Benefits of plerixafor for mobilization of peripheral blood stem cells prior to autologous transplantation: a dual-center retrospective cohort study

Background aimsBefore autologous stem cell transplantation (ASCT), hematopoietic stem cells must be stimulated to move from the bone marrow to the peripheral blood for harvesting. Plerixafor, a C-X-C chemokine receptor type 4 antagonist, is used to increase stem cell harvests. However, the effects of plerixafor on post-ASCT outcomes remain unclear.MethodsIn a dual-center retrospective cohort study of 43 Japanese patients who received ASCT, the authors compared transplantation outcomes in patients who underwent stem cell mobilization with granulocyte colony-stimulating factor with (n = 25) or without (n = 18) plerixafor.ResultsThe number of days to neutrophil and platelet engraftment was significantly shorter with plerixafor than without plerixafor, as assessed by univariate (neutrophil, P = 0.004, platelet, P = 0.002), subgroup, propensity score matching and inverse probability weighting analyses. Although the cumulative incidence of fever was comparable with or without plerixafor (P = 0.31), that of sepsis was significantly lower with plerixafor than without (P < 0.01). Thus, the present data indicate that plerixafor leads to earlier neutrophil and platelet engraftment and a reduction of infectious risk.ConclusionsThe authors conclude that plerixafor may be safe to use and that it reduces the risk of infection in patients with a low CD34+ cell count the day before apheresis.     

Non-cryopreserved hematopoietic stem cells in autograft patients with lymphoma: a matched-pair analysis comparing a single center experience with the use of cryopreserved stem cells reported to the European Society for Blood and Marrow Transplantation registry

Background aimsAround 50 000 autologous stem cell transplantations are done each year worldwide using cryopreserved peripheral blood stem cells (PBSCs). Cryopreservation is time-consuming and expensive. Since 2007, several retrospective studies have shown that PBSCs can be stored at 4°C for 2–3 days, allowing autologous stem cell transplantation in patients with multiple myeloma receiving high-dose melphalan. Data with non-cryopreserved PBSCs in patients autografted for lymphoma following longer pre-conditioning regimens are limited. In addition, no controlled comparison has been able to detect unforeseen differences.MethodsThe authors compared outcomes of 94 consecutive adult patients with lymphoma (66 with Hodgkin lymphoma) autografted in our department in Oran (Algeria) using PBSCs stored at 4°C, from 2009 to 2018, with patients receiving cryopreserved stem cells reported to the European Society for Blood and Marrow Transplantation registry. Patients autografted in Oran were matched with patients receiving cryopreserved PBSCs in the registry (four controls per patient in Oran).ResultsNeutrophil engraftment was significantly faster with cryopreserved PBSCs (P = 0.003). By day 10, only 17% of patients receiving non-cryopreserved PBSCs engrafted versus 48% for cryopreserved PBSCs. Likewise, platelet recovery to 20 000/mm³ was significantly faster in patients receiving cryopreserved PBSCs (P = 0.01). However, all patients in both groups had recovered by day 20. There were no significant differences in non-relapse mortality (9% versus 7%, P = 0.4), relapse incidence (22% versus 32%, P = 0.13), progression-free survival (70% versus 61%, P = 0.4) or overall survival (85% versus 75%, P = 0.3).ConclusionsThis analysis suggests that, in patients with lymphoma receiving pre-transplant regimens such as carmustine, etoposide, cytarabine and melphalan, PBSCs stored at 4°C for up to 6 days can be used safely in centers with no cryopreservation facility. However, the kinetics of hematopoietic recovery showed a significant, albeit small, delay in engraftment for both neutrophils and platelets, which favors the use of cryopreservation if available.     

Advantages of peripheral blood stem cells from unrelated donors versus bone marrow transplants in outcomes of adult acute myeloid leukemia patients

