Unrelated umbilical cord blood transplants in adults: Early recovery of neutrophils by supportive co-transplantation of a low number of highly purified peripheral blood CD34+ cells from an HLA-haploidentical donor

New player in CAR-T manufacture field: comparison of umbilical cord to peripheral blood strategies

One of the most successful treatments in hematologic cancer is chimeric antigen receptor (CAR)-T cell-based immunotherapy. However, CAR-T therapy is not without challenges like the costly manufacturing process required to personalize each treatment for individual patients or graft-versus-host disease. Umbilical cord blood (UCB) has been most commonly used for hematopoietic cell transplant as it offers several advantages, including its rich source of hematopoietic stem cells, lower risk of graft-versus-host disease, and easier matching for recipients due to less stringent HLA requirements compared to bone marrow or peripheral blood stem cells. In this review, we have discussed the advantages and disadvantages of different CAR-T cell manufacturing strategies with the use of allogeneic and autologous peripheral blood cells. We compare them to the UCB approach and discuss ongoing pre-clinical and clinical trials in the field. Finally, we propose a cord blood bank as a readily available source of CAR-T cells.

Haplo-cord transplant. Realizing the potential of umbilical cord blood grafts. - A review of techniques and analysis of outcomes

The combination of cord blood transplant with progenitor cells from partially HLA-matched adult donors (haplo-cord transplant) has been used over the past two decades. In Europe and the US the adult donor graft is CD34 selected and provides early hematopoiesis, but durable engraftment derives from the cord blood graft (CD34 selected haplo-cord). Neutrophil recovery is prompt and rates of acute and chronic GVHD are low. Recent Chinese studies combine cord blood grafts with T-replete haplo-identical grafts (unmodified haplo-cord). The haplo graft usually establishes dominance and UCB chimerism is rarely detected. Comparison studies suggest considerably decreased rates of relapse and improved outcomes, compared with either haplo-identical transplant or CBU transplant, particularly in patients with advanced leukemia. A recent prospective randomized study confirms this. Haplo-cord mitigates the engraftment delay of UCB transplant. The unique biology of UCB grafts results in low GVHD and improved GVL especially beneficial in high-risk disease.

HIV-1 remission and possible cure in a woman after haplo-cord blood transplant

Previously, two men were cured of HIV-1 through CCR5Δ32 homozygous (CCR5Δ32/Δ32) allogeneic adult stem cell transplant. We report the first remission and possible HIV-1 cure in a mixed-race woman who received a CCR5Δ32/Δ32 haplo-cord transplant (cord blood cells combined with haploidentical stem cells from an adult) to treat acute myeloid leukemia (AML). Peripheral blood chimerism was 100% CCR5Δ32/Δ32 cord blood by week 14 post-transplant and persisted through 4.8 years of follow-up. Immune reconstitution was associated with (1) loss of detectable replication-competent HIV-1 reservoirs, (2) loss of HIV-1-specific immune responses, (3) in vitro resistance to X4 and R5 laboratory variants, including pre-transplant autologous latent reservoir isolates, and (4) 18 months of HIV-1 control with aviremia, off antiretroviral therapy, starting at 37 months post-transplant. CCR5Δ32/Δ32 haplo-cord transplant achieved remission and a possible HIV-1 cure for a person of diverse ancestry, living with HIV-1, who required a stem cell transplant for acute leukemia.

Comparison of Haploidentical Hematopoietic Stem Cell Transplant With or Without Unrelated Cord Blood Infusion in Severe Aplastic Anemia: Outcomes of a Multicenter Study

The purpose of this study in severe aplastic anemia (SAA) patients was to compare the feasibility and efficacy of haploidentical hematological stem cell transplantation combined with a single unrelated cord blood (UCB) infusion (Haplo-cord-HSCT) or haplo-identical HSCT (Haplo-HSCT) alone. The five-year graft-versus-host disease (GVHD)-free or failure-free survival (GFFS) was similar between the two groups (72.4 ± 3.4% vs. 65.4 ± 5.2%, P = 0.178); however, the five-year overall survival (OS) was more favorable in the Haplo-cord-HSCT group than that in the Haplo-HSCT group (84.0 ± 2.8% vs. 72.6 ± 4.9%, P = 0.022), as was transplantation-related mortality (16.4% vs. 27.4%, P = 0.039). Multivariate analysis showed that Haplo-cord HSCT was the only independent determinant of increased OS (P = 0.013). Explorative subgroup analysis showed that only an Human leukocyte antigen-A (HLA-A) allele match between UCB and the recipient was a beneficial factor for GFFS in the Haplo-cord-HSCT group (P = 0.011). In the haplo-cord with an HLA-A match (n = 139) or mismatch (n = 32) or Haplo-HSCT groups, a haplo-cord HLA-A allele match was associated with lower I-IV and III-IV acute GVHD. The haplo-cord with an HLA-A match subgroup also had higher five-year OS than the Haplo-HSCT group (85.4 ± 3.0% vs. 72.6 ± 4.9%, P = 0.013), and higher five-year GFFS than the Haplo-cord HLA-A allele mismatch subgroup (76.2 ± 3.6% vs. 56.3 ± 8.8%, P = 0.011). These findings suggest that the coinfusion of a single UCB potentially improves survival of Haplo-HSCT in SAA patients and that an HLA-A allele-matched UCB is the preferred option.

Allogeneic stem cell transplantation with omidubicel in sickle cell disease

Many patients with sickle cell disease (SCD) do not have HLA-matched related donors for hematopoietic stem cell transplantation (HSCT). Unrelated cord blood (UCB) is an alternative graft option but is historically associated with high graft failure rates, with inadequate cell dose a major limitation. Omidubicel is a nicotinamide-based, ex vivo-expanded UCB product associated with rapid engraftment in adults with hematologic malignancies. We hypothesized that increasing the UCB cell dose with this strategy would lead to improved engraftment in pediatric patients undergoing myeloablative HSCT for SCD. We report the outcomes of a phase 1/2 study in 13 patients with severe SCD who received omidubicel in combination with an unmanipulated UCB graft and 3 who received a single omidubicel graft. Grafts were minimally matched with patients at 4 of 6 HLA alleles. Median age at transplant was 13 years. A median CD34+ expansion of ∼80-fold was observed in omidubicel and led to rapid neutrophil engraftment (median, 7 days). Long-term engraftment was derived from the unmanipulated graft in most of the double cord blood recipients. Two of the 3 single omidubicel recipients also had sustained engraftment. Incidence of acute graft-versus-host disease (GVHD) was high, but resolved in all surviving patients. Event-free survival in the double cord group was 85% (median follow-up 4 years). All 3 patients in the single cord group were alive at 1 year after transplantation. Ex vivo expansion of UCB with omidubicel supports engraftment in patients with SCD. This approach to decreasing the incidence of GVHD should be optimized for general use in patients with SCD. This study was registered at www.clinicaltrials.gov as #NCT01590628.

