MMD. Thirty-eight out of the 44 evaluable patients engrafted successfully. Primary and secondary graft failure was observed in five and three patients, respectively. Rates of grade II-IV and III-IV acute graft-versus-host disease (aGVHD) were 25% and 18%, respectively. Nine patients developed chronic GVHD (cGVHD).

CONCLUSION

Overall survival rates observed after HLA matched donors transplant for DBA were comparable to those reported from higher-income countries and international registries.

Long-term outcome after allogeneic hematopoietic stem cell transplantation for Shwachman-Diamond syndrome: a retrospective analysis and a review of the literature by the Severe Aplastic Anemia Working Party of the European Society for Blood and Marrow Transplantation (SAAWP-EBMT)

Allogeneic hematopoietic stem cell transplantation (HSCT) is a curative procedure in patients with Shwachman-Diamond syndrome (SDS) with bone marrow abnormalities. The results of 74 patients with SDS (6 acute myeloid leukemia, 7 myelodysplastic syndrome, and 61 bone marrow failure) treated with HSCT between 1988 and 2016 are reported. The donor source was: 24% sibling, 8% parent, and 68% unrelated donor. The stem cell source was: 70% bone marrow, 19% peripheral blood stem cells, and 11% cord blood. The conditioning regimen was myeloablative in 54% and reduced intensity in 46%. Neutrophil engraftment was achieved in 84% of patients after a median time of 17.5 days. Graft failure occurred in 15% of HSCTs. Grades I-IV acute and chronic GVHD were observed in 55% and 20% of patients, respectively. After a median follow-up of 7.3 years (95% CI 4.8-10.2), 28 patients died for progression/relapse (7) or toxicity (21). The 5-year overall survival and nonrelapse mortality were 63.3% (95% CI 50.8-73.4) and 19.8% (95% CI 10.8-30.8), respectively. In conclusion, this is the largest series so far reported and confirms that HSCT is a suitable option for patients with SDS. Further efforts are needed to lower transplant-related toxicity and reduce graft failure.

Cord blood transplantation for bone marrow failure syndromes: state of art

Hematopoietic stem cell transplantation (HSCT) and immunosuppressive therapy (IST) represent the milestones of the treatment algorithm for idiopathic and inherited bone marrow failure (BMF) disorders. However, patients lacking a suitable donor or failing IST still have a poor prognosis. Cord blood transplantation (CBT) has extended the possibility of HSCT for many patients in case of the absence of an eligible donor, and although in the last years, this procedure is less used in several hematological diseases, it remains an option for the treatment of patients with BMF syndromes. Nevertheless, optimization of conditioning regimen and cord blood unit selection is warranted to reduce the risk of graft failure and transplant-related mortality. This review summarizes the state of art of CBT in the field of BMF diseases, focusing on historical and recent issues in idiopathic aplastic anemia and inherited disorders.

Clinical Outcomes after Allogeneic Hematopoietic Stem Cell Transplantation in Children with Juvenile Myelomonocytic Leukemia: A Report from the Japan Society for Hematopoietic Cell Transplantation

Hematopoietic stem cell transplantation (HSCT) is the only curative treatment for juvenile myelomonocytic leukemia (JMML), but few large studies of HSCT for JMML exist. Using data from the Japan Society for Hematopoietic Cell Transplantation registry, we analyzed the outcomes of 129 children with JMML who underwent HSCT between 2000 and 2011. The 5-year overall survival (OS) rate and cumulative incidence of relapse were 64% and 34%, respectively. A regimen of busulfan/fludarabine/melphalan was the most commonly used (59 patients) and provided the best outcomes; the 5-year OS rate reached 73%, and the cumulative incidences of relapse and transplantation-related mortality were 26% and 9%, respectively. In contrast, the use of the irradiation-based myeloablative regimen was the most significant risk factor for OS (hazard ratio [HR], 2.92; P = .004) in the multivariate model. In addition, chronic graft-versus-host disease (GVHD) was strongly associated with lower relapse (HR, 0.37; P = .029) and favorable survival (HR, 0.22; P = .006). The current study has shown that a significant proportion of children with JMML can be cured with HSCT, especially those receiving the busulfan/fludarabine/melphalan regimen. Based on the lower relapse and better survival observed in patients with chronic GVHD, additional treatment strategies that focus on enhancing graft-versus-leukemia effects may further improve survival.