Background aimsIn allogeneic stem cell transplantation, unrelated donors are chosen in cases where appropriate related donors are not available. Peripheral blood stem cells (PBSCs) are more often selected as a graft source than bone marrow (BM). However, the prognostic benefits of PBSCs versus BM transplants from unrelated donors have not been carefully examined in patients with acute myeloid leukemia (AML). This study compared outcomes of adult AML patients who underwent unrelated PBSC and BM transplantation, evaluating post-transplant complications, including engraftment, graft-versus-host disease (GVHD) and infections, and determined subgroups of patients who are most likely to benefit from unrelated PBSCs compared with BM transplants.MethodsThe authors analyzed 2962 adult AML patients who underwent unrelated PBSC or BM transplants between 2011 and 2018 (221 PBSC and 2741 BM) using the Japanese nationwide registry database, in which graft source selection is not skewed toward PBSCs.ResultsIn 49.7% of patients, disease status at transplantation was first complete remission (CR1). In 57.1% of cases, HLA-matched donors were selected. Myeloablative conditioning was performed in 75.1% of cases, and anti-thymocyte globulin (ATG) was added to conditioning in 10.5%. Multivariate analyses showed a trend toward favorable non-relapse mortality (NRM) in PBSC recipients compared with BM recipients (hazard ratio [HR], 0.731, P = 0.096), whereas overall survival (OS) (HR, 0.959, P = 0.230) and disease-free survival (DFS) (HR, 0.868, P = 0.221) were comparable between PBSC and BM recipients. Although the rate of chronic GVHD (cGVHD) was significantly higher in PBSC patients (HR, 1.367, P = 0.016), NRM was not increased, mainly as a result of significantly reduced risk of bacterial infections (HR, 0.618, P = 0.010), reflecting more prompt engraftments in PBSC recipients. Subgroup analyses revealed that PBSC transplantation was advantageous in patients transplanted at CR1 and in those without ATG use. PBSC recipients experienced significantly better OS and/or DFS compared with BM recipients in this patient group.ConclusionsThe authors' results confirmed the overall safety of unrelated PBSC transplantation for adult AML patients and suggested an advantage of PBSCs, especially for those in CR1. Further optimization of the prophylactic strategy for cGVHD is required to improve the overall outcome in transplantation from unrelated PBSC donors.     

Early lymphocyte reconstitution is associated with improved transplant outcome after cord blood transplantation

Background aimsPrevious studies have shown that rapid recovery of the absolute lymphocyte count (ALC) is associated with improved transplant outcomes after related and unrelated donor allogeneic stem cell transplantation (allo-SCT). No consistent association has been reported between lymphocyte recovery and transplant outcome after cord blood transplantation (CBT)MethodsWe reviewed the records of 40 consecutive CBT patients at our institution to determine the impact of lymphocyte recovery on transplant outcomeResultsThe majority of patients (83%) received CBT for hematologic malignancies. Patients with ALC ≥150/μL at 30 days post-CBT had decreased non-relapse mortality (NRM) (P = 0.011) and improved survival (P = 0.013) compared with ALC < 150/μL. Patients with ALC < 100/μL at 30 days post-CBT had a significantly higher rate of graft failure than those with ALC ≥100/μL (four of 10 versus one of 29; P = 0.011). ALC was positively correlated with the nucleated cell dose and inversely correlated with the patient's age. There was no relationship between disease risk, type of conditioning regimen, anti-thymocyte globulin and number of cord units on ALC recoveryConclusionsOur results indicate that ALC 30 days post-CBT is a surrogate for engraftment, and that low ALC (<150/μL) identifies an ‘at-risk’ population of patients after CBT. Studies are needed to determine ways to increase ALC cell numbers post-CBT, including ex vivo-expanded natural killer cells using adoptive immunotherapy, which might improve outcome after CBT.     

Cryopreservation of hematopoietic cells using a pre-constituted,protein-free cryopreservative solution with 5% dimethyl sulfoxide

Background aimsAdequate cryopreservation techniques are critical to ensure optimal recovery of functional progenitor cells in hematopoietic cell (HC) transplantation, minimize risk of contamination and prevent infusion-related adverse events (irAEs). In this article, we provide graft function and infusion safety results observed by decreasing the concentration of dimethyl sulfoxide (DMSO) in cryopreservative media and by minimizing processor-dependent formulation.MethodsTen HC products, collected after standard mobilization of multiple myeloma patients, were cryopreserved with PRIME-XV FreezIS (FreezIS) and compared with products previously cryopreserved with media formulated in-house to achieve a final DMSO concentration of 10% (Std10) and 5% (Std5). At infusion, HCs were analyzed for recovery of CD34+ cells and viability; irAEs and time to engraftment of neutrophils and platelets were also monitored.ResultsMedian CD34+ cell recovery for HC cryopreserved with Std10, Std5 and FreezIS was 38%, 78% and 68%, respectively (P = 0.0002). There were less frequent irAEs with Std5 and FreezIS (10%) compared with Std10 (80%) (P ≤ 0.0001). Median time to neutrophil engraftment was comparable (11 days) for all three groups, while platelet engraftment occurred at a median of 20, 19 and 17 days, respectively (p-values not significant).ConclusionsFreezIS, a Good Manufacturing Practice-grade, pre-constituted cryopreservative with low DMSO content, maintains functional viability of the HC product while reducing the incidence of irAEs compared with 10% DMSO solutions. The pre-constituted nature of this agent also decreases processor-dependent handling, hence decreasing the risk of variability and infection.     