Eltrombopag for enhancement of platelet engraftment in patients undergoing allogeneic cord blood transplantation

Platelet recovery after allogeneic umbilical cord blood (UCB) transplantation is delayed compared to other graft sources. We conducted a multicenter phase 2a study to explore whether eltrombopag, a thrombopoietin-receptor agonist, would enhance platelet recovery after UCB transplantation. Between 02/2013 and 07/2016, 12 (10 adults, 2 children) individuals (median age 50; range 6-74 years) with hematological malignancies in complete remission were enrolled. Eltrombopag was given for a median of 76 (range 15-175) days and was safe even at doses of 300 mg/day. Median time to neutrophil engraftment was 23 (range 16-40) days. Median time to platelets >20,000/µl and >50,000/µl was 55 (range 25-199) and 66 (range 31-230) days, respectively. A historical cohort comparison did not reveal an advantage for eltrombopag. In conclusion, in the present study eltrombopag seems safe. Based on our limited data, it seems unlikely that eltrombopag could enhance platelet engraftment after UCB transplantation.

Combined haploidentical and cord blood transplantation for refractory severe aplastic anaemia and hypoplastic myelodysplastic syndrome

Umbilical cord blood (UCB) transplantation is a potentially curative treatment for patients with refractory severe aplastic anaemia (SAA), but has historically been associated with delayed engraftment and high graft failure and mortality rates. We conducted a prospective phase 2 trial to assess outcome of an allogeneic transplant regimen that co-infused a single UCB unit with CD34⁺ -selected cells from a haploidentical relative. Among 29 SAA patients [including 10 evolved to myelodysplastic syndrome (MDS)] who underwent the haplo cord transplantation (median age 20 years), 97% had neutrophil recovery (median 10 days), and 93% had platelet recovery (median 32 days). Early myeloid engraftment was from the haplo donor and was gradually replaced by durable engraftment from UCB in most patients. The cumulative incidences of grade II-IV acute and chronic graft-versus-host disease (GVHD) were 21% and 41%, respectively. With a median follow-up of 7·5 years, overall survival was 83% and GVHD/relapse-free survival was 69%. Patient- and transplant-related factors had no impact on engraftment and survival although transplants with haplo-versus-cord killer-cell immunoglobulin-like receptor (KIR) ligand incompatibility had delayed cord engraftment. Our study shows haplo cord transplantation is associated with excellent engraftment and long-term outcome, providing an alternative option for patients with refractory SAA and hypoplastic MDS who lack human leucocyte antigen (HLA)-matched donors.

Therapeutic Potential of Umbilical Cord Stem Cells for Liver Regeneration

The liver is a vital organ for life and the only internal organ that is capable of natural regeneration. Although the liver has high regeneration capacity, excessive hepatocyte death can lead to liver failure. Various factors can lead to liver damage including drug abuse, some natural products, alcohol, hepatitis, and autoimmunity. Some models for studying liver injury are APAP-based model, Fas ligand (FasL), D-galactosamine/endotoxin (Gal/ET), Concanavalin A, and carbon tetrachloride-based models. The regeneration of the liver can be carried out using umbilical cord blood stem cells which have various advantages over other stem cell types used in liver transplantation. UCB-derived stem cells lack tumorigenicity, have karyotype stability and high immunomodulatory, low risk of graft versus host disease (GVHD), low risk of transmitting somatic mutations or viral infections, and low immunogenicity. They are readily available and their collection is safe and painless. This review focuses on recent development and modern trends in the use of umbilical cord stem cells for the regeneration of liver fibrosis.

Engraftment kinetics after transplantation of double unit cord blood grafts combined with haplo-identical CD34+ cells without antithymocyte globulin

Double unit cord blood (dCB) transplantation (dCBT) is associated with high engraftment rates but delayed myeloid recovery. We investigated adding haplo-identical CD34+ cells to dCB grafts to facilitate early haplo-identical donor-derived neutrophil recovery (optimal bridging) prior to CB engraftment. Seventy-eight adults underwent myeloablation with cyclosporine-A/mycophenolate mofetil immunoprophylaxis (no antithymocyte globulin, ATG). CB units (median CD34+ dose 1.1 × 10⁵/kg/unit) had a median 5/8 unit-recipient human leukocyte antigen (HLA)-match. Haplo-identical grafts had a median CD34+ dose of 5.2 × 10⁶/kg. Of 77 evaluable patients, 75 had sustained CB engraftment that was mediated by a dominant unit and heralded by dominant unit-derived T cells. Optimal haplo-identical donor-derived myeloid bridging was observed in 34/77 (44%) patients (median recovery 12 days). Other engrafting patients had transient bridging with second nadir preceding CB engraftment (20/77 (26%), median first recovery 12 and second 26.5 days) or no bridge (21/77 (27%), median recovery 25 days). The 2 (3%) remaining patients had graft failure. Higher haplo-CD34+ dose and better dominant unit-haplo-CD34+ HLA-match significantly improved the likelihood of optimal bridging. Optimally bridged patients were discharged earlier (median 28 versus 36 days). ATG-free haplo-dCBT can speed neutrophil recovery but successful bridging is not guaranteed due to rapid haplo-identical graft rejection.

Reduced-Intensity Allogeneic Transplant for Acute Myeloid Leukemia and Myelodysplastic Syndrome Using Combined CD34-Selected Haploidentical Graft and a Single Umbilical Cord Unit Compared with Matched Unrelated Donor Stem Cells in Older Adults

Haplo/cord transplantation combines an umbilical cord blood (UCB) graft with CD34-selected haploidentical cells and results in rapid hematopoietic recovery followed by durable UCB engraftment. We compared outcomes of transplants in older patients with acute myeloid leukemia (AML) or high-risk myelodysplastic syndromes (MDS) who received either HLA-matched unrelated donor (MUD) cells or haplo/cord grafts. Between 2007 and 2013, 109 adults ages 50 and older underwent similar reduced-intensity conditioning with fludarabine and melphalan and antibody-mediated T cell depletion for AML (n = 83) or high-risk MDS (n = 26) followed by either a MUD (n = 68) or haplo/cord (n = 41) graft. Patient characteristics were similar for each graft source except for more minority patients receiving a haplo/cord transplant (P = .01). One half of the AML patients were not in remission. Two-year progression-free survival (PFS), overall survival (OS), and graft-versus-host disease-free relapse-free survival were 38%, 48%, and 32.1% for MUD and 33%, 48%, and 33.8% for haplo/cord transplants (P = .62 for PFS; P = .97 for OS; P= .84), respectively. Acute grades II to IV and chronic graft-versus-host-disease rates did not differ at 19.5% and 4.9% in haplo/cord compared with 25% and 7.4% after MUD (P = .53 and P = .62, respectively). Multivariate analysis confirmed no significant differences in transplant outcomes by donor type. Haplo/cord reduced-intensity transplantation achieves similar outcomes relative to MUD in older AML and MDS patients, making this a promising option for those without matched donors.

