Unrelated Cord Blood Units Research Articles

Alternative Donor Graft Sources for Adults with Hematologic Malignancies: A Donor for All Patients in 2017!

The goal of this review is to increase the awareness of oncology practitioners to the availability of alternative donor stem cell transplants for patients with hematologic malignancies. Despite new agents, stem cell transplant remains the only curative therapy for many patients with acute and chronic leukemia, myelodysplasia, and lymphoma. Given the variety of different donor stem cell sources available today, nearly every patient who needs an allogeneic stem cell transplant will have a donor.

Alternative Donor/Unrelated Donor Transplants for the β-Thalassemia and Sickle Cell Disease.

Considerable progress with respect to donor source has been achieved in allogeneic stem cell transplant for patients with hemoglobin disorders, with matched sibling donors in the 1980s, matched unrelated donors and cord blood sources in the 1990s, and haploidentical donors in the 2000s. Many studies have solidified hematopoietic progenitors from matched sibling marrow, cord blood, or mobilized peripheral blood as the best source-with the lowest graft rejection and graft versus host disease (GvHD), and highest disease-free survival rates. For patients without HLA-matched sibling donors, but who are otherwise eligible for transplant, fully allelic matched unrelated donor (8/8 HLA-A, B, C, DRB1) appears to be the next best option, though an ongoing study in patients with sickle cell disease will provide data that are currently lacking. There are high GvHD rates and low engraftment rates in some of the unrelated cord transplant studies. Haploidentical donors have emerged in the last decade to have less GvHD; however, improvements are needed to increase the engraftment rate. Thus the decision to use unrelated cord blood units or haploidentical donors may depend on the institutional expertise; there is no clear preferred choice over the other. Active research is ongoing in expanding cord blood progenitor cells to overcome the limitation of cell dose, including the options of small molecule inhibitor compounds added to ex vivo culture or co-culture with supportive cell lines. There are inconsistent data from using 7/8 or lower matched unrelated donors. Before routine use of these less matched donor sources, work is needed to improve patient selection, conditioning regimen, GvHD prophylaxis, and/or other strategies.

Engraftment of Donor Cells after Allogeneic Stem Cell Transplantation: Comparison and Impact of Chimerism in Whole Blood and Peripheral CD3+ T-Cells

Introduction: After allogeneic stem cell transplantation (allo-SCT), engraftment can be assessed by quantitative polymerase chain reaction (qPCR) using differing donor/recipient markers (Alizadeh et al. Blood, 2002), identified in peripheral blood DNA cells before transplant. We report here on the concomitant examination of the proportions of donor and recipient DNA in peripheral whole blood (WB) and sorted CD3+ T-cells on days +60 and +90, looking at their impact on survival.Patients, material and methods: This monocentric study evaluated the impact on outcomes of early WB and sorted CD3+ T cells chimerism independently and of the four possible combinations of chimerism between WB and sorted CD3+ T-cells. All follow-up chimerism samples from allo-SCT patients performed in adults at Nantes University Hospital between October 2009 and October 2016 were reviewed, focusing on those where both PB and/or CD3+ T-cells were evaluated on days +60 (45-75) and/or +90 (75-120) after allo-SCT. A global cohort of 229 patients (239 grafts) was retrieved, which includes 52 patients evaluable on day +60 only, 67 evaluable on day +90 only and 120 evaluable on both days +60 and +90. A threshold of >95% donor DNA was considered for complete chimerism. Disease free survival (DFS) was calculated from the date of graft until relapse, death or last follow-up. Overall survival (OS) was calculated from the date of graft until death or last follow-up. Chi square tests were used to compare incidences. Log rang test and Kaplan Meier were used to evaluate DFS and OS.Results: The whole cohort comprised 62% males and had a median age of 58 years old (20-74) at the time of allo-SCT. Patients were treated for myeloid-lineage disease in 59% of the cases. Reduced-intensity conditioning was used in 89% (n=212), donors were familial in 45% (n=107), registry in 48% (n=114). Unrelated cord blood units were used in 8% of the cases (n=18). Post-transplant cyclophosphamide (PTCY) was performed in 48 procedures including 33 and 15 with haplo (HG) and matched donors respectively. Considering the 239 allograft procedures, the median follow-up was 5.8 years (95% CI: 3.1-5.8), the rate of relapse 27% and the rate of death 31%.Complete WB chimerism was observed for 80% and 71% of the cases on day +60 and day +90 respectively. Complete CD3+ chimerism was present for 53% and 51% of the grafts at days +30 and +90 respectively. Thus, cases displaying both complete WB and CD3+ chimerism on days +60 and +90 were 53% and 51% respectively, while 27% and 20% were documented with full WB and mixed CD3+ chimerism on days +60 and +90. Mixed chimerism was observed in both WB and CD3+ cells in 14% of the cases on day +60 and 22% on day +90. Finally, a small proportion of patients (6% and 7% at days +60 and +90) displayed an intriguing complete chimerism in CD3+ cells yet mixed WB chimerism. None of these features appeared associated to disease lineage (lymphoid or myeloid) nor cord blood allo-SCT. Interestingly, of the 27 grafts with myeloablative conditioning, only 14 had full WB/CD3+ engraftment on day +60 or +90, and thus all 27 were retained for the study.None of the four WB/CD3 chimerism combinations at the two times considered had an impact on DFS in this cohort. Surprisingly, although full or mixed WB chimerism had no impact on DFS and OS at days +60 and +90, the presence of a mixed CD3+ chimerism (vs full) at day+90 was associated with a significantly better OS (median: 5.8 months years [95%CI: -not reached] versus 3.1 years [95%CI: 2.2- 3.1]; p=0.025). CD3+ chimerism at day+60 has no impact on OS.All HG resulted in full CD3+ chimerism at both time points compared to non HG (100% vs 52%, p<0.0001). The same was almost true when considering PTCY procedures: 90% at day+60 and 92% at day +90. Of note, there was no influence on DFS nor OS of WB or CD3+ chimerism status when considering only HG or PTCY grafts vs others in this series.Discussion: In this large series, early WB chimerism status did not predict outcome. Surprisingly, mixed CD3+ chimerism at day+90 appears to be significantly associated with a longer OS, suggesting that remaining recipient memory lymphocytes could be beneficial. This result has to be confirmed prospectively. It remains also to define the place of donor lymphocyte infusions (DLI) to prevent relapse in patients with full or mixed CD3+ chimerism post-transplant (analyses of DLI received in our patients are on-going). DisclosuresMoreau:Bristol-Myers Squibb: Honoraria; Takeda: Honoraria; Novartis: Honoraria; Amgen: Honoraria; Janssen: Honoraria, Speakers Bureau; Celgene: Honoraria.

