神田 善伸

This 3+3 dose-escalation phase I multicenter study investigated the optimal dose of azacitidine (AZA) for post-hematopoietic stem cell transplantation (HSCT) maintenance, which remains unknown in Japan. Recipients of a first HSCT for high-risk myelodysplastic syndromes (MDS, n = 12) or acute myeloid leukemia (AML) with antecedent MDS (n = 3) received post-HSCT AZA maintenance in 2015-2019. The optimal AZA dose was defined as the dose at which 50-70% of patients can complete four cycles without dose-limiting toxicity (DLT). The initial dose level 1 was set as 30 mg/m2 for 5 days per 28-day cycle, and dose levels 0, 2, and 3 were set as 20, 40, and 50 mg/m2. DLT was defined as any grade 3 non-hematological or grade 4 hematological toxicity. The 15 evaluable patients were 55 (37-64) years old. The median observation of the post-HSCT survivors was 935 (493-1915) days. The median number of days post-HSCT to the start of AZA was 101 (59-176). In the first, second, and third cohorts, five of nine patients completed four cycles at dose level 1. In the final cohort, five of six additional patients completed at the same dose. In total, 10 (67%) patients tolerated AZA 30 mg/m2, which was determined as optimal. DLT occurred in five cases: grade 3 hepatotoxicity, pneumonia, enterocolitis, and grade 4 thrombocytopenia and neutropenia. The 2-year overall survival and disease-free survival rates post-HSCT were 77.0% and 73.3%. Post-HSCT AZA maintenance was well-tolerated and merits further evaluation for patients with MDS or AML with antecedent MDS. Trial registration: UMIN000018791.

We analyzed a Japanese registry database to elucidate the incidence, risk factors, and outcomes of adenovirus (AdV) disease after autologous and allogeneic hematopoietic cell transplantation (HCT) in contemporary real-world patients. We evaluated the cumulative incidence of AdV disease, as well as risk factors and survival and treatment details, among 25233 patients who underwent autologous HCT and 48380 patients who underwent allogeneic HCT between 2005 and 2019. The 1-year cumulative incidences of AdV disease after autologous and allogeneic HCT were 0.18% and 1.52%, respectively, in children, and 0.49% and 2.99%, respectively, in adults. Among patients with AdV disease, renourinary infection was the most common manifestation, and viremia or disseminated disease occurred in 6% of those after autologous HCT and 19% of those after allogeneic HCT. In multivariate analysis, age ≥50 years and lymphoma were associated with AdV disease after autologous HCT, while patient age ≥50 years, male patients, lymphoma, HCT-specific comorbidity index ≥3, HLA-mismatched or haploidentical donors, cord blood, in vivo T-cell depletion, HCT from 2005-2009, acute graft-versus-host disease (GVHD), and chronic GVHD were associated with AdV disease after allogeneic HCT. The 1-year probabilities of survival after disease diagnosis were 65% in autologous HCT and 44% in allogeneic HCT. Regardless of AdV disease burden, there was an increased risk of mortality after both autologous and allogeneic HCT. The most commonly used antiviral agents were cidofovir and vidarabine. The probabilities of improvement and survival with currently available agents were suboptimal. AdV disease after HCT remains a challenge. Better antiviral modalities are necessary. This article is protected by copyright. All rights reserved.

In general, the recipient's ABO blood type changes to the donor's ABO blood type after ABO-incompatible allogeneic hematopoietic stem cell transplantation (HSCT). However, we experienced a 26-year-old male with acute myelogenous leukemia (AML) who underwent ABO-incompatible HSCT twice and persistently showed his original blood type even after demonstrating complete donor-type chimerism. Based on the results of various examinations, we considered that the antigen of the recipient's original blood type persistently synthesized in the recipient's non-hematopoietic organs was secreted and adsorbed on the surface of donor-derived RBCs. We should therefore perform detailed examinations to determine the precise blood type after ABO-incompatible HSCT.

Anti-melanoma differentiation-associated gene 5 (MDA5) antibody is one of auto-immune antibodies which is associated with a rare subtype of dermatomyositis (DM), and MDA5-DM is well-characterized by rapid progressive interstitial lung disease (ILD) which in part resembles pulmonary complications after allogeneic hematopoietic cell transplantation (allo-HCT). However, previous studies about anti-MDA5 antibody after allo-HCT were extremely limited. Here, we present 4 cases of ILD with anti-MDA5 antibody after allo-HCT. All of the cases showed rapidly progressive clinical course and 3 of 4 cases died despite intensive immunosuppressive therapies which included prednisolone, cyclophosphamide and calcineurin inhibitor. Additionally, 3 of 4 cases had tested positive for anti-MDA5 antibody by using cryopreserved plasma which were collected about 2-3 months before the diagnosis of MDA5-DM-ILD. It suggests that an inflammatory condition due to MDA5-DM-ILD might have sub-clinically occurred before the development of respiratory failure. The current cases suggest that the clinical feature was relatively similar to classical MDA5-DM-ILD, although it is difficult to distinguish MDA5-DM-ILD from chronic GVHD and other pulmonary complications after allo-HCT. Since clinical courses of MDA5-DM-ILD is considerably aggressive, it is important to discriminate MDA5-DM-ILD from other complications after allo-HCT.

BACKGROUND: Pancreatic atrophy after allogeneic hematopoietic cell transplantation (HCT) is one of the symptoms associated with chronic graft-versus-host disease (GVHD). Although pancreatic atrophy has been considered to cause exocrine insufficiency and weight loss, it is not yet clear what kinds of recipients can be expected to recover their body weight (BW) or pancreatic thickness. In addition, the effect of pancreatic atrophy on the prognosis has not been clarified. METHODS: We retrospectively analyzed 170 recipients who received allogeneic bone marrow transplantation or peripheral blood stem cell transplantation, and evaluated them using the CT scan images obtained closest to 1, 2, 3, and 4 years after HCT. RESULTS: Fifty-five recipients (32.4%) demonstrated pancreatic atrophy, and 11 (20%) of them recovered their pancreatic thickness. While recipients without pancreatic atrophy gradually recovered their BW (P < 0.001), those with atrophy did not (P = 0.12). Moderate and severe chronic GVHD tended to be slightly more common in the atrophy group (47.3% vs 38.3%), whereas the pancreatic thickness tended to recover in these recipients (30.8% vs 10.3%). HCT from a female donor to a male recipient showed superior pancreatic recovery compared to other donor and recipient sex combinations. Pancreatic atrophy treated as a significantly associated with inferior survival (HR 4.91, P < 0.001) and an increased risk of non-relapse mortality (HR 8.75, P < 0.001). CONCLUSIONS: These results suggest that it is important to monitor pancreatic thickness after HCT. Further prospective investigations are warranted to clarify the significance of pancreatic atrophy on clinical outcomes.