Current status of umbilical cord blood transplantation in children

The first umbilical cord blood (UCB) transplantation was performed 30 years ago. UCB transplantation (UCBT) is now widely used in children with malignant and non-malignant disorders who lack a matched family donor. UCBT affords a lower incidence of graft-versus-host disease compared to alternative stem cell sources, but also presents a slower immune recovery and a high risk of infections if serotherapy is not omitted or targeted within the conditioning regimen. The selection of UCB units with high cell content and good human leucocyte antigen match is essential to improve the outcome. Techniques, such as double UCBT, ex vivo stem cell expansion and intra-bone injection of UCB, have improved cord blood engraftment, but clinical benefit remains to be demonstrated. Cell therapies derived from UCB are under evaluation as potential novel strategies to reduce relapse and viral infections following transplantation. In recent years, improvements within haploidentical transplantation have reduced the overall use of UCBT as an alternative stem cell source; however, each may have its relative merits and disadvantages and tailored use of these alternative stem cell sources may be the optimal approach.

Hematopoietic Stem Cell Transplantation: A Neonatal Perspective

Allogeneic hematopoietic stem cell transplantation (HSCT) is indicated in various nonmalignant disorders that arise from genetic, hematopoietic, and immune system defects. Many of the disorders described here have life-threatening consequences in the absence of HSCT, a curative intervention. However, timing and approach to HSCT vary by disorder and optimum results are achieved by performing transplantation before irreversible disease-related morbidity or infectious complications. This article details the principles of HSCT in the very young, lists indications, and explores the factors that contribute to successful outcomes based on transplantation and disease-related nuances. It provides an overview into the HSCT realm from a neonatologist's perspective, describes the current status of transplantation for relevant disorders of infancy, and provides a glimpse into future efforts at improving on current success.

Advancements and frontiers in nano-based 3D and 4D scaffolds for bone and cartilage tissue engineering

Given the enormous increase in the risks of bone and cartilage defects with the rise in the aging population, the current treatments available are insufficient for handling this burden, and the supply of donor organs for transplantation is limited. Therefore, tissue engineering is a promising approach for treating such defects. Advances in materials research and high-tech optimized fabrication of scaffolds have increased the efficiency of tissue engineering. Electrospun nanofibrous scaffolds and hydrogel scaffolds mimic the native extracellular matrix of bone, providing a support for bone and cartilage tissue engineering by increasing cell viability, adhesion, propagation, and homing, and osteogenic isolation and differentiation, vascularization, host integration, and load bearing. The use of these scaffolds with advanced three- and four-dimensional printing technologies has enabled customized bone grafting. In this review, we discuss the different approaches used for cartilage and bone tissue engineering.

Rescue from lethal acute radiation syndrome (ARS) with severe weight loss by secretome of intramuscularly injected human placental stromal cells

BACKGROUND

Most current cell-based regenerative therapies are based on the indirect induction of the affected tissues repair. Xenogeneic cell-based treatment with expanded human placenta stromal cells, predominantly from fetal origin (PLX-RAD cells), were shown to mitigate significantly acute radiation syndrome (ARS) following high dose irradiation in mice, with expedited regain of weight loss and haematopoietic function. The current mechanistic study explores the indirect effect of the secretome of PLX-RAD cells in the rescue of the irradiated mice.

METHODS

The mitigation of the ARS was investigated following two intramuscularly (IM) injected 2 × 10⁶ PLX-RAD cells, 1 and 5 days following 7.7 Gy irradiation. The mice survival rate and their blood or bone marrow (BM) cell counts were followed up and correlated with multiplex immunoassay of a panel of related human proteins of PLX-RAD derived secretome, as well as endogenous secretion of related mouse proteins. PLX-RAD secretome was also tested in vitro for its effect on the induction of the migration of BM progenitors.

RESULTS

A 7.7 Gy whole body mice irradiation resulted in ~25% survival by 21 days. Treatment with two IM injections of 2 × 10⁶ PLX-RAD cells on days 1 and 5 after irradiation mitigated highly significantly the subsequent lethal ARS, with survival rate increase to nearly 100% and fast regain of the initial weight loss (P < 0,0001). This was associated with a significant faster haematopoiesis recovery from day 9 onwards (P < 0.01). Nine out of the 65 human proteins tested were highly significantly elevated in the mouse circulation, peaking on days 6-9 after irradiation, relative to negligible levels in non-irradiated PLX-RAD injected mice (P < 0.01). The highly elevated proteins included human G-CSF, GRO, MCP-1, IL-6 and lL-8, reaching >500 pg/mL, while MCP-3, ENA, Eotaxin and fractalkine levels ranged between ~60-160pg/mL. The detected radiation-induced PLX-RAD secretome correlated well with the timing of the fast haematopoiesis regeneration. The radiation-induced PLX-RAD secretome seemed to reinforce the delayed high levels secretion of related mouse endogenous cytokines, including GCSF, KC, MCP-1 and IL-6. Additional supportive in vitro studies also confirmed the ability of cultured PLX-RAD secretome to induce accelerated migration of BM progenitors.