A Naive NK Cell Repertoire in the Circulation of Haploidentical Stem Cell Donors Pre Mobilization Predicts Rejection of Cord Myeloid Cells in Patients Undergoing Combined Haploidentical and Unrelated Cord Blood HSCT

Background: For patients (pts) with severe aplastic anemia (SAA) lacking an HLA identical donor, outcomes of hematopoietic stem cell transplantation (HSCT) using unrelated cord blood (UCB) units or haplo-identical donors (HDs) have historically been associated with high graft failure rates and poor survival. In an ongoing clinical trial at the NHLBI, we have observed excellent engraftment (100%) and survival (91%) in SAA pts (n=27) receiving a transplant that co-infuses a single UCB unit with CD34-selectedCD3-depletedcells from a haplo-identical relative. Although cord myeloid engraftment(defined as cord ANC >500/μL) occurred at<day 100 in the majority of pts, a significant fraction of pts had delayed (>day 100) or no cord myeloid engraftment. In this analysis, we investigated factors that may have impeded cord myeloid engraftment following UCB/HD transplantation.Methods: Flow-based NK cell phenotyping using a BD Fortessa II instrument was performed on blood obtained pre-transplant from HDs used for the first 18 SAA pts undergoing UCB/HD transplantation. Lineage specific chimerism was measured by PCR of microsatellites (PowerPlex 16 HS Systemkit/Promega) using DNA from flow sorted cells (BD FACSAria) collected multiple time points post-transplant.KIR-ligand incompatibility in the HD vs UCB directionwas defined using high-resolution HLA typing.Results: 13/18 (72%) pts had cord myeloid engraftment before day 100 while 5/18 (28%) had delayed or no cord myeloid engraftment. Remarkably, delayed or no cord myeloid engraftment occurred exclusively in pts transplanted with KIR-ligand incompatibility in the HD vs UCB direction (n=9) (Figure 1A). In contrast, all 9 pts transplanted with KIR-ligand compatibility in the HD vs UCB direction achieved cord myeloid engraftment by ²day 48 (median day 35) post-transplant. Chimerism analysis performed on blood obtained 30+ days post-transplant revealed NK cell chimerism was ³ 90% cord in origin in all 9 pts transplanted with KIR-ligand compatible grafts. In contrast, amongst the 9 pts receiving a KIR-ligand incompatible transplant, NK cell chimerism was predominantly HD in origin with only a minor fraction of cord NK cells detected 30-200 days post-transplant (Figure 1B). Predominant HD NK cell chimerism in pts receiving a KIR-ligand incompatible transplant was associated with lower degrees of cord myeloid chimerism compared to KIR-ligand compatible recipients. Further analysis of the KIR-ligand incompatible cohort revealed distinct heterogeneity in the time to cord myeloid engraftment (Figure 1A). Although delayed or no cord myeloid engraftment was observed in 5/9 recipients of KIR-ligand incompatible transplants, 4/9 pts in this cohort had cord engraftment at a similar time as pts transplanted with KIR-ligand compatible grafts (median 35 vs. 35 days). This variability in time to cord myeloid engraftment was not associated with stem cell dose, degree of HD NK cell chimerism, type of KIR-ligand incompatibility or KIR haplotype. However, we observed a strong correlation between the proportion of naive NK cells in circulation of HDs before stem cell mobilization with delayed or no myeloid cord engraftment (Figure 1C). With the exception of one patient who had failed HD engraftment, only transplants of CD34+ cells from HDs with a predominantly naive NK cell repertoire, expressing high frequencies of the NKG2A receptor concomitant with low frequencies of NKG2C, Lir-1 and CD57 resulted in delayed or no cord myeloid engraftment (p<0.05).Conclusions: Our study provides the first evidence that NK cells from engrafting CD34+ cells from selected HDs can significantly delay or completely inhibit cord myeloid engraftment following UCB/HD transplantation. Suppression of cord hematopoiesis appears to be restricted to NK cells originating from HDs withHD vs UCB KIR-ligand incompatibility who have a large naive NK cell repertoire in their circulation prior to stem cell mobilization. The myelosuppressive effects of these NK cells are consistent with recentlypublished data showing a naive NK cell repertoire in stem cell donors predicts a reduced risk of AML relapse post-allogeneic HSCT.Further studies defining the mechanisms through which naive NK cells suppress cord hematopoiesis followingUCB/HDtransplantation could shed insights into methods to optimize NK cell mediated graft-vs-leukemia followingallogeneicHSCT of myeloid leukemias. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Pediatric Hematopoietic Stem Cell Transplantation in India: Status, Challenges and the Way Forward : Based on Dr. K. C. Chaudhuri Oration 2016.

Hematopoietic stem cell transplantation (HSCT) refers to therapies that aim to eliminate a patient's hematopoietic and immune system and replace it with his own (autologous) or someone else's (allogenic) system. The applications of this therapy are vast and growing, and include several malignant and benign diseases incurable by any other existing modalities. Pediatric patients constitute a minority of HSCT recipients with unique concerns. Despite substantial progress in the last two decades, limitations due to financial, infrastructural, manpower and research constraints act as barriers to fulfilling the large need for pediatric HSCT services in our country. Limited availability of unrelated donors and cord blood units is another constraint. Here in this oration, we discuss the current issues pertaining to pediatric HSCT in India and describe our experience with the same.