TEMPI syndrome is a rare disease associated with plasma cell neoplasms. Although previous studies have reported that bortezomib is effective as a 1st-line treatment for TEMPI syndrome, some cases are refractory to this treatment. Pomalidomide, a kind of immunomodulatory drugs, is widely used for the treatment of relapsed or refractory multiple myeloma and could be administered without dose modification in patients with renal dysfunction. We present a case of bortezomib-refractory TEMPI syndrome with renal insufficiency that was successfully treated with a combination of pomalidomide and low-dose dexamethasone with minimal adverse effects, followed by autologous hematopoietic stem cell transplantation. To the best of our knowledge, this is the first case of TEMPI syndrome that was successfully treated with pomalidomide. Pomalidomide may be suitable for patients who do not respond to a proteasome inhibitor-based treatment. In addition, a subsequent ASCT could also be effective for achieving a further treatment response.

We compared the outcomes of autologous stem cell transplantation (auto-SCT) with those of allogeneic stem cell transplantation (allo-SCT) from a human leukocyte antigen-matched related donor in patients with Philadelphia chromosome-negative B-lineage acute lymphoblastic leukemia (ALL). Newly diagnosed patients who underwent allo-SCT (n = 486) or auto-SCT (n = 99) after achieving first complete remission (CR) were included. Propensity score matching (PS) and an inverse probability of the treatment weighting (IPTW) analysis were applied to compensate for imbalances in baseline characteristics. The 5 years rates of overall survival (OS) among those in the PS-matched cohorts were 57% [95% confidence interval (CI) 46-67%] for those who received allo-SCT and 44% (95% CI 33-54%) for those who received auto-SCT. Multivariable, propensity score-matched, and IPTW analyses all revealed no statistically significant differences in OS between the two groups [hazard ratios (HR) 0.81, 95% CI 0.53-1.27, p = 0.36; HR 0.84, 95% CI 0.40-1.78, p = 0.65; HR 0.71, 95% CI 0.25-2.02, p = 0.53, respectively]. Prospective trials that include autologous transplantation as a treatment option are needed to examine the potential of autologous transplantation.

Disease relapse is a major cause of treatment failure after allogeneic hematopoietic cell transplantation (HCT) and the mechanisms of relapse remain unclear. We encountered a 58-year-old man with chronic myelomonocytic leukemia (CMML) that relapsed after haploidentical HCT from his daughter. Peripheral blood samples collected at HCT and at relapse were analyzed, and CD14+/CD16- monocytes that typically accumulate in CMML were isolated by flow cytometry. Whole-exome sequencing of the monocytes revealed 8 common mutations in CMML at HCT. In addition, a PHF6 nonsense mutation not detected at HCT was detected at relapse. RNA sequencing could not detect changes in expression of HLA or immune-checkpoint molecules, which are important mechanisms of immune evasion. However, gene set enrichment analysis (GSEA) revealed that a TNF-α signaling pathway was downregulated at relapse. Ubiquitination of histone H2B at lysine residue 120 (H2BK120ub) at relapse was significantly decreased at the protein level, indicating that PHF6 loss might downregulate a TNF-α signaling pathway by reduction of H2BK120ub. This case illustrates that PHF6 loss contributes to a competitive advantage for the clone under stress conditions and leads to relapse after HCT.

Chromosome analysis is a powerful prognostic tool in myeloid malignancies. Recipients who experience relapse after allogeneic hematopoietic cell transplantation (allo-HCT) often show chromosomal changes between diagnosis and relapse. However, the clinical impact of chromosomal changes and the efficacy of post-relapse treatment according to chromosomal changes have not been fully investigated. We retrospectively analyzed 72 recipients who had experienced relapse after allo-HCT for acute myeloid leukemia or myelodysplastic syndrome. We categorized them into two groups: with or without clonal chromosomal changes at relapse after allo-HCT. Post-relapse survival was shorter in the clonal chromosomal change group (median 117 days vs 275 days, P = 0.019). Moreover, acquisition of chromosome 7 abnormality or complex changes tended to be associated with inferior survival in a univariate analysis (median 92 days vs median 173 days, P = 0.043), and this adverse impact was confirmed in a multivariate analysis (hazard ratio 2.07, P = 0.024). The patterns of chromosomal changes from diagnosis to relapse after allo-HCT were heterogenous, and further investigations are required to clarify the effect of individual chromosomal changes.

High-dose cytarabine (HD-AraC) or anthracycline-containing chemotherapies are used as post-remission therapy for acute myeloid leukemia (AML) patients. However, it remains unclear which regimen would be better as post-remission therapy before allogeneic hematopoietic stem cell transplantation (allo-HSCT). Thus, we compared the incidence of cardiac events and event-free survival (EFS) after allo-HSCT at two Japanese hospitals between HD-AraC and anthracycline-containing post-remission therapy to clarify the safety of post-remission therapy. Of a total of 132 patients, 68 received HD-AraC (HD-AraC group) and 64 received anthracycline-containing chemotherapy (ANT group). HD-AraC was preferentially selected for core-binding factor AML patients (p = 0.008). The median cumulative anthracycline dose was 115.2 mg/m2 in the HD-AraC group and 318.7 mg/m2 in the ANT group (p < 0.0001). Cardiac events were observed in 18 (13.6%) patients during the follow-up period. The 3-year cumulative incidence of cardiac events was 9.1% in the HD-AraC group and 11.0% in the ANT group (p = 0.70). EFS at 3 years after allo-HSCT was 40.9% in the HD-AraC group and 39.6% in the ANT group (p = 0.51). In conclusion, incidence of cardiac events did not differ significantly between post-remission therapy regimens in AML patients who underwent allo-HSCT.

Idiopathic pneumonia syndrome (IPS) is a fatal pulmonary complication after allogeneic hematopoietic stem cell transplantation (allo-HCT). However, it is often difficult to diagnose IPS, since a considerable number of IPS patients are critically ill, which makes it difficult for them to undergo bronchoscopy. In this study, we explored the risk factors of IPS based on two definitions. Definite IPS was diagnosed based on the results of bronchoscopy, whereas clinical IPS was diagnosed based on the clinical condition and bronchoscopy was not mandatory. Among 444 allo-HCT recipients at our center, 30 definite IPS and 54 clinical IPS were identified. In a multivariable analysis, a high ferritin level was associated with a higher incidence of definite IPS, whereas clinical IPS was frequently associated with older age, MAC, high ferritin level, low %DLCO and second allo-HCT due to graft failure. These risk factors may contribute to the accurate and early diagnosis of IPS.

Recent studies have reported that measurable residual disease (MRD) analysis using NPM1 mutations helps determine whether allogeneic hematopoietic stem cell transplantation (allo-HSCT) is indicated in acute myeloid leukemia (AML) patients. However, the optimal timing and cutoff value for measuring MRD using genomic DNA remain undetermined. This study aimed to investigate the optimal timing and cutoff value to ascertain the value of NPM1 mutation in MRD assessment. NPM1-mutated MRD was quantified by real-time polymerase chain reaction of bone marrow samples from 56 patients with NPM1-positive AML who achieved hematological remission. The area under the receiver-operating characteristic curve was greatest when MRD was assessed after two courses of post-remission therapy with a cutoff value of 0.010% (specificity, 68.4%; sensitivity, 87.0%). Patients whose MRD was below the cutoff value throughout the course of treatment had significantly better overall survival and relapse-free survival rates. Of the 33 patients who did not undergo transplantation during the first remission, all of the 11 who were never MRD-negative at any point experienced a relapse. Evaluating MRD with a cutoff value of 0.010% after two courses of post-remission therapy helps predict prognosis and determine the indication for allo-HSCT.