CONCLUSIONS

A well-regulated and orchestrated secretion of major pro-regenerative BM supporting secretome in high dose irradiated mice, treated with xenogeneic IM injected PLX-RAD cells, can explain the observed mitigation of ARS. This seemed to coincide with faster haematopoiesis regeneration, regain of severe weight loss and the increased survival rate. The ARS-related stress signals activating the IM injected PLX-RAD cells for the remote secretion of the relevant human proteins deserve further investigation.

Bioactive hydrogels for bone regeneration

Bone self-healing is limited and generally requires external intervention to augment bone repair and regeneration. While traditional methods for repairing bone defects such as autografts, allografts, and xenografts have been widely used, they all have corresponding disadvantages, thus limiting their clinical use. Despite the development of a variety of biomaterials, including metal implants, calcium phosphate cements (CPC), hydroxyapatite, etc., the desired therapeutic effect is not fully achieved. Currently, polymeric scaffolds, particularly hydrogels, are of interest and their unique configurations and tunable physicochemical properties have been extensively studied. This review will focus on the applications of various cutting-edge bioactive hydrogels systems in bone regeneration, as well as their advantages and limitations. We will examine the composition and defects of the bone, discuss the current biomaterials for bone regeneration, and classify recently developed polymeric materials for hydrogel synthesis. We will also elaborate on the properties of desirable hydrogels as well as the fabrication techniques and different delivery strategies. Finally, the existing challenges, considerations, and the future prospective of hydrogels in bone regeneration will be outlined.

Stem cell banking: Are South Indian mothers aware?

Umbilical cord blood (UCB) is an important source of stem cells, the heart of regenerative medicine. As the globalization and population of the world continues to increase, we are faced with an inundation of new diseases, affecting millions of people. Research work considering stem cells is essential for developing therapy for various conditions. Reduced availability of UCB serves as a hindrance to promote further research. Hence, India being one of the most densely populated countries in the world, can be considered a potential UCB repository. In this study 428 mothers of children born in the period from 2012 to 2017 were asked to fill questionnaires that evaluated their awareness regarding stem cell banking. This investigation deliberates if expectant mothers in this region are aware of stem cell banking and if there is a significant pattern regarding awareness based on parameters like age, educational qualification, locality, annual income and consulted hospitals. Although, majority of the women were unaware of this facility, knowledge was heightened in wealthy, educated, women from urban areas who consulted private hospitals. Hence, great efforts need to be made to further the awareness of expectant mothers in South India regarding UCB storage and donation.

Impact of Graft-Recipient ABO Compatibility on Outcomes after Umbilical Cord Blood Transplant for Nonmalignant Disease

Existing literature shows mixed conclusions regarding the impact of ABO incompatibility on outcomes after hematopoietic stem cell transplantation. Because the future for umbilical cord blood (UCB) expansion technologies is bright, we assessed whether this typically overlooked graft characteristic impacted various outcomes after UCB transplantation (UCBT) for nonmalignant disorders (NMDs). A prospectively maintained institutional blood and marrow transplant program database was queried for all patients undergoing first UCBT for NMDs. UCB and recipient ABO compatibility was considered as matched, major mismatched, minor mismatched, or bidirectional mismatched. The impact of ABO incompatibility was assessed on overall survival, graft failure, acute and chronic graft-versus-host disease (GVHD), time to neutrophil and platelet recovery, day 0 to day 100 RBC transfusion burden, and donor hematopoietic chimerism. Through December 2014, 270 patients have undergone first UCBT for various NMDs. In both univariable and multivariable analyses, ABO compatibility status did not appear to impact any outcomes assessed, although a trend toward increased grades III to IV acute GVHD was seen in recipients of major mismatched units. When considering UCBT for treatment of NMDs, ABO compatibility between the donor unit and intended recipient does not appear to be an important consideration in the UCB unit choice.