HLA-A, -B and -DRB1 genotyping and haplotype frequencies of 3892 cord blood units in the Hong Kong Chinese Cord Blood Registry

HLA-A, -B and -DRB1 gene and haplotype frequencies have been calculated from 3892 southern Chinese unrelated cord blood units in a Hong Kong Cord Blood Registry. This is the first large-scale paper to report the distribution of A-B-DRB1 alleles in Hong Kong Chinese Cord Blood Units. This information is important for estimating the optimal and economically cost-effective donor size and likelihood of obtaining appropriately matched cord blood units for Chinese patients awaiting haematopoietic stem cell transplantation. The data are available in the Allele Frequencies Net Database under the population name ‘‘Hong Kong Chinese Cord Blood Registry’’ and the identifier (AFND003358).

HapLogic: A Predictive Human Leukocyte Antigen–Matching Algorithm to Enhance Rapid Identification of the Optimal Unrelated Hematopoietic Stem Cell Sources for Transplantation

The search for a suitable human leukocyte antigen (HLA)–matched unrelated adult stem cell donor (URD) or umbilical cord blood unit (UCB) is a complex process. The National Marrow Donor Program (NMDP) developed a search algorithm known as HapLogic, which is currently provided within the NMDP Traxis application. The HapLogic algorithm has been in use since 2006 and has advanced URD/UCB HLA-matching technology. The algorithm has been shown to have high predictive accuracy, which can streamline URD/UCB selection and drive efficiencies in the search process to the benefit of the stem cell transplantation community. Here, we describe the fundamental components of the NMDP matching algorithm, output, validation, and future directions.

The impact of HLA haplotype and alleles mismatches of donor-recipient pairs on outcome of haploidentical hematopoietic stem cell transplantation with a third part cord blood unit

目的在HLA-A、-B、-C、-DRB1、-DQB1高分辨基因分型的基础上，分析供受者单倍型和等位基因错配在单倍体联合第三方脐血移植对预后的影响。方法回顾性分析2012年1月至2014年12月期间行单倍体联合第三方脐血移植的230例恶性血液病患者，采用基因测序和寡核苷酸探针杂交方法进行供受者HLA-A、-B、-C、-DRB1、-DQB1高分辨基因分型。结果供受者根据HLA-A、-B、-C、-DRB1、-DQB1基因分型结果及相合度，分为HLA-5/10、-6/10、-7/10、≥8/10四组，其3年总生存（OS）率分别为48.7%、59.3%、71.1%、38.3%（P=0.068）。供受者HLA-6/10相合组与HLA-5/10相合组相比，3年OS率差异有统计学意义（P=0.041）。在供受者HLA-6/10相合组：当HLA-Ⅰ类位点（HLA-A、-B、-C）相合3年OS率为61.5%，与HLA-5/10相合组相比差异有统计学意义（P=0.017），且HLA-A位点等位基因相合3年OS及无事件生存（EFS）率分别为90.5％和84.4%，明显高于HLA-5/10相合组（P= 0.013，P=0.013）。供受者与脐血单倍型相合88例，不合51例，两者巨核系重建累积发生率分别为95.3％和86.2%（P=0.007），粒系重建累积发生率分别为98.8％和96.1%（P=0.022）。结论在单倍体联合第三方脐血移植的供者选择中，HLA相合度及等位基因错配对预后均有意义，选择与供受者单倍型相合的第三方脐血可促进移植后造血重建。

Single- vs double-unit cord blood transplantation for children and young adults with acute leukemia or myelodysplastic syndrome

AbstractTransplantation of 2 unrelated cord blood (UCB) units instead of 1 has been proposed to increase the cell dose. We report a prospective randomized study, designed to compare single- vs double-UCB transplantation in children and young adults with acute leukemia in remission or myelodysplasia. Eligible patients had at least two 4-6 HLA-identical UCBs with >3 × 107 nucleated cells/kg for the first and >1.5 × 107 for the second. The primary end point was the 2-year cumulative incidence of transplantation strategy failure, a composite end point including transplant-related mortality (TRM), engraftment failure, and autologous recovery. Randomized patients who did not proceed to transplantation due to refractory disease were considered transplantation failures. A total of 151 patients were randomized and included in the intent-to-treat analysis; 137 were transplanted. Double-UCB transplantation did not decrease transplantation strategy failure (23.4% ± 4.9% vs 14.9% ± 4.2%). Two-year posttransplant survival, disease-free survival, and TRM were 68.8% ± 6.0%, 67.6% ± 6.0%, and 5.9% ± 2.9% after single-unit transplantation compared with 74.8% ± 5.5%, 68.1% ± 6.0%, and 11.6% ± 3.9% after double-unit transplantation. The final relapse risk did not significantly differ, but relapses were delayed after double-unit transplantation. Overall incidences of graft-versus-host disease (GVHD) were similar, but chronic GVHD was more frequently extensive after double-UCB transplantation (31.9% ± 5.7% vs 14.7% ± 4.3%, P = .02). In an exploratory subgroup analysis, we found a significantly lower relapse risk after double-unit transplantation in patients receiving total body irradiation without antithymocyte globulin (ATG), whereas the relapse risk was similar in the group treated with busulfan, cyclophosphamide, and ATG. Single-UCB transplantation with adequate cell dose remains the standard of care and leads to low TRM. Double-unit transplantation should be reserved for patients who lack such units. This trial was registered at www.clinicaltrials.gov as #NCT01067300.

Using EasyMatch® to anticipate the identification of an HLA identical unrelated donor: A validated efficient time and cost saving method

In the absence of an HLA matched familial donor, a search for an unrelated donor or cord blood unit is initiated through worldwide registries. Although a first look-up on available HLA information of donors in the “book” at BMDW (Bone Marrow Donor Worldwide) can provide a good estimation of the number of compatible donors, the variety of resolution typing levels requires confirmatory typing (CT) which are expensive and time consuming. In order to help recipient centers in their work. The French donor registry (France Greffe de Moelle/Agence de la Biomedecine) has recently developed a software program called “EasyMatch®” that uses haplotype frequencies to compute the likelihood of phenotypic match in donors according to various typing resolution levels.The goal of our study is to report a single monocentric user-experience with EasyMatch®, demonstrating that its routine use reduced the cost and the delay of the donor search in our center, allowing the definition of a new strategy to search compatible unrelated donors.The strategy was first established on a retrospective cohort of 217 recipients (185 adults and 32 children=before score) and then validated on a prospective cohort of 171 recipients (160 adults and 11 children=after score).For all patients, we calculated the delay between the registration day and the donor identification day, and the number of CT requested to the donor centre. Considering both groups, we could observe a significant decrease of the number of CT from 8 to 2 (p<0,001), and a significant decrease of the median delay to identify a suitable donor from 43 to 31days (p<0.0001).EasyMatch® estimates the number of potentially identical donors, but doesn’t foresee availability of the donors. It provides us an easy tracking of mismatches, an estimation of the number of potential donors, the selection of population following ethnic origin of patients and a high prediction when probability is high or low. It affords a new approach of donor search in our daily work and improves the efficiency in the great challenge of the compatible donor identification.

