Cord blood (CB) offers a number of advantages over other sources of hematopoietic stem cells, including a lower rate of chronic graft-versus-host disease (cGVHD) in the presence of increased HLA ...disparity. Recent research in experimental models of autoimmunity and in patients with autoimmune or alloimmune disorders has identified a functional group of interleukin-10 (IL-10)-producing regulatory B cells (Bregs) that negatively regulate T-cell immune responses. At present, however, there is no consensus on the phenotypic signature of Bregs, and their prevalence and functional characteristics in CB remain unclear. Here, we demonstrate that CB contains an abundance of B cells with immunoregulatory function. Bregs were identified in both the naive and transitional B-cell compartments and suppressed T-cell proliferation and effector function through IL-10 production as well as cell-to-cell contact involving CTLA-4. We further show that the suppressive capacity of CB-derived Bregs can be potentiated through CD40L signaling, suggesting that inflammatory environments may induce their function. Finally, there was robust recovery of IL-10–producing Bregs in patients after CB transplantation, to higher frequencies and absolute numbers than seen in the peripheral blood of healthy donors or in patients before transplant. The reconstituting Bregs showed strong in vitro suppressive activity against allogeneic CD4+ T cells, but were deficient in patients with cGVHD. Together, these findings identify a rich source of Bregs and suggest a protective role for CB-derived Bregs against cGVHD development in CB recipients. This advance could propel the development of Breg-based strategies to prevent or ameliorate this posttransplant complication.
•Cord blood is a rich source of B cells with immunoregulatory function.•IL-10–producing B cells may protect against cGVHD after cord blood transplantation.
Blastic Plasmacytoid Dendritic Cell Neoplasm (BPDCN) is an aggressive hematological malignancy; however, some patients achieve durable remission with allogeneic hematopoietic cell transplantation ...(allo-HCT). We report on all 17 patients with BPDCN who underwent allo-HCT at our center between 2000 and 2020. The median age was 39 (18-67) years. All (n = 16, 94%), except one patient, had systemic disease involving bone marrow and/or other organs. Ten patients (59%) were in first complete remission (CR1) at allo-HCT. The donor source was matched related or unrelated in ten (59%) and alternate donor in seven (41%) patients. Five (31%) patients developed acute graft-versus-host disease (GVHD), all grade I-II. The cumulative incidence (CI) of chronic GVHD at five-year was 34%. The CI of non-relapse mortality at one-year was 29%. Progression-free survival (PFS) rates at two-year and five-year were 49% (95% CI = 22-71%) and 39% (95% CI = 14-64%), respectively. The two-year and five-year overall survival (OS) rates were 65% (95% CI = 38-82%) and 40% (95% CI = 12-68%), respectively. The five-year rate for both PFS and OS was 80% in CR1 patients versus 0% in patients not in CR1. In conclusion, allo-HCT provides long-lasting remissions in BPDCN patients, particularly when performed in CR1.
Delayed engraftment is a major limitation of cord blood transplantation (CBT), due in part to a defect in the cord blood (CB) cells’ ability to home to the bone marrow. Because this defect appears ...related to low levels of fucosylation of cell surface molecules that are responsible for binding to P- and E-selectins constitutively expressed by the marrow microvasculature, and thus for marrow homing, we conducted a first-in-humans clinical trial to correct this deficiency. Patients with high-risk hematologic malignancies received myeloablative therapy followed by transplantation with 2 CB units, one of which was treated ex vivo for 30 minutes with the enzyme fucosyltransferase-VI and guanosine diphosphate fucose to enhance the interaction of CD34+ stem and early progenitor cells with microvessels. The results of enforced fucosylation for 22 patients enrolled in the trial were then compared with those for 31 historical controls who had undergone double unmanipulated CBT. The median time to neutrophil engraftment was 17 days (range, 12-34 days) compared with 26 days (range, 11-48 days) for controls (P = .0023). Platelet engraftment was also improved: median was 35 days (range, 18-100 days) compared with 45 days (range, 27-120 days) for controls (P = .0520). These findings support ex vivo fucosylation of multipotent CD34+ CB cells as a clinically feasible means to improve engraftment efficiency in the double CBT setting. The trial is registered to www.clinicaltrials.gov as #NCT01471067.
•Ex vivo fucosylation of cord blood cells improves their homing capacities, leading to faster neutrophil and platelet engraftments.•This method is quick, safe, and does not require a GMP laboratory; therefore, it can be used widely.
The role of hematopoietic cell transplantation (HCT) in the management of newly diagnosed adult acute myeloid leukemia (AML) is reviewed and critically evaluated in this evidence-based review. An AML ...expert panel, consisting of both transplant and nontransplant experts, was invited to develop clinically relevant frequently asked questions covering disease- and HCT-related topics. A systematic literature review was conducted to generate core recommendations that were graded based on the quality and strength of underlying evidence based on the standardized criteria established by the American Society of Transplantation and Cellular Therapy Steering Committee for evidence-based reviews. Allogeneic HCT offers a survival benefit in patients with intermediate- and high-risk AML and is currently a part of standard clinical care. We recommend the preferential use of myeloablative conditioning in eligible patients. A haploidentical related donor marrow graft is preferred over a cord blood unit in the absence of a fully HLA-matched donor. The evolving role of allogeneic HCT in the context of measurable residual disease monitoring and recent therapeutic advances in AML with regards to maintenance therapy after HCT are also discussed.