Positive immunomagnetic CD34+ cell selection in haplo-identical transplants in β-thalassemia patients: removal of platelets using an automated system

Background aimsImmunomagnetic CD34⁺ cell selection (ICS) is utilized in autologous and allogeneic transplants. In the first case it is used to reduce the neoplastic contamination of concentrates, while in the second case it is needed to carry out a T-depletion of cell concentrates in order to reduce the incidence of graft-versus-host disease (GvHD) in patients who have undergone haplo-identical transplants.MethodsThe efficacy of CliniMACS technology, after reduction of platelet contamination, incubation of monoclonal antibodies (MAb) and successive washings of concentrates, performed in 16 ICS using the standard method without reducing platelet content, was compared with the use of the automated system CytoMate, which was carried out in 46 ICS.ResultsIn the group of ICS carried out after automatic manipulation, a significant statistical difference in purity was noted (91.39% versus 83.57, P = 0.017) compared with the group of ICS carried out with the standard procedure. The same significant difference was noted in relation to the remaining percentages of CD3⁺ and CD19⁺ cells (2.31% versus 5.68%, P = 0.012, and 1.58% versus 2.71%, P = 0.014, respectively). Recovery of CD34+ cells overlapped in the two groups (70.49% versus 68.39%, P = 0.774).ConclusionsImmunomagnetic selection carried out using the automated procedure was more efficient, producing a purer sample, more efficient T-depletion and optimal reduction of B cells, without influencing cell recovery. Furthermore, conforming to good manufacturing practice (GMP) guidelines, the entire procedure with CytoMate took place in a contamination-controlled environment.     

Overcoming minimal residual disease using intensified conditioning with medium-dose etoposide,cyclophosphamide and total body irradiation in allogeneic stem cell transplantation for Philadelphia chromosome-positive acute lymphoblastic leukemia in adults

Background aimsAn intensified conditioning regimen incorporating medium-dose etoposide (VP16) is an option for patients with acute lymphoblastic leukemia (ALL). However, the prognostic impacts of the addition of VP16 to cyclophosphamide (CY) and total body irradiation (TBI) in patients with Philadelphia chromosome-positive (Ph+) ALL with regard to minimal residual disease (MRD) status have not been elucidated.MethodsThe authors retrospectively compared the outcomes of patients with Ph+ ALL who underwent allogeneic transplantation following VP16/CY/TBI (n = 101) and CY/TBI (n = 563).ResultsAt 4 years, the VP16/CY/TBI group exhibited significantly better disease-free survival (DFS) (72.6% versus 61.7%, P = 0.027) and relapse rate (11.5% versus 21.1%, P = 0.020) and similar non-relapse mortality (16.0% versus 17.2%, P = 0.70). In subgroup analyses, the beneficial effects of the addition of VP16 on DFS were more evident in patients with positive MRD status (71.2% versus 48.4% at 4 years, P = 0.022) than those with negative MRD status (72.8% versus 66.7% at 4 years, P = 0.24). Although MRD positivity was significantly associated with worse DFS in patients who received CY/TBI (48.4% versus 66.7%, P < 0.001), this was not the case in those who received VP16/CY/TBI (71.2% versus 72.8%, P = 0.86).ConclusionsThis study demonstrated the benefits of the addition of VP16 in Ph+ ALL patients, especially those with positive MRD status. VP16/CY/TBI could be a potential strategy to overcome the survival risk of MRD positivity.     

Ethnic diversity and cord blood banking: satisfying the unmet need

Background aimsIn this study, the authors sought to assess whether cord blood units (CBUs) collected from donors of non-European ethnic backgrounds are utilized for umbilical cord blood transplantation (UCBT) at a different rate than those of European ethnic backgrounds. The authors also examined potential methods of enriching these under-represented ethnic backgrounds in cord blood bank (CBB) inventories without increasing financial overheads and without compromising total inventory utilization or post-transplant outcomes.MethodsData from N = 6506 searchable or shipped Anthony Nolan Cell Therapy Centre grafts were used in this study. Banked grafts were graded from A+ to D based on total nucleated cell and CD34+ cell content. Utilizations of each grade group were further stratified by graft ethnic background. The Mantel–Cox log-rank test was performed in conjunction with Kaplan–Meier survival analysis to compare utilization rates and post-transplant outcomes. For shipped grafts, levels of HLA matching at HLA-A, HLA-B and HLA-DR loci were also analyzed by graft ethnic background and grade using data from the Eurocord/EBMT registry.ResultsOverall utilization of non-European grafts did not significantly differ from that of European grafts (2.5% versus 2.2%, P = 0.23). However, significant differences were found when stratifying utilization rates by cell content. The probability of non-European D grade grafts being utilized was 3-fold higher than that of European D grade grafts (1.1% versus 0.4%, P = 0.03) and comparable to that of European C grade grafts (1.1% versus 0.9%, P = 0.90). No significant differences were found between D and C grade grafts in terms of overall survival (OS) (P = 0.12), in part due to a disproportionate utilization of D grade grafts for pediatric UCBT (74% versus 39%, age difference P < 0.001). Furthermore, non-European graft shipments were 4-fold less likely to be a 6/6 HLA match to their recipients relative to European graft shipments (7% versus 29%).ConclusionsThe authors have identified a niche for CBUs of low cell content collected from donors of non-European ethnic backgrounds that has been overlooked by previous studies. Banking of these CBUs for pediatric UCBT instead of CBUs from European donors containing modestly higher cell content is an ethical approach to increasing the ethnic diversity of CBB inventory—and, consequently, the probability of non-European recipients finding a 6/6 HLA-matched graft—without compromising post-transplant OS or overall rate of inventory utilization.     