Frequency and Risk Factors Associated with Cord Graft Failure after Transplant with Single-Unit Umbilical Cord Cells Supplemented by Haploidentical Cells with Reduced-Intensity Conditioning

Delayed engraftment and cord graft failure (CGF) are serious complications after unrelated cord blood (UCB) hematopoietic stem cell transplantation (HSCT), particularly when using low-cell-dose UCB units. The haplo-cord HSCT approach allows the use of a lower dose single UCB unit by co-infusion of a CD34+ selected haploidentical graft, which provides early transient engraftment while awaiting durable UCB engraftment. We describe the frequency, complications, and risk factors of CGF after reduced-intensity conditioning haplo-cord HSCT. Among 107 patients who underwent haplo-cord HSCT, 94 were assessable for CGF, defined as <5% cord blood chimerism at day 60 in the myeloid and CD3 compartments, irrespective of neutrophil and platelet counts. CGF occurred in 14 of 94 assessable patients (15%). Median survival after CGF was 12.7 months with haploidentical or mixed haploidentical–autologous hematopoiesis persisting in the 7 surviving. Median progression-free survival after CGF was 7.7 months and was not statistically different from those without CGF (10.47 months; P = .18). In univariate analyses, no UCB factors were associated with CGF, including cell dose, cell viability, recipient major ABO mismatch against the UCB unit, or degree of HLA match. We also found no association of CGF with recipient cytomegalovirus serostatus, haploidentical donor age, or day 30 haploidentical chimerism. However, higher haploidentical total nucleated and CD34+ cell doses and day 30 UCB chimerism < 5% in either the myeloid or CD3 compartments were associated with greater risk of CGF. We conclude that assessing chimerism at day 30 may foretell impending CGF, and avoidance of high haploidentical cell doses may reduce risk of CGF after haplo-cord HSCT. However, long-term survival is possible after CGF because of predominant haploidentical or mixed chimerism and hematopoietic function.

A Phase I Study of Reduced-Intensity Conditioning and Allogeneic Stem Cell Transplantation Followed by Dose Escalation of Targeted Consolidation Immunotherapy with Gemtuzumab Ozogamicin in Children and Adolescents with CD33+ Acute Myeloid Leukemia

Myeloablative conditioning and allogeneic hematopoietic stem cell transplant (alloHSCT) in children with acute myeloid leukemia (AML) in first complete remission (CR1) may be associated with significant acute toxicity and late effects. Reduced-intensity conditioning (RIC) and alloHSCT in children is safe, feasible, and may be associated with less adverse effects. Gemtuzumab ozogamicin (GO) induces a response in 30% of patients with CD33+ relapsed/refractory AML. The dose of GO is significantly lower when combined with chemotherapy. We examined the feasibility and toxicity of RIC alloHSCT followed by GO targeted immunotherapy in children with CD33+ AML in CR1/CR2. Conditioning consisted of fludarabine 30 mg/m2 × 6 days, busulfan 3.2 to 4 mg/kg × 2 days ± rabbit antithymocyte globulin 2 mg/kg × 4 days followed by alloHSCT from matched related/unrelated donors. GO was administered ≥60 days after alloHSCT in 2 doses (8 weeks apart), following a dose-escalation design (4.5, 6, 7.5, and 9 mg/m2). Fourteen patients with average risk AML received RIC alloHSCT and post-GO consolidation: median age 13.5 years at transplant (range, 1 to 21), male-to-female 8:6, and disease status at alloHSCT 11 CR1 and 3 CR2. Eleven patients received alloHSCT from 5-6/6 HLA-matched family donors: 8 received peripheral blood stem cells, 2 received bone marrow, and 1 received related cord blood transplantation. Three patients received an unrelated allograft (two 4-5/6 and one 9/10) from unrelated cord blood unit and bone marrow, respectively. Neutrophil and platelet engraftment was observed in all assessable patients (100%), achieved at median 15.5 days (range, 7 to 31) and 21 days (range, 10 to 52), respectively. Three patients received GO at dose level 1 (4.5 mg/m2 per dose), 5 at dose level 2 (6 mg/m2 per dose), 3 at dose level 3 (7.5 mg/m2 per dose), and 3 at dose level 4 (9 mg/m2 per dose). Three of 14 patients received only 1 dose of GO after alloHSCT. One patient experienced grade III transaminitis, which resolved; no grade IV transaminitis, no grade III/IV hyperbilirubinemia, or sinusoidal obstructive syndrome were observed. The second dose of GO was given at median of 143 days (range, 120 to 209) after alloHSCT. Probability of grades II to IV acute and chronic graft-versus-host disease were 21% and 33.5%, respectively. Probability of overall survival after RIC alloHSCT and GO consolidation at 1 and 5 years was 78% and 61%, respectively. Probability of 5-year event-free survival after RIC alloHSCT and GO consolidation in patients in CR1 was 78%. No dose-limiting toxicities probably or directly related to GO were observed in this cohort. This preliminary data demonstrate that RIC followed by alloHSCT and consolidation with GO appears to be safe in children and adolescents with CD33+ AML in CR1/CR2. A phase II trial is currently underway investigating this approach with a GO dose of 9 mg/m2 per dose.

Use of alternative donors for allogeneic stem cell transplantation.

