Letermovir prophylaxis reduced cytomegalovirus reactivation and resistance post umbilical cord blood transplantation.

To explore the impact of letermovir (LET) prophylaxis on cytomegalovirus (CMV) reactivation and resistance in both adult and paediatric umbilical cord blood transplantation (UCBT) patients, we retrospectively compared 43 UCBT patients who received LET as CMV prophylaxis with a historical cohort of 207 UCBT patients without LET usage. LET was administered from Day +1 to Day +100. The 180-day cumulative incidence of CMV reactivation (47.3% vs. 74.4%, p < 0.001) and the proportion of refractory CMV reactivation (15.0% vs. 42.9%, p = 0.016) were significantly lower than those in the control group. However, more frequent late CMV infection (31.0% vs. 4.3%, p = 0.002) and the 180-day cumulative incidence of Epstein-Barr virus (EBV) reactivation (9.3% vs. 3.4%, p = 0.087) were observed in UCBT patients with LET prophylaxis. Meanwhile, older age (>15 years old) and the occurrence of pre-engraftment syndrome were identified as the significant risk factors for CMV reactivation, and in patients at high risk, the incidence of CMV reactivation in the LET group was lower than that in the control group (46.7% vs. 86.5%, p < 0.001), while this decline was less pronounced among patients at low risk (47.8% vs. 62.1%, p = 0.120).

Nipping cytomegalovirus in the bud for umbilical cord blood transplantation.

Real data confirm an excellent toxicity profile and effectiveness of letermovir prophylaxis with decreased cytomegalovirus reactivation and resistance in umbilical cord blood transplantation for both paediatric and adult patients. Commentary on: Yan et al. Letermovir prophylaxis reduced cytomegalovirus reactivation and resistance post umbilical cord blood transplantation. Br J Haematol 2024;204:2378-2389.

Outcome of first or second transplantation using unrelated umbilical cord blood without ATG conditioning regimen for pediatric bone marrow failure disorders.

BACKGROUND: Unrelated umbilical cord blood transplantation (UCBT) for bone marrow failure (BMF) disorders using conditioning regimens without Anti-Thymocyte Globulin (ATG) has been used as an alternative transplantation for emerging patients without matched-sibling donors. Experience with this transplant modality in children is limited, especially as a secondary treatment for transplant failure patients. PROCEDURE: We retrospectively reviewed 17 consecutive bone marrow failure patients who underwent unrelated umbilical cord blood transplantation in our center and received conditioning regimens of Total Body Irradiation (TBI) or Busulfan (BU) + Fludarabine (FLU) + Cyclophosphamide (CY). RESULTS: Among the 17 BMF patients, 15 patients were treated with first cord blood transplantation and another 2 with secondary cord blood transplantation because of graft failure after first haploidentical stem cell transplantation at days +38 and +82. All patients engrafted with a median donor cell chimerism of 50 % at days +7 (range, 16 %-99.95 %) and finally rose to 100 % at days +30. Median time to neutrophil engraftment was 19 days (range, 12-30) and time to platelet engraftment was 32 days (range, 18-61). Pre-engraftment syndrome (PES) was found in 16 patients (94.11 %, 16/17). Cumulative incidence of grades II to IV acute GVHD was 58.8 % (95 % CI: 32.7-84.9 %), and 17.6 % (95 % CI: 2.6-37.9 %) of patients developed chronic GVHD. The 3-year overall survival (OS) and failure-free survival (FFS) rates were 92.86 ± 6.88 %. CONCLUSION: UCBT is an effective alternative treatment for bone marrow failure pediatric patients. TBI/BU + FLU + CY regimen ensure a high engraftment rate for unrelated umbilical cord blood transplantation, which overcomes the difficulty of graft failure. Secondary salvage use of cord blood transplantation may still be useful for patients who have failed after other transplantation.

Nomogram for Predicting Early Mortality after Umbilical Cord Blood Transplantation in Children with Inborn Errors of Immunity.