Unraveling stem cell and progenitor subsets in autologous grafts according to methods of mobilization: implications for prediction of hematopoietic recovery

Background aimsIn the autologous setting, granulocyte colony-stimulating factor (G-CSF) (G), or, when failing, G plus plerixafor (G+P), are common regimens for mobilization of stem cells into peripheral blood. To delineate mobilization effects on graft composition and hematopoietic recovery, we compared contents of stem cells and progenitor cells in products of G+P- and G patients. Paired samples of G+P patients and prior insufficient G mobilization were available for analyses.MethodsSubset analyses of grafts were performed by flow cytometry and myeloid colony-forming assay. In search of new markers to ascertain graft quality, we determined the fractions of aldehyde dehydrogenase bright (ALDH^br) cells.ResultsG grafts contained higher percentages of CD34+ cells, CD34+CD38- cells, and committed progenitors (CD34+CD38+) compared with G+P grafts. A detailed characterization of the mobilized CD34+ cell subset showed higher percentages of CD38– among the CD34+ cells of the G+P group (P = 0.032). In contrast, the CD34+ cell subset in G grafts was characterized by a higher percentage of ALDH^br cells (P < 0.0001). Studying engraftment and day +100 graft function the G and G+P transplanted patients were comparable with respect to neutrophils, whereas in platelets they differed. In the prediction of engraftment and hematopoietic recovery, the dose of infused ALDH^br cells correlated best to both platelet (r = 0.565, P = 0.002) and neutrophil reconstitution (r = 0.366, P = 0.06).ConclusionsBesides showing dissimilar distributions of CD34+CD38– cells and progenitors in G and G+P grafts, this study further designated ALDH^br as a promising marker in determination and prediction of graft quality and hematopoietic recovery.     

Viability and engraftment of hematopoietic progenitor cells after long-term cryopreservation: effect of diagnosis and percentage dimethyl sulfoxide concentration

Background aimsWe carried out a retrospective analysis of viability by diagnosis and dimethyl sulfoxide (DMSO) concentration in patients who had undergone autologous transplants using hematopoietic progenitor cells (HPC) after long-term storage (up to 17.8 years).MethodsViability was tested using flow cytometry for HPC that were harvested and preserved using a controlled rate freezer and 5% or 10% DMSO with human serum albumin, then stored in liquid nitrogen. Data from 262 samples were analyzed (249 myeloma patients and 13 other diagnoses): 100 consecutively thawed samples with a storage time of <1 year (all 10% DMSO), 50 consecutive samples stored for 1–4.9 years (10% DMSO), 50 samples stored for 5–9 years (5% DMSO) and all samples stored and used for transplant after >9 years (60 samples, 5% DMSO; two samples, 10% DMSO).ResultsNo statistically significant difference in viability between the 5% DMSO and 10% DMSO groups was observed (P = 0.08), so the 1–4.9 years and 5–9 years were combined and the three groups (<1 year, 1–9 years and >9 years) were compared using an anova test. There was no difference in viability based on cryostorage period (P = 0.23) or between myeloma and other diagnoses (P = 0.45). No difference was seen in time to White blood cell (WBC) engraftment (P = 0.10) or to platelet engraftment between groups (P = 0.52).ConclusionsThese data suggest that long-term storage in 5% DMSO and human serum albumin is safe.     