Immunosuppressive therapy versus alternative donor hematopoietic stem cell transplantation for children with severe aplastic anemia who lack an HLA-matched familial donor

We compared the outcomes of immunosuppressive treatment (IST) with those of alternative donor hematopoietic stem cell transplantation (HSCT) in children and adolescents with severe aplastic anemia (SAA). The medical records of 42 patients with SAA who received frontline IST (N=19) or frontline HSCT with an alternative donor (N=23) between 1998 and 2012 were analyzed retrospectively. Six patients responded in the frontline IST group, whereas 11 underwent salvage HSCT after IST failure. Twenty-one of 23 patients who underwent frontline HSCT survived without treatment failure. The estimated failure-free survival rate of the frontline HSCT group was higher than that of the frontline IST group (91.3% vs 30.7% respectively, P<0.001). Six of 11 patients who underwent salvage HSCT experienced event-free survival (EFS). The estimated EFS of the frontline HSCT group was higher than that of the salvage HSCT group (91.3% vs 50.9% respectively, P=0.015). The outcome of alternative donor HSCT was better than commonly reported rates, especially in patients who underwent frontline HSCT. These results suggest that frontline alternative donor HSCT may be a better treatment option than IST for children and adolescents with SAA who lack a human leukocyte Ag-matched familial donor.

Allogeneic hematopoietic stem cell transplantation for inherited bone marrow failure syndromes

Inherited bone marrow failure (IBMF) syndromes are a heterogeneous group of rare hematological disorders characterized by the impairment of hematopoiesis, which harbor specific clinical presentations and pathogenic mechanisms. Some of these syndromes may progress through clonal evolution, myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML). Most prominent are failures of DNA repair such as Fanconi Anemia and much rarer failure of ribosomal apparatus, e.g., Diamond Blackfan Anemia or of telomere elongation such as dyskeratosis congenita. In these congenital disorders, hematopoietic stem cell transplantation (HSCT) is often a consideration. However, HSCT will not correct the underlying disease and possible co-existing extra-medullary (multi)-organ defects, but will improve BMF. Indications as well as transplantation characteristics are most of the time controversial in this setting because of the rarity of reported cases. The present paper proposes a short overview of current practices.

Umbilical Cord Blood: Counselling, Collection, and Banking

OBJECTIVE

To review current evidence regarding umbilical cord blood counselling, collection, and banking and to provide guidelines for Canadian health care professionals regarding patient education, informed consent, procedural aspects, and options for cord blood banking in Canada.

OPTIONS

Selective or routine collection and banking of umbilical cord blood for future stem cell transplantation for autologous (self) or allogeneic (related or unrelated) treatment of malignant and non-malignant disorders in children and adults. Cord blood can be collected using in utero or ex utero techniques.

OUTCOMES

Umbilical cord blood counselling, collection, and banking, education of health care professionals, indications for cord blood collection, short- and long-term risk and benefits, maternal and perinatal morbidity, parental satisfaction, and health care costs.

EVIDENCE

Published literature was retrieved through searches of Medline and PubMed beginning in September 2013 using appropriate controlled MeSH vocabulary (fetal blood, pregnancy, transplantation, ethics) and key words (umbilical cord blood, banking, collection, pregnancy, transplantation, ethics, public, private). Results were restricted to systematic reviews, randomized control trials/controlled clinical trials, and observational studies. There were no date limits, but results were limited to English or French language materials. Searches were updated on a regular basis and incorporated in the guideline to September 2014. Grey (unpublished) literature was identified through searching the websites of health technology assessment and health technology-related agencies, clinical practice guideline collections, and national and international medical specialty societies.

VALUES

The quality of evidence in this document was rated using the criteria described in the Report of the Canadian Task Force on Preventive Health Care (Table 1).

BENEFITS, HARMS, AND COSTS

Umbilical cord blood is a readily available source of hematopoetic stem cells used with increasing frequency as an alternative to bone marrow or peripheral stem cell transplantation to treat malignant and non-malignant conditions in children and adults. There is minimal harm to the mother or newborn provided that priority is given to maternal/newborn safety during childbirth management. Recipients of umbilical cord stem cells may experience graft-versus-host disease, transfer of infection or genetic abnormalities, or therapeutic failure. The financial burden on the health system for public cord blood banking and on families for private cord blood banking is considerable. Recommendations 1. Health care professionals should be well-informed about cord blood collection and storage and about factors that influence the volume, quality, and ability to collect a cord blood unit. (III-A) 2. Health care professionals caring for women and families who choose private umbilical cord blood banking must disclose any financial interests or potential conflicts of interest. (III-A) 3. Pregnant women should be provided with unbiased information about umbilical cord blood banking options, including the benefits and limitations of public and private banks. (III-A) 4. Health care professionals should obtain consent from mothers for the collection of umbilical cord blood prior to the onset of active labour, ideally during the third trimester, with ample time to address any questions. (III-A) 5. Health care professionals must be trained in standardized procedures (ex utero and in utero techniques) for cord blood collection to ensure the sterility and quality of the collected unit. (II-2A) 6. Umbilical cord blood should be collected with the goal of maximizing the content of hematopoietic progenitors through the volume collected. The decision to bank the unit will depend upon specific measures of graft potency. (II-2A) 7. Umbilical cord blood collection must not adversely affect the health of the mother or newborn. Cord blood collection should not interfere with delayed cord clamping. (III-E) 8. Health care professionals should inform pregnant women and their partners of the benefits of delayed cord clamping and of its impact on cord blood collection and banking. (II-2A) 9. Cord blood units collected for public or private banking can be used for biomedical research, provided consent is obtained, when units cannot be banked or when consent for banking is withdrawn. (II-3B) 10. Mothers may be approached to donate cells for biomedical research. Informed consent for research using cord blood should ideally be obtained prior to the onset of active labour or elective Caesarean section following established research ethics guidelines. (II-2A).

