Double Umbilical Cord Blood Transplantation Research Articles

178 - No Change in Viral Infections, But Low Relapse Rate, with the Elimination of Anti-Thymocyte Globulin Prior to Double Umbilical Cord Blood Transplantation

178 - No Change in Viral Infections, But Low Relapse Rate, with the Elimination of Anti-Thymocyte Globulin Prior to Double Umbilical Cord Blood Transplantation

201 - Long-Term Reconstitution of Cellular Immunity and Specific T Cell Responses in Adult Recipients of Double Umbilical Cord Blood Transplantation

201 - Long-Term Reconstitution of Cellular Immunity and Specific T Cell Responses in Adult Recipients of Double Umbilical Cord Blood Transplantation

Impact of Delayed Infusion Time in Umbilical Cord Blood Transplantation

In umbilical cord blood (UCB) transplantation, UCB units are typically thawed, washed, and infused into the patient as rapidly as possible. In some instances there is a delay in the time from the unit thaw and wash procedure to infusion into the patient. Therefore, we examined the effect of thaw duration time on engraftment outcomes in 567 patients undergoing UCB transplantation. With a range of 32 to 523 minutes, a prolonged thaw duration had no obvious effect on the incidence of neutrophil engraftment or time to recovery. This was true for recipients of single UCB transplantation (incidence: 97% versus 93%, P = .13; time to neutrophil recovery: 21 days versus 21 days, P = .32; and platelet recovery: 79% versus 78%, P = .48), and similar results were observed in double UCB transplantation (time to neutrophil engraftment: 20 days versus 19 days, P = .71). However, there was a trend toward better platelet recovery in recipients of double UCB transplants with prolonged thaw duration (HR, 1.28; P = .06). In conclusion, this study demonstrates prolonged thaw duration has no detrimental effect on engraftment after single or double UCB transplantation.

The effect of inter-unit HLA matching in double umbilical cord blood transplantation for acute leukemia.

The effects of inter-unit HLA-match on early outcomes with regards to double cord blood transplantation have not been established. Therefore, we studied the effect of inter-unit HLA-mismatching on the outcomes of 449 patients with acute leukemia after double cord blood transplantation. Patients were divided into two groups: one group that included transplantations with inter-unit mismatch at 2 or less HLA-loci (n=381) and the other group with inter-unit mismatch at 3 or 4 HLA-loci (n=68). HLA-match considered low resolution matching at HLA-A and -B loci and allele-level at HLA-DRB1, the accepted standard for selecting units for double cord blood transplants. Patients’, disease, and transplant characteristics were similar in the two groups. We observed no effect of the degree of inter-unit HLA-mismatch on neutrophil (Hazard Ratio 1.27, P=0.11) or platelet (Hazard Ratio 0.1.13, P=0.42) recovery, acute graft-versus-host disease (Hazard Ratio 1.17, P=0.36), treatment-related mortality (Hazard Ratio 0.92, P=0.75), relapse (Hazard Ratio 1.18, P=0.49), treatment failure (Hazard Ratio 0.99, P=0.98), or overall survival (Hazard Ratio 0.98, P=0.91). There were no differences in the proportion of transplants with engraftment of both units by three months (5% after transplantation of units with inter-unit mismatch at ≤2 HLA-loci and 4% after transplantation of units with inter-unit mismatch at 3 or 4 HLA-loci). Our observations support the elimination of inter-unit HLA-mismatch criterion when selecting cord blood units in favor of optimizing selection based on individual unit characteristics.

Fewer circulating natural killer cells 28 days after double cord blood transplantation predicts inferior survival and IL-15 response

AbstractNatural killer (NK) cell immune reconstitution after double umbilical cord blood transplantation (dUCBT) is rapid and thought to be involved in graft-versus-leukemia (GvL) reactions. To investigate the role of NK cell recovery on clinical outcomes, the absolute number of NK cells at day 28 after dUCBT was determined, and patients with low numbers of NK cells had inferior 2-year disease-free survival (hazard ratio 1.96; P = .04). A detailed developmental and functional analysis of the recovering NK cells was performed to link NK recovery and patient survival. The proportion of NK cells in each developmental stage was similar for patients with low, medium, and high day 28 NK cell numbers. As compared with healthy controls, patients posttransplant showed reduced NK functional responses upon K562 challenge (CD107a, interferon-γ, and tumor necrosis factor-α); however, there were no differences based on day 28 NK cell number. Patients with low NK numbers had 30% less STAT5 phosphorylation in response to exogenous interleukin-15 (IL-15) (P = .04) and decreased Eomes expression (P = .025) compared with patients with high NK numbers. Decreased STAT5 phosphorylation and Eomes expression may be indicative of reduced sensitivity to IL-15 in the low NK cell group. Incubation of patient samples with IL-15 superagonist (ALT803) increased cytotoxicity and cytokine production in all patient groups. Thus, clinical interventions, including administration of IL-15 early after transplantation, may increase NK cell number and function and, in turn, improve transplantation outcomes.