Association of Hyperglycemia with Prolonged Hospital Stay But No Effect on Engraftment After Autologous Hematopoietic Stem Cell Transplantation

ObjectiveTo determine the effect of hyperglycemia, which is associated with poor outcome of various diseases, on the outcome of hematopoietic stem cell transplantation (HSCT).MethodsWe examined the influence of blood glucose concentration (BGC) on the outcome of autologous HSCT. Patients had at least one BGC determination every morning during their hospitalization. The relationships of BGC with time to engraftment and length of hospital stay (LOHS) after transplantation were analyzed.ResultsThe correlation of LOHS after transplantation was found only with posttransplant averaged BGC (P = .0004) in patients without diabetes (N = 240) but not with pretransplant averaged BGC or BGC on the morning of transplantation. The correlation remained significant after adjustment for sex, age, and body mass index (P = .0002) and for use of glucocorticoids and total parenteral nutrition (P = .04). No correlation was observed, however, between BGC and timing of engraftment. We further analyzed the entire data set of subjects (N = 335) on the basis of posttransplant morning BGC and divided these patients into 2 groups: those with BGC < 150 mg/dL and those with BGC ≥ 150 mg/dL. No difference in engraftment time was noted between these 2 groups, but a correlation was observed with LOHS after transplantation (14 ± 4 days versus 17 ± 6 days, respectively; P < .0001).ConclusionWe observed that posttransplant averaged BGC significantly correlated with LOHS after transplantation. BGC, however, had no effect on the timing of engraftment. Thus, our results suggest that better glycemic control could potentially shorten hospital stay after HSCT.(Endocr Pract. 2012;18:508-518)     

Incomplete chimerism following myeloablative and anti-thymocyte globulin-conditioned hematopoietic cell transplantation is a risk factor for relapse and chronic graft-versus-host disease

Background aimsThe value of routine chimerism determination after myeloablative hematopoietic cell transplantation (HCT) is unclear, particularly in the setting of anti-thymocyte globulin (ATG)-based graft-versus-host disease (GVHD) prophylaxis.MethodsBlood samples were collected at 3 months post-HCT from 558 patients who received myeloablative conditioning and ATG-based GVHD prophylaxis. Chimerism was assessed using multiplex polymerase chain reaction of short tandem repeats in sorted T cells (CD3+) and leukemia lineage cells (CD13+CD33+ for myeloid malignancies and CD19+ for B-lymphoid malignancies). ATG exposure was determined using a flow cytometry-based assay. The primary outcomes of interest were relapse and chronic GVHD (cGVHD).ResultsIncomplete (<95%) T-cell chimerism and leukemia lineage chimerism were present in 17% and 4% of patients, respectively. Patients with incomplete T-cell chimerism had a significantly greater incidence of relapse (36% versus 22%, subhazard ratio [SHR] = 2.03, P = 0.001) and lower incidence of cGVHD (8% versus 25%, SHR = 0.29, P < 0.001) compared with patients with complete chimerism. In multivariate modeling, patients with high post-transplant ATG area under the curve and any cytomegalovirus (CMV) serostatus other than donor/recipient seropositivity (non-D+R+) had an increased likelihood of incomplete T-cell chimerism. Patients with incomplete leukemia lineage chimerism had a significantly greater incidence of relapse (50% versus 23%, SHR = 2.70, P = 0.011) and, surprisingly, a greater incidence of cGVHD (45% versus 20%, SHR = 2.64, P = 0.003).ConclusionsHigh post-transplant ATG exposure and non-D+R+ CMV serostatus predispose patients to incomplete T-cell chimerism, which is associated with an increased risk of relapse. The increased risk of cGVHD with incomplete B-cell/myeloid chimerism is a novel finding that suggests an important role for recipient antigen-presenting cells in cGVHD pathogenesis.     

Prevention of chronic diabetic complications in type 1 diabetes by co-transplantation of umbilical cord mesenchymal stromal cells and autologous bone marrow: a pilot randomized controlled open-label clinical study with 8-year follow-up

Background aimsTo explore the long-term safety and benefit of umbilical cord mesenchymal stromal cell (MSCs) plus autologous bone marrow mononuclear cell (aBM-MNC) stem cell transplantation (SCT) without immunotherapy in established type 1 diabetes (T1D).MethodsIn the primary completion of this trial (ClinicalTrials.gov identifier: NCT01374854), the authors randomized patients (n = 21 per group) to either SCT or standard care (control) and previously reported effects on insulin secretion. The authors report about the incidence of chronic diabetes complications (primary endpoint) after 8 years of follow-up. The authors also report on secondary endpoints, safety, islet function and metabolic control.ResultsData were obtained from 14 of 21 patients in the SCT group and 15 of 21 patients in the control group who completed follow-up. At 8 years, the incidence of peripheral neuropathy was 7.1% (one of 14) in the SCT group versus 46.7% (seven of 15) in the control group (P = 0.017). The incidence of diabetic nephropathy was 7.1% (one of 14) in the SCT group versus 40.0% (six of 15) in the control group (P = 0.039). The incidence of retinopathy was 7.1% (one of 14) in the SCT group versus 33.3% (five of 15) in the control group (P = 0.081). Two patients (two of 14, 14.3%) in the SCT group and 11 patients (11 of 15, 73.3%) in the control group developed at least one complication (P = 0.001). One and six patients in the SCT group and control group, respectively, had at least two complications (P = 0.039). No malignancies were reported in the treated group.ConclusionsCo-transplantation of umbilical cord MSCs and aBM-MNCs in patients with established T1D was associated with reduced incidence of chronic diabetes complications.     