The graft-versus-leukemia (GVL) effect is one of the curative mechanisms of allogeneic hematopoietic stem cell transplantation (allo-HCT). H-Y antigens, which are encoded by Y chromosome, are important targets of the GVL effect. Thus, deletion of the Y chromosome (del[Y]) might cause the GVL effect to deteriorate in a transplantation involving a female donor and male recipient, although the clinical significance of the del(Y) group remains to be elucidated. In this study, we evaluated adult male patients who underwent allo-HCT between 2010 and 2019 in Japan. There were 155 cases in the del(Y) group and 4149 cases without del(Y) who underwent female-to-male allo-HCT. Del(Y) was significantly associated with inferior overall survival (hazard ratio [HR], 1.24; 95% confidence interval [CI], 1.00-1.53; P = .049) and an increased risk of relapse (HR, 1.40; 95% CI, 1.08-1.80; P = .0098) in multivariate analyses. There was no significant difference in nonrelapse mortality between recipients with and without del(Y) (HR, 1.08; 95% CI, 0.769-1.51; P = .67). In contrast, del(Y) was not significantly associated with any clinical outcomes in the cohort of male-to-male allo-HCT. A higher incidence of relapse might have been caused by attenuation of the GVL effect resulting from a lack of H-Y antigens. Because a GVL effect resulting from sex mismatch may not be expected in men with del(Y) who undergo allo-HCT with a female donor, additional post-allo-HCT strategies might be required to prevent disease relapse.

BACKGROUND: Even in the era of high-intensity chemotherapy, disease recurrence remains a major cause of treatment failure in adult patients with Philadelphia chromosome-negative B-cell acute lymphoblastic leukemia (Ph-negative B-ALL). For patients who achieved second complete remission (CR2) with salvage chemotherapy, allogeneic hematopoietic stem cell transplantation (allo-HSCT) could be the best curative treatment. However, Limited data are available on the outcomes of allo-HSCT for adult Ph-negative B-ALL in CR2 in the high-intensity chemotherapy era. OBJECTIVE: We evaluated the transplant outcomes of adult patients with Ph-negative B-ALL in CR2 compared with those in CR1. We also clarified the prognostic factors among adult allo-HSCT recipients with Ph-negative B-ALL in CR2. STUDY DESIGN: We conducted a nationwide retrospective study using the data form Japanese transplant registry database. Patients aged ≥16 years and underwent their first allo-HSCT between 2003 and 2017 were included. RESULTS: The 3-year overall survival (OS) rate of the patients in CR2 (n=382) was significantly lower than that in first complete remission (n=1375) (51.8% vs. 68.1%, P<0.001), accompanied by a higher relapse rate (34.2% vs. 17.6% at 3 years, P<0.001). In a multivariate analysis among CR2 patients, time from diagnosis to allo-HSCT (≤2 years) was a significant factor for OS (hazard ratio [HR] 1.87, P<0.001) and relapse (HR 1.88, P<0.001), while age at allo-HSCT (≥30 years) was a significant factor for OS (HR 2.10, P<0.001) and non-relapse mortality (HR 2.68, P<0.001). By assigning a score of 1 to each factor, the 3-year OS rate of CR2 patients significantly stratified: 70.7% in patients with score 0, 56.4% with score 1, and 28.4% with score 2 (P<0.001). CONCLUSION: The survival outcomes of allo-HSCT in adult Ph-negative B-ALL patients in CR2 were inferior to those in CR1 in the high-intensity chemotherapy era, mainly because of the higher relapse rate. Among the CR2 patients, the short time between diagnosis and allo-HSCT was a significant risk factor for disease recurrence and overall mortality. Better disease control with novel treatment strategies may be needed for early relapse. In addition, the NRM rate in patients over 30 years of age was particularly high among CR2 patients, suggesting the need for improved supportive care for these patients. Further studies are warranted on the outcomes of allo-HSCT after achieving CR2 with novel drugs, such as inotuzumab ozogamicin and blinatumomab.

There are limited data comparing myeloablative conditioning with fludarabine/busulfan (Flu/Bu4) and reduced-intensity conditioning with fludarabine/busulfan (Flu/Bu2) in patients with myelodysplastic syndrome (MDS) undergoing allogeneic hematopoietic stem cell transplantation (allo-HSCT). We retrospectively analyzed nationwide registry data and compared the outcomes of adult patients with MDS receiving Flu/Bu4 and Flu/Bu2 by propensity score (PS) matching. Patients who met the following criteria were eligible for enrollment: (1) age ≥16 years; (2) diagnosis of de novo MDS; (3) first allo-HSCT between 2006 and 2018; (4) related bone marrow transplantation (BMT) or peripheral blood stem cell transplantation from an HLA-matched donor, unrelated BMT from an HLA-matched or HLA-1 allele-mismatched donor, or unrelated cord blood transplantation; and (5) receiving Flu/Bu4 or Flu/Bu2 as a conditioning regimen. Flu/Bu4 comprised intravenous busulfan (total dose, 12.8 mg/kg) combined with fludarabine (total dose, 125-180 mg/m2). Flu/Bu2 comprised intravenous busulfan (total dose, 6.4 mg/kg) combined with the same dose of fludarabine. To minimize selection bias and confounding factors, we performed a propensity score (PS)-matched analysis. The primary endpoint was overall survival (OS) after allo-HSCT. A total of 3386 patients with de novo MDS underwent their first allo-HSCT between 2006 and 2018. Among them, 202 patients were assigned each to the Flu/Bu4 and Flu/Bu2 groups after PS-matched analysis. The median age was 61 (interquartile, 57-65) years. The 3-year OS rates were 44.8% (95% confidence interval [CI], 37.1-52.1%) and 46.9% (95% CI, 39.2-54.2%) in the Flu/Bu4 and Flu/Bu2 groups, respectively (P = .67). The 3-year rates of graft-versus-host disease (GVHD)-free survival, relapse-free survival (GRFS) were 28.8% (95% CI, 22.2-35.7%) and 33.0% (95% CI, 26.2-40.0%), respectively (P = .36). The 3-year cumulative incidence rates of relapse were 28.9% (95% CI, 22.6-35.6%) and 30.0% (95% CI, 23.6-36.6%), respectively (P = .47). The 3-year cumulative incidence rates of non-relapse mortality (NRM) were 28.2% (95% CI, 21.7-35.0%) and 27.1% (95% CI, 20.6-33.9%), respectively (P = .60). The 100-day cumulative incidence rate of grade II-IV acute GVHD was significantly higher in the Flu/Bu4 group than in the Flu/Bu2 group (41.7% [95% CI, 34.8%-48.4%] versus 29.3% [95% CI, 23.2%-35.7%], P = 0.012). To identify patients who had more favorable outcomes with 1 of the 2 regimens, we compared the outcomes between the 2 groups after stratifying by age, hematopoietic cell transplantation-comorbidity index, cytogenetic risk, disease status at allo-HSCT, stem cell source, and donor type. OS, GRFS, relapse, and NRM did not differ between the 2 groups in any subgroup analyses. There were no significant interactions between the choice of conditioning regimens and any other factors. There are no differences in survival between Flu/Bu4 and Flu/Bu2, although our study population was highly selected by PS matching. Data from more patients and prospective studies are needed to determine the optimal intensity of conditioning regimens in patients with MDS.