PURPOSE: Pediatric patients with inborn errors of immunity (IEI) undergoing umbilical cord blood transplantation (UCBT) are at risk of early mortality. Our aim was to develop and validate a prediction model for early mortality after UCBT in pediatric IEI patients based on pretransplant factors. METHODS: Data from 230 pediatric IEI patients who received their first UCBT between 2014 and 2021 at a single center were analyzed retrospectively. Data from 2014-2019 and 2020-2021 were used as training and validation sets, respectively. The primary outcome of interest was early mortality. Machine learning algorithms were used to identify risk factors associated with early mortality and to build predictive models. The model with the best performance was visualized using a nomogram. Discriminative ability was measured using the area under the curve (AUC) and decision curve analysis. RESULTS: Fifty days was determined as the cutoff for distinguishing early mortality in pediatric IEI patients undergoing UCBT. Of the 230 patients, 43 (18.7%) suffered early mortality. Multivariate logistic regression with pretransplant albumin, CD4 (absolute count), elevated C-reactive protein, and medical history of sepsis showed good discriminant AUC values of 0.7385 (95% CI, 0.5824-0.8945) and 0.827 (95% CI, 0.7409-0.9132) in predicting early mortality in the validation and training sets, respectively. The sensitivity and specificity were 0.5385 and 0.8154 for validation and 0.7667 and 0.7705 for training, respectively. The final model yielded net benefits across a reasonable range of risk thresholds. CONCLUSION: The developed nomogram can predict early mortality in pediatric IEI patients undergoing UCBT.

Adverse events caused by cord blood infusion in Japan during a 5-year period.

BACKGROUND AND OBJECTIVES: In Japan, cord blood is used for more than half of all unrelated stem cell transplantations. The public cord blood banks (CBBs) have been collecting information on cord blood transplantation-related adverse events from physicians on a voluntary basis, without common definitions of the adverse reactions. The aims of this study were to compare two classification systems to improve the reporting system and to clarify the actual risk from cord blood infusion, which can then provide the impetus to take appropriate measures to reduce adverse events. MATERIALS AND METHODS: We classified the reports according to existing criteria; one is the Proposed Standard Definitions for Surveillance of Non-Infectious Adverse Transfusion Reactions by the International Society of Blood Transfusion (ISBT) Working Party on Haemovigilance, and the other is the Common Terminology Criteria for Adverse Events (CTCAE). There were 140 cases with adverse events reported from April 2014 through March 2019. RESULTS: Twelve cases, such as donor-derived leukaemia/myelodysplastic syndromes (MDS) and chromosomal aberrations reported after engraftment, were excluded from this analysis. Of the 128 cases with adverse events at cord blood infusion, the CTCAE and ISBT criteria could not classify 6 cases and 68 cases, respectively. Classifying by the CTCAE, the most common side effect was hypertension in 35 cases, followed by anaphylaxis, allergic reactions, nausea, urticaria, etc. Serious adverse events (grades 4 and 5) were mainly anaphylaxis, with a frequency of 0.23%. CONCLUSION: It is necessary not only to provide information on adverse events but also to standardize the reporting of adverse events to support measures to reduce them.

Umbilical Cord Blood Transplantation for Myelodysplastic Syndromes with Donor-Specific Anti-HLA Antibodies against HLA-DP.

The presence of donor-specific anti-human leukocyte antigen (HLA) antibodies (DSAs) against anti-HLA-A, -B, -C, and -DRB1 in HLA-mismatched hematopoietic stem cell transplantation (HSCT) is associated with graft failure. DSAs against HLA-A, -B, -C, and -DRB1 with a mean fluorescence intensity (MFI) of greater than > 1,000 was shown to increase the risk of graft failure in single-unit umbilical cord blood transplantation (UCBT). Nevertheless, the impact of DSAs against HLA-DP or -DQ on transplantation outcomes is not fully understood. In this report, we present a case of UCBT in a patient with myelodysplastic syndrome who was positive for DSAs against HLA-DP with MFI of 1,263 before UCBT but successfully achieved neutrophil engraftment. If HLA-DP or -DQ is mismatched in UCBT, evaluating DSAs against HLA-DP or -DQ is crucial to avoid graft failure. However, the criteria for DSAs against HLA-A, -B, -C, and -DRB1 may not be directly applicable to those against HLA-DP or -DQ.