Evaluation of mobilized peripheral stem cells according to CD34 and aldehyde dehydrogenase expression and effect of SSClo ALDHbr cells on hematopoietic recovery

Background aimsWe evaluated hematopoietic stem cells according to CD34 expression and aldehyde dehydrogenase (ALDH) activity in peripheral blood and apheresis product samples from patients after mobilization with granulocyte–colony-stimulating factor (G-CSF) alone or G-CSF after high-dose cyclophosphamide (4 g/m² once daily, intravenously on day 1). We also investigated the relationship between the number of SSC^lo CD45^dim CD34^hi cells, SSC^lo ALDH^br cells and engraftment.MethodsThirty patients (20 males and 10 females), who were candidates for autologous peripheral blood stem cell transplantation, were included in the study. Cyclophosphamide + G-CSF was used for 17 and G-CSF alone for 24 mobilizations. Primary diagnoses were multiple myeloma (n% = 14), Hodgkin's lymphoma (n% = 7), non-Hodgkin's lymphoma (n% = 2), acute myloid leukemia (n% = 2), chronic lymphocytic leukemia (n% = 1) and germ cell testis tumor (n% = 1).ResultsNumbers of SSC^lo CD45^dim CD34^hi cells and SSC^lo ALDH^br cells were highly correlated in both peripheral blood and apheresis products (P < 0.001). We could not find a relationship between the transplanted SSC^lo CD45^dim CD34^hi cell dose or SSC^lo ALDH^br cell dose and platelet or neutrophil recovery. The optimal thresholds for SSC^lo CD45^dim CD34^hi cells were 5.40 × 10⁶/kg for neutrophil recovery and 7.22 × 10⁶/kg for platelet recovery. The optimal thresholds for SSC^lo ALDH^br cells were 6.53 × 10⁶/kg for neutrophil recovery and 8.72 × 10⁶/kg platelet recovery.ConclusionsAccording to our data, numbers of SSC^lo ALDH^br cells are in very good agreement with numbers of SSC^lo CD45^dim CD34^hi cells and can be a predictor of stem cell mobilization.     

Mesenchymal stromal cell supported umbilical cord blood ex vivo expansion enhances regulatory T cells and reduces graft versus host disease

Background aimsDouble cord blood transplantation (DCBT) may shorten neutrophil and platelet recovery times compared with standard umbilical cord blood transplantation. However, DCBT may be associated with a higher incidence of graft versus host disease (GVHD). In this study, we explored the effect of ex vivo expansion of a single cord blood unit (CBU) in a DCBT setting on GVHD and engraftment.MethodsPost-thaw cryopreserved CBUs from cord blood banks, hereinafter termed “banked” CBUs, were co-cultured with confluent bone marrow mesenchymal stromal cells (MSCs) supplemented with a cytokine cocktail comprising 100 ng/mL stem cell factor, 50 ng/mL flt3-ligand, 100 ng/mL thrombopoietin and 20 ng/mL insulin-like growth factor binding protein 2 for 12 days.ResultsWhen DCBT of one unexpanded and one expanded CBU was performed in non-obese diabetic/severe combined immunodeficient-IL2Rgamma^null (NOD/SCID-IL2γ^?/?, NSG) mice, the expanded CBU significantly boosted in vivo hematopoiesis of the unexpanded CBU. The median survival of NSG mice was significantly improved from 63.4% (range, 60.0–66.7%) for mice receiving only unexpanded units to 86.5% (range, 80.0–92.9%) for mice receiving an expanded unit (P < 0.001). The difference in survival appeared to be due to a lower incidence of GVHD in the mice receiving expanded cells. This effect on GVHD was mediated by a significant increase in regulatory T cells seen in the presence of MSC co-culture.ConclusionsMSC-supported ex vivo expansion of “banked” CBU boosted unexpanded CBU hematopoiesis in vivo, increased regulatory T cell content and decreased the incidence of GVHD.     

