Antibody response after third dose of COVID-19 mRNA vaccination in allogeneic hematopoietic stem cell transplant recipients is comparable to that in healthy counterparts

To determine the efficacy of SARS-CoV-2 mRNA vaccination for allogeneic hematopoietic stem cell transplantation (allo-HSCT) recipients, we measured antibody titer serially in 92 allo-HSCT patients. Among the evaluable 87 patients, median age at vaccination was 53 years (range, 18-75). The average time between allo-HSCT and vaccination was 3.3 years (range, 0.5-15.7). One month after the second dose, 70 patients (80.5%) had a positive response, whereas 17 patients (19.5%) had a negative response (< 20 U/mL). Only patients older than 44 years had a negative response. Low IgM level was the only significant predictor of vaccine failure in elderly patients. When antibody response before and after the third vaccination was examined in 47 patients, antibodies increased significantly from a median of 18.3 U/mL to 312.6 U/mL (P < 0.01). The median antibody titer after the third vaccination of healthy individuals (n = 203) was 426.4 U/mL, which was comparable to that of patients (P = 0.2). The antibody titer after the third mRNA vaccination increased even in patients whose first two mRNA vaccinations failed. These findings suggest that allo-HSCT recipients should receive the mRNA vaccine regularly.

Poor outcome of allogeneic transplantation for therapy-related acute myeloid leukemia induced by prior chemoradiotherapy

Therapy-related acute myeloid leukemia (t-AML) is a therapeutic challenge as a late complication of chemotherapy (CHT) and/or radiotherapy (RT) for primary malignancy. Allogeneic hematopoietic stem cell transplantation (allo-HSCT) presents itself as a curative approach. To establish the optimal allo-HSCT strategy for t-AML, we evaluated the relationship between characteristics of primary malignancy and allo-HSCT outcomes. Patients with t-AML or de novo acute myeloid leukemia (AML) who underwent first allo-HSCT in Japan from 2011 to 2018 were identified using a nationwide database. The detailed background of t-AML was obtained by additional questionnaires. Multivariate analysis and propensity score matching (PSM) analysis were performed to detect the prognostic factors associated with t-AML and compare outcomes with de novo AML. We analyzed 285 t-AML and 6761 de novo AML patients. In patients with t-AML, receiving both CHT and RT for primary malignancy was an independent poor-risk factor for relapse and overall survival (OS) (hazard ratio (HR) 1.62; p = 0.029 and HR 1.65; p = 0.009, reference: CHT alone group), whereas other primary malignancy-related factors had no effect on the outcome. Compared to the CHT alone group, complex karyotypes were significantly increased in the CHT + RT group (86.1% vs. 57.5%, p = 0.007). In the PSM cohort, t-AML patients with prior CHT and RT had significantly worse 3-year OS than those with de novo AML (25.2% and 42.7%; p = 0.009). Our results suggest that prior CHT and RT for primary malignancy may be associated with increased relapse and worse OS of allo-HSCT in t-AML.

External validation and extended application of the transplant conditioning intensity score in acute myeloid leukemia

This study aimed to validate the utility of the transplant conditioning intensity (TCI) score in 1714 patients with acute myeloid leukemia (AML) undergoing allogeneic bone marrow or peripheral blood stem cell transplantation (BMT/PBSCT) and assess its applicability to 753 patients with AML undergoing umbilical cord blood transplantation (UCBT) both during first complete remission. Patients classified into a high TCI group accounted for 63% and 56% in the BMT/PBSCT and UCBT cohorts, respectively. In the BMT/PBSCT cohort, the risk of relapse was lower in patients in the high versus intermediate TCI group (P = 0.002), although non-relapse mortality (NRM) did not differ among the three TCI groups. In the UCBT cohort, both relapse and NRM did not differ among the TCI groups. Increasing cutoff points for intermediate and high TCI categories significantly improved the ability to predict relapse and NRM in the BMT/PBSCT cohort (P = 0.030 and 0.006, respectively), and relapse but not NRM in the UCBT cohort (P = 0.005 and 0.364, respectively). These findings highlight the difference in the threshold level of the TCI score for outcome discrimination between European and Japanese cohorts. The TCI scheme appears less effective for UCBT than for BMT/PBSCT.

Novel risk assessment for the intensity of conditioning regimen in older patients

Reduced-intensity conditioning (RIC) regimens have long-term outcomes that are generally comparable with those of myeloablative conditioning (MAC) because of a lower risk of nonrelapse mortality (NRM) but a higher risk of relapse. However, it is unclear how we should select the conditioning intensity in individual cases. We propose the risk assessment for the intensity of conditioning regimen in elderly patients (RICE) score. We retrospectively analyzed 6147 recipients aged 50 to 69 years using a Japanese registry database. Based on the interaction analyses, advanced age (≥60 years), hematopoietic cell transplantation-specific comorbidity index (≥2), and umbilical cord blood were used to design a scoring system to predict the difference in an individual patient's risk of NRM between MAC and RIC: the RICE score, which is the sum of the 3 factors. Zero or 1 implies low RICE score and 2 or 3, high RICE score. In multivariate analyses, RIC was significantly associated with a decreased risk of NRM in patients with a high RICE score (training cohort: hazard ratio [HR], 0.73; 95% confidence interval [CI], 0.60-0.90; P = .003; validation cohort: HR, 0.57; 95% CI, 0.43-0.77; P < .001). In contrast, we found no significant