For patients without a human leukocyte antigen (HLA)-matched sibling or unrelated donor, options include transplantation from HLA-mismatched related donors, HLA-mismatched unrelated donors, or unrelated cord blood units. Graft failure remains a problem in 10%-20% of cord blood transplants that contain a limited number of hematopoietic cells. Many approaches are tested in clinical trials to offset the risk of graft failure after cord blood transplantation. GVHD remains a hurdle with any HLA mismatched graft. The use of post-transplant cyclophosphamide holds the promise to overcome the HLA barrier and prevent GVHD despite donor mismatch for a full HLA haplotype. Priority should be given to enrolling patients onto transplant protocols addressing the fundamental problems of engraftment, GVHD, relapse or treatment-related mortality tested with one or more of the alternative stem cell sources. Principles for prioritization of alternative stem cell sources are discussed separately for children and adults who cannot be enrolled on clinical trials. It is difficult ranking currently available sources in the face of multiple factors affecting outcomes, rapidly changing transplant technology and without results from comparative trials.

Excellent Engraftment and Long-Term Survival in Patients with Severe Aplastic Anemia (SAA) Undergoing Allogeneic Hematopoietic Stem Cell Transplantation (HSCT) with Haplo-Identical CD34+ Cells Combined with a Single Umbilical Cord Blood Unit

For SAA patients (pts) lacking an HLA identical donor, outcomes of HSCT using single or dual unrelated cord blood (UCB) transplants or haplo-identical donors have been associated with high graft failure rates and poor survival. We investigated whether co-infusion of a single UCB unit with CD34+ selected cells from a haplo-identical relative following a highly immunosuppressive conditioning could improve transplant outcome for this high-risk population.Methods: Eligible pts for HSCT were required to be between the ages of 4-55, have a diagnosis of SAA or SAA evolved to MDS, be unresponsive to immunosuppressive therapy, have severe neutropenia (ANC<500 cells/µL), lack an HLA-matched donor, have an available haploidentical family member, and at least one ≥ 4/6 HLA-matched UCB unit with a minimum TNC dose ≥1.5x107 cells/kg. Pts received conditioning with cyclophosphamide (120 mg/kg), fludarabine (125 mg/m2), equine-ATG (160 mg/kg) and 200 cGy of total body irradiation. On Day 0, pts received a CD34-selected (Miltenyi CliniMacs) G-CSF mobilized haplo-donor allograft combined with a single UCB. Tacrolimus and MMF were used for GVHD prophylaxis. Results: 21 pts (median age: 19.6 yrs, range: 4.5-48.6) including 14 with SAA and 7 with SAA that evolved to early stage MDS (< 5% blasts) underwent haplo-cord transplant. 14 pts received 4/6, and seven pts received a 5/6 HLA-matched UCB unit. UCB units contained a median 3.77x107 TNCs/kg (range: 1.96-6.93), a median 1.54x105 CD34+ cells/kg (range 0.46-3.45), and the haplo-graft contained a median 3.2x106 CD34+ cells/kg (range: 3.0-4.1) and a median 0.95x103 CD3+ cells/kg (range 0.3-5.04). All 21 pts engrafted, which was sustained and associated with transfusion independence in 20/21 pts. At a median follow-up of 3 yrs (1116 days, range: 226-2572), 19/21 pts survive for an overall survival rate of 90%. 2 pts died at day 414 and 402 post-HSCT from viral related complications (CMV pneumonitis and limbic encephalopathy). Neutrophil and platelet recovery occurred at a median 10 (range: 9-22), and 30 (range: 16-129) days respectively. Cord myeloid engraftment (cord ANC>500 cells/µl, calculated from chimerism data) occurred in 18/21 pts at a median 42 days while 3/21 did not achieve a cord ANC>500 but had haplo-donor engraftment which was sustained in 2 cases. The cumulative incidence of grade II-IV acute GVHD (aGVHD) was 28.6%, with only 1 pt (4.8%) developing grade III and no cases of grade IV or steroid refractory aGVHD. The cumulative incidence of chronic GVHD (cGVHD) was 47.8%, with 37% mild, 11% moderate, and no severe cGVHD. Engraftment profiles showed 16 achieved full cord chimerism in all cell lineages, 2 remained mixed haplo-cord chimeras, and 2 failed to have UCB engraftment but had sustained 100% haplo-donor myeloid chimerism. Higher degrees of HLA matching between recipient and UCB unit were associated with faster rates of cord engraftment (P =0.012) and the achievement of full cord chimerism (P= 0.004). Among the 16 pts who had lower degrees of HLA matching (≤5/8 HLA alleles) between the recipient and UCB unit, 9 received grafts with KIR ligand incompatibility in the haplo vs. cord direction ( defined as the presence of a KIR ligand in the haplo-donor graft that was absent in the UCB unit at HLA epitopes Bw4, HLA-C Groups 1 & 2, HLA-A3, and HLA-A11); KIR ligand incompatibility had a negative impact on cord myeloid engraftment as 6/9 (67%) of these pts failed to achieve full cord myeloid chimerism by day 400 and 5/9 (56%) pts failed to achieve a cord ANC>500 by day 250 post-HSCT. In contrast, cord myeloid engraftment occurred quicker in the 12 pts who did not have haplo vs. cord KIR ligand incompatibility including 7 pts with lower degrees of HLA matching (≤5/8 HLA alleles between the recipient and UCB) and 5 pts with higher degrees of HLA matching, where the median times to achieve a cord ANC>500 and full cord myeloid chimerism was 42 days (range: 28-58) and 60 days (range: 14-230) respectively ( both P<0.01 compared to the pts that received grafts with KIR ligand incompatibility). Conclusion: Transplantation of haplo-identical CD34+ cells with a single UCB unit in neutropenic pts with SAA and SAA evolved to MDS was associated with rapid neutrophil recovery, durable donor engraftment and excellent long-term survival. These results suggest that haplo-cord HSCT is an effective treatment option associated with excellent survival in pts with SAA who lack an HLA-matched donor. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Feasibility and Outcome of Allogeneic Hematopoietic Stem-Cell Transplantation in High-Risk AML: Real-Life Perspective from a Single Institution