Hematopoietic Cell Transplantation for Inborn Errors of Immunity Other than Severe Combined Immunodeficiency in Japan: Retrospective Analysis for 1985-2016.

PURPOSE: Hematopoietic cell transplantation (HCT) is a curative therapy for most patients with inborn errors of immunity (IEI). We conducted a nationwide study on HCT for patients with IEI other than severe combined immunodeficiency (non-SCID) in Japan. METHODS: Data from the Japanese national database (Transplant Registry Unified Management Program, TRUMP) for 566 patients with non-SCID IEI, who underwent their first HCT between 1985 and 2016, were retrospectively analyzed. RESULTS: The 10-year overall survival (OS) and event-free survival (EFS) were 74% and 64%, respectively. The 10-year OS for HCT from unrelated bone marrow (URBM), accounting for 39% of HCTs, was comparable to that for HCT from matched sibling donor (MSD), 79% and 81%, respectively. HCT from unrelated cord blood (URCB), accounting for 28% of HCTs, was also common, with a 10-year OS of 69% but less robust engraftment. The intensity of conditioning was not associated with OS or neutrophil recovery; however, myeloablative conditioning was more frequently associated with infection-related death. Patients who received myeloablative irradiation showed poor OS. Multivariate analyses revealed that HCT in 1985-1995 (hazard ratio [HR], 2.0; P = 0.03), URCB (HR, 2.0; P = 0.01), and related donor other than MSD (ORD) (HR, 2.9; P < 0.001) were associated with poor OS, and URCB (HR, 3.6; P < 0.001) and ORD (HR, 2.7; P = 0.02) showed a higher incidence of retransplantation. CONCLUSIONS: We present the 1985-2016 status of HCT for non-SCID IEI in Japan with sufficient statistical power, highlighting the potential of URBM as an alternative donor and the feasibility of reduced intensity conditioning.

Impact of posttransplant cyclophosphamide on the outcome of patients undergoing unrelated single-unit umbilical cord blood transplantation for pediatric acute leukemia.

BACKGROUND: Umbilical cord blood transplantation (UCBT) from unrelated donors is one of the successful treatments for acute leukemia in childhood. The most frequent side effect of UCBT is peri-engraftment syndrome (PES), which is directly associated with the greater prevalence of acute and chronic graft-versus-host-disease (aGvHD and cGvHD). In haploidentical stem cell transplantation, posttransplant cyclophosphamide (PTCY) has been demonstrated to be an effective method against GvHD. However, the effects of PTCY as a GvHD prophylactic in UCBT had not been investigated. This study aimed to evaluate the effects of PTCY on the outcomes of UCBT for pediatric acute leukemia. METHODS: This retrospective study included 52 children with acute leukemia who underwent unrelated single-unit UCBT after myeloablative conditioning regimens. The results from the PTCY and non-PTCY groups were compared. RESULTS: The incidence of transplantation-related mortality in non-PTCY and PTCY were 5% and 10% (p = 0.525), respectively. The incidence of relapse in non-PTCY and PTCY were 5% and 23% (p = 0.095), respectively. Second complete remission status (CR2) was an independent risk factor for relapse-free survival (hazard ratio = 9.782, p = 0.001). The odds ratio for sepsis or bacteremia incidence was significantly greater in the PTCY group (9.524, p = 0.017). PTCY group had increased rates of cytomegalovirus activity and fungal infection. The incidence of PES, aGvHD, cGvHD, and hemorrhagic cystitis in the PTCY group was lower than that in the non-PTCY group, although it was not significantly different. Additionally, higher doses of PTCY (29 mg/kg and 40 mg/kg) were associated with lower incidences of aGvHD and severe GvHD (65% and 29%, respectively) than lower doses (93% and 57%, respectively). Engraftment time and graft failure incidence were similar across groups. CONCLUSION: The results support the safety and efficiency of PTCY as part of PES controlling and GvHD prophylaxis in single-unit UCBT for children with acute leukemia. A PTCY dosage of 29 mg/kg to 40 mg/kg appears to be more effective in GvHD prophylaxis for UCBT patients.