Mesenchymal Stem Cells and Mononuclear Cells From Cord Blood: Cotransplantation Provides a Better Effect in Treating Myocardial Infarction

The aim of this study was to evaluate the effect of cotransplanting mononuclear cells from cord blood (CB-MNCs) and mesenchymal stem cells (MSCs) as treatment for myocardial infarction (MI). Transplanting CD34+ cells or MSCs separately has been shown effective in treating MI, but the effect of cotransplanting CB-MNCs and MSCs is not clear. In this study, MSCs were separated by their adherence to the tissue culture. The morphology, immunophenotype, and multilineage potential of MSCs were analyzed. CB-MNCs were separated in lymphocyte separation medium 1.077. CD34+ cell count and viability were analyzed by flow cytometry. Infarcted male Sprague-Dawley rats in a specific-pathogen-free grade were divided into four treatment groups randomly: group I, saline; group II, CB-MNCs; group III, MSCs; and group IV, CB-MNCs plus MSCs. The saline, and CB-MNCs and/or MSCs were injected intramyocardially in infarcted rats. Their cardiac function was evaluated by echocardiography. The myocardial capillary density was analyzed by immunohistochemistry. Both cell types induced an improvement in the left ventricular cardiac function and increased tissue cell proliferation in myocardial tissue and neoangiogenesis. However, CB-MNCs plus MSCs were more effective in reducing the infarct size and preventing ventricular remodeling. Scar tissue was reduced significantly in the CB-MNCs plus MSCs group. MSCs facilitate engraftment of CD34+ cells and immunomodulation after allogeneic CD34+ cell transplantation. Cotransplanting MSCs and CB-MNCs might be more effective than transplanting MSCs or CB-MNCs separately for treating MI. This study contributes knowledge toward effective treatment strategies for MI.

Case Reports of Severe Congenital Neutropenia Treated With Unrelated Cord Blood Transplantation With Reduced-intensity Conditioning

Allogeneic stem cell transplantation is a curative treatment for severe congenital neutropenia (SCN). However, a standard conditioning regimen and donor source have not been established. We report 3 consecutive cases of SCN who were successfully treated by cord blood transplantation (CBT) with reduced-intensity conditioning consisting of fludarabine, melphalan, and low-dose total body irradiation. All cases achieved complete donor chimerism without severe infectious complications and have maintained normal neutrophil counts for between 3 and 9 years after CBT. These results suggest that CBT with reduced-intensity conditioning can be an alternative therapy for SCN when human leukocyte antigen-matched bone marrow donor is unavailable.

Comparison of the Effects of Different Cryoprotectants on Stem Cells from Umbilical Cord Blood

Purpose. Cryoprotectants (CPA) for stem cells from umbilical cord blood (UCB) have been widely developed based on empirical evidence, but there is no consensus on a standard protocol of preservation of the UCB cells. Methods. In this study, UCB from 115 donors was collected. Each unit of UCB was divided into four equal parts and frozen in different kinds of cryoprotectant as follows: group A, 10% ethylene glycol and 2.0% dimethyl sulfoxide (DMSO) (v/v); group B, 10% DMSO and 2.0% dextran-40; group C, 2.5% DMSO (v/v) + 30 mmol/L trehalose; and group D, without CPA. Results. CD34⁺, cell viability, colony forming units (CFUs), and cell apoptosis of pre- and postcryopreservation using three cryoprotectants were analyzed. After thawing, significant differences in CD34⁺ count, CFUs, cell apoptosis, and cell viability were observed among the four groups (P < 0.05).  Conclusion. The low concentration of DMSO with the addition of trehalose might improve the cryopreservation outcome.