Introduction: Allogeneic stem cell transplant (alloHSCT) is the treatment of choice in patients with high-risk acute myeloid leukemia (AML). However, it is uncertain exactly how many of these patients actually undergo alloHSCT as planned initially. Moreover, the real efficacy of this therapeutic option remains controversial. Since few studies have addressed these questions, to shed light on these issues, we have analyzed the results of a policy of early donor search, the proportion of patients in which initially planned alloHSCT was performed, and the outcome of alloHSCT in our center.Patients and Methods: We included in the study 246 AML patients (median age, 51 years, 16-70; 51% males) considered fit for intensive chemotherapy, who were treated according to 3 consecutive protocols of the Spanish CETLAM cooperative group (CETLAM-99, CETLAM-2003, and CETLAM-2012). Patients were diagnosed between 2003 and 2013 in our center or referred to our center for alloHSCT; median follow-up of alive patients was 70.4 months (12.5-143.8). Indication of allloHSCT in CR1 was established according to the stratification risk of each protocol, based on AML origin (de novo vs. secondary), cytogenetics, number of courses to achieve CR, NPM1/FLT3-ITD/CEBPA mutational profile, and MRD status at end of consolidation. Statistical analyses were performed using R v3.1 and SPSS v20. The effect of alloHSCT was analyzed by Mantel-Byar test with SCT as a time-dependent covariable.Results: AlloSCT was planned in 167 (68%) patients deemed of high-risk and it was actually performed in 130 out of these high-risk AML patients (78%). Types of donor were: matched related donor (MRD), n=63; 7/8 or 8/8 matched unrelated donor (MUD), n=51 (HLA matching: 8/8 or 10/10= 32; 7/8 and 9/10, n=19); unrelated cord blood (UCB) n=14; and family haploidentical donor, n= 2. Status at SCT was first CR (CR1) in 63 patients (48%), ≥CR2 n=23 (18%), and non-CR AML in 44 patients (34%). The type of conditioning regimen was myeloablative in 66 (51%) of the patients.Ninety-eight patients out of 167 patients with an indication for alloHSCT, lacked a MRD (59%). An unrelated donor search was performed in 80 (82%) out of these 98 patients, and was successful in 54 (67.5%). An UCB unit was selected in 14 patients without a MUD in a timely fashion. The main reasons for not initiating an unrelated donor search were poor performance status (n=5), refractory disease (n=4), and age (n=4). Median time from start of search to finding of an adequate donor was 50 days, and median time from start of search to SCT was 131 days.The overall outcome of these 167 patients with an indication of alloHSCT was 2-year OS: 48±8% and 5-year LFS: 36%±8% with a markedly better outcome among patients in whom alloHSCT was finally performed (2-year OS: 57±8% vs. 11%±10%; Mantel Byar, p<0.0001). The beneficial effect of alloHSCT was maintained in the subset of patients in CR1 for whom alloHSCT was planned (2-year OS: 60±12%; vs. 33±16%; Mantel Byar p=0.001). Intere stingly, the outcome of patients with an indication of alloHSCT did not differ between patients with an HLA-identical sibling and patients in whom a donor search was started (2-year OS: 50±12%; vs. 52±11%; p=0.97), in an intention-to-treat analysis. Moreover, the outcome of alloHSCT did not vary among different donor sources (MRD, MUD, and alternative donors) (2-year OS from alloHSCT: 59%±14% vs. 61%±18% vs. 44%±30, p= 0.6).Conclusions: A policy of early search of MUD enabled alloHSCT to be performed in the majority of patients for whom it was planned. Performing of alloHSCT in patients improved outcome of this cohort of high-risk AML patients, compared to patients not achieving alloHSCT. An adequate MUD was identified in a two thirds of patients, and a similar outcome was found after alloHSCT for all donor sources (MRD, MUD, and alternative source) in this study. DisclosuresRosiñol:Celgene, Janssen: Honoraria.

Cord Blood Unit Cryopreservation: Positioning Segments for Potency Assessment

Introduction: Banked, unrelated umbilical cord blood units (CBU) are a rich source of hematopoietic stem cells for hematopoietic reconstitution. Potency assays on attached segments have been used for CBU release from the bank to the transplant center. CBUs have historically been manufactured and cryopreserved in bags with three segments (made from the tubing used to fill the bag) arranged across the top of the cassette. Prior to cryopreservation, the CBU is overwrapped, placed in a metal cassette and frozen in a control-rate freezer and submerged under liquid nitrogen for long-term storage. After cryopreservation, segments can be removed from the cassette, without disturbing the bag, for HLA typing, potency assays, or other testing. Last year, in an effort to increase the number of segments available for testing, we changed the configuration of the cryobag to create a fourth segment. To fit in the cassette, the segments were arranged with two segments across the top and two segments bent at 90 degrees to fit between the 20% and 80% portions of the bag. When performing our annual stability testing, we realized that the two distal segments, positioned between the 20% and 80% compartments yielded lower potency results than the segments positioned across the top of the cassette. We investigated this finding as described below.Method: Three large fresh CBUs were processed separately on a Sepax cell processor (Biosafe, Geneva, Switzerland) and evenly divided into two cryopreservation bags. For each CBU, one bag was created with three segments and the other bag with four segments. The cryopreservative, dimethylsulfoxide in dextran, was added at a final concentration of 10% to both bags prior to cryopreservation. Segments were positioned either across the top (3 segments) or in the bent configuration (4 segments) for each of the paired CBUs. All units were cryopreserved and stored in a Thermogenesis Bioarchive. After two weeks in storage, the CBUs were tested. The bags and segments were assayed for ALDHbr, viable CD34, CD45, glycophorin A and viability (7-AAD) along with colony forming units (CFUs), the potency assay used by our bank.Results: The segments configured across the top of the bag correlated with results from the cryobag for ALDHbr (as a percent of viable CD45+, Table 1), CD34+ (as a percent of viable CD45+) and CFU. In contrast, segments placed between the 20% and 80% compartments were significantly lower than the bag for both ALDHbr (as a percent of viable CD45+) and CFU, although CD34+ (as a percent of viable CD45+) was equivalent.Conclusions: Segments attached to CBUs can predict potency of the CBU by various parameters. However, proper placement of the segments within the cryopreservation cassette must be performed to ensure that potency measured on the segments reflects potency measured on the cord blood unit. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Second-Generation Relative Donor for T-Replete Haplo-Identical Allogeneic Stem Cell Transplantation with High-Dose Post-Transplant Cyclophosphamide: Towards Disappearance of the HLA Barrier