Poor survival and prediction of prolonged isolated thrombocytopenia post umbilical cord blood transplantation in patients with hematological malignancies.

Prolonged isolated thrombocytopenia (PIT) is a common complication after umbilical cord blood transplantation (UCBT). However, data on PIT prediction and impacts on transplantation outcomes for UCBT patients are rare. We retrospectively analyzed 244 patients with hematological malignancies who received single-unit UCBT at the First Affiliated Hospital of USTC between August 2018 and December 2019. Among them, PIT occurred in 49 recipients, with a crude incidence of 20.1%. In the PIT patients, the 2-year cumulative incidence of transplant-related mortality (TRM) was significantly higher, and the probabilities of 2-year overall survival, leukemia-free survival and graft-versus-host disease (GVHD)-free relapse-free survival were significantly poorer (57.1% vs. 88.6%; 53.1% vs. 81.9%; 22.4% vs. 59.8%; p < 0.001), without remarkable increases in the cumulative incidence of relapse or chronic GVHD. Importantly, the multivariate analysis revealed that lower high-resolution HLA compatibility (≤6/10), lower infused CD34+ cell count (≤1.78 × 105 /kg), grade II-IV acute GVHD preplatelet engraftment, a lower pretransplantation platelet count (≤100 × 109 /L), and a longer neutrophil engraftment time (≥17 days) were independent risk factors for PIT after UCBT. These results demonstrate that PIT is common after UCBT, predicting inferior survival and the need for more monitoring during the early phase.

Sequential infection of Epstein-Barr virus and cryptococcal encephalitis after umbilical cord blood transplantation in a child with X-linked adrenoleukodystrophy.

Dual infection with two pathogens can be found in few cases of encephalitis. Cases of sequential infection with EBV and cryptococcal encephalitis in post-transplant patients are rare. We describe a 5-year-old boy with X-linked adrenoleukodystrophy who presented sequential infection with EBV and cryptococcal encephalitis after umbilical cord blood transplant. The patient showed fever, vomiting and emotional agitation with EBV DNA detected in CSF on day 100. The child underwent 3 doses of intravenous rituximab with a good response. However, the child presented with right facial paralysis, headache, and fever on day 130 after 2 weeks of clinical stability. Brain MRI demonstrated chronic granuloma formed with ring enhancement. FilmArray ME PCR confirmed the existence of Cryptococcus neoformans/gattii in the CSF. The child underwent sequential treatment with amphotericin liposome B and flucytosine. Maintenance treatment with fluconazole was administered for 1 year. Facial paralysis was on longer present on day 260. Cryptococcus neoformans/gattii was not detected on day 310. The biochemistry and cell count of the CSF were completely normal on day 520. Follow-up 2.5 years after presentation, brain MRI changes showed near complete resolution of the lesions. The child survived for 3 years to the last following-up. Invasive cryptococcal encephalitis is rare and life-threatening complication of transplantation. It is important to recognize dual infections, and perform treatment quickly to improve the prognosis of encephalitis after transplantation.

Population pharmacokinetics of tacrolimus in umbilical cord blood transplant patients focusing on the variation in red blood cell counts.

WHAT IS KNOWN AND OBJECTIVE: The distribution of tacrolimus (TAC), an immunosuppressant used during cord blood transplantation (CBT)-one of the haematopoietic stem cell transplantations, to red blood cell (RBC) is approximately 90% in whole blood. In CBT patients, the total RBC count shows dramatic fluctuation due to conditioning before transplantation, including anticancer agents and total body irradiation, as well as RBC transfusions during the treatment period. Therefore, the amount of TAC in whole blood may show wide variation. However, therapeutic drug monitoring (TDM) of TAC has been performed based on the whole blood concentration. In this study, to contribute to TDM of TAC in CBT, we performed the population pharmacokinetic (PPK) analysis of TAC in 56 CBT patients and investigated the factors that affected the concentration of TAC, focusing the variation of RBC count. METHOD: A one-compartment model was applied to the observed whole blood TAC concentrations, and a PPK analysis was conducted with a non-linear mixed effect model. RESULTS AND DISCUSSION: Our final PPK model indicated good robustness and accuracy. In addition, haemoglobin (Hb) level was an influential covariate on Vd, which was expressed as Vd(L) = 91.4 × (Hb/8.2)(-1.07) . WHAT IS NEW AND CONCLUSION: In this study, our results showed the necessity for the Hb level monitoring during TDM of TAC in CBT patients and provided useful information for improving TDM strategy of TAC.