Lack of impact of umbilical cord blood unit processing techniques on clinical outcomes in adult double cord blood transplant recipients

Background aimsDespite widespread use of umbilical cord blood (UCB) transplantation and distinct practice preferences displayed by individual UCB banks and transplant centers, little information exists on how processing variations affect patient outcomes. MethodsWe reviewed 133 adult double UCB transplants performed at a single center: 98 after reduced-intensity and 35 after myeloablative conditioning. Processing associated with contributing UCB banks and units was surveyed to identify differences in practice. We analyzed effect of selected variables on clinical outcomes of engraftment, dominance, transplant-related mortality, and survival. ResultsEighty-eight percent of banks queried currently practice red blood cell (RBC) depletion before cryopreservation. This reflects a shift in practice because previously 65% of banks employed RBC-replete processing methods (i.e., cryopreservation or plasma/volume reduction). Neither neutrophil nor platelet engraftment was affected by processing conditions analyzed. RBC depletion was not associated with clinical outcomes, except in 17 recipients of 2 RBC-replete units, where survival was better than that observed in 116 recipients of ≥1 RBC-depleted units (hazard ratio 3.26, P = 0.004). When analyzed by attributes of the dominant unit, RBC depletion, time in storage, bank years in existence, and inventory size did not affect clinical outcomes. Postthaw viability and CD34 dose were factors impacting engraftment. Notably, all RBC-replete units in this cohort were washed in dextran-human serum albumin before infusion. DiscussionThese findings support continued utilization of the entire existing pool of cord blood units, despite recent trends in processing, and have important implications for banking resources and UCB selection practices.

Revisiting Graft-Versus-Leukemia Effects after Umbilical Cord Blood Transplantation for Acute Myeloid Leukemia : A Report from Eurocord, the Acute Leukemia Working Party and the Cord Blood Committee of the Cellular Therapy & Immunobiology Working Party of the European Society for Blood and Marrow Transplantation

Background. The efficacy of umbilical cord blood transplantation (UCBT) as treatment for acute myeloid leukemia (AML) relies heavily on immune-mediated graft-versus-leukemia effects. Following bone marrow or peripheral blood stem cell transplantation, there is a strong association between occurrence of graft-versus-host disease (GVHD) and a lower risk of AML relapse. Here, we evaluated the kinetics of relapse rate in correlationto GVHD occurrence after UCBT.Methods. The study population included adult patients with de novo or secondary AML, receiving single or double UCBT between 2004 and 2014 at EBMT-affiliated centers.The kinetics of relapse rate over time in correrlation to occurence of GVHD was assessed by calculating the relapse rate per patient-year within sequential 90-day intervals (as previously reported by Inamoto et al., Blood 2011, 14 : 456-463). The smoothed rates were plotted as curves for each GVHD condition (no GVHD, acute GVHD or chronic GVHD). The impact of GVHD on relapse and overall mortality was also assessed with Cox models adjusted for patient age, status at transplantation, cytogenetics, total nucleated cells (TNC), and single versus double UCBT, modeling acute and chronic GVHD as time-dependent covariates.Results. The study included data from 1069 patients given single (n=567) or double (n=501) UCBT. Median patient age at transplantation was 45 (range, 18-73) years. The proportion of patients with grade II, III and IV acute GVHD was 20%, 7% and 4%, respectively. At 2 years, the cumulative incidence of chronic GVHD was 42%, the cumulative incidence of relapse was 32% and overall survival was 32% as well. As shwon in the figure 1, relapse rates declined gradually over time during the first 30 months after transplantation and were lower in patients with chronic GVHD than in those without GVHD. Furthermore , in a multivariate Cox model, there was a suggestion for lower incidence of relapse in patients who experienced chronic GVHD (HR 0.6, P=0.1). In contrast, there was a significant increase in the risk of mortality in patients with grade III-IV acute (HR 2.4, P<0.001) and those with de novo chronic GVHD (HR 3.2, P<0.001) due to increased non relapse mortality.Conclusions. Although this study suggest that chronic GVHD might be associated with lower risk of AML recurrence after UCBT, grade III-IV acute and chronic GVHD each increased overall mortality. [Display omitted] DisclosuresMichallet:Bristol-Myers Squibb: Consultancy, Honoraria, Research Funding; Pfizer: Consultancy, Honoraria; Novartis: Consultancy, Honoraria; Pfizer: Consultancy, Honoraria; Astellas Pharma: Consultancy, Honoraria; MSD: Consultancy, Honoraria; Genzyme: Consultancy, Honoraria.

Adult Umbilical Cord Blood Transplantation Using Myeloablative Total Body Irradiation, Fludarabine, and Thiotepa Conditioning