Introduction: Allogeneic stem cell transplantations (allo-SCT) using alternative donors are increasingly used in patients lacking suitable matched sibling or unrelated donor. Recently, the use of post-transplant cyclophosphamide (CY) has allowed to re-consider first-generation relatives (brother, sister, father, mother, son or daughter) as haplo-identical donors for allo-SCT. Indeed, the incidence of severe acute GVHD is lowered by post-transplant administration of CY, due to the early destruction of putative alloreactive T cells. Still, some patients may not have a suitable relative donor for various reasons such as older age of the parents, no siblings nor children, no cord blood available, or because use of a graft from a first-generation haplo-identical relatives is contra-indicated. The probability of having a haplo-identical donor among siblings is 50% while it is almost 100% when considering both biological parents and offspring. When considering as a potential donor the child of a matched or haplo-identical sibling, the probabilities for the donor to be haplo-identical with the recipient remain 50% and 25%, respectively. Thus, second-generation relative donor (i.e. nephew or niece) may be finally considered as a source of stem cell graft.Methods: Here we report the case of a 61-year old man who received a T-replete haplo-identical allo-SCT with high-dose post-transplant CY from his second-generation relative nephew. In 2010, the patient was diagnosed with ALK- CD30+ anaplastic T-cell lymphoma and received 8 cycles of CHOD allowing to obtain morphologic and metabolic partial response. The patient received an allo-SCT from a sibling matched donor (brother) on November 2010 after an FB2A2 reduced-intensity conditioning regimen but secondary graft failure was rapidly documented in spite of donor lymphocyte infusions. Relapse occurred in September 2014 and brentuximab vedotin was administered each 21 days for seven cycles allowing to obtain a complete morphologic and metabolic response. It was decided to perform a second allograft using a different donor. The patient was childless and no unrelated donor or cord blood units were available. It was thus chosen to ask for donor the son of the matched brother, who was haplo-identical and had no antibodies directed against the patient's HLA specificities. This nephew had a O- blood group and negative CMV serology while the recipient was O+ and CMV+.Results: The second allograft was performed on April 2nd 2015 using the Baltimore (Luznik, BBMT 2008) conditioning regimen with 2 days of post-transplant CY. A megadose of peripheral blood stem cell was administered (14.16x106 CD34+ cells/Kg) at day 0. Neutrophils and platelets recovery (>50 Giga/L) were achieved as early as days +18 and +33, respectively, with full donor whole blood chimerism (99.8%) at day +30, persisting on day +60 and +100 (both whole blood 99.9%, CD3+ T cells: 99.9%).Grade 2 acute cutaneous GVHD occurred at day +21. The evolution was favorable after initiating corticosteroids at 2 mg/kg/day with tapering thereafter. Not surprisingly, CMV reactivation was documented at day+22, controlled by ganciclovir treatment. Immune reconstitution evaluated at days +30, +60 and +100 showed normal monocyte counts while B lymphocytes were undetectable. NK cells increased from 42/mm3 at day+30 to 453/mm3 at day +60 and 665/mm3 at day +100. Interestingly, after profound lymphopenia within the first 100 days post-transplant, CD8+ T large granular lymphocytes expansion was documented at day + 110. At four months post-transplant, the patient is alive in persistent metabolic remission with no active acute or chronic GVHD nor active infection. His outcomes will be updated for the meeting.Conclusion: T-replete haplo-identical allo-SCT with high-dose post-transplant CY using a second-generation relative donor was feasible allowing for full engraftment and moderate acute GVHD in our patient. This result expands the possibility to find a donor for a selected patient, meanwhile paving the way for using unrelated haplo-identical donor, which could be of interest when considering solid transplantation. Indeed, combining solid organ transplantation and allo-SCT from the same haplo-identical donor may open the door to withdraw immunosuppression in this particular setting, because stable tolerance may be induced, as it has been already reported for kidney transplant (Kawai, NEJM 2013). DisclosuresMoreau:Celgene: Honoraria, Other: Adboard; Amgen: Other: Adboard; Takeda: Other: Adboard; Janssen: Other: Adboard; Novartis: Other: Adboard.

Unrelated cord blood transplantation for adult patients with acute myeloid leukemia: higher incidence of acute graft-versus-host disease and lower survival in male patients transplanted with female unrelated cord blood--a report from Eurocord, the Acute Leukemia Working Party, and the Cord Blood Committee of the Cellular Therapy and Immunobiology Working Party of the European Group for Blood and Marrow Transplantation.

BackgroundIn the setting of allogeneic human leukocyte antigen (HLA)-matched bone marrow transplantation, transplanting male patients with grafts from female donors has been associated with a higher incidence of graft-versus-host disease (GVHD) and of nonrelapse mortality (NRM). The aim of the current analysis was to compare transplantation outcomes in male patients given female unrelated cord blood (UCB) versus other gender combinations.Patients and methodsData from 552 consecutive patients with acute myeloid leukemia (AML) given a single UCB transplantation between 2000 and 2014 were included.ResultsIn comparison with other gender combination, male patients given female UCB (n = 131) had a trend for a higher incidence of grades II–IV acute GVHD (33 versus 25 %, P = 0.08), a trend for a higher incidence of NRM (41 versus 33 %, P = 0.06), and a lower leukemia-free (LFS, 30 versus 41 %, P = 0.01) and overall survival (OS, 33 versus 45 %, P = 0.008). In multivariate analyses, taking into consideration all patients for which data on HLA-matching and cell dose transplanted were fully available (n = 363), male patients transplanted with a female UCB had a trend for a higher incidence of grade III–IV acute GVHD (hazard ratio (HR) = 2.0, P = 0.06), a trend for a higher NRM (HR = 1.5, P = 0.06), and a worse LFS (HR = 1.4, P = 0.04) and OS (HR = 1.3, P = 0.06).ConclusionsOur data suggest that male patients transplanted with female UCB might have higher risk of acute GVHD and of NRM leading to worse LFS and OS. These results should be confirmed in other large cohorts of patients before used for determining the choice of an UCB unit.Electronic supplementary materialThe online version of this article (doi:10.1186/s13045-015-0207-4) contains supplementary material, which is available to authorized users.