The significance of antibody-identified epitopes stimulating humoral alloimmunity is not well understood in the identification of non-permissive human leukocyte antigen (HLA) mismatching patterns in hematopoietic stem cell transplantation (HSCT). This was a retrospective study in a cohort of 9,991 patients who underwent their first HSCT for hematologic malignancies from unrelated bone marrow donors in the Transplant Registry Unified Management Program (TRUMP). HLA eplet mismatches (EMM) were quantified using HLAMatchmaker (HLAMM). The median age of patients was 48 years (range, 16 to 77). The number of EMM in recipient-donor pairs in our study population ranged from 0 to 37 in HLA class I (median, 0) and 0 to 60 in HLA class II (median, 1). In addition to the known high-risk mismatch patterns in the Japanese cohort, HLA-C EMM in the GVH direction was associated with a significantly higher risk for grade III-IV aGVHD, leading to a higher risk of non-relapse mortality and lower overall survival (compared with HLA-C matched patients, HR 1.67, 95% CI 1.44–1.95; HR 1.39, 95% CI 1.25–1.54; HR 1.20, 95% CI 1.10–1.30, respectively). HLAMM-based epitope matching might be useful for identifying patients who are at high risk for serious complications after HSCT from HLA mismatched unrelated donors.

An HLA-matched relative is the first-choice donor for patients with Philadelphia chromosome (Ph)-negative acute lymphoblastic leukemia (ALL) in first complete remission (CR1). The most promising alternative donor is thought to be an HLA-matched unrelated donor (MUD) in patients who do not have an HLA-matched related donor. Cord blood transplantation (CBT) is an alternative option. Higher rates of engraftment failure and nonrelapse mortality (NRM) are significant problems, but the ready availability of cord blood can be an advantage, because patients can immediately undergo transplantation before progression. This study was conducted to identify an appropriate alternative donor in patients with Ph-negative ALL in CR1 who do not have an HLA-matched related donor (MRD). Decision analyses using a Markov model were performed to compare immediate CBT, in which CBT was performed at 1 month after the achievement of CR1, with elective unrelated bone marrow transplantation (uBMT) from an 8/8 MUD (8/8 uBMT) or uBMT from a 7/8 MUD (7/8 uBMT), in which uBMT was performed at 4 months, in patients age 16 to 55 years with Ph-negative ALL in CR1 who did not have an MRD. We constructed a decision tree. The cycle length was set at 3 months, and analyses were performed for 19 cycles for uBMT and 20 cycles for CBT, resulting in evaluation of the 5-year life expectancy after both decisions. Transition probabilities (TPs) and utilities were estimated from prospective and retrospective Japanese studies and the registry database of Japan. Subgroup analyses were performed according to risk stratification based on WBC count and cytogenetics at diagnosis and according to age stratification, with a cutoff of 25 years. One-way sensitivity analyses for TPs and utilities were performed as well. The baseline analyses showed that 8/8 uBMT or 7/8 uBMT had superior results to CBT, with quality-adjusted life years (QALYs) of 2.86 in 8/8 uBMT, 2.84 in 7/8 uBMT, and 2.75 in CBT. One-way sensitivity analyses showed that the results of the baseline analyses were reversed if the probability of NRM in CBT improved. Subgroup analyses showed similar results in younger, older, and high-risk patients. However, QALY was worse in 8/8 uBMT compared with CBT in standard-risk patients. In one-way sensitivity analyses, the probabilities of NRM in uBMT and CBT affected the baseline results in all analyses except for comparisons between 8/8 uBMT and CBT in younger and high-risk patients. In these 2 populations, the superiority of 8/8 uBMT was consistently demonstrated throughout the one-way sensitivity analyses. For patients with Ph-negative ALL in CR1 who decide to undergo transplantation from an alternative donor, elective uBMT from either an 8/8 MUD or a 7/8 MUD is expected to yield a better outcome than immediate CBT. Nonetheless, CBT is a viable option, and improvements to reduce the risk of NRM in CBT may change these results.

BACKGROUND: It has been reported that prolonged neutropenia during post-remission chemotherapy is associated with a reduced risk of disease relapse in pediatric acute myeloid leukemia (AML) patients. METHODS: We retrospectively reviewed the charts of adult AML patients in first complete remission (CR1) who underwent consolidation chemotherapy with high-dose cytarabine. Those receiving allogeneic hematopoietic cell transplantation in CR1 were excluded. We calculated the D-index, which is an area-based neutropenia index. The patients were divided into 2 groups using the median value of the D-index during the first cycle of consolidation chemotherapy (C#1). RESULTS: Fifty-six patients were included. The 2-year cumulative incidence of relapse was 54.8% (95% confidence interval (CI): 37.5-73.8) in patients with a D-index < 5,118 and 62.0% (95%CI: 42.7-81.4) in those with a D-index ≥ 5,118 (P = 0.56). In a multivariate analysis, intermediate / adverse cytogenetic risk (HR 2.76), performance status ≥ 2 (HR 5.55) and 2 cycles of induction chemotherapy required to achieve CR1 (HR 4.29) were identified as significant factors associated with relapse. The D-index at C#1 did not have a significant impact. CONCLUSIONS: In contrast to pediatric patients, the severity of neutropenia is not associated with a risk of disease relapse in adult AML patients.

New drugs for multiple myeloma (MM) have dramatically improved patients' overall survival (OS). Autologous stem cell transplantation (ASCT) remains the mainstay for transplant-eligible MM patients. To investigate whether the post-ASCT prognosis of MM patients has been improved by new drugs, we undertook a retrospective observational analysis using the Transplant Registry Unified Management Program database in Japan. We analyzed 7323 patients (4135 men and 3188 women; median age, 59 years; range 16-77 years) who underwent upfront ASCT between January 2007 and December 2018. We categorized them by when they underwent ASCT according to the drugs' introduction in Japan: group 1 (2007-2010), group 2 (2011-2016), and group 3 (2017-2018). We compared the groups' post-ASCT OS. The 2-year OS rates (95% confidence interval [CI]) of groups 1, 2, and 3 were 85.8% (84.1%-87.4%), 89.1% (88.0%-90.1%), and 92.3% (90.0%-94.2%) (P < .0001) and the 5-year OS (95% CI) rates were 64.9% (62.4%-67.3%), 71.6% (69.7%-73.3%), and not applicable, respectively (P < .0001). A multivariate analysis showed that the post-ASCT OS was superior with these factors: age less than 65 years, performance status 0/1, low International Staging System (ISS) stage, receiving SCT for 180 days or less post-diagnosis, better treatment response pre-ASCT, later year of ASCT, and receiving SCT twice. A subgroup analysis showed poor prognoses for the patients with unfavorable karyotype and poor treatment response post-ASCT. The post-ASCT OS has thus improved over time (group 1 < 2 < 3) with the introduction of new drugs for MM. As the prognosis of high-risk-karyotype patients with ISS stage III remains poor, their treatment requires improvement.