Introduction: Umbilical cord blood (UCB) extends the curative potential of stem cell transplantation to adult patients without a suitable donor. The most commonly used myeloablative preparative regimen results in an unacceptably high 6-month treatment related mortality rate of approximately 32% (Barker J et al. Br J Haematol. 2015). In an attempt to reduce treatment related mortality, we piloted a modified myeloablative regimen with total body irradiation (TBI), fludarabine, and thiotepa. We report clinical outcomes from a cohort of patients who received single or double UCBT after conditioning with this regimen.Methods: Thirty-one consecutive adult patients ≥ 18 years old with hematologic malignancies who underwent single or double umbilical cord blood transplantation at Duke University from 2010 to 2015 were included in this study. The conditioning regimen consisted of thiotepa 5 mg/kg/day i.v. x 2 days (days -11 to -10), TBI 150 cGy twice a day for total nine fractions (1350 cGy days -9 to -5), and fludarabine 40 mg/m2/day i.v. x 4 days (days -5 to -2). Cord blood units were matched to the recipient at 4 or more HLA loci (intermediate-resolution for A and B, high-resolution for DRB1). Graft versus host disease (GVHD) prophylaxis was with tacrolimus (target level 10-15 ng/ml) and mycophenolate mofetil 1000 mg TID. Antimicrobial prophylaxis and supportive care measures including GCSF administration until ANC > 1000 were conducted per institutional protocol. Probabilities of neutrophil and platelet recovery, acute and chronic GVHD, and treatment-related mortality were estimated by the cumulative incidence method. Relapse-free and overall survival rates were estimated by the Kaplan-Meier method.Results: Thirty-one patients (median age 46 years; range, 19-65) with hematologic malignancies were evaluated. Twenty-four patients (77%) had acute leukemia or myelodysplastic syndrome, while 7 patients (23%) had non-Hodgkin's lymphoma or multiple myeloma. By the "Disease Risk Index" (Armand P et al. Blood. 2014), 20 patients (65%) had low or intermediate risk disease, while 11 patients (35%) had high or very high risk disease. 30 patients underwent double UCB and 1 patient received single UCB transplantation. The median cryopreserved total nucleated cell dose was 5.4 x 107/kg (range: 3.2-8.4 x 107/kg). The cumulative incidence of neutrophil engraftment was 90% (95% CI, 82%-99%; Figure 1) at a median time of 21 days (95% CI, 19-26). Three patients did not have neutrophil engraftment; two patients had early death at days 7 and 14 prior to engraftment, while one patient had graft failure requiring second transplant. The cumulative incidence of platelet engraftment was 86% (95% CI, 75%-97%) at a median time of 47 days (95% CI, 37-73). Cumulative incidences of grades II-IV and grades III-IV acute GVHD were 48% (95% CI, 34%-69%) and 10% (95% CI, 3%-28%), respectively. The overall incidence of chronic GVHD was 40% (95% CI, 27%-59%), with 17% (95% CI, 8%-37%) of patients experiencing moderate to severe chronic GVHD. Treatment-related mortality at 6 months was 13% (Figure 2), while at 1 year and 3 years was 27% and 33%, respectively. With a median follow-up of 35.5 months (95% CI, 12.7-52.2), disease-free and overall survival at 3 years was 51% (95% CI, 29%-69%) and 57% (95% CI, 36%-73%), respectively.Conclusion: UCB transplantation with the modified myeloablative conditioning regimen of TBI, fludarabine, and thiotepa results in reliable neutrophil engraftment with reduced early treatment related mortality as compared to standard myeloablative conditioning consisting of TBI, fludarabine, and cyclophosphamide. It provides a promising disease-free and overall survival in an older (median age 46), heterogeneous patient population. This regimen represents a reasonable alternative to standard conditioning with TBI, fludarabine, and cyclophosphamide and warrants further study. [Display omitted] [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Impact of Refined Disease Risk Index after Single and Double Umbilical Cord Blood Transplantation in Adults with Hematological Malignancies