Combined Haploidentical and Umbilical Cord Blood Allogeneic Stem Cell Transplantation for High-Risk Lymphoma and Chronic Lymphoblastic Leukemia

Limited studies have reported on outcomes for lymphoid malignancy patients receiving alternative donor allogeneic stem cell transplants. We have previously described combining CD34-selected haploidentical grafts with umbilical cord blood (haplo-cord) to accelerate neutrophil and platelet engraftment. Here, we examine the outcome of patients with lymphoid malignancies undergoing haplo-cord transplantation at the University of Chicago and Weill Cornell Medical College. We analyzed 42 lymphoma and chronic lymphoblastic leukemia (CLL) patients who underwent haplo-cord allogeneic stem cell transplantation. Patients underwent transplant for Hodgkin lymphoma (n = 9, 21%), CLL (n = 5, 12%) and non-Hodgkin lymphomas (n = 28, 67%), including 13 T cell lymphomas. Twenty-four patients (52%) had 3 or more lines of therapies. Six (14%) and 1 (2%) patients had prior autologous and allogeneic stem cell transplant, respectively. At the time of transplant 12 patients (29%) were in complete remission, 18 had chemotherapy-sensitive disease, and 12 patients had chemotherapy-resistant disease. Seven (17%), 11 (26%), and 24 (57%) patients had low, intermediate, and high disease risk index before transplant. Comorbidity index was evenly distributed among 3 groups, with 13 (31%), 14 (33%), and 15 (36%) patients scoring 0, 1 to 2, and ≥3. Median age for the cohort was 49 years (range, 23 to 71). All patients received fludarabine/melphalan/antithymocyte globulin conditioning regimen and post-transplant graft-versus-host disease (GVHD) prophylaxis with tacrolimus and mycophenolate mofetil. The median time to neutrophil engraftment was 11 days (range, 9 to 60) and to platelet engraftment 19.5 days (range, 11 to 88). Cumulative incidence of nonrelapse mortality was 11.6% at 100 days and 19 % at one year. Cumulative incidence of relapse was 9.3% at 100 days and 19% at one year. With a median follow-up of survivors of 42 months, the 3-year rates of GVHD relapse free survival, progression-free survival, and overall survival were 53%, 62%, and 65%, respectively, for these patients. Only 8% of the survivors had chronic GVHD. In conclusion, haplo-cord transplantation offers a transplant alternative for patients with recurrent or refractory lymphoid malignancies who lack matching donors. Both neutrophil and platelet count recovery is rapid, nonrelapse mortality is limited, excellent disease control can be achieved, and the incidence of chronic GVHD is limited. Thus, haplo-cord achieves high rates of engraftment and encouraging results.

Single umbilical cord blood with or without CD34+ cells from a third-party donor in adults with leukemia

We retrospectively compared the clinical outcomes of adults with acute leukemia who received single-unit umbilical cord blood (UCB) transplantation (sUCBT) (n = 135) or stem cell transplant using coinfusion of a UCB graft with CD34⁺ cells from a third-party donor (Haplo-Cord) (n = 72) at different institutions within the Grupo Español de Trasplante Hematopoyético. In multivariable analysis, patients in the Haplo-Cord group showed more rapid neutrophil (hazard ratio [HR], 2.3; 95% confidence interval [CI], 1.5-3.3; P < .001) and platelet recovery (HR, 1.6; 95% CI, 1.2-2.3; P = .015) and lower incidence of chronic graft-versus-host disease (GVHD) (relative risk, 0.5; 95% CI, 0.3-0.8; P = .01). Nonrelapse mortality, relapse, disease-free survival (DFS), and GVHD/relapse-free survival were similar in the 2 groups. Regarding disease-specific outcomes, DFS in both acute myeloid leukemia (AML) and acute lymphoblastic leukemia patients was not significantly different; however, a significantly higher relapse rate was found in patients with AML treated with Haplo-Cord (HR, 2.3; 95% CI, 1-5.4; P = .04). Our study confirms that Haplo-Cord was an effective strategy to accelerate neutrophil and platelet recovery and shows that, in the context of specific treatment platforms, sUCBT and Haplo-Cord offer similar long-term outcomes.

Engineering cord blood to improve engraftment after cord blood transplant

Umbilical cord blood transplant (CBT) has traditionally been associated with slower engraftment of neutrophils, delayed immune reconstitution and consequently higher risk of infections as compared with peripheral blood progenitor cell (PBPC) or bone marrow (BM) transplants. This is primarily due to low numbers of total nucleated cells (TNCs) and the naive nature of CB immune cells. The use of double unit CB transplant (DCBT) increases the total cell dose in the graft, but it still does not produce as rapid engraftment as seen with PBPC or even BM transplants. Herein, we discuss strategies to improve engraftment after CBT. We describe methods of (I) expansion of CB graft ex vivo to increase the total cell dose; and (II) enhancement of BM homing capability of CB progenitor cells; (III) ex vivo expansion of CB derived T cells for improving T cell function against viruses, tumors and protection from graft versus host disease (GVHD). With these novel approaches, engraftment after CBT is now reaching levels comparable to that of other graft types.

Regulation and roles of CD26/DPPIV in hematopoiesis and diseases

Dipeptidyl peptidase IV (DPPIV),¹ on the surface of certain cells, where it is also referred to as CD26, is involved in a vast majority of biological and pathological processes. CD26/DPPIV function contributes to cancer and tumor metastasis as well as inhibition of its expression which alters the expression of immune response-related genes. CD26/DPPIV is a widely distributed multifunctional integral membrane and secreted protein that is defined as early predictive biomarker in HIV, cancer and autoimmunity diseases like diabetes and multiple sclerosis. CD26/DPPIV-chemokine interaction may have a functional role in T-cells and overall immune function. It is expressed at low density on resting T cells, but is upregulated with T cell activation. In this review, we summarize valuable information about detailed biological aspects and pharmacokinetic characteristics of CD26/DPPIV and its clinical efficacy, focusing particularly on the role of CD26/DPPIV in immunological and non-immunological diseases. We also describe our recent work about umbilical cord blood (UCB)² hematopoietic stem cell transplantation strategies in which identified CD26+ cells can be differentiated to immune cells under certain culture condition.

Haplo-Cord transplantation compared to haploidentical transplantation with post-transplant cyclophosphamide in patients with AML

For patients with AML, the best alternative donor remains to be defined. We analyze outcomes of patients who underwent myeloablative umbilical cord blood or haploidentical hemopoietic stem cell transplantation (HSCT) in Spain. Fifty-one patients underwent single umbilical cord blood transplantation supported by a third party donor (Haplo-Cord) between 1999 and 2012, and 36 patients received an haploidentical HSCT with post-transplant cyclophosphamide (PTCY-haplo) between 2012 and 2014 in GETH centers. The Haplo-Cord cohort included a higher proportion of patients with high disease risk index and use of TBI in the conditioning regimen, and hematopoietic cell transplantation-age Comorbidity Age Index was higher in PTCY-haplo patients. Cumulative incidence of neutrophil engraftment was 97% in the Haplo-Cord and 100% in the PTCY-haplo group, achieved in a median of 12 and 17 days, respectively (P=0.01). Grade II-IV acute GvHD rate was significantly higher in the PTCY-haplo group (9.8% vs 29%, P=0.02) as well as chronic GvHD rates (20% vs 38%, P=0.03). With a median follow-up of 61 months for the Haplo-Cord group and 26 months for the PTCY-haplo cohort, overall survival at 2 years was 55% and 59% (P=0.66), event-free survival was 45% vs 56% (P=0.46), relapse rate was 27% vs 21% (P=0.79), and non-relapse mortality was 17% vs 23% (P=0.54), respectively. In this multicenter experience, Haplo-Cord and PTCY-haplo HSCT offer valid alternatives for patients with AML. Neutrophil engraftment was faster in the Haplo-Cord cohort, with similar survival rates, with higher GvHD rates after haploidentical HSCT.