Cytomegalovirus reactivation is still a critical concern following allogeneic hematopoietic cell transplantation, and cellular immune reconstitution of cytomegalovirus-specific cytotoxic T-cells is necessary for the long-term control of cytomegalovirus reactivation after allogeneic hematopoietic cell transplantation. Here we show the features of repertoire diversity and the gene expression profile of HLA-A24 cytomegalovirus-specific cytotoxic T-cells in actual recipients according to the cytomegalovirus reactivation pattern. A skewed preference for BV7 genes and sequential "G" amino acids motif is observed in complementarity-determining region-3 of T cell receptor-β. Increased binding scores are observed in T-cell clones with complementarity-determining region-3 of T cell receptor-β with a "(G)GG" motif. Single-cell RNA-sequence analyses demonstrate the homogenous distribution of the gene expression profile in individual cytomegalovirus-specific cytotoxic T-cells within each recipient. On the other hand, bulk RNA-sequence analyses reveal that gene expression profiles among patients are different according to the cytomegalovirus reactivation pattern, and are associated with cytokine production or cell division. These methods and results can help us to better understand immune reconstitution following hematopoietic cell transplantation, leading to future studies on the clinical application of adoptive T-cell therapies.

Relapsed acute leukemia after allogeneic hematopoietic stem cell transplantation (allo-HSCT) is associated with poor prognosis. In a subset of patients, durable remissions can be achieved with a second allo-HSCT (allo-HSCT2). However, many patients experience relapse after allo-HSCT2 and they may be considered for a third allo-HSCT (allo-HSCT3). Nevertheless, the benefit of allo-HSCT3 remains unconfirmed. Thus, herein a retrospective analysis of 253 allo-HSCT3s in patients with relapsed/refractory acute leukemia was carried out. In total, 29 (11.5%) survived at a median follow-up of 794 days (range: 87-4 619). The 3-year leukemia-free survival and overall survival (OS) rates were 9.7% and 10.9%, respectively. Patients who maintained remission for ≥2 years after allo-HSCT2 had a significantly better 3-year OS (35.8%) than those who experienced early relapse (<1 year, 7.8%; 1-2 years, 14.0%; P = 0.004). Complete remission at allo-HSCT3, performance status score of 0-1 at allo-HSCT3, grade I acute graft-versus-host disease after allo-HSCT2, and relapse ≥2 years after allo-HSCT2 were associated with better survival in patients who received allo-HSCT3. The prognosis after allo-HSCT3 in patients with relapsed/refractory acute leukemia is generally unfavorable. However, given the lack of alternative treatment options, allo-HSCT3 may be considered in a group of patients.

BACKGROUND: We assessed the kinetics of cytomegalovirus (CMV) reactivation using the area under the curve (AUC), which simultaneously reflects both the viral load at each time point and the duration of CMV antigenemia (CMV-AG). METHODS: We performed a single-institute retrospective analysis in patients who received allogeneic hematopoietic stem cell transplantation (HSCT) between 2007 and 2017 and survived more than 100 days after HSCT. The AUC of CMV-AG (CMV-AUC) was calculated by a trapezoidal method using the number of CMV-AG tested by the C10/C11 method after logarithmic transformation, and plotted weekly up to day 100. RESULTS: CMV reactivation was observed in 195 cases and the median CMV-AUC for CMV-reactivated patients was 8.7 (range 0.5-30.7). Older age, corticosteroid administration, CMV-seropositive transplant recipients, HSCT from an unrelated donor, and underlying diseases were independent predictive factors for higher CMV-AUC. Higher CMV-AUC was associated with poor overall survival (OS) with borderline significance in a univariate analysis (p = .07), but was not significant in a multivariate analysis. Older age, high-risk disease status, and female gender were identified as significant factors associated with poor OS in this study. On the other hand, CMV-AUC (hazard ratio: no reactivation reference, low 0.98, high 2.49, p < .01), older age, HCT-CI ≥3, and corticosteroid administration were identified as significant factors associated with increased incidence of non-relapse mortality (NRM). CONCLUSIONS: The kinetics of CMV reactivation in terms of CMV-AUC reflect both the severity and duration of CMV reactivation. High CMV-AUC was associated with an increased incidence of NRM in survivors over 100 days.

Myeloablative conditioning with fludarabine/busulfan (Flu/Bu4) prior to allogeneic hematopoietic stem cell transplantation (allo-HSCT) is effective for acute myeloid leukemia. However, the effectiveness of Flu/Bu4 for myelodysplastic syndrome (MDS) remains poorly understood. Therefore, we retrospectively analyzed nationwide registry data in Japan from 2006 to 2018 and compared transplant outcomes of adult MDS patients receiving Flu/Bu4 and busulfan/cyclophosphamide (Bu4/Cy) using propensity score (PS) matching. The primary endpoint was overall survival (OS). Among 2,482 MDS patients, 153 patients were assigned each to the Flu/Bu4 and Bu4/Cy groups. The 3-year OS rates were 52.7% (95% confidence interval [CI], 43.8-60.8%) and 49.5% (95% CI, 40.8-57.6%) in the Flu/Bu4 and Bu4/Cy group, respectively (P = 0.548). The 3-year progression-free survival (P = 0.858), the cumulative incidence of relapse (P = 0.536), and cumulative incidence of non-relapse mortality (P = 0.684) were not significantly different between the two groups. According to the findings of subgroup analyses, no patient had a favorable OS when using either of the two regimens. In conclusion, although our PS-matched cohort mainly comprised older patients who had a low hematopoietic cell transplantation-comorbidity index and low-risk disease status, Flu/Bu4 could be an alternative to Bu4/Cy for MDS patients prior to allo-HSCT.

Antithymocyte globulin (ATG) decreases chronic graft-versus-host disease (cGVHD) in peripheral blood stem cell transplantation (PBSCT); however, the optimal ATG dose has not been elucidated. We conducted a matched-pair analysis to evaluate whether low-dose ATG could inhibit cGVHD in HLA-matched PBSCT after myeloablative conditioning. A total of 70 patients who were enrolled in the JSCT-ATG15 study, a multicenter phase II clinical trial of 2 mg/kg of ATG (thymoglobulin) given on days -2 and -1, were compared with 210 patients not receiving ATG, who were matched for age, sex, disease, and calcineurin inhibitor selected from the database in Japan. The primary endpoint, cumulative incidence of extensive cGVHD at 2 years was significantly less in the ATG group than that in the non-ATG group (8.7% [95% CI, 3.5%-16.8%] versus 26.2% [95% CI, 20.3%-32.5%], P = .002). ATG significantly reduced the incidence of overall cGVHD and inhibited multiple organ involvement. The ATG group had favorable outcome compared to the non-ATG group in GVHD-free, and relapse-free survival at 2 years. In conclusion, low-dose ATG effectively inhibits chronic GVHD in PBSCT.