Durable engraftment and correction of hematological abnormalities in children with congenital amegakaryocytic thrombocytopenia following myeloablative umbilical cord blood transplantation

The use of HSCT is the only potentially curative treatment for CAMT, but access is limited by the availability of suitable donors. We report five consecutive patients with CAMT who received MAC and partially HLA-mismatched, UCBT (unrelated, n = 4). Median times to neutrophil (>500/μL) and platelet (≥20 000 and ≥50 000/μL) engraftment were 19, 57, and 70 days, respectively. Acute GvHD, grade II, developed in one patient, who subsequently developed limited chronic GvHD. At median follow-up of 14 yr, all patients are alive with sustained donor cell engraftment. To our knowledge, this is the largest single-center series of UCBT for patients with this disease and suggests that UCBT is a successful curative option for patients with CAMT.

Successful use of reduced-intensity conditioning and matched-unrelated hematopoietic stem cell transplant in a child with Diamond-Blackfan anemia and cirrhosis

For patients with DBA who are transfusion dependent, HSCT is the only cure. Chronic transfusions can lead to cirrhosis secondary to iron overload, making them poor candidates for myeloablative HSCT. RIC regimens are associated with lower morbidity and mortality compared to myeloablative regimens, but use of RIC in DBA has been limited. Here we present a 14-yr-old girl with DBA and multiple comorbidities including liver cirrhosis, who underwent MUD HSCT utilizing a RIC regimen that is novel to this condition. She tolerated the regimen well, and at 21 months, she remains transfusion independent with chimerisms at 99%.

Allogeneic haematopoietic stem cell transplantation for mitochondrial neurogastrointestinal encephalomyopathy

Haematopoietic stem cell transplantation has been proposed as treatment for mitochondrial neurogastrointestinal encephalomyopathy, a rare fatal autosomal recessive disease due to TYMP mutations that result in thymidine phosphorylase deficiency. We conducted a retrospective analysis of all known patients suffering from mitochondrial neurogastrointestinal encephalomyopathy who underwent allogeneic haematopoietic stem cell transplantation between 2005 and 2011. Twenty-four patients, 11 males and 13 females, median age 25 years (range 10-41 years) treated with haematopoietic stem cell transplantation from related (n = 9) or unrelated donors (n = 15) in 15 institutions worldwide were analysed for outcome and its associated factors. Overall, 9 of 24 patients (37.5%) were alive at last follow-up with a median follow-up of these surviving patients of 1430 days. Deaths were attributed to transplant in nine (including two after a second transplant due to graft failure), and to mitochondrial neurogastrointestinal encephalomyopathy in six patients. Thymidine phosphorylase activity rose from undetectable to normal levels (median 697 nmol/h/mg protein, range 262-1285) in all survivors. Seven patients (29%) who were engrafted and living more than 2 years after transplantation, showed improvement of body mass index, gastrointestinal manifestations, and peripheral neuropathy. Univariate statistical analysis demonstrated that survival was associated with two defined pre-transplant characteristics: human leukocyte antigen match (10/10 versus <10/10) and disease characteristics (liver disease, history of gastrointestinal pseudo-obstruction or both). Allogeneic haematopoietic stem cell transplantation can restore thymidine phosphorylase enzyme function in patients with mitochondrial neurogastrointestinal encephalomyopathy and improve clinical manifestations of mitochondrial neurogastrointestinal encephalomyopathy in the long term. Allogeneic haematopoietic stem cell transplantation should be considered for selected patients with an optimal donor.

Stem cell transplantation in severe congenital neutropenia: an analysis from the European Society for Blood and Marrow Transplantation

Allogeneic hematopoietic stem cell transplantation (HSCT) is the only curative treatment of severe congenital neutropenia (SCN), but data on outcome are scarce. We report on the outcome of 136 SCN patients who underwent HSCT between 1990 and 2012 in European and Middle East centers. The 3-year overall survival (OS) was 82%, and transplant-related mortality (TRM) was 17%. In multivariate analysis, transplants performed under the age of 10 years, in recent years, and from HLA-matched related or unrelated donors were associated with a significantly better OS. Frequency of graft failure was 10%. Cumulative incidence (day +90) of acute graft-versus-host disease (GVHD) grade 2-4 was 21%. In multivariate analysis, HLA-matched related donor and prophylaxis with cyclosporine A and methotrexate were associated with lower occurrence of acute GVHD. Cumulative incidence (1 year) of chronic GVHD was 20%. No secondary malignancies occurred after a median follow-up of 4.6 years. These data show that the outcome of HSCT for SCN from HLA-matched donors, performed in recent years, in patients younger than 10 years is acceptable. Nevertheless, given the TRM, a careful selection of HSCT candidates should be undertaken.