This study reviews the past, present, and future of cord transplantation, including the potential use of single‐ and double‐unit cord blood transplantation in multiple hematological malignancies ...including leukemia and aggressive lymphomas in light of recent discoveries. Current excitement in the field revolves around the development of safer techniques to improve homing, engraftment, and immune reconstitution after cord blood transplantation.
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.
The ability of cord blood transplantation (CBT) to prevent relapse depends partly on donor natural killer (NK) cell alloreactivity. NK effector function depends on specific killer-cell ...immunoglobulin-like receptors (KIR) and HLA interactions. Thus, it is important to identify optimal combinations of KIR-HLA genotypes in donors and recipients that could improve CBT outcome. We studied clinical data, KIR and HLA genotypes, and NK-cell reconstitution in CBT patients (n = 110). Results were validated in an independent cohort (n = 94). HLA-KIR genotyping of recipient germline and transplanted cord blood (CB) grafts predicted for large differences in outcome. Patients homozygous for HLA-C2 group alleles had higher 1-year relapse rate and worse survival after CBT than did HLA-C1/C1 or HLA-C1/C2 (HLA-C1/x) patients: 67.8% vs 26.0% and 15.0% vs 52.9%, respectively. This inferior outcome was associated with delayed posttransplant recovery of NK cells expressing the HLA-C2-specific KIR2DL1/S1 receptors. HLA-C1/x patients receiving a CB graft with the combined HLA-C1-KIR2DL2/L3/S2 genotype had lower 1-year relapse rate (6.7% vs 40.1%) and superior survival (74.2% vs 41.3%) compared with recipients of grafts lacking KIR2DS2 or HLA-C1. HLA-C2/C2 patients had lower relapse rate (44.7% vs 93.4%) and better survival (30.1% vs 0%) if they received a graft with the combined HLA-C2-KIR2DL1/S1 genotype. Relapsed/refractory disease at CBT, recipient HLA-C2/C2 genotype, and donor HLA-KIR genotype were independent predictors of outcome. Thus, we propose the inclusion of KIR genotyping in graft selection criteria for CBT. HLA-C1/x patients should receive an HLA-C1-KIR2DL2/L3/S2 CB graft, while HLA-C2/C2 patients may benefit from an HLA-C2-KIR2DL1/S1 graft.
•Patients homozygous for HLA-C2 group alleles have worse outcomes after CBT.•CB selection based on the combination of NK licensing and activating KIRs may improve outcomes after CBT.
Allogeneic SCT for older patients remains challenging at least in part due to graft-versus-host disease (GVHD) and higher non-relapse mortality (NRM). We conducted a prospective pilot study primarily ...for older patients undergoing matched unrelated donor (MUD) SCT using a reduced-intensity (RIC) melphalan-based conditioning and post-transplant cyclophosphamide (PTCy)-based GVHD prophylaxis with tacrolimus and mycophenolate mofetil. Twenty-two patients (median age 64, IQR 58, 66) underwent RIC MUD SCT for high-risk hematological malignancies including AML/MDS (73%), CML/MPD (18%), and other (10%). Two (9%) patients had early death; the rest (100%) engrafted. After a median follow-up of 17 months, 11 patients were alive and disease-free with an estimated 2-year progression-free (PFS) and overall (OS) survival of 48%. The cumulative incidences of grades 2-4 and 3-4 acute GVHD (aGVHD) at day + 100 and 2-years were 32 and 4%, and 59 and 24%, respectively. No cases of chronic GVHD (cGVHD) were noted. However, late acute GVHD was observed in 6 (27%) patients. In conclusion, RIC MUD SCT with melphalan-based conditioning and PTCy-based GVHD-based prophylaxis for older patients appears effective in controlling relapse. While cGVHD was not seen and early aGVHD appears controllable, a significant proportion developed late aGVHD responsible for higher NRM seen in these patients.
Previously considered rare, inherited hematologic malignancies are increasingly identified. Germline mutations in the RNA helicase
predispose to increased lifetime risks of myeloid neoplasms with ...disease often occurring later in life which presents challenges for germline recognition. To improve identification of germline
, individuals presenting with ≥1
alteration on an institutional MDS/AML next-generation sequencing based panel with at least one at >40% variant allele frequency were flagged for review and genetic counseling referral. Of 5,801 individuals, 90 (1.5%) had ≥1
mutation(s) identified. Thirty-eight (42%) patients with a median age of 66 years were referred for genetic counseling; thirty-one were male (81.5%). Thirty-five (92%) referred patients elected to pursue germline evaluation and in 33/35 (94%) a germline
variant was confirmed. Twenty-two patients (66%) with germline variants reported antecedent cytopenias, seven (21%) had a prior history of malignancy, and twenty-seven (82%) reported a family history of cancer. Predictive genetic testing for healthy family members under consideration as stem cell transplant donors was successfully performed in 11 family members, taking an average of 15 days. Near-heterozygous
mutations identified on next-generation sequencing, particularly nonsense/frameshift variants or those at recurrent germline "hot spots" are highly suggestive of a germline mutation. Next-generation sequencing screening is a feasible tool to screen unselected myeloid neoplasms for germline
mutations, enabling timely and appropriate care.
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