Identifying pre-transplant risk factor before allogeneic transplantation (HSCT) is important, regardless of the graft source. Nonetheless, it has been demonstrated that disease type and status at the time of HSCT significantly affect outcome. Disease risk index (DRI) has been recently defined for stratifying large and heterogeneous cohorts of patients (pts) undergoing HSCT. The original DRI included all hematological malignancies (except very rare diseases) and was able to define 4 distinct groups with different outcomes, dividing patients by disease type and status and considering cytogenetics that turned to be determinant for acute myeloid leukemia and myelodysplastic syndromes (MDS). Recently, DRI was refined by including rare diseases and improving MDS stratification by blast percentage, cytogenetics and response to prior therapy. DRI has been demonstrated to be applicable to pts undergoing HSCT regardless of age, conditioning regimen and graft source, and it has also been validated in pts undergoing T-cell depleted HSCT. Currently, there are no available reports on large cohort of pts undergoing umbilical cord blood transplantation (UCBT). Our aim was to determine the impact of DRI after UCBT. We retrospectively analyzed 2337 adults who underwent UCBT between 2004 and 2014, were reported to Eurocord and had available data for DRI scoring. Diagnosis was acute leukemia (AL) in 66% of the cases; 56% of AL were transplanted in first complete remission (CR), 39% in CR2 and 6% in >CR2. The median age at UCBT was 43 (range 18-76) years. Cytomegalovirus (CMV) serology was positive in 62% of pts; 45% of pts were female. Performance status at UCBT was <90% in 56% of pts and >90% in 44%. Fifty-two percent of pts received double and 48% single UCBT. Conditioning regimen was reduced intensity (RIC) for 52% of pts, and the most common regimen was cyclophosphamide+fludarabine+low dose total body irradiation (2Gy) for 72% of pts. Cyclosporine A (CsA) and mycophenolate mofetil (MMF) were used for graft-versus-host-disease (GVHD) prophylaxis in 61% of the pts. Anti-thymocyte globulin (ATG) was given in 41% of pts. Median TNC at cryopreservation was 4.2 x 107/Kg (range 0.4-13) and 56% of pts received a graft with 2or more HLA mismatches.The median follow-up was 30 (range 1-120) months. Overall survival (OS) and progression free survival (PFS) were 44% and 38% at 2 years, respectively. Refined DRI stratified pts in 4 subgroup (low risk, n=352, intermediate, n=1303, high, n=544, and very high-risk, n=138). OS was 56±3% for pts with low-risk DRI, 48±2% for intermediate-risk DRI, 31±2% for pts with high-risk DRI and 26±4% for pts with very high-risk DRI (p <0.0001). PFS was 46±3%, 42±2%, 25±2%, 22±4% for low, intermediate, high and very-high risk, respectively (p <0.0001).According toconditioning intensity regimen and DRI, OS was 49% (for low risk), 47% (for intermediate), 29% (for high risk) and 20% (for very high risk) (p< 0.0001) for myeloablative (MAC) regimen and 60% (for low risk), 49% (for intermediate), 33% (for high risk) and 32% (for very high risk) for RIC (p < 0.0001). DRI was also statistically associated with different PFS stratifying for type of conditioning regimen (MAC and RIC)(p <0.0001).In multivariate analysis adjusted for ATG use, CMV serology, DRI, median age at UCBT, median TNC at cryopreservation and type of UCBT (single or double), ATG use (HR=1.52, CI 95%=1.3-1.7, p< 0.0001), age at UCBT (median) (HR=1.4, CI 95%=1.2-1.6, p <0.001), very-high DRI (HR=2.7, CI 95%=2-3.7, p< 0.001), positive CMV serology (HR=1.2, CI 95%=1.07-1.4, p 0.03) were associated with a decreased OS. Furthermore, ATG use (HR=1.4, CI 95%=1.2-1.5, p< 0.0001), age at UCBT (median) (HR=1.3, CI 95%=1.2-1.5, p <0.0001), very-high DRI (HR=2.2, CI 95%=1.6-3, p< 0.0001), positive CMV serology (HR=1.2, CI 95%=1.04-1.4, p 0.008) were associated with decreased PFS.Refined DRI is a valid system for risk-stratifying pts with different diseases undergoing UCBT in retrospective large cohort studies. This index represents a simple and robust means of stratifying large cohort of pts in the UCBT setting, complementary to other existing pre-transplant index. Our results confirm the prognostic value of refined DRI in UCBT and support the use of this simple tool for prospective trials in the future. DisclosuresBloor:Janssen: Honoraria, Speakers Bureau; Roche: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; GSK: Consultancy, Speakers Bureau; Gilead: Honoraria; Abbvie: Membership on an entity's Board of Directors or advisory committees.

Chronic Graft-Versus-Host Disease in Double Cord Blood Transplantation According to National Institutes of Health 2005 Criteria: A Study on Behalf of Eurocord and Cord Blood Committee of Cellular Therapy and Immunobiology Working Party of the EBMT

Chronic Graft-versus-Host Disease (cGVHD) has a negative impact on transplant related death and quality of life after hematopoietic stem cell transplantation. In an attempt to thoroughly assess cGVHD after double umbilical cord blood transplantation (dUCBT), we used the major revised consensus criteria (NCC 2005) proposed by the National Institutes of Health (NIH) in 2005.Material and methods: This is a retrospective study using Eurocord-EBMT database. A specific questionnaire including the NCC 2005 characteristics and features was sent to each transplant centers for collecting data. Eligible pts were adults >18years, who received dUCBT for hematological malignancy in an EBMT center between 2006 and 2014, achieved neutrophil engraftment, survived ≥100 days and developed cGVHD.Results: A total of 154 pts were included. Median age at dUCBT was 43 years (18-70). The primary diagnosis was acute myeloid leukemia in 40%, acute lymphoblastic leukemia in 21%, myelodysplastic/myeloproliferative disease in 19%, and other hematological disorders in 20%. The majority of pts was transplanted in CR, including 51% in CR1, 37% in CR2. Reduced intensity conditioning regimen (mainly with low dose total body irradiation) was used in 60% of cases. 24% pts received anti-thymocyte globulin before transplant.Cyclosporine and mycophenolate mofetil (MMF) was the most common (79%) combination for GVHD prophylaxis. 70% (n=107) of pts received gender mismatched grafts, and 59% had 1-2 major ABO incompatibility. Most (>80%) grafts had 2 HLA mismatches with the recipients. Median number of total nucleated cells at cryopreservation was 5.1(2.3-13.3) ×107/Kg.All pts achieved neutrophil engraftment in a median of 25 days and 89% had full donor chimerism at day 100. Median follow-up was 27.5 (3-103) months, 45 pts relapsed and 60 pts died (28 of relapse, 12 of GVHD and 20 of other TRM).Grade II-IV acute GVHD occurred in 88 pts in a median time of 24 (6-106) days. Grade III-IV aGVHD was reported in 43 pts, mainly with skin and gastrointestinal (GI) tract involvement.Median time for cGVHD onset was 219 (47-2056) days, and most of these were reported within the first 1.5-2 years. Based on Seattle criteria, cGVHD was limited in 73 (47%) pts and extensive in 81 (53%) pts. According to NIH criteria (NCC2005), global cGVHD severity was scored as mild in 67 (44%), moderate in 53 (35%) and severe in 33 pts (21%).cGVHD presented mainly as one or two organs involvement, with skin being the most common site. 56% pts (n=86) had a single organ involvement (mainly skin n=60; 38%). Skin, GI tract, and oral mucosa were the top three affected sites (93%; n=143), both in solo and multiple involvements. 23 patients had > 3 affected organs, skin being most common (n=20; 87%). No joint or fascia involvement was reported as a single organ involvement in any grade.Mild and moderate cGVHD presented as one or two organs involvement, mainly affecting skin, GI and oral mucosa. Severe cGVHD often involved skin, GI, lung and liver. Severe GI tract cGVHD was mostly reported as a single organ involvement. Severe lung involvement was reported in 12 pts (8%).Major functional impact by scoring grade 3 was observed in skin (n=7), GI (n=8), liver (n=5), eye (n=3), oral mucosa (n=2), and lung (n=5).Twenty %pts (n=31) received only topical or no treatment, for 1 or 2 organs involvement and mild to moderate grade cGVHD. The first line treatment of cGVHD included systemic steroids +/- calcineurin inhibitors (CNI) or MMF based regimen, and was used in 72% pts (n=111).cGVHD resolved in 94 pts (61%), and remained clinically significant in 57 pts (mild, n=14; moderate, n=20 and severe, n=23). Among the 12 pts who died of cGVHD, there was multiple organs involvement in most cases; and 6 pts had severe lung cGVHD.Conclusion: According to NCC 2005 criteria, we report that, after dUCBT, cGVH was usually mild with skin being the most common site resulting, in this small group of patients, in a relatively low incidence of severe cGVH with as a consequence a better survival and quality of life. DisclosuresMichallet:Bristol-Myers Squibb: Consultancy, Honoraria, Research Funding; Pfizer: Consultancy, Honoraria; Novartis: Consultancy, Honoraria; Pfizer: Consultancy, Honoraria; Astellas Pharma: Consultancy, Honoraria; MSD: Consultancy, Honoraria; Genzyme: Consultancy, Honoraria.