Use of Alefacept for Preconditioning in Multiply Transfused Pediatric Patients with Nonmalignant Diseases

Transfusion-related alloimmunization is a potent barrier to the engraftment of allogeneic hematopoietic stem cells in patients with nonmalignant diseases (NMDs). Memory T cells, which drive alloimmunization, are relatively resistant to commonly used conditioning agents. Alefacept, a recombinant leukocyte function antigen-3/IgG1 fusion protein, targets CD2 and selectively depletes memory versus naive T cells. Three multiply transfused pediatric patients with NMD received a short course of high-dose i.v. alefacept (.25 mg/kg/dose on days -40 and -9 and .5 mg/kg/dose on days -33, -26, -19, and -12) before undergoing unrelated allogeneic transplant in the setting of reduced-intensity pretransplant conditioning and calcineurin inhibitor-based post-transplant graft-versus-host disease (GVHD) prophylaxis. Alefacept infusions were well tolerated in all patients. Peripheral blood flow cytometry was performed at baseline and during and after alefacept treatment. As expected, after the 5 weekly alefacept doses, each patient demonstrated selective loss of CD2(hi)/CCR7(-)/CD45RA(-) effector memory (Tem) and CD2(hi)/CCR7(+)/CD45RA(-) central memory (Tcm) CD4(+) and CD8(+) T cells with relative preservation of the CD2(lo) Tem and Tcm subpopulations. In addition, depletion of CD2(+) natural killer (NK) cells also occurred. Neutrophil recovery was rapid, and all 3 patients had 100% sorted (CD3/CD33) peripheral blood donor chimerism by day +100. Immune reconstitution (by absolute neutrophil, monocyte, and lymphocyte counts) was comparable with a cohort of historical control patients. All 3 patients developed GVHD but are all now off immune suppression and >2 years post-transplant with stable full-donor engraftment. These results suggest that alefacept at higher dosing can deplete both memory T cells and NK cells and that incorporating CD2-targeted depletion into a reduced-intensity transplant regimen is feasible and safe in heavily transfused patients.

Outcomes of Cord Blood Transplantation Using Reduced-Intensity Conditioning for Chronic Lymphocytic Leukemia: A Study on Behalf of Eurocord and Cord Blood Committee of Cellular Therapy and Immunobiology Working Party, Chronic Malignancies Working Party of the European Society for Blood and Marrow Transplantation, and the Societé Française de Greffe de Moelle et Therapie Cellulaire

Outcomes after umbilical cord blood transplantation (UCBT) for chronic lymphocytic leukemia (CLL)/small lymphocytic lymphoma (SLL) are unknown. We analyzed outcomes of 68 patients with poor-risk CLL/SLL who underwent reduced-intensity (RIC) UCBT from 2004 to 2012. The median age was 57 years and median follow-up 36 months; 17 patients had del 17p/p53mutation, 19 patients had fludarabine-refractory disease, 11 relapsed after autologous stem cell transplantation, 8 had diagnosis of prolymphocytic leukemia, 4 had Richter syndrome, and 8 underwent transplantation with progressive or refractory disease. The most common RIC used was cyclophosphamide, fludarabine, and total body irradiation (TBI) in 82%; 15 patients received antithymocyte globulin. Most of the cord blood grafts were HLA mismatched and 76% received a double UCBT. Median total nucleated cells collected was 4.7 × 10(7)/kg. The cumulative incidences (CI) of neutrophil and platelet engraftment were 84% and 72% at 60 and 180 days respectively; day 100 graft-versus-host disease (GVHD) (grade II to IV) was 43% and 3-year chronic GVHD was 32%. The CI of relapse, nonrelapse mortality, overall survival, and progression-free survival (PFS) at 3 years were 16%, 39%, 54%, and 45%, respectively. Fludarabine-sensitive disease at transplantation and use of low-dose TBI regimens were associated with acceptable PFS. In conclusion, use of RIC-UCBT seems to be feasible in patients with poor-risk CLL/SLL and improved outcomes were observed in patients with fludarabine-sensitive disease who received low-dose TBI regimens.

Hematopoietic Cell Transplantation Using Reduced-Intensity Conditioning Is Successful in Children with Hematologic Cytopenias of Genetic Origin