This study aimed to clarify the risk factors and prognosis associated with blood stream infection (BSI) in allogeneic hematopoietic cell transplantation (allo-HCT), and the relationship between BSI and acute graft-versus-host disease (aGVHD). This retrospective analysis included 11,098 patients in the Japanese national transplant registry. A total of 2172 patients developed BSI after allo-HCT, with 2332 identified pathogens. The cumulative incidences of BSI were 15.5% at 30 days and 20.9% at 100 days after allo-HCT. In a multivariate analysis, severe (grade III-IV) aGVHD was associated with a higher risk of BSI (vs. grade 0-I aGVHD: hazard ratio [HR] 3.34 [95% confidence interval (CI), 2.85-3.92; P < 0.001]). In a multivariate analysis, severe aGVHD before BSI was associated with a higher risk of overall mortality after BSI (vs. grade 0-I aGVHD: HR 2.61 [95% CI 2.18-3.11; P < 0.001]). In addition, BSI (vs. no-BSI: HR 1.20 [95% CI, 1.12-1.29; P < 0.001]) and severe aGVHD (vs. grade 0-I aGVHD: HR 1.97 [95% CI, 1.83-2.12; P < 0.001]) were independent risk factors for overall mortality after allo-HCT. In the setting of allo-HCT, severe aGVHD was associated with increases in both BSI incidence and post-BSI overall mortality. Furthermore, BSI was an independent risk factor for overall mortality.

PURPOSE: The anti-leukemic activity of allogeneic hematopoietic cell transplantation (HCT) depends on both the intensity of conditioning regimen and the strength of the graft-versus-leukemia (GVL) effect. However, it is unclear whether the sensitivity of the GVL effects differs between donor type and graft source. EXPERIMENTAL DESIGN: We retrospectively evaluated the effect of acute and chronic graft-versus-host disease (GVHD) on transplant outcomes for adults with acute leukemia (n = 6,548) between 2007 and 2017 using a Japanese database. In all analyses, we separately evaluated three distinct cohorts based on donor type [(8/8 allele-matched sibling donor, 8/8 allele-matched unrelated donor, and unrelated single-cord blood (UCB)]. RESULTS: The multivariate analysis, in which the development of GVHD was treated as a time-dependent covariate, showed a reductive effect of grade I-II acute GVHD on treatment failure (defined as 1-leukemia-free survival; P < 0.001), overall mortality (OM; P < 0.001), relapse (P < 0.001), and non-relapse mortality (NRM; P < 0.001) in patients receiving from UCB. A reductive effect of limited chronic GVHD on treatment failure (P < 0.001), OM (P < 0.001), and NRM (P < 0.001) was also shown in patients receiving from UCB. However, these effects were not always shown in patients receiving from other donors. The beneficial effects of mild acute and chronic GVHD after UCB transplantation on treatment failure were noted relatively in subgroups of patients with acute myelogenous leukemia and a non-remission status. CONCLUSIONS: These data suggested that the development of mild GVHD could improve survival after UCB transplantation for acute leukemia.

Molecular relapse after allogeneic hematopoietic cell transplantation (allo-HCT) has been thought to predict clinical relapse in patients with Philadelphia chromosome-positive acute lymphoblastic leukemia (PhALL). Tyrosine kinase inhibitor (TKI) administration after allo-HCT may dynamically change the status from molecular relapse to molecular remission, but these state changes cannot be accurately represented by conventional survival indicators such as relapse-free survival, where events are usually considered irreversible. We aimed to develop novel indicators of transplant outcomes for allo-HCT recipients with PhALL and to visualize current molecular-relapse-free survival (CMRFS) and current on-TKI status (CTKI), treating molecular relapse or TKI administration after allo-HCT as a reversible event. We retrospectively analyzed 286 patients with PhALL who received allo-HCT between 2000 and 2016 in order to develop the indicators. CMRFS was defined as the probability of molecular remission without clinical relapse or death at any time after allo-HCT. Similarly, CTKI was defined as the probability of TKI administration without clinical relapse or death at any time after allo-HCT. The 1- and 5-year CMRFS rates were 67% and 59%, respectively, whereas the 1- and 5-year conventional molecular relapse-free survival rates were 42% and 37%. The 1- and 5-year CTKI rates were 14% and 8%, respectively. In a post hoc analysis focusing on patients who had achieved a molecular complete remission within 6 weeks (n = 201), the 5-year CMRFS rate (71%) was similar to the 5-year conventional molecular relapse-free survival (molRFS) rate (70%) in the non-TKI group. On the other hand, the 5-year CMRFS rate in the TKI group was 61%, whereas the 5-year conventional molRFS rate was only 38%. CMRFS and CTKI might become useful indicators of transplant success in terms of survival, leukemia-free status, and treatment-free status at any time point. Future extension of these survival models to other clinical situations is warranted.

Mutations of CCAAT/enhancer binding protein alpha (CEBPAmu) are found in 10-15% of de novo acute myeloid leukemia (AML) cases. Double-mutated CEBPA (CEBPAdm) is associated with a favorable prognosis; however, single-mutated CEBPA (CEBPAsm) does not appear to improve prognosis. We investigated the CEBPAmu for prognosis in 1028 AML patients, registered in the Multi-center Collaborative Program for Gene Sequencing of Japanese AML. It was found that CEBPAmu in the basic leucine zipper domain (bZIP) was strongly associated with a favorable prognosis, but CEBPAmu out of the bZIP domain was not. The presence of CEBPAmu in bZIP was a strong indicator of a higher chance of achieving complete remission (p<0.001), better overall survival (OS; p<0.001) and a lower risk of relapse (p<0.001). The prognostic significance of CEBPAmu in bZIP was also observed in the subgroup with CEBPAsm (all patients, OS: p=0.008; the cumulative incidence of relapse (CIR): p=0.063. patients aged ≤70 years and with intermediate-risk karyotype, OS: p=0.008; CIR: p=0.026). Multivariate analysis of 744 patients aged ≤70 years showed that CEBPAmu in bZIP was the most potent predictor of OS (hazard ratio: 0.3287; p<0.001). CEBPAdm was validated as a cofounding factor, which was overlapping with CEBPAmu in bZIP. In summary, these findings indicate that CEBPAmu in bZIP is a potent marker for AML prognosis. It holds potential in the refinement of treatment stratification and the development of targeted therapeutic approaches in CEBPA mutated AML.