Multiple allogeneic progenitors in combination function as a unit to support early transient hematopoiesis in transplantation

Cord blood (CB) is a valuable donor source in hematopoietic cell transplantation. However, the initial time to engraftment in CB transplantation (CBT) is often delayed because of low graft cell numbers. This limits the use of CB. To overcome this cell dose barrier, we modeled an insufficient dose CBT setting in lethally irradiated mice and then added hematopoietic stem/progenitor cells (HSCs/HPCs; HSPCs) derived from four mouse allogeneic strains. The mixture of HSPCs rescued recipients and significantly accelerated hematopoietic recovery. Including T cells from one strain favored single-donor chimerism through graft versus graft reactions, with early hematopoietic recovery unaffected. Furthermore, using clinically relevant procedures, we successfully isolated a mixture of CD34(+) cells from multiple frozen CB units at one time regardless of HLA-type disparities. These CD34(+) cells in combination proved transplantable into immunodeficient mice. This work provides proof of concept that when circumstances require support of hematopoiesis, combined multiple units of allogeneic HSPCs are capable of early hematopoietic reconstitution while allowing single-donor hematopoiesis by a principal graft.

Haploidentical cord transplantation-The best of both worlds

Haploidentical (haplo)-cord transplantation combines infusion of an umbilical cord blood (UCB) unit with CD34-selected cells usually from human leukocyte antigen (HLA) mismatched donors. Initial rapid count recovery from the haplo-hematopoietic progenitors, is gradually replaced by durable engraftment from UCB progenitors. UCB grafts used for haplo-cord are smaller, but better matched than those required for single or double UCB stem cell transplant (SCT). More than 200 patients with hematological malignancies have been transplanted. Median age was 54 years (range 17-74) and 77 were over age 60. One-year survival was 64% for patients with intermediate- and low-risk disease, with no deaths beyond 2 years. In high-risk disease, 1-year survival was 44%. In a comparison with patients undergoing double UCB SCT, haplo-cord transplant resulted in faster hematopoietic recovery, lower rates of acute and chronic graft-versus-host disease (GVHD), lower rates of disease recurrence, and improved GVHD- and relapse-free survival (GRFS). Excellent results were also reported for patients with aplastic anemia where 18 of 21 patients had sustained cord blood engraftment. Rates of GVHD and of disease recurrence after haplo-cord are encouraging. However, in the approximately 10% of patients with failure of the UCB graft disease recurrence is high, supporting the important role of UCB-mediated graft-versus-leukemia (GVL). Ongoing efforts are aimed at identifying determinants of UCB engraftment, at reducing rates of disease recurrence in high risk patients and at optimizing dose and schedule of ATG -necessary to avoid early haplo-graft rejection, but also contributing to early post-transplant immunocompromise. For those lacking haploidentical donors, unrelated donors have been successfully utilized.

Reduced intensity haplo plus single cord transplant compared to double cord transplant: improved engraftment and graft-versus-host disease-free, relapse-free survival

Umbilical cord blood stem cell transplants are commonly used in adults lacking HLA-identical donors. Delays in hematopoietic recovery contribute to mortality and morbidity. To hasten recovery, we used co-infusion of progenitor cells from a partially matched related donor and from an umbilical cord blood graft (haplo-cord transplant). Here we compared the outcomes of haplo-cord and double-cord transplants. A total of 97 adults underwent reduced intensity conditioning followed by haplo-cord transplant and 193 patients received reduced intensity conditioning followed by double umbilical cord blood transplantation. Patients in the haplo-cord group were more often from minority groups and had more advanced malignancy. Haplo-cord recipients received fludarabine-melphalan-anti-thymocyte globulin. Double umbilical cord blood recipients received fludarabine-cyclophosphamide and low-dose total body irradiation. In a multivariate analysis, haplo-cord had faster neutrophil (HR=1.42, P=0.007) and platelet (HR=2.54, P<0.0001) recovery, lower risk of grade II-IV acute graft-versus-host disease (HR=0.26, P<0.0001) and chronic graft-versus-host disease (HR=0.06, P<0.0001). Haplo-cord was associated with decreased risk of relapse (HR 0.48, P=0.001). Graft-versus-host disease-free, relapse-free survival was superior with haplo-cord (HR 0.63, P=0.002) but not overall survival (HR=0.97, P=0.85). Haplo-cord transplantation using fludarabine-melphalan-thymoglobulin conditioning hastens hematopoietic recovery with a lower risk of relapse relative to double umbilical cord blood transplantation using the commonly used fludarabine-cyclophosphamide-low-dose total body irradiation conditioning. Graft-versus-host disease-free and relapse-free survival is significantly improved. Haplo-cord is a readily available graft source that improves outcomes and access to transplant for those lacking HLA-matched donors. Trials registered at clinicaltrials.gov identifiers 00943800 and 01810588.

Alternative donor transplantation--"mixing and matching": the role of combined cord blood and haplo-identical donor transplantation (haplo-cord SCT) as a treatment strategy for patients lacking standard donors?

In the past decade, haplo-cord stem cell transplantation (SCT) using myeloablative or reduced intensive conditioning regimens has been shown to result in reliable and fast engraftment of neutrophils and platelets comparable to HLA-matched donors and much faster than after cord stem cell transplant. Haplo-cord SCT also has a low incidence of early non-relapse mortality, low incidences of acute and chronic graft-vs-host disease (GVHD), and excellent graft-vs-leukemia (GVL) effects. Favorable long-term outcomes for high-risk patients with hematologic malignancies have been reported, including older patients. Haplo-cord SCT will likely overcome the limitations of cell dose during cord stem cell selection and might significantly expand the use of cord stem cell transplant in the adult population. The comparable survival outcomes of matched related donor (MRD), matched unrelated donor (MUD), and haplo-cord stem cell transplant strongly argue that haplo-cord SCT should be considered as effective alternative stem cell transplant for high-risk patients lacking standard donors. Further improvement in supportive care and incorporation of a better understanding of the human fetal immune development into the haplo-cord SCT are required to further improve this strategy.

Indications for allo- and auto-SCT for haematological diseases, solid tumours and immune disorders: current practice in Europe, 2015

This is the sixth special report that the European Society for Blood and Marrow Transplantation regularly publishes on the current practice and indications for haematopoietic SCT for haematological diseases, solid tumours and immune disorders in Europe. Major changes have occurred in the field of haematopoietic SCT over the last years. Cord blood units as well as haploidentical donors have been increasingly used as stem cell sources for allo-SCT, thus, augmenting the possibility of finding a suitable donor for a patient. Continuous refinement of conditioning strategies has also expanded not only the number of potential indications but also has permitted consideration of older patients or those with co-morbidity for a transplant. There is accumulating evidence of the role of haematopoietic SCT in non-haematological disorders such as autoimmune diseases. On the other hand, the advent of new drugs and very effective targeted therapy has challenged the role of SCT in some instances or at least, modified its position in the treatment armamentarium of a given patient. An updated report with revised tables and operating definitions is presented.