Genetically derived hematologic cytopenias are a rare heterogeneous group of disorders. Allogeneic hematopoietic cell transplantation (HCT) is curative but offset by organ toxicities from the preparative regimen, graft rejection, graft-versus-host disease (GVHD), or mortality. Because of these possibilities, consideration of HCT can be delayed, especially in the unrelated donor setting. We report a prospective multicenter trial of reduced-intensity conditioning (RIC) with alemtuzumab, fludarabine, and melphalan and HCT in 11 children with marrow failure of genetic origin (excluding Fanconi anemia) using the best available donor source (82% from unrelated donors). The median age at transplantation was 23 months (range, 2 months to 14 years). The median times to neutrophil (>500 × 10(6)/L) and platelet (>50 × 10(9)/L) engraftment were 13 (range, 12 to 24) and 30 (range, 7 to 55) days, respectively. The day +100 probability of grade II to IV acute GVHD and the 1-year probability of limited and extensive GVHD were 9% and 27%, respectively. The probability of 5-year overall and event-free survival was 82%; 9 patients were alive with normal blood counts at last follow-up and all were successfully off systemic immunosuppression. In patients with genetically derived severe hematologic cytopenias, allogeneic HCT with this RIC regimen was successful in achieving a cure. This experience supports consideration of HCT early in such patients even in the absence of suitable related donors.

Advances in unrelated and alternative donor hematopoietic cell transplantation for nonmalignant disorders

PURPOSE OF REVIEW

The role of hematopoietic cell transplantation in non-malignant disorders has increased exponentially with the recognition that multiple diseases can be controlled or cured if engrafted with donor-derived cells. This review provides an overview of advances made in alternative donor transplants for nonmalignant disorders.

RECENT FINDINGS

Stem cell sources, novel transplant methods, and sophisticated supportive care have simultaneously made giant strides toward improving the safety and efficacy of hematopoietic cell transplantation. This has led to the utilization of marrow, cord, peripheral blood stem cell and haploidentical stem cell sources, and novel reduced toxicity or reduced intensity conditioning regimens to transplant non-malignant disorders such as immune dysfunctions, marrow failure syndromes, metabolic disorders and hemoglobinopathies. Transplant complications such as graft rejection, infections, and graft versus host disease are better combated in this modern era of medicine, achieving better survival with decreased late effects. These aspects of transplant for non-malignant disorders are discussed.

SUMMARY

This review presents the progress made in the realm of hematopoietic cell transplantation for non-malignant disorders. It advocates the consideration of alternative donor transplants in the absence of human leukocyte antigen matched siblings when indicated by disease severity. The ultimate goal is to provide curative transplant options for more patients that can benefit from this intervention, prior to detrimental outcomes.

Influence of a dual-injection regimen, plerixafor and CXCR4 on in utero hematopoietic stem cell transplantation and engraftment with use of the sheep model

BACKGROUND AIMS

Inadequate engraftment of hematopoietic stem cells (HSCs) after in utero HSC transplantation (IUHSCT) remains a major obstacle for the prenatal correction of numerous hereditary disorders. HSCs express CXCR4 receptors that allow homing and engraftment in response to stromal-derived factor 1 (SDF-1) ligand present in the bone marrow stromal niche. Plerixafor, a mobilization drug, works through the interruption of the CXCR4-SDF-1 axis.

METHODS

We used the fetal sheep large-animal model to test our hypotheses that (i) by administering plerixafor in utero before performing IUHSCT to release fetal HSCs and thus vacating recipient HSC niches, (ii) by using human mesenchymal stromal/stem cells (MSCs) to immunomodulate and humanize the fetal BM niches and (iii) by increasing the CXCR4(+) fraction of CD34(+) HSCs, we could improve engraftment. Human cord blood-derived CD34(+) cells and human bone marrow-derived MSCs were used for these studies.

RESULTS

When MSCs were transplanted 1 week before CD34(+) cells with plerixafor treatment, we observed 2.80% donor hematopoietic engraftment. Combination of this regimen with additional CD34(+) cells at the time of MSC infusion increased engraftment levels to 8.77%. Next, increasing the fraction of CXCR4(+) cells in the CD34(+) population albeit transplanting at a late gestation age was not beneficial. Our results show engraftment of both lymphoid and myeloid lineages.

CONCLUSIONS

Prior MSC and HSC cotransplantation followed by manipulation of the CXCR4-SDF-1 axis in IUHSCT provides an innovative conceptual approach for conferring competitive advantage to donor HSCs. Our novel approach could provide a clinically relevant approach for enhancing engraftment early in the fetus.

Management of thrombocytopenia

Thrombocytopenia is one of the most common hematologic disorders, characterized by an abnormally low number of platelets from multiple causes. The normal count of thrombocytes (platelets) is between 150,000 and 450,000 per microliter. The clinical expression of thrombocytopenia has broad variation from asymptomatic to life-threatening bleeding. Various syndromes and diseases are associated with thrombocytopenia. Thrombocytopenia is sometimes a first sign of hematologic malignancies, infectious diseases, thrombotic microangiopathies, and autoimmune disorders, and is also a common side effect of many medications. There are more than 200 diseases that include low number of platelets among their symptoms. A brief discussion of the most common etiologies and management of them is provided in this review.