Cord blood is the optimal graft source for the treatment of pediatric patients with lysosomal storage diseases: clinical outcomes and future directions

Initially used as an alternative hematopoietic stem cell source for patients without a human leukocyte antigen–matched bone marrow or peripheral blood stem cell donor, unrelated cord blood (UCB) is now the preferred donor source when hematopoietic stem cell transplantation (HSCT) is used to treat patients with lysosomal storage disorders (LSD). Without transplantation, these patients have serious progressive multi-system deterioration and premature death. UCB transplantation favorably alters the natural history of these diseases and prolongs survival. It primarily works through cellular enzyme replacement by healthy engrafted donor cells providing a continuous endogenous supply of enzyme throughout the body and, thorough engraftment of donor-derived microgial cells, in the central nervous system. HSCT in LSD, the majority performed in patients with mucopolysaccharidoses and leukodystrophies, is associated with remarkably high rates of engraftment and survival. Importantly, recipients of UCB, as compared with other donor sources, more often achieve full-donor chimerism and normalization of enzyme levels, which has been associated with superior long-term clinical prognosis. Additionally, UCB units are readily available, reducing time to transplantation and thereby providing access to transplant at young ages, another highly important predictor for long-term neuro-developmental function. For these reasons, UCB grafts are nowadays considered to be the optimal graft source for HSCT in patients with LSD.

High Incidence of Late, Sustained and Clinically Inconsequential Epstein Barr Virus (EBV) Reactivation Following Combined Unrelated Cord Blood and Haploidentical CD34+ Cell Transplantation

Introduction: Unrelated cord blood (UCB) transplantation is a useful alternative for patients (pts) with malignant or non-malignant hematological disorders who lack an HLA matched donor. However, because UCB is devoid of memory T-cells, viral infections are more problematic following this transplant approach. EBV is a latent γ-herpesvirus that infects more than 90% of the world’s population. Following UCB transplantation, early (<100 days) reactivation of latent EBV is common and is associated with a high risk of post-transplant lymphoproliferative disorder (PTLD). The likelihood of PTLD following late EBV reactivation (>100 days) is less well characterized. We investigated EBV reactivation and PTLD development in early vs late post-transplant periods in severe aplastic anemia (SAA) pts undergoing combined UCB and haploidentical CD34+ cell transplantation.Methods: Pts with SAA and life-threatening neutropenia (ANC <500/uL) refractory to ≥2 immunosuppressive agents were eligible for treatment if they lacked an HLA-matched donor. Conditioning consisted of cyclophosphamide (120 mg/kg), fludarabine (125 mg/m2), equine ATG (160 mg/kg) and a single dose of 200 cGy of total body irradiation. Graft-vs-host disease (GVHD) prophylaxis consisted of tacrolimus and mycophenolate mofetil. Pts received a single ³4/6 HLA antigen matched UCB unit co-infused with a G-CSF mobilized, T-cell depleted CD34+ selected (Miltenyi CliniMacs system) allograft collected by apheresis of a haploidentical relative. EBV copy numbers were measured weekly for the first six months post-transplant and thereafter as clinically warranted.Results: 18 pts with treatment refractory SAA (median age 18 years; range 4-30), including 4 with SAA evolved to myelodysplastic syndrome (MDS) were transplanted. All pts were platelet and RBC transfusion-dependent. 11 pts received a ≥4/6 HLA matched UCB unit and 7 received a 5/6 HLA-matched unit. UCB units contained a median 2.8 x 107 TNCs/kg (range 1.7- 5.2) and 2.1 x 105CD34+cells/kg (range 0.5- 4.7) and haploidentical peripheral blood grafts contained a median 3.2 x106 CD34+cells/kg (range 3- 4.1) and 2.3 x 103 CD3+cells/kg (range 0.8- 5). All 18 pts were EBV IgG seropositive pretransplant. With a median follow-up of 689 days (range 160-2022), 16 pts survive, all disease free and transfusion independent. 16/18 (89%) pts developed EBV reactivation (EBV copy number >1000 copies/ml of whole blood or >150 genome equivalents/million PBMC) at a median 42 days post-transplant (range 2-1165). 12 pts (67%) had EBV reactivation before transplant day 100 (defined as early reactivation). Among those with early reactivation, 10/12 (83%) were treated preemptively with rituximab while 2/12 (17%) did not receive treatment and cleared the EBV viremia without intervention. Late EBV reactivation (defined as reactivation occurring after day 100) occurred in 15/18 (83%) pts. Among those with late reactivation, 12/15 (80%) were not treated while 3/15 (20%) received rituximab, which was given preemptively for PTLD in 2 pts and used to treat biopsy-confirmed PTLD on day 343 in one pt. The median time to first rituximab use was 37 days (range 8-343). Among the 12 pts with late EBV reactivation not given treatment, 9 (50% of those transplanted) had sustained viremia of >1000 copies lasting >30 days (defined as late and sustained EBV reactivation). All pts with late and sustained EBV reactivation remained asymptomatic despite high viral copy numbers, including 4 who had peak EBV copy numbers >30,000 copies/ml (Figure). There was no statistically significant difference in immune reconstitution, as determined by quantitative serum IgG levels and absolute numbers of CD4+ and CD8+ T-cells on day 100, 6 months, 1 year and > 1 year post-transplant in those with vs without late and sustained EBV reactivation.Conclusion: We observed that late and sustained EBV reactivation occurs commonly following combined UCB/haploidentical selected CD34+ cell transplantation, even in pts off immunosuppressive therapy and without CD4 and/or CD8 lymphopenia. In most cases, it was clinically inconsequential, and did not require rituximab treatment. The factors contributing to late sustained EBV reactivation including potential defects in viral-specific immunity remain under investigation.Figure: [Display omitted] DisclosuresNo relevant conflicts of interest to declare.