Concise review: umbilical cord blood transplantation: past, present, and future

Allogeneic hematopoietic stem cell transplantation is an important treatment option for fit patients with poor-risk hematological malignancies; nevertheless, the lack of available fully matched donors limits the extent of its use. Umbilical cord blood has emerged as an effective alternate source of hematopoietic stem cell support. Transplantation with cord blood allows for faster availability of frozen sample and avoids invasive procedures for donors. In addition, this procedure has demonstrated reduced relapse rates and similar overall survival when compared with unrelated allogeneic hematopoietic stem cell transplantation. The limited dose of CD34-positive stem cells available with single-unit cord transplantation has been addressed by the development of double-unit cord transplantation. In combination with improved conditioning regimens, double-unit cord transplantation has allowed for the treatment of larger children, as well as adult patients with hematological malignancies. Current excitement in the field revolves around the development of safer techniques to improve homing, engraftment, and immune reconstitution after cord blood transplantation. Here the authors review the past, present, and future of cord transplantation.

Coinfusion of mobilized hematopoietic stem cells from an HLA-mismatched third-party donor with umbilical cord blood graft to support engraftment

We evaluated the role of mismatched third-party hematopoietic stem cells (TPC) in shortening the neutropenia after umbilical cord blood transplantation (UCBT). A TPC graft was given to 7/37 children with UCBT to support engraftment due to anticipated increased risk of nonengraftment (N=6) or active infection (N=1). TPC grafts were collected with apheresis from haploidentical family members. The median UCB and CD34 cell counts were 5.10 (range, 4.13 to 9.98)×10/kg and 5.98 (range, 4.40 to 14.00)×10/kg, respectively. The median time to neutrophil engraftment was shorter in the patients with TPC (12 d; range, 9 to 24 d) than those without (23 d; range, 12 to 44 d) (P=0.010). TPC chimerism was lost in median at 28 (range, 24 to 103) days posttransplant. TPC grafts from mothers engrafted similarly as the grafts from other family members. UCB graft cell count and the use of methotrexate posttransplant strongly contributed to engraftment. TPC may form a valuable transient bridging graft over the neutropenia after UCBT in patients with anticipated high-risk of nonengraftment or toxicity due to pretransplant infections.

Haplo-cord transplantation using CD34+ cells from a third-party donor to speed engraftment in high-risk patients with hematologic disorders

Among the strategies to optimize engraftment of cord blood (CB) stem cell transplantation (SCT), single CB with the coinfusion of CD34(+) stem cells from an HLA-mismatched auxiliary donor (haplo-cord) provides a valid alternative for adult patients without a suitable donor. A total of 132 high-risk adult patients with hematological malignancies from 3 Spanish institutions underwent myeloablative haplo-cord SCT. The median age was 37 years and median weight was 70 kg; 37% had active disease. The median number of postprocessing CB total nucleated and CD34(+) cells was 2.4 × 10(7)/kg (interquartile range [IQR], 1.8 to 2.9) and 1.4 × 10(5)/kg (IQR, .9 to 2), respectively. Neutrophil engraftment occurred in a median of 11.5 days (IQR, 10.5 to 16.5) and platelet engraftment at 36 days (IQR, 25.5 to 77). Graft failure was 2% overall and only 9% for CB. Cumulative incidence of acute graft-versus-host disease (GHVD) grades II to IV was 21% and cumulative incidence of chronic GVHD was 21%. Median follow-up was 60 months (range, 3.5 to 163). Overall survival was 43.5%, event-free survival was 38.3%, nonrelapse mortality was 35%, and relapse was 20% at 5 years. Myeloablative haplo-cord SCT results in fast engraftment of neutrophils and platelets, low incidences of acute and chronic GVHD, and favorable long-term outcomes using single CB units with relatively low cell content. Moreover, CB cell dose had no impact on CB engraftment and survival in this study. Therefore, haplo-cord SCT expands donor availability while reducing CB cell dose requirements.

Early peripheral blood and T-cell chimerism dynamics after umbilical cord blood transplantation supported with haploidentical cells

Single-unit umbilical cord blood (CB) SCT is limited by low total nucleated cell (TNC) dose. Co-infusion of CD34+ cells from a third party HLA-mismatched donor, known as dual or haplo-cord transplant, reduces the period of post-transplant neutropenia and related complications. The aim of this study was to analyze the value of early post-transplant peripheral blood (PB) and T cell chimerism after 28 dual transplants regarding CB engraftment. Cumulative incidence of myeloid engraftment at 30 days was 93% with a median time to engraftment of 14 days (10-29). Patients who developed CB graft failure (n=5) showed very low percentages of CB cells on days +14, +21 and +28 with decreasing dynamics. On the other hand, percentages of CB cells in patients who achieved CB engraftment increased over time. Interestingly, such patients showed two distinct chimerism dynamics in PB, but all of them showed a predominance of CB T cells early after SCT with increasing dynamics over time. Early post-transplant chimerism dynamics in PB and T cells predicts CB graft failure enabling rapid therapeutic measures to be applied. On the other hand, early increasing percentages of CB T cells correlates with ultimate CB engraftment.

Graft-versus-tumor effect after allogeneic stem cell transplantation in HIV-positive patients with high-risk hematologic malignancies

Allogeneic hematopoietic stem cell transplantation (Allo-HSCT) is a well-established therapeutic option for hematological malignancies. Combination antiretroviral therapy (cART) has enabled the treatment of medical conditions in patients infected with the human immunodeficiency virus (HIV) in the same way as in the general population. Moreover, improvements in supportive care have allowed HIV-infected patients with life-threatening hematological disorders to be treated with Allo-HSCT. We report on four HIV-infected patients with hematological malignancies receiving an Allo-HSCT in our institution, and on the use of donor lymphocyte infusions to successfully treat post-Allo-HSCT relapse. Of note, one of them is the first HIV(+) patient to receive a "dual transplant" (unrelated umbilical cord blood stem cells combined with mobilized T cell-depleted CD34(+) stem cells from a mismatched third party donor). cART drugs interactions were satisfactorily managed. This approach provided long-term control of the hematological disease. Nevertheless, despite adequate immune reconstitution, infections were the main cause of morbidity and mortality after Allo-HSCT.