Prostaglandin E2 Alters the Differentiation and Function of Antigen-Specific T Cells By Targeting the Metabolic Gene Regulatory Network Downstream of mTORC1

Umbilical cord blood transplantation (UCBT) has extended the availability of hematopoietic stem cell transplantation to patients without compatible adult donors. Studies in zebrafish and mouse models have shown that the prostaglandin compound, 16,16 dimethyl prostaglandin E2 (PGE2), increases HSC number and homing. In a human clinical trial of double UCBT, PGE2 decreased time to engraftment, promoted early T cell chimerism, favored generation of long-lived memory CD8+ cells and reduced the incidence of CMV viremia. To obtain mechanistic insight of how PGE2 affects the differentiation program of antigen-specific T cells, we used a well-established model of T effector (TEFF) vs. T memory (TM) differentiation of TCR-transgenic OTI T cells. OTI cells were stimulated with Ova257-264 plus APC with or without PGE2, followed by incubation with either IL-2 or IL-7, which are critical for the development of CD8+ TEFF and TM, respectively. Antigen-specific stimulation with or without PGE2 followed by IL-2 resulted in differentiation to CD44+CD62L- TEFF cells. In contrast, antigen-specific stimulation followed by IL-7 resulted in generation of CD44+CD62L+ central memory T cells. Under these conditions, PGE2 treatment gave rise to a phenotype of CD44-CD62L+Bcl2+Sca1+ cells, consistent with T stem cell memory. Two key pathways regulated by AMPK and mTOR have a decisive role on TM differentiation. AMPK can promote the generation of TM cells. However, we found that PGE2 inhibited AMPK activation indicating that differentiation of TM by PGE2 is not mediated by AMPK. Because the mTORC1-specific inhibitor rapamycin can promote the generation of TM, we focused our studies on the effects of PGE2 on mTORC1. Two classes of direct downstream targets of mTORC1 have been well characterized. mTOR phosphorylates the ribosomal protein S6 kinases (S6K1/2) and the eukaryotic initiation factor 4E (eIF4E)-binding proteins (4E-BP1/2), both of which control specific steps in the initiation of cap-dependent translation. mTORC1 activation can stimulate glycolysis as well as lipid biosynthesis. This is achieved through the activation of a transcriptional program affecting metabolic gene targets of hypoxia inducible factor 1a (HIF1a) and sterol regulatory element-binding protein (SREBP1/2). HIF1a is regulated downstream of 4E-BP whereas SREBP is regulated downstream of S6K1. Although the mTORC1 inhibitor rapamycin can promote differentiation of TM and Treg cells, recent studies revealed that mTORC1, via its effects on lipid metabolism has a mandatory role on Treg differentiation. We found that PGE2 treatment during antigen-specific stimulation of OTI cells with Ova257-264 resulted in activation of mTOR as determined by phosphorylation of mTOR, 4E-BP and S6K and phosphorylation of Akt on the mTOR-specific site. Surprisingly, when antigen-specific stimulation was followed by IL-7, PGE2 treatment inhibited expression of the 4E-BP downstream targets Myc, HIF1a, the glycolysis genes Glut1, HK2, LDH-A, and the uptake of glucose. Phosphorylation of S6K was also impaired and lipid biosynthesis was suppressed as determined by decreased expression of fatty acid synthase FASN. In contrast, a metabolic program of lipid utilization was activated, characterized by increase of CPT1a, which promotes fatty acid transport in the mitochondria for b-oxidation, and the lipid oxidase Acox1. Mitochondria biogenesis analyzed by Mitotracker staining and expression of mitochondrial genes MTOC-1, TIMM50 and COX5a were also enhanced. In bioenergetics studies control-treated antigen-specific T cells had a glycolytic phenotype with elevated extracellular acidification rate (ECAR) whereas PGE2-treated cells had elevated oxygen consumption rate (OCR) and increased OCR/ECAR ratio, indicating preferential use of oxidative phosphorylation to generate energy. Thus, mTORC1 might regulate differentiation of antigen-specific T cells to TM by promoting lipid biosynthesis upon engaging distinct downstream targets in response to extracellular cues, thereby providing the required fuel for the bioenergetic demands of TM cells. Our studies reveal an unexpected mechanism by which PGE2 regulates the functional fate of T cells by modifying mTORC1 downstream signals and altering T cell metabolic imprints. These findings have implications for harnessing immune memory in the context of tumor-specific and pathogen-specific immunity. DisclosuresNo relevant conflicts of interest to declare.