To evaluate whether outcomes following allogeneic hematopoietic cell transplantation differ according to disease type, a three-way comparison for patients with de novo acute myeloid leukemia (AML) (n = 3318), AML evolving from myelodysplastic syndromes (MDS) (n = 208), and MDS with excess blasts (MDS-EB) (n = 994) was performed. The 5-year probabilities of overall survival (OS) for de novo AML, AML evolving from MDS, and MDS-EB were 60%, 42%, and 41% (p < 0.001), respectively. Multivariate analysis revealed that, compared to de novo AML, AML evolving from MDS was associated with a higher risk of NRM (p = 0.030) and MDS-EB with a higher risk of relapse (p < 0.001), both leading to lower OS (p = 0.010 and p < 0.001, respectively). These findings demonstrate inter-disease differences in post-transplant outcomes and highlight the needs to reduce NRM for AML evolving from MDS and to reduce relapse for MDS-EB.

Recipient cytomegalovirus (CMV) seropositivity is known to be a risk factor for CMV reactivation after allogeneic hematopoietic stem cell transplantation (allo-HCT). We explored the association of CMV-IgG titer of recipients with CMV reactivation after allo-HCT and developed a model for predicting CMV reactivation for the purpose of identifying a high-risk group. In addition, we evaluated the impact of CMV-IgG titer on survival outcomes and acute graft-versus-host disease (GVHD). We retrospectively analyzed 309 patients who achieved neutrophil engraftment after allo-HCT and evaluated whether pretransplantation recipient CMV-IgG titer was associated with transplantation outcomes, including CMV reactivation. Using the best cutoff value determined by a receiver operating characteristic curve analysis, we divided the study cohort into 3 groups: high-titer, low-titer, and negative. CMV reactivation occurred most frequently in the high-titer group, followed by the low-titer and negative groups (81%, 37%, and 16%, respectively, at 180 days after allo-HCT; P < .01). In a multivariate analysis, recipient CMV-IgG titer was significantly associated with subsequent CMV reactivation (hazard ratio [HR], 9.31 in the high-titer group [P < .01] and 2.91 in the low-titer group [P = .023]). CMV diseases were observed exclusively in the high-titer group. Overall survival (OS) was lower in the high-titer group compared with the other 2 groups (2-year OS, 56%, 60%, and 80%, respectively; P = .075), whereas the cumulative incidences of grade II-IV acute GVHD, nonrelapse mortality (NRM), and relapse were not significantly different among the 3 groups. In multivariate analyses, CMV-IgG titer was not associated with increased risks of these outcomes, although CMV reactivation itself was identified as a risk factor for NRM (HR, 3.05; P = .002). Our data demonstrate that a higher titer of recipient CMV-IgG is predictive of CMV reactivation after allo-HCT. Further investigation is needed to determine how to apply these results to prophylactic or preemptive strategies against CMV, considering recipient CMV-IgG titer for effective risk stratification.

Allogeneic haematopoietic stem cell transplantation (allo-HSCT) is one of the curative treatment options for acute lymphoblastic leukaemia (ALL). However, the outcomes in patients transplanted without complete remission (non-CR) have not yet been fully reported, and detailed analyses are required to identify subgroups in which optimal prognosis is expected and to optimize pre-transplant therapeutic strategies. Hence, we performed a multicentred retrospective cohort study including a total of 663 adult ALL patients transplanted at non-CR status; the median bone marrow (BM) blast counts at HSCT was 13·2%, and 203 patients (30·6%) were treated at primary induction failure status. The overall survival (OS) was 31·1% at two years, and the multivariate analyses identified five prognostic risk factors, including older age (≥50 years), increased BM blasts (≥10%), poor performance status, high haematopoietic cell transplantation (HCT)-comorbidity index, and relapsed disease status, among which BM blast was the most significantly related. A predictive scoring system composed of these risk factors clearly stratified OS (15·6-59·5% at two years). In conclusion, this is the first large-scale study to analyze the correlation of patient characteristics with post-transplant prognosis in ALL transplanted at non-CR status. The importance of blast control before HSCT should be focused on for better patient prognosis.

Minimal residual disease (MRD) monitoring by quantitative real-time reverse transcription PCR (qRT-PCR) is the standard of care in Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph-positive ALL). We evaluated the impact of MRD status at hematopoietic cell transplantation (HCT) on relapse, as measured by a unified protocol at a central laboratory. Only patients with Ph-positive ALL who had minor transcripts (e1a2) and who underwent allogeneic HCT in first complete remission between 2008 and 2017 were included. First, patients with negative-MRD (n = 196) and positive-MRD (n = 61) at HCT were analyzed. As expected, MRD positivity at HCT was significantly associated with an increased risk of hematological relapse (hazard ratio [HR], 2.91; 95% CI 1.67-5.08; P < 0.001) in the multivariate analysis. Next, patients with positive-MRD were divided into low-MRD (n = 39) and high-MRD (n = 22) groups. In the multivariate analysis, high-MRD at HCT was not significantly associated with an increased risk of hematological relapse compared to the low-MRD group (HR 1.10; 95% CI 0.54-2.83; P = 0.620). These results indicate that the therapeutic decisions should be made based on MRD positivity, rather than on the MRD level, at HCT.

Impact of donor age considering HLA disparity on hematopoietic cell transplantation (HCT) outcomes has not been fully evaluated. We evaluated 8486 patients who received unrelated bone marrow transplantation (UR-BMT) from 8/8 or 7/8 HLA-matched donors. Compared to 8/8 HLA-matched younger donors (<40 years), 8/8 HLA-matched older donors (subdistribution hazard ratio [SHR], 1.16; 95% CI, 0.97-1.38) and 7/8 HLA-matched younger donors (SHR, 1.33; 95% CI, 1.11-1.58) were associated with increased risk of grade III-IV acute graft-versus-host disease (aGVHD). 7/8 HLA-matched older donors had further increased risk (SHR, 2.00; 95% CI, 1.68-2.38) due to interaction between donor age and HLA disparity (p for interaction = 0.038). Progression-free survival (PFS) after UR-BMT with 8/8 HLA-matched younger donors was comparable to that after UR-BMT with 8/8 HLA-matched older donors, whereas UR-BMT with 7/8 HLA-matched younger or older donors was significantly associated with lower PFS than UR-BMT with 8/8 HLA-matched younger donors (younger donor; HR, 1.12; 95% CI, 1.04-1.21, older donor; HR, 1.28; 95% CI, 1.17-1.40; p for interaction = 0.079). In conclusion, adverse effect of increased donor age requires attention, especially in HLA-mismatched UR-BMT due to interaction between donor age and HLA disparity. Intensive aGVHD prophylaxis may be required to improve outcomes after HCT with mismatched older donors.