Complement fragment 3a priming of umbilical cord blood progenitors: safety profile

Preclinical data showed that priming CD34(+) hematopoietic progenitor cells with complement fragment 3a (C3a) improved homing and engraftment. Thus, we hypothesized that priming of umbilical cord blood (UCB) hematopoietic progenitors with C3a would facilitate homing and could potentially be used to address the need for improved engraftment after UCB transplantation. We primed 1 of 2 UCB units for double UCB transplantation after nonmyeloablative conditioning. This design provided adequate safety and the potential to observe skewed long-term chimerism in favor of the C3a-primed unit as a surrogate measure of efficacy. C3a priming of 1 UCB unit did not result in infusional toxicity. Increased grades 1 to 3 hypertension were the only infusional adverse events observed in 9 (30%) patients. We observed no activation of inflammatory or coagulation pathways downstream of C3a. As tested, C3a priming did not impair engraftment, but did not skew chimerism toward the treated unit. As compared with historical controls, mortality and survival were not adversely affected. Thus, before any additional clinical studies, C3a priming to promote engraftment will require further preclinical optimization.

Cord Blood Transplantation: Can We Make it Better?

Umbilical cord blood is an established source of hematopoietic stem cells for transplantation. It enjoys several advantages over bone marrow or peripheral blood, including increased tolerance for Human Leukocyte Antigen mismatches, decreased incidence of graft-versus-host disease, and easy availability. Unrelated cord blood does have limitations, however, especially in the treatment of adults. In the 24 years since the first umbilical cord blood transplant was performed, significant progress has been made, but delayed hematopoietic engraftment and increased treatment-related mortality remain obstacles to widespread use. Here we summarize the latest results of unrelated cord blood transplants, and review strategies under investigation to improve clinical outcomes.

Umbilical cord blood transplantation supported by third-party donor cells: rationale, results, and applications

Low incidence of graft-versus-host disease provides the major rational for pursuing umbilical cord blood (UCB) stem cell transplantation (SCT). Considerable evidence also suggests a lower rate of recurrence after UCB SCT than after transplantation from adult donors. Recent advances in understanding of the human fetal immune development provide a rational underpinning for these clinical outcomes. The fetal immune system is geared toward maintaining tolerance to foreign antigens, particularly to the maternal antigens to which it is exposed throughout gestation. To this purpose it is dominated by a unique population of peripheral T regulatory cells that actively maintain tolerance. This and other features of the UCB lymphoid system explains the low incidence of graft-versus-host disease and superior outcomes of UCB SCT with noninherited maternal antigen-matched grafts. At the same time, highly sensitized maternal microchimeric cells are frequently detected in UCB and likely contribute to superior graft-versus-leukemia effects and low rates of disease recurrence in inherited paternal antigen-matched UCB recipients. However, historically erratic and slow hematopoietic recovery after UCB SCT leads to increased early morbidity and mortality, excessive hospitalization, and increased costs. This has held up the widespread utilization of UCB SCT in adults. Here we summarize recent data on UCB SCT with an emphasis on studies of co-infusion of adult CD34 selected hematopoietic stem cells with UCB SCT. This procedure, through transient engraftment of adult hematopoietic stem cells, largely overcomes the problem of delayed engraftment. It also results in predictable engraftment of a UCB with the desired characteristics. We also briefly discuss unresolved issues and possible future applications of this technology.

Cord-blood engraftment with ex vivo mesenchymal-cell coculture

BACKGROUND

Poor engraftment due to low cell doses restricts the usefulness of umbilical-cord-blood transplantation. We hypothesized that engraftment would be improved by transplanting cord blood that was expanded ex vivo with mesenchymal stromal cells.

METHODS

We studied engraftment results in 31 adults with hematologic cancers who received transplants of 2 cord-blood units, 1 of which contained cord blood that was expanded ex vivo in cocultures with allogeneic mesenchymal stromal cells. The results in these patients were compared with those in 80 historical controls who received 2 units of unmanipulated cord blood.

RESULTS

Coculture with mesenchymal stromal cells led to an expansion of total nucleated cells by a median factor of 12.2 and of CD34+ cells by a median factor of 30.1. With transplantation of 1 unit each of expanded and unmanipulated cord blood, patients received a median of 8.34×10(7) total nucleated cells per kilogram of body weight and 1.81×10(6) CD34+ cells per kilogram--doses higher than in our previous transplantations of 2 units of unmanipulated cord blood. In patients in whom engraftment occurred, the median time to neutrophil engraftment was 15 days in the recipients of expanded cord blood, as compared with 24 days in controls who received unmanipulated cord blood only (P<0.001); the median time to platelet engraftment was 42 days and 49 days, respectively (P=0.03). On day 26, the cumulative incidence of neutrophil engraftment was 88% with expansion versus 53% without expansion (P<0.001); on day 60, the cumulative incidence of platelet engraftment was 71% and 31%, respectively (P<0.001).

CONCLUSIONS

Transplantation of cord-blood cells expanded with mesenchymal stromal cells appeared to be safe and effective. Expanded cord blood in combination with unmanipulated cord blood significantly improved engraftment, as compared with unmanipulated cord blood only. (Funded by the National Cancer Institute and others; ClinicalTrials.gov number, NCT00498316.).

Umbilical cord blood transplantation: a maturing technology

The use of umbilical cord blood (CB) as a source of hematopoietic progenitor cells for patients with high-risk hematologic disorders receiving allogeneic hematopoietic cell transplantations (HCTs) has increased significantly. Single-institution and registry studies have shown a decreased relapse rate and an increased transplantation-related mortality rate with similar overall survival rates after allogeneic HCT with CB compared with other donor sources. The transplantation of double CB units has overcome the dose limitation inherent in a single CB unit and thus has markedly extended the use of CB to larger children and adults. Similarly, the use of reduced intensity conditioning in the CB transplantation setting has allowed the treatment of older patients who would be unable to tolerate the myeloablative regimens used in the original CB transplantation protocols.

Single cord blood combined with HLA-mismatched third party donor cells: comparable results to matched unrelated donor transplantation in high-risk patients with hematologic disorders

Matched unrelated donor (MUD) transplantation is the first alternative in the absence of a matched sibling donor. For patients without a suitable adult donor, we have adopted the dual stem cell transplantation protocol consisting of cord blood (CB) in combination with CD34(+) cells from a third party HLA-mismatched donor. We analyzed the outcomes of patients undergoing both procedures in a single center. Starting in 2004, a total of 20 patients with high-risk disease underwent 22 dual transplants and 25 patients underwent myeloablative MUD transplantation. The 30-day cumulative incidence of neutrophil engraftment was similar in both groups (91% and 95%), with a median time to engraftment of 14 and 16 days, respectively. Grade II-IV acute graft-versus-host disease was more frequent in the MUD group (40% versus 5%). Except for a tendency toward a higher incidence of viral hemorrhagic cystitis in the dual transplantation group, posttransplantation infectious events were comparable in the 2 groups. The 3-year cumulative incidence rates of relapse (41% versus 44%) and nonrelapse mortality (30% versus 25%) were similar in the MUD and dual transplantation cohorts. Estimated 3-year overall survival and disease-free survival were 47% and 41%, respectively, with no survival advantage for either group. In our experience, dual transplantation offers survival rates comparable to those from myeloablative MUD transplantation with similar nonrelapse mortality rates.