Day 4 collection of granulocyte colony-stimulating factor-mobilized HLA-matched sibling donor peripheral blood allografts demonstrates no long-term increase in chronic graft-versus-host disease or relapse rates

Background aimsIn a previous pilot study of HLA-matched sibling donor hematopoietic cell transplantation (HCT), the authors determined the feasibility of day 4 versus day 5 granulocyte colony-stimulating factor (G-CSF)-mobilized peripheral blood stem cell (PBSC) collection compared with a historical cohort. Given identified differences in the PBSC product (day 4 cohort with significantly lower infused total nucleated, mononuclear and CD3 cells compared with other collection cohorts), the authors performed a follow-up study to determine long-term post-HCT outcomes, including detailed characterization of chronic graft-versus-host disease (GVHD).MethodsThis was a prospective observational study, and the authors collected data on chronic GVHD, staging, sites of involvement and treatments. Performance status, incidence of relapse, overall survival and duration of immunosuppressive therapy (IST) were also evaluated. Data were examined retrospectively. To account for differences in length of follow-up among cohorts, the authors also determined performance status and chronic GVHD staging, sites and treatment at 2 years post-HCT.ResultsAt 2 years post-HCT, the overall survival rate was 71.7% in the day 4 cohort compared with 61.5%, 52% and 56% in the day 5, 2-day and historical cohorts, respectively (P = 0.283). The cumulative incidence of chronic GVHD was 65.2% in the day 4 cohort versus 46.4% in the day 5 cohort, 51.1% in the 2-day cohort and 65% in the historical cohort (P = 0.26). There was no significant difference in the maximum overall stage of chronic GVHD (P = 0.513), median number of sites involved (P = 0.401) or cumulative incidence of discontinuation of IST (P = 0.32). Death from chronic GVHD was less common in the day 4 and day 5 cohorts compared with the 2-day and historical cohorts, though this did not reach statistical significance.ConclusionsThe authors’ preliminary results demonstrated that collection of allogeneic matched sibling donor PBSCs on day 4 of G-CSF was feasible, reduced donor exposure to growth factor and was associated with an initial cost savings. Importantly, the authors now demonstrate that transplantation of day 4 mobilized PBSCs is not associated with any adverse outcomes post-HCT, including late effects such as chronic GVHD. Further investigation of donor G-CSF collection algorithms is merited in other HCT settings, including unrelated and mismatched related donors.     

Combined use of N-acetylcysteine and Liberase improves the viability and metabolic function of human hepatocytes isolated from human liver

Background aimsSuccessful hepatocyte isolation is critical for continued development of cellular transplantation. However, most tissue available for research is from diseased liver, and the results of hepatocyte isolation from such tissue are inferior compared with normal tissue. Liberase and N-acetylcysteine (NAC) have been shown separately to improve viability of isolated hepatocytes. This study aims to determine the effect of Liberase and NAC in combination on human hepatocyte isolation from normal and diseased liver tissues.MethodsHepatocytes were isolated from 30 liver specimens through the use of a standard collagenase digestion technique (original protocol) and another 30 with the addition of NAC and standard collagenase substituted by Liberase (new protocol). Viability and success, defined as maintenance of cell adhesion and morphology for 48 hours, were assessed. Metabolic function was assessed by means of albumin and urea synthesis.ResultsBaseline factors were similar for both groups. The delay to tissue processing was slightly shorter in the new protocol group (median, 2 versus 4 hours; P = 0.007). The success rate improved from 12 of 30 (40.0%) to 21 of 30 (70.0%) with the use of the new protocol (P = 0.037), and median viable cell yield increased from 7.3 × 10⁴ to 28.3 × 10⁴ cells/g tissue (P = 0.003). After adjusting for delay, success rate (P = 0.014) and viable cell yield/g tissue (P = 0.001) remained significantly improved. Albumin and urea synthesis were similar or superior in the new protocol group.ConclusionsNAC and Liberase improve the success of hepatocyte isolation, with a significantly higher yield of viable cells. The use of these agents may improve the availability of hepatocytes for transplantation and laboratory research.     

Effects of stem cells on non-ischemic cardiomyopathy: a systematic review and meta-analysis of randomized controlled trials