Matching at Human Leukocyte Antigen-C Improved the Outcomes after Double Umbilical Cord Blood Transplantation for Recipients of Two to Four of Six Human Leukocyte Antigen–Matched Grafts

We studied the effect of HLA-C matching in 515 patients after double umbilical cord blood (UCB) transplantation. After HLA matching HLA-A, -B, and -DRB1 at the allele level, we scored patients according to number of donor-recipient HLA-C matches at 4 possible loci: 2 from each donor unit, at the allele level. Given a direct interaction between HLA-A, -B, and -DRB1 matching and HLA-C score, we analyzed HLA-C matching in those receiving at least 1 2/6 to 4/6 HLA–matched unit (n = 389) versus those receiving only 5/6 or 6/6–matched units (n = 126). In those with at least 1 2/6 to 4/6 HLA–matched unit, a better HLA-C matching score was associated with significantly lower risk of death of any cause and nonrelapse mortality and better disease-free survival. There was no association with the risk of relapse, acute and chronic graft-versus-host disease, and hematopoietic recovery. In contrast, among patients receiving only allele-level 5/6 or 6/6 HLA–matched UCB units, HLA-C match had no demonstrable effect on any outcome. For patients receiving at least 1 allele-level 2/6 to 4/6 HLA–matched UCB unit, matching at HLA-C reduces nonrelapse mortality and improves survival.

CD4+ T-cell alloreactivity toward mismatched HLA class II alleles early after double umbilical cord blood transplantation

AbstractAlthough double umbilical cord blood transplantation (dUCBT) in adult patients may be associated with less graft failure compared with single UCBT, hematopoietic recovery generally originates from a single cord blood unit (CBU). CBU predominance is still incompletely understood. We recently showed that blood CD4+ T-cell numbers rapidly increase after dUCBT, and early CD4+ T-cell chimerism predicts for graft predominance. Given the frequent HLA class II allele mismatches between CBUs in dUCBT, we hypothesized that alloreactive HLA class II–specific CD4+ T cells from the “winning” CBU may contribute to rejection of the “loser” CBU. We evaluated whether CD4+ T cells originating from the predominant (PD)-CBU would recognize HLA class II allele mismatches, expressed by the nonengrafting (NE)-CBU. Alloreactive effector CD4+ T cells toward 1 or more mismatched HLA class II alleles of the NE-CBU were detected in 11 of 11 patients, with reactivity toward 29 of 33 (88%) tested mismatches, and the strongest reactivity toward DR and DQ alleles early after dUCBT. Mismatched HLA class II allele-specific CD4+ T cells recognized primary leukemic cells when the mismatched HLA class II allele was shared between NE-CBU and patient. Our results suggest that cytotoxicity exerted by CD4+ T cells from the PD-CBU drives the rapid rejection of the NE-CBU, whose alloreactive effect might also contribute to graft-versus-leukemia.

Nonfluorodeoxyglucose-Avid Persistent Splenomegaly at Time of Transplantation Delays Neutrophil and Platelets Engraftment without Affecting Survival in Patients with Lymphomas Undergoing Allogeneic Hematopoietic Cell Transplantation

It is unclear if persistent splenomegaly in the presence of a negative positron emission tomography (PET) scan before allogeneic hematopoietic cell transplantation (HCT) influences post-transplantation outcomes in patients with lymphoma. We retrospectively reviewed records of 152 patients who underwent allogeneic HCT for various lymphomas. Centralized review of pretransplantation computed tomography (CT) and PET images was performed. Spleen volume (SV) was measured using the freehand volume segmentation tool in AW Workstation software (General Electric, Waukesha, WI). Splenic index (SI) was calculated as a product of width, thickness, and length of the spleen. Normal SV was defined as SV < 314.5 cm3 and normal SI was defined as SI ≤ 480 cm3, as described in the literature. Among the study population, 42.8% received an allogeneic HCT from an HLA-matched related donor, 36.2% from a matched unrelated donor, 12.5% from a mismatched unrelated donor, and 8.6% received a double umbilical cord blood transplantation. Most (61.8%) received myeloablative conditioning. Median age at transplantation was 52 (range, 21 to 68) years. Pre–allogeneic HCT spleen CT and PET images were available on 88% and 70.3% patients, respectively. SV ranged from 90 cm3 to 4684 cm3 with a median of 290.5 cm3 and a mean of 400.3 cm3. SI calculation showed a range from 50.3 cm3 to 8276.4 cm3 with a median of 582.1 cm3 and a mean of 771.2 cm3. The majority of patients (83.1%) had PET-negative spleen before allogeneic transplantation. Engraftment was delayed in PET-negative patients with persistent splenomegaly, with median days to neutrophil engraftment of 17 versus 16 (P = .03) and median days to platelet engraftment of 16 versus 14 (P = .04) when using SV. However, persistent splenomegaly did not appear to impact progression-free survival (P = .11) or overall survival (P = .37). Splenomegaly in the setting of a PET-negative study before allogeneic HCT delays neutrophil and platelet engraftment but does not appear to affect survival. Future studies using registry data or larger multicenter studies would be required to evaluate the impact of splenomegaly and its fluorodeoxyglucose avidity on allogeneic HCT outcomes in specific subtypes of lymphomas.