Single-unit umbilical cord blood transplantation from unrelated donors in patients with hematological malignancy using busulfan, thiotepa, fludarabine and ATG as myeloablative conditioning regimen

Attempts to optimize outcomes in cord blood transplantation (CBT) by using new conditioning regimens and standardization of cord blood unit selection are warranted. In all, 88 patients (18 children and 70 adults) with hematological malignancy from nine Spanish institutions underwent a single-unit CBT after an i.v. BU-based myeloablative conditioning regimen. All evaluable patients except one engrafted. The overall cumulative incidence (CI) of myeloid engraftment was 94% at a median time of 19 days. In multivariate analysis, nonadvanced disease stage was the only factor with a favorable impact on myeloid engraftment. The CI of acute GVHD grades II-IV and chronic extensive GVHD were 24% each. The CI of nonrelapse mortality at 100 days, 180 days and 5 years was 14, 23 and 44%, respectively. The 5-year CI of relapse was 18%, whereas disease-free survival (DFS) was 46%, 39% and 11% for patients transplanted in early, intermediate and advanced stages of the disease, respectively. Our study shows high rates of engraftment with fast neutrophil recovery in patients undergoing single-unit CBT using a BU-based conditioning regimen. Long-term DFS can be achieved in a substantial number of patients with high-risk hematological malignancies, particularly when transplanted in an early stage of the disease.

Umbilical Cord Blood Transplantation for the Treatment of Hematologic Malignancies

Background

The use of unrelated umbilical cord blood (UCB) has grown as an allogeneic source of hematopoietic cells for transplantation of patients with hematologic malignancies. As the number of UCB transplantation procedures has grown, an increasing number of publications have focused on disease-specific outcomes.

Methods

This review focuses on the outcome data following UCB transplantation in subsets of hematologic malignancies in which experience with this graft source is greater.

Results

Registry and single-institution reports regarding the outcomes of children and adults with acute leukemias after UCB transplantation include many patients, while data on the clinical outcomes of other leukemias are limited due in part to the small number of patients with these diseases. UCB is now routinely used as a source of hematopoietic stem cells (HSCs) in pediatric allogeneic transplantation when a suitable sibling donor is not available. Data also support the use of UCB as an alternative source of HSC for transplantation of patients with hematologic malignancies who lack a more conventional donor. Current data also support UCB for patients who require an allograft in the setting of prospective clinical trials.

Conclusions

Along with safety and feasibility in UCB transplantation, continued study is needed that focuses on issues such as accelerating engraftment, extending access, ensuring quality, and examining outcomes in specific subgroups of patients.

Cell recovery comparison between plasma depletion/reduction- and red cell reduction-processing of umbilical cord blood

BACKGROUND AIMS

Limited cell dose has hampered the use of cord blood transplantation (CBT) in adults. One method of minimizing nucleated cell loss in cord blood (CB) processing is to deplete or reduce plasma but not red blood cells - plasma depletion/reduction (PDR).

METHODS

The nucleated cell loss of PDR was studied, and determined to be less than 0.1% in the discarded supernatant plasma fraction in validation experiments. After testing and archival sampling, the median nucleated cell recovery for PDR processing was 90%, and median CD34(+) cell recovery 88%. In a CB bank inventory of 12 339 products with both pre- and post-processing total nucleated cells (TNC), PDR processing resulted in median post-processing TNC recoveries of 90.0% after testing and archival samples removal. Using the same 10 CB units divided into two halves, we compared directly the recovery of PDR against hydroxyethyl starch red cell reduction (RCR) for TNC, CD34(+) cells and colony-forming units (CFU-GM, CFU-E, CFU-GEMM and total CFU) after parallel processing. We also compared the loss of very small embryonic-like stem cells (VSEL).

RESULTS

We demonstrated significantly higher recoveries using PDR for TNC (124%), CD34(+) cells (121%), CFU-GM (225%), CFU-GEMM (201%), total CFU (186%) and VSEL (187%). The proportion of high TNC products was compared between 10 912 PDR and 38 819 RCR CB products and found to be 200% higher for products that had TNC ≥150 × 10(7) (P = 0.0001) for the PDR inventory.

CONCLUSIONS

Our data indicate that PDR processing of CB provides a significantly more efficient usage of this valuable and scarce resource.

An overview of the progress on double umbilical cord blood transplantation

Umbilical cord blood transplantation has been increasingly used over the past years for both malignant and non-malignant hematologic and other diseases as an alternative to mismatched-related or matched-unrelated bone marrow or peripheral blood hematopoietic stem cell transplantation. A disadvantage of cord blood is its low cell content which limits cord blood transplantation to generally low weight recipients, such as children. Various alternatives have been used to overcome this limitation, including co-infusion of two partially HLA-matched cord blood units. According to Eurocord Registry data, this strategy has been applied in approximately 993 adult patients with hematologic diseases since the first double umbilical cord blood transplantation in 1999. In fact, since 2005, the number of adult patients receiving double umbilical cord blood transplantation has surpassed the number of adults transplanted with single cord blood units. The engraftment rate is comparable for both single and double umbilical cord blood transplantation, although the latter is accompanied by a higher incidence of grade II acute graft-versus-host disease and lower leukemia relapse for patients in first complete remission. In the majority of patients undergoing double umbilical cord blood transplantation, transient chimerism, due to the presence of cells from both donor units early post transplant, is replaced by sustained dominance of one unit from which long-term hematopoiesis is derived. Although the biology and the factors that determine unit dominance have not been clarified, the implication of immune-mediated mechanisms has been reported. Preliminary data have demonstrated the safety of double umbilical cord blood transplantation. Ongoing clinical trials and prolonged follow up of the patients will clarify the immunology and determine the efficacy of this approach. We present here a brief overview of the clinical experience on double umbilical cord blood transplantation and its underlying biology.

Cord blood-derived hematopoietic stem/progenitor cells: current challenges in engraftment, infection, and ex vivo expansion

Umbilical cord blood has served as an alternative to bone marrow for hematopoietic transplantation since the late 1980s. Numerous clinical studies have proven the efficacy of umbilical cord blood. Moreover, the possible immaturity of cells in umbilical cord blood gives more options to recipients with HLA mismatch and allows for the use of umbilical cord blood from unrelated donors. However, morbidity and mortality rates associated with hematopoietic malignancies still remain relatively high, even after cord blood transplantation. Infections and relapse are the major causes of death after cord blood transplantation in patients with hematopoietic diseases. Recently, new strategies have been introduced to improve these major problems. Establishing better protocols for simple isolation of primitive cells and ex vivo expansion will also be very important. In this short review, we discuss several recent promising findings related to the technical improvement of cord blood transplantation.

Risk factors and options to improve engraftment in unrelated cord blood transplantation

Use of umbilical unrelated cord-blood (UCB) cells as an alternative source of hematopoietic cell transplantation has been widely used mainly for patients lacking an HLA-matched donor. UCB present many advantages over bone marrow or mobilized peripheral blood from volunteer donors, such as rapid availability, absence of risk for the donor, and decreased incidence of acute graft-versus-host disease. However, a significant clinical problem is delayed engraftment that is directly correlated with the number of hematopoietic stem cells in a cord-blood unit. The identification of prognostic factors associated with engraftment that can be easily modified (e.g., strategies for donor choice) and the development of new approaches including use of multiple donors, intrabone injection of UCB, ex vivo expansion, and cotransplantation with accessory cells are of crucial importance in order to circumvent the problem of delayed engraftment after UCB transplantation. Those approaches may increase the quality and availability of UCB for transplantation.