Updated Comparison of 7/8 HLA Allele-Matched Unrelated Bone Marrow Transplantation and Single-Unit Umbilical Cord Blood Transplantation as Alternative Donors in Adults with Acute Leukemia.

The outcomes of 7/8 allele-matched unrelated bone marrow transplantation (7/8 UBMT) and umbilical cord blood transplantation (UCBT) have been improving. We retrospectively analyzed adults with acute leukemia who underwent their first 7/8 UBMT or UCBT in Japan. Between January 2008 and December 2017, a total of 4150 patients were recorded, including 488 who underwent 7/8 UBMT and 3662 who underwent UCBT. Only 32 patients with 7/8 UBMT had graft-versus-host-disease (GVHD) high-risk HLA mismatched pairs. Overall survival at 3 years was 54% for 7/8 the UBMT group and 46% for the UCBT group, a nonsignificant difference in multivariate analysis (hazard ratio [HR], 1.01; 95% confidence interval [CI], .88 to 1.17; P = .89). The 7/8 UBMT and UCBT groups showed a similar nonrelapse mortality rate (HR, 1.16; 95% CI, .96 to 1.45; P = .16) and relapse rate (HR, .85; 95% CI, .71 to 1.02; P = .08). However, the UCBT group had a lower risk of grade II-IV acute GVHD (HR, .76; 95% CI, .65 to .88; P < .001) and chronic GVHD (HR, .77; 95% CI, .66- .91; P = .002) compared with the 7/8 UBMT group. In stratified analyses combining disease risk with conditioning intensity, 7/8 UBMT showed superior overall survival to UCBT in standard risk and myeloablative conditioning (HR, .72; 95% CI, .56 to .93; P = .014). Both 7/8 UBMT and UCBT are appropriate alternative donor procedures. The stem cell source can be selected on the basis of disease risk, patient tolerability, or concerns regarding GVHD.

Comparative Study of Tacrolimus and Short-Term Methotrexate: 2-Day versus 3-Day Methotrexate as Graft-versus-Host-Disease Prophylaxis after Umbilical Cord Blood Transplantation in Adults.

Methotrexate (MTX) in combination with a calcineurin inhibitor has been commonly used for prophylaxis of graft-versus-host disease (GVHD) following umbilical cord blood transplantation (UCBT) in Japan. However, the appropriate prophylactic MTX dosage in UCBT has not been established to date. To determine the preferential GVHD prophylaxis in UCBT, this study retrospectively investigated the administration of short-term MTX for 2 days versus 3 days. Of 103 adult patients submitted to UCBT enrolled in the study, 73 received tacrolimus (TAC) with 2 days of MTX given at 10 mg/m2 on day 1 and 7 mg/m2 on day 3 (very short-term [vs] MTX), whereas 30 patients received TAC with 3 days of MTX given at 10 mg/m2 on day 1, 7 mg/m2 on day 3, and 7 mg/m2 on day 6 (short-term [s] MTX). In univariate analysis, neutrophil engraftment was shown to be significantly better (P = .039) in the vsMTX/TAC group. Among high-risk patients, the vsMTX/TAC group also exhibited earlier neutrophil engraftment (P = .042); however, the incidence of acute GVHD was higher in the vsMTX/TAC group (P = .035) on univariate analysis. In multivariate analysis, compared with sMTX/TAC, vsMTX/TAC was associated with lower risk of relapse (hazard ratio, .27; 95% confidence interval, .11 to .64; P = .003) . These results suggest that vsMTX/TAC can be appropriate GVHD prophylaxis after UCBT, especially in higher-risk patients.

Time-Varying Effects of Graft Type on Outcomes for Patients with Acute Myeloid Leukemia Undergoing Allogeneic Hematopoietic Cell Transplantation.

This study aimed to investigate time-varying effects of graft type on outcomes for patients with acute myeloid leukemia undergoing allogeneic hematopoietic cell transplant. For this purpose we analyzed 3952 patients, 720 of whom underwent matched related bone marrow transplantation (BMT), 1004 matched related peripheral blood stem cell transplantation (PBSCT), 856 matched unrelated BMT, and 1372 umbilical cord blood transplantation (UCBT) during complete remission. The 4-year relapse-free survival (RFS) rates were 59.1%, 52.8%, 59.5%, and 50.6%, respectively. Compared with related BMT, related PBSCT, unrelated BMT, and UCBT were associated with higher risk of nonrelapse mortality and unrelated BMT and UCBT with lower risk of relapse. As a result, both RFS and overall survival were comparable between related BMT and unrelated BMT but were worse for related PBSCT and UCBT than for related BMT. Adverse impact of UCBT was observed only during the early phase of transplant, whereas that of related PBSCT continued even after 2 years post-transplant. Our findings raise concerns about the increased risk of late nonrelapse mortality with the use of PBSC grafts and suggest that related BMT is preferable to related PBSCT; matched unrelated BMT is the next choice in the absence of a matched related donor.

Prospective Randomized Study Comparing Myeloablative Unrelated Umbilical Cord Blood Transplantation versus HLA-Haploidentical Related Stem Cell Transplantation for Adults with Hematologic Malignancies.

In this prospective randomized study, we compared the outcomes of single-unit umbilical cord blood transplantation (UCBT) and unmanipulated haploidentical stem cell transplantation (haplo-SCT) with post-transplantation cyclophosphamide (PTCy) in adults with hematologic malignancies. All patients received a myeloablative conditioning (MAC) regimen consisting of thiotepa, busulfan, and fludarabine, with antithymocyte globulin (ATG) added for UCBT recipients. Nineteen patients were randomized to UCBT and the other 26 to haplo-HSCT. Four patients (15%) allocated to the haplo-HSCT arm lacked a suitable donor and were crossed over to the UCBT arm. Finally, 23 underwent UCBT and 22 underwent haplo-HSCT. The cumulative incidence of neutrophil recovery was 87% at a median of 19 days (range, 13 to 24 days) in the UCBT arm versus 100% at a median of 17 days (range, 13 to 25 days) in the haplo-SCT arm (P = .04). Platelet recovery was 70% at a median of 40 days (range, 18 to 129 days) in the UCBT arm versus 86% at a median of 24 days (range, 12 to 127 days) in the haplo-HCT arm (P = .02). Rates of acute graft-versus-host disease (GVHD) grade II-IV or grade III-IV, overall chronic GVHD, and extensive chronic GVHD in the UCBT and Haplo-SCT arms were 43% versus 36% (P = .8), 9% versus 9% (P = 1), 66% versus 43% (P = .04), and 41% versus 23% (P = .2), respectively. Two-year nonrelapse mortality and relapse in the 2 arms were 52% versus 23% (P = .06) and 17% versus 23% (P = .5), respectively. Two-year disease-free survival, overall survival, and GVHD/relapse-free survival in the 2 arms were 30% versus 54% (P = .2), 35% versus 59% (P = .1), and 17% versus 40% (P = .04), respectively. Our data show that in the context of an MAC regimen, haplo-SCT with PTCy provides improved outcomes compared with ATG-containing single-unit UCBT.

Rapid reconstitution of regulatory T-cell subsets is associated with reduced rates of acute graft-versus-host disease and absence of viremia after cord blood transplantation in children with reduced-intensity conditioning using alemtuzumab.

Forkhead box P3 (FOXP3)+ regulatory T cell (Treg) reconstitution after unrelated donor umbilical cord blood transplantation in chemotherapy-naïve children is incompletely characterized. We studied 21 children with nonmalignant diseases receiving an identical alemtuzumab-containing regimen. We hypothesized that Treg recovery may be perturbed in patients not only by acute graft-versus-host disease (aGVHD) but also by viremia. Tregs and their memory and naïve subsets were serially monitored for proliferation and apoptosis along with conventional T cells (Tcon). A "reconstitution index" (RI) was calculated relative to pretransplantation values for each parameter. At 3 months post-UCBT, the RI of Tregs was faster compared with other immune components tested and was most rapid in patients free of aGVHD and viremia. There were significantly fewer Tregs in patients experiencing grade I-II aGVHD and/or viremia, leading to an imbalance between Tregs-Tcon ratios. Central and effector memory Tregs were most affected at this time point when they dominated in the circulation. Impaired Treg proliferation without increased apoptosis accounted for the reduced Treg-Tcon ratio. In patients affected with grade II aGVHD and viremia, the overall reduction in circulating Treg pool were associated with a more oligoclonal T-cell receptor ß repertoire. Taken together, aGVHD and viremia can lead to defective Treg expansion homeostasis.

Reduced dose of MTX for GVHD prophylaxis promotes engraftment and decreases non-relapse mortality in umbilical cord blood transplantation.

Although a combination of calcineurin inhibitor and methotrexate (MTX) is used for graft-versus-host disease (GVHD) prophylaxis in umbilical cord blood transplantation (CBT), optimal dose of MTX for CBT remains to be determined.We conducted a retrospective study to evaluate the safety and efficacy of standard-dose MTX (St-MTX, 15 mg/m2 on day 1 and 10 mg/m2 on days 3 and 6) and mini-dose MTX (Mini-MTX, 5 mg/m2 on days 1, 3 and 6) for GVHD prophylaxis in patients who underwent single unit CBT against hematological malignancies.Thirty-two and 26 patients received St-MTX and Mini-MTX, respectively. Cumulative incidence of neutrophil engraftment was significantly higher in the Mini-MTX group than in the St-MTX group (88.5% vs 65.6%, P = 0.00448). Cumulative incidences of grade II to IV and grade III to IV of acute graft-versus-host disease (GVHD) were 34.4% and 6.2% in the St-MTX group, and 34.6% and 7.7% in the Mini-MTX group with no statistical significance. One-year non-relapse mortality (NRM) was significantly lower in the Mini-MTX group compared to the St-MTX group (31.2% vs 3.8%, P = 0.00938), whereas relapse rate was not different between the groups. Multivariate analysis also indicated that Mini-MTX significantly improved engraftment (HR, 0.5359; 95% CI, 0.3082 to 0.9318; P = 0.0270) and reduced NRM (HR, 0.117; 95% CI, 0.0151 to 0.9067; P = 0.040).Our study suggests that GVHD prophylaxis using Mini-MTX in CBT is feasible and associated with improvement of engraftment and reduction in NRM.

Role of antithymocyte globulin in patients with hematologic diseases undergoing umbilical cord blood transplantation: A systematic review and meta-analysis.

The role of antithymocyte globulin (ATG) in patients with hematologic diseases undergoing umbilical cord blood transplantation (UCBT) remains controversial. This systematic review and meta-analysis was conducted to comprehensively evaluate this issue. PubMed, Embase, and the Cochrane Library were systematically searched. Clinical studies reporting the impact of ATG- vs non-ATG-containing conditioning regimens on transplantation outcomes were identified. Twenty-five studies were included. ATG significantly prevented grade II-IV and grade III-IV acute graft-vs-host disease (GVHD) (11 studies, 5020 patients, HR: 0.49, 95% CI: 0.42-0.56, P < .001; 5 studies, 5490 patients, HR: 0.60, 95% CI: 0.46-0.80, P < .001) but not chronic GVHD (8 studies, 5952 patients, HR: 0.78, 95% CI: 0.51-1.20, P = .266). However, use of ATG was associated with increased transplantation-related mortality and inferior overall survival (9 studies, 4244 patients, HR: 1.79, 95% CI: 1.38-2.33, P < .001; 8 studies, 5438 patients, HR: 1.96, 95% CI: 1.56-2.46, P < .001). Our study did not recommend routine use of ATG in UCBT. Individualizing the ATG timing and dose based on patient characteristics to retain the prophylactic effects of ATG on GVHD without compromising the survival of UCBT recipients may be reasonable.

Reduction in Mortality after Umbilical Cord Blood Transplantation in Children Over a 20-Year Period (1995-2014).

Infections and graft-versus-host disease (GVHD) have historically resulted in high mortality among children undergoing umbilical cord blood transplantation (UCBT). However, recent advances in clinical practice have likely improved outcomes of these patients. We conducted a retrospective cohort study of children (<18years of age) undergoing UCBT at Duke University between January 1, 1995 and December 31, 2014. We compared 2-year all-cause and cause-specific mortality during 3 time periods based on year of transplantation (1995 to 2001, 2002 to 2007, and 2008 to 2014). We used multivariable Cox regression to identify demographic and UCBT characteristics that were associated with all-cause mortality, transplantation-related mortality, and death from invasive aspergillosis after adjustment for time period. During the 20-year study period 824 children underwent UCBT. Two-year all-cause mortality declined from 48% in 1995 to 2001 to 30% in 2008 to 2014 (P = .0002). White race and nonmalignant UCBT indications were associated with lower mortality. Black children tended to have a higher risk of death for which GVHD (18% versus 11%; P = .06) or graft failure (9% versus 3%; P = .01) were contributory than white children. Comparing 2008 to 2014 with 1995 to 2001, more than half (59%) of the reduced mortality was attributable to a reduction in infectious mortality, with 45% specifically related to reduced mortality from invasive aspergillosis. Antifungal prophylaxis with voriconazole was associated with lower mortality from invasive aspergillosis than low-dose amphotericin B lipid complex (hazard ratio, .09; 95% confidence interval, .01 to .76). With the decline in mortality from invasive aspergillosis, adenovirus and cytomegalovirus have become the most frequentinfectious causes of death in children after UCBT. Advances in clinical practice over the past 20years improved survival of children after UCBT. Reduced mortality from infections, particularly invasive aspergillosis, accounted for the largest improvement in survival and was associated with use of voriconazole for antifungal prophylaxis.

Umbilical Cord Blood Transplantation Using Reduced-Intensity Conditioning without Antithymocyte Globulin in Adult Patients with Severe Aplastic Anemia.

Umbilical cord blood transplantation (UCBT) is a possible option for patients with aplastic anemia (AA) without a related or unrelated HLA-matched donor, particularly if immunosuppressive therapy (IST) has failed or transplantation is urgently needed. However, a higher rate of graft failure after UCBT remains a major problem, and the optimal conditioning regimen for stable engraftment after UCBT has not been established. Here we investigated 6 adult patients with AA who underwent UCBT using a reduced-intensity conditioning (RIC) regimen comprising fludarabine 125 mg/m2, cyclophosphamide 120 mg/kg, and 4 Gy of total body irradiation (Flu/CY/TBI4Gy) without antithymocyte globulin (ATG). Five patients underwent UCBT after IST failure, and 1 patient underwent UCBT as a first-line treatment due to a fulminant clinical finding of a neutrophil count of 0, despite granulocyte colony-stimulating factor administration. Regarding graft-versus-host disease (GVHD) prophylaxis, 2 patients received tacrolimus plus short-term methotrexate and 4 patients received tacrolimus plus mycophenolate mofetil, and all patients achieved sustained engraftment of both neutrophils and platelets, at a median of 17.5 days (range, 14 to 37 days) and 38.5 days (range, 31 to 86 days), respectively, with complete donor chimerism confirmed in all patients at a median of 14 days (range, 14 to 32 days). Three patients developed grade II acute GVHD (aGVHD), but grade III/IV aGVHD was not observed, whereas 4 patients developed chronic GVHD involving only skin. At the time of this report, all 6 patients were alive without the need for blood transfusion, at a median follow-up of 16 months (range, 12 to 131 months). Although further study is needed, our findings suggest that conditioning with Flu/CY/TBI4Gy without ATG might allow stable engraftment in UCBT for adults with AA.