Sirolimus and Mycophenolate Mofetil as Calcineurin Inhibitor–Free Graft-versus-Host Disease Prophylaxis for Reduced-Intensity Conditioning Umbilical Cord Blood Transplantation

The use of calcineurin inhibitors (CNIs) to reduce the risk of graft-versus-host disease (GVHD) after hematopoietic cell transplantation (HCT) requires intensive post-transplantation toxicity monitoring. Sirolimus-based GVHD prophylaxis is associated with a favorable toxicity profile and requires less intensive monitoring. However, the efficacy of sirolimus-based regimen compared with CNI-based regimen has not been evaluated in the setting of reduced-intensity conditioning (RIC) double umbilical cord blood (UCB) HCT. We compared outcomes of patients receiving sirolimus/mycophenolate mofetil (MMF) (n = 37) or cyclosporine (CSA)/MMF (n = 123) in an ongoing phase II study of RIC UCB transplantation. In multiple regression analysis, sirolimus/MMF did not influence the risk of grades II to IV or grades III and IV acute GVHD. In addition, there was no association between type of GVHD prophylaxis and hematopoietic engraftment. Infection density analysis found a significantly lower risk of infections with sirolimus/MMF between days +46 and +180 after HCT compared with CSA/MMF (3.4 versus 6.3 per 1000 patient-days, P = .03); however, no difference was observed before day +45. Sirolimus/MMF use resulted in no thrombotic microangiopathy, fewer instances of elevated serum creatinine >2 mg/dL (14% versus 45%; P < .01), and similar rates of sinusoidal obstruction syndrome (2.7% versus 4%; P = .68), compared with CSA/MMF. Disease-free survival at 1 year was 51% for sirolimus/MMF and 41% for CSA/MMF (P = .41), and sirolimus/MMF use did not influence the risk of nonrelapse mortality or survival. In conclusion, sirolimus/MMF GVHD prophylaxis was better tolerated and resulted in similar rates of GVHD and survival as compared to CSA/MMF after RIC double UCB transplantation.

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

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

Outcomes of unrelated cord blood transplantation in patients with multiple myeloma: a survey on behalf of Eurocord, the Cord Blood Committee of Cellular Therapy and Immunobiology Working Party, and the Chronic Leukemia Working Party of the EBMT.

Although allogeneic stem cell transplantation is not a standard therapy for multiple myeloma, some patients can benefit from this intense therapy. There are few reports on outcomes after umbilical cord blood transplantation in multiple myeloma, and investigation of this procedure is warranted. We retrospectively analyzed 95 patients, 85 with multiple myeloma and 10 with plasma cell leukemia, receiving single or double umbilical cord blood transplantation from 2001 to 2013. Median follow up was 41 months. The majority of patients received a reduced intensity conditioning. The cumulative incidence of neutrophil engraftment was 97%±3% at 60 days, and that of 100-day acute graft-versus-host disease grade II-IV was 41%±5%. Chronic graft-versus-host disease at two years was 22%±4%. Relapse and non-relapse mortality was 47%±5% and 29%±5% at three years, respectively. Three-year progression-free survival and overall survival were 24%±5% and 40%±5%, respectively. Anti-thymocyte globulin was associated with decreased incidence of acute graft-versus-host disease, higher non-relapse mortality, decreased overall and progression-free survival. Patients with high cytogenetic risk had higher relapse, and worse overall and progression-free survival. In conclusion, umbilical cord blood transplantation is feasible for multiple myeloma patients.

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.

Double umbilical cord blood transplant is effective therapy for relapsed or refractory Hodgkin lymphoma

A sub-group of patients with Hodgkin Lymphoma (HL) who relapse after autologous stem cell transplant can achieve long-term disease-free-survival after allogeneic stem cell transplant (alloSCT). There is limited information regarding the tolerability and efficacy of double umbilical cord blood transplant (dUCBT) for relapsed/refractory HL. We analyzed 27 consecutive, heavily pre-treated patients receiving dUCBT for relapsed/refractory HL at two centers from 2003–2014. The majority of patients relapsed <6 months after autologous stem cell transplant. A total of 15 patients received myeloablative (most commonly melphalan, fludarabine, thiotepa and anti-thymocyte globulin [ATG]) and 12 non-myeloablative conditioning regimens (fludarabine, cyclophosphamide, 200cGy total body irradiation +/- ATG). All patients engrafted; median time to neutrophil and platelet engraftment was 17 and 37 days, respectively. Overall response rate was 68%; 58% achieved complete remission. Median progression-free survival (PFS) was 12.2 months; median overall survival was 27 months. Cumulative incidences of relapse and of non-relapse mortality at 5 years were 30% and 37.9%, respectively; 5-year PFS was 31.3% (95%CI 10.1–52.5). There was a trend toward inferior PFS in patients with lymph node size ≥2 cm at the time of alloSCT (p = 0.07) and toward inferior survival in patients with chemorefractory disease pre-alloSCT (p = 0.12). dUCBT is feasible in patients with heavily pre-treated HL and can achieve long-term disease-free survival in approximately 30% of patients.

Selecting Double Cord Blood Units for Adults with Hematological Malignancies: Impact of ABO, HLA and Cell Dose on Outcomes after Double Cord Blood Transplants a CBC-Cellular Therapy & Immunobiology Working Party, EBMT and Eurocord Study

Despite the increased inventory of "rich" and more diverse HLA cord blood units (CBUs), most adults are still transplanted with double unrelated CBUs. Many studies have described criteria for CBU selection for single UCBT (SUCBT) based on cell dose, low and high resolution (LR and HR) HLA typing, KIR and NIMA. However, the criteria based on these factors for selecting double CBUs are still not as well defined. Moreover, most of SUCBT are performed in children whereas double UCBT (DUCBT) are commonly used for adults, therefore CBUs selection criteria may be different between in these two settings.With the aim of studying the impact of CBUs, patient and transplantation-related factors in DUCBT, we conducted a retrospective registry-based study in a large series of adults transplanted with DUCBT in EBMT centers, for whom we had available data on cell dose and HLA for both CBUs. Overall, 934 adults met the eligibility criteria: 55% had acute leukemia, 21% lymphoid mature malignancies, 10% MDS and 14% MPD or multiple myeloma. Patients' median age at DUCBT was 47 years (y) and median weight was 71 kg. Median time from diagnosis to DUCBT was 17 months. Conditioning regimen was myeloablative (MAC) in 32% and antithymocyte globulin (ATG) was used in 24% of the cases. GvHD prophylaxis consisted mostly of cyclosporine+mycophenolate mofetil. Median number of TNC at collection and infusion were 4.9 x107/kg (n=934) and 3.6x107/kg (n=735), respectively. Median number of collected and infused CD34 cells were 1.9x105/kg (n=893) and 1.6 x105/kg (n=695), respectively. Number of HLA disparities was defined according to the CBU with the highest degree of mismatches with the recipient, based on LR typing for HLA-A and -B and HR typing for -DRB1. Overall, 1% of the patients received a 6/6, 26% a 5/6, 67% a 4/6 and 6% a 3/6 HLA-matched DUCBT. ABO match was also classified according to the CBU with the highest incompatibility with the recipient: 18% of the patients received two ABO compatible CBUs, 30% at least one CBU with minor ABO incompatibility and 52% received at least one CBU with a major ABO incompatibility.At day 60, estimated absolute neutrophil count (ANC>500) recovery was 87%. In multivariate analysis (MVA) greater ANC recovery was associated with TNC dose at collection≥ 4.9x107/kg (HR:0.66; p=0.002), as well as female recipient, negative CMV serology and other diagnosis than MDS. Impact of CD34 cell dose was observed in univariate analysis: probability of ANC recovery was 91% if ≥1.9x105/kg versus 84% for a lower dose (p<0.001). At day-100, the incidence of acute GvHD (aGvHD) grade II-IV was 42% and III-IV was 20%. In MVA, increased aGVHD (II-IV) was associated with absence of ATG, use of MAC and HLA-match ≥4/6 (HR: 1.51, p=0.007), whereas increased aGVHD (III-IV) was associated with recipient's age (>47y), advanced disease, HLA-match ≥4/6 (HR: 1.55; p=0.048) and ABO major incompatibility (HR:1.44; p=0.039). The 2y NRM was 35%. Factors associated with higher NRM were positive CMV serology, advanced disease, use of ATG, ABO incompatibility (HR:1.55; p=0.023) and HLA-match ≥4/6 (HR:1.39; p=0.046). Relapse incidence (RI) at 2y was 20% and none of the CBU related factors impacted on RI. Overall Survival (OS) at 2y was 47%. In MVA, positive CMV serology, diagnosis of MDS and use of ATG were associated with decreased OS. Number of HLA disparities and degree of ABO compatibility were also associated with survival: 2y OS was 45% for patients transplanted with at least one ≥4/6 HLA-matched CBU, and 54% for those transplanted with both 6/6 or at least one 5/6 HLA-matched CBU (HR:1.26; p=0.05). Interestingly, OS at 2y was 57% for patients transplanted with both ABO compatible CBUs, 47% for those transplanted with at least one CBU with ABO minor incompatibility and 39% for those transplanted with at least one major ABO incompatibility (HR:1.16; p=0.029). In MVA for DFS, positive CMV serology, advanced disease, use of ATG and ABO incompatibility (HR:1.46;p=0.004) were associated with decreased DFS.This analysis suggests that a dose at collection of TNC ≥ 4.9x107/kg and/or of CD34 ≥ 1.9x105/kg, as well as better ABO and HLA compatibility are important factors that should be included in the selection algorithm for CBUs in DUCBT. DisclosuresNo relevant conflicts of interest to declare.