Improved engraftment with minimal graft-versus-host disease after major histocompatibility complex-mismatched cord blood transplantation with photochemically treated donor lymphocytes

There is a significant risk of severe graft-versus-host disease (GVHD) and graft failure after unrelated umbilical cord blood transplantation (CBT) if donor-recipient pairs are mismatched at major histocompatibility complex (MHC) loci. To mitigate these risks after MHC-mismatched CBT, we infused psoralen-treated, photochemically inactivated, mature donor T-lymphocytes with MHC (H2-haplotype) mismatched murine donor fetal near-term peripheral blood (FNPB) cells after sublethal irradiation. We analyzed the rates of donor engraftment, GVHD and long-term survival in H2 haplotype disparate (C57BL/6 [H-2(b)/Thy1.1] → AKR [H-2(k)/Thy1.2]) recipient mice. We observed inconsistent donor engraftment after transplantation with cord blood alone, but superior engraftment and long-term survival after FNPB transplantation supplemented with psoralen-treated donor T-lymphocytes. Additionally, there was fatal GVHD after FNPB co-infusion with untreated donor T-lymphocytes, but minimal GVHD after FNPB supplemented with psoralen-treated donor T-lymphocytes transplantation. Donor MHC(high)/c-Kit(+)/lineage(-)/CD34(-) stem cells were noted in the recipient bone marrow compartment following co-infusion of photochemically inactivated T-cells with FNPB. Despite the non-myeloablative preparation before FNPB infusion, complete hematological recovery was delayed until 50-60 d after transplantation. We observed that co-transplantation of psoralen-treated donor T-lymphocytes with FNPB facilitated durable engraftment of donor hematopoietic stem cells in the marrow and splenic compartments with complete but delayed recovery of all hematopoietic lineages. This CBT model establishes the possibility of ensuring donor engraftment across a MHC barrier without severe GVHD.

Haematopoietic transplants combining a single unrelated cord blood unit and mobilized haematopoietic stem cells from an adult HLA-mismatched third party donor. Comparable results to transplants from HLA-identical related donors in adults with acute leukaemia and myelodysplastic syndromes

We describe results of the strategy, developed by our group, of co-infusion of mobilized haematopoietic stem cells as a support for single-unit unrelated cord blood transplant (dual CB/TPD-MHSC transplants) for treatment of haematological malignancies in adults, and a comparative analysis of results obtained using this strategy and transplants performed with mobilized haematopoietic stem cells from related HLA-identical donors (RTD) for treatment of adults with acute leukaemia and myelodysplastic syndromes. Our data show that the dual CB/TPD-MHSC transplant strategy results in periods of post-transplant neutropenia, final rates of full donor chimerism and transplant-related mortality rates comparable to those of the RTD. Final survival outcomes are comparable in adults transplanted because of acute leukaemia, with different incidences of the complications that most influence these: a higher incidence of infections related to late recovery of protective immunity dependent on T cell functions, and a lower incidence of serious acute graft-versus-host disease and relapses. Recent advances in cord blood transplant techniques allow allogeneic haematopoietic stem cell transplantation (HSCT) to be a viable option for almost every patient who may benefit from this therapeutic approach. Development of innovative strategies to improve the post-transplant recovery of T cells function is currently the main challenge to further improving the possibilities of unrelated cord blood transplantation.

Transplantation of two populations of stem cells to improve engraftment: WO2008060932

BACKGROUND

The application is in the field of haematopoietic stem cells (HSCs) and cellular therapy.

OBJECTIVE

It aims at improving the outcome and rate of success of HSC transplantation for treating patients with haematologic diseases, primarily following allogeneic transplantation.

METHODS

The patients are administered two intravenous infusions of cord blood (CB) tissue between a 2 and 24 h interval.

RESULTS

Patients who receive a first infusion of CB stem cells, followed by a second infusion within a 24 h interval, elicit a better outcome and rate of success of CB transplantation than patients receiving only one injection or two injections in whom the second injection was administered several days or weeks following the first one. The double infusion of CB tissue, within a 24 h interval, accelerates the time to neutrophil and platelet engraftment and immune reconstitution following myeloablative therapy.

CONCLUSION

The application claims the transplantation of at least two populations of HSCs, separated by an interval of time between 2 and 24 h, to improve the outcome of HSC transplantation for the treatment of haematologic diseases. The procedure may be extended to other types of stem cells for treating a broad range of diseases and injuries.

Umbilical cord blood transplantation from unrelated donors in adult patients with chronic myeloid leukaemia

Allogeneic haematopoietic stem cell transplantation (HSCT) remains an important treatment option for patients with chronic myeloid leukaemia (CML) failing tyrosine-kinase inhibitors or progressing to an advanced phase. In this setting, umbilical cord blood (UCB) could be used as an alternative stem cell source for patients in whom allogeneic HSCT is indicated and lack a human leucocyte antigen (HLA)-matched adult donor. However, very little information exists on the outcome after UCB transplantation (UCBT) of these patients. Early registry-based studies of patients undergoing UCBT suggested a particularly poor outcome for patients with CML. However, more recent reports with special focus on patients with CML have confirmed feasibility and efficacy of the procedure and identified variables influencing short- and long-term outcomes. Currently, UCBT should be considered as a potential curative alternative for CML patients requiring allogeneic HSCT but lacking an appropriate adult donor.

Extending cord blood transplant to adults: dealing with problems and results overall

The development of newer strategies to overcome, in particular, the cell dose limitation, has increased the availability of umbilical cord blood (UCB) as a source of hematopoietic stem cells (HSC) for transplantation of adults. Among these strategies is the development of the double UCB, ex vivo, and reduced-intensity transplantation platforms. Several ongoing registry-based and single-institution and multicenter clinical trials are investigating ways to make UCB transplantation safer and to improve the outcomes of adults after UCB transplantation. We review the background data and promising newer strategies that will further expand the utilization of UCB for the treatment of adults.

Improving outcomes of cord blood transplantation: HLA matching, cell dose and other graft- and transplantation-related factors

The use of unrelated umbilical cord blood (UCB) as an alternative source of haematopoietic stem cells transplantation (HSCT) has been widely used for patients lacking a human leucocyte antigen (HLA) matched donor. One of the disadvantages of using UCB is the limited number of haematopoietic stem cells and, consequently, delayed engraftment and increased risk of early mortality. Many approaches have been investigated in the attempt to improve engraftment and survival. Among those, studies analysing prognostic factors related to patients, disease, donor and transplantation have been performed. Variable factors have been identified, such as factors related to donor choice (HLA, cell dose and others) and transplantation (conditioning and graft-versus-host disease prophylaxis regimens). This review will focus on the interactions between HLA, cell dose and other modifiable factors related to the UCB unit selection and transplantation that may improve outcomes after UCB transplantation.