Background aimsTo assess the impacts of stem cell therapy on clinical outcomes in patients with non-ischemic cardiomyopathy (NICM). The effect of stem cell therapy on prognosis is unclear and controversial.MethodsThe authors performed a systematic review and meta-analysis of the effects of autologous stem cell transplantation in patients with NICM on a composite outcome of all-cause mortality and heart transplantation, left ventricular ejection fraction (LVEF), left ventricular end-diastolic diameter (LVEDD), New York Heart Association (NYHA) classification, 6-minute walk test (6-MWT) distance and serum brain natriuretic peptide (BNP) level, considering studies published before March 19, 2020.ResultsTwelve trials with 623 subjects met inclusion criteria. Compared with the control group, stem cell therapy improved LVEF (weighted mean difference [WMD], 4.08%, 95% confidence interval [CI], 1.93–6.23, P = 0.0002) and 6-MWT distance (WMD, 101.49 m, 95% CI, 45.62–157.35, P = 0.0004) and reduced BNP level (–294.94 pg/mL, 95% CI, –383.97 to –205.90, P < 0.00001) and NYHA classification (–0.70, 95% CI, –0.98 to –0.43, P < 0.00001). However, LVEDD showed no significant difference between the two groups (WMD, –0.09 cm, 95% CI, –0.23 to 0.06, P = 0.25). In 10 studies (535 subjects) employing the intracoronary route for cell delivery, mortality and heart transplantation were decreased (risk ratio [RR], 0.73, 95% CI, 0.52–1.00, P = 0.05). Furthermore, in four studies (248 subjects) with peripheral CD34+ cells, either all-cause mortality (RR, 0.44, 95% CI, 0.23–0.86, P = 0.02) or mortality and heart transplantation (RR, 0.45, 95% CI, 0.27–0.77, P = 0.003) improved in the treatment group compared with the control. The trial sequential analysis suggested the information size of LVEF, 6-WMT and BNP has been adequate for evidencing the benefits of stem cells on NICM. However, to determine the potential survival benefit, more clinical data are required to make the statistical significance in meta-analysis more conclusive.ConclusionsThis meta-analysis demonstrates that stem cell therapy may improve survival, exercise capacity and cardiac ejection fraction in NICM, which suggests that stem cells are a promising option for NICM treatment.     

Recherche de facteurs de risque de la thrombopénie induite par le 177Lu-DOTATATE dans le bilan de suivi standard

PurposeThe thrombocytopenia induced by the ¹⁷⁷Lu-DOTATATE is one of its frequent, adverse effects. Its persistence causing problems in the subsequent management of patients, especially when the disease progression occurs, predicting it is a major issue. Due to the lack of knowledge about this subject, we searched to determine the existence of predisposing factors concerning the platelet toxicity in the standard follow-up.Material and methodsThis monocentric retrospective study included 20 patients with gastroenteropancreatic neuroendocrine tumors. Various parameters were analyzed, including: the standard blood analysis, the osteomedullary invasion factor, the spleen's volume and the estimated activity in the bone marrow or the spleen 24 hours post-injection.ResultsFour patients had a persistent grade 2 thrombocytopenia, one year after the last treatment. A decrease in platelet count after the first treatment above 30% and an osteomedullary invasion factor above 30% were highlighted as risk factors odds-ratio = ∞ (P = 0.0379) and odds-ratio = ∞ (P = 0.003) respectively. The initial platelet count, splenic length and estimated activity in the spleen after 24 h were correlated with platelet nadir value r = 0.5459 (P = 0.0128); r = − 0,8105 (P < 0,0001) and r = − 0.467; (P < 0.0001) respectively.ConclusionThis study has shown that the decrease of platelet's count after the first round of treatment and the scale of osteomedullary invasion are risk factors for thrombocytopenia and has brought to light that the spleen acts as a factor impacting the severity of this thrombocytopenia.     

Mobilization and engraftment of peripheral blood stem cells in healthy related donors >55 years old

Background aimsThe increasing scarcity of young related donors has led to the use of older donors for related allogeneic hematopoietic stem cell transplantation (HSCT). This study analyzed the influence of age on the results of mobilization of peripheral blood stem cells (PBSCs) in healthy donors as well as on the engraftment and outcome of HSCT.MethodsA retrospective analysis from a single center was performed comparing the results of PBSC mobilization from related healthy donors according to their age.ResultsThe study included 133 consecutive related donors. The median age was 50 years (range, 4–77 years); 70 (53%) donors were males, and 44 (33%) were >55 years old. All donors were mobilized with granulocyte colony-stimulating factor for 5 days. The peak CD34⁺ cell count in peripheral blood was higher in younger than in older donors (median, 90.5 CD34⁺ cells/μL [range, 18–240 CD34⁺ cells/μL] versus 72 CD34⁺ cells/μL [range, 20–172.5 CD34⁺ cells/μL], P = 0.008). The volume processed was lower in younger than in older donors (16,131 mL [range, 4424–36,906 mL] versus 18,653 mL [range, 10,003–26,261 mL], P = 0.002) with similar CD34⁺ cells collected (579.3 × 10⁶ cells [range, 135.14 × 10⁶–1557.24 × 10⁶ cells] versus 513.69 × 10⁶ cells [range, 149.81 × 10⁶–1290 × 10⁶ cells], P = 0.844). There were no differences in time to recovery of neutrophils and platelets or in the incidences of acute and chronic graft-versus-host disease, overall survival, non-relapse mortality and relapse incidence.ConclusionsDonors >55 years old mobilized fewer CD34⁺ cells and required a greater volume to collect a similar number of CD34⁺ cells. The outcome of HSCT was not influenced by donor age. Donor age should not be a limitation for related allogeneic HSCT.