Posttransplant relapse represents the greatest obstacle to the success of allogeneic hematopoietic cell transplantation (HCT) for patients with acute myeloid leukemia (AML). This study investigated clinical features and outcomes of posttransplant relapse of AML based on data for 1265 patients with AML suffering relapse after allogeneic HCT conducted during complete remission (CR). Relapse occurred at a median of 6.1 months. The incidence rate of relapse peaked at 29.0 per 100 patient-years during the first 3-6 months period post transplant, after which the rate declined over time, and after 3 years remained consistently at less than 1 per 100 patient-years. The probability of overall survival (OS) after posttransplant relapse was 19% at 2 years, with 68% of deaths being attributed to leukemia. The interval from transplantation to relapse was identified as the strongest indicator for OS. Donor lymphocyte infusion (DLI) and second allogeneic HCT (HCT2) were administered to 152 (12%) and 481 (38%) patients, respectively. Landmark analyses showed some signs of survival benefit when these procedures were performed during CR, but no benefit was gained when performed during non-CR. Our findings clarify clinical features of posttransplant relapse of AML, and indicate the urgent need for developing effective bridging to cellular therapies.

Allogeneic hematopoietic cell transplantation (HCT) is a potentially curative post-remission therapy for adult patients with acute myeloid leukemia (AML) in complete remission (CR). The availability of alternative human leukocyte antigen (HLA)-mismatched donors, such as cord blood and haploidentical related donors, could allow patients to receive allogeneic HCT who are without an HLA-matched sibling or unrelated donor. The use of these alternative donors is preferable for patients with advanced disease due to the rapid availability. However, comparative data for cord blood transplantation (CBT) and haploidentical related donor transplantation (haplo-HCT) are limited for adult patients with AML in CR. We sought to compare overall survival (OS); leukemia-free survival (LFS); graft-versus-host disease (GVHD)-free, relapse-free survival (GRFS); and chronic GVHD-free, relapse-free survival (CRFS) between single-unit CBT (SCBT) and haplo-HCT recipients for adult patients with intermediate- or poor-risk AML in CR. We retrospectively analyzed and compared the results of allogeneic hematopoietic cell transplantation in 1313 adult patients with intermediate- or poor-risk AML in CR who received either SCBT (n = 1102) or unmanipulated haplo-HCT (n = 211) between 2007 and 2018 in Japan. Among the whole cohort, the cumulative incidences of neutrophil and platelet recovery were significantly lower in SCBT recipients compared with those in haplo-HCT recipients (P < .001 for neutrophil, P < .001 for platelet). SCBT was significantly associated with a higher incidence of grade II to IV acute GVHD and lower incidence of extensive chronic GVHD compared to haplo-HCT (P = .013 for grades II to IV acute GVHD; P = .006 for extensive chronic GVHD). Haplo-HCT recipients developed a higher incidence of cytomegalovirus (CMV) antigenemia compared to SCBT recipients (P = .004). In the multivariate analysis, there were no significant differences for grades III or IV acute GVHD (hazard ratio [HR], 1.17; 95% confidence interval [CI], .88 to 1.57; P = .26), relapse incidence (HR, 1.09; 95% CI, .76 to 1.58; P = .61), non-relapse mortality (HR, .83; 95% CI, .58 to 1.18; P = .32), OS (HR, .92; 95% CI, .70 to 1.20; P = .56), LFS (HR, .94; 95% CI, .73 to 1.21; P = .67), GRFS (HR, 1.12; 95% CI, .90 to 1.40; P = .27), or CRFS (HR, 1.15; 95% CI, .92 to 1.44; P = .19) between the two donor types. In the propensity score matching analysis, which identified 180 patients in each cohort, there were no significant differences in transplant outcomes between the two donor types, except for delayed neutrophil (P < .001) and platelet recovery (P < .001) and a higher incidence of grades II to IV acute GVHD (P = .052) in SCBT. SCBT and unmanipulated haplo-HCT had similar survival outcomes for adult patients with AML in CR despite the lower hematopoietic recovery and higher grade II to IV acute GVHD in SCBT recipients and the higher CMV antigenemia in haplo-HCT recipients.

Most acute leukemia patients receive consecutive intensive chemotherapy, which usually takes several months before allogeneic hematopoietic stem cell transplantation (allo-HCT). Intensive chemotherapy often induces gastrointestinal adverse events. These adverse events leave patients in a state of malnutrition, leading to a reduction in body weight. In this study, we analyzed the impact of body weight loss before allo-HCT on survival outcomes of acute leukemia patients (acute myeloid leukemia, acute lymphoid leukemia and mixed phenotype acute leukemia). A loss of body weight (LBW), which was a reduction of body weight from diagnosis or relapse to transplantation, was calculated in 182 acute leukemia patients who received first allo-HCT at our center between June 2006 and September 2019. A receiver operating characteristics curve for nonrelapse mortality (NRM) was plotted for defining the cut-off value of LBW. The cutoff value of LBW was defined as 13.2%. A higher LBW was significantly associated with inferior NRM and overall survival (OS) (2-year [2y] NRM 36.1% versus 11.5%, P = .0025; 2y-OS 39.9% versus 65.8%, P = .020). The adverse impact of LBW was also confirmed in multivariate analyses for NRM and OS (HR of NRM 2.74 [1.25-6.03], P = .0012; HR of OS 2.06 [1.00-3.07], P = .0049). The main cause of death included disease progression (n = 34) and infection (n = 35). Death cause by infection was more frequently observed in the high-LBW group (15 cases [35.7%] versus 20 cases [14.3%]; P = .0035). In addition, subgroup analyses based on a combination of the body mass index at diagnosis and LBW were performed. When the non-overweight-low LBW group (body mass index [BMI] ≤25 and LBW ≤13.2%) was used as a reference in multivariate analysis, the overweight-high LBW group (BMI >25 and LBW >13.2%) showed an increased risk of poor survival outcomes (HR of NRM 4.27 [95% confidence interval {CI}, 1.82-10.0], P < .001; HR of OS 1.93 [95%, CI 1.00-3.71], P = .050). High LBW was significantly associated with inferior survival outcomes, and the adverse effect of malnutrition might be greater than the favorable effect of the reduction in overweight.

Mesenchymal stromal cells (MSCs) have been shown to inhibit aerobic glycolysis in activated T cells, leading to increased autophagy. Although tryptophan depletion induced by indoleamine 2,3-dioxygenase (IDO) generated by MSCs has been suggested as a potential mechanism, we found that this inhibition was completely abolished when T cells were physically separated from MSCs using the Transwell system. Instead, in the current study, we demonstrate that programmed cell death 1 receptor (PD-1) and its ligand PD-L1, the expression of which is induced on activated T cells and MSCs, respectively, in response to IFN-γ are involved in this inhibition. Blockade of PD-1/PD-L1 interaction by blocking antibodies significantly restored glucose uptake, glycolytic activity, and cluster formation of activated T cells, whereas a specific inhibitor of IDO, 1-methyl-DL-tryptophan, had no effect. Neither surface nor cytoplasmic glucose transporter-1 expression on T cells was changed by MSCs. In addition, glycolytic gene expression in activated T cells was not inhibited despite the presence of MSCs. However, we found that hexokinase II (HK2) protein expression was markedly decreased in activated T cells that had been cocultured with MSCs. PD-1 blocking antibody restored HK2 expression. Taken together, our findings indicate that the PD-1/PD-L1 axis is involved in the MSC-mediated suppression of T cell glycolysis by negatively regulating HK2 activity at the protein level, but not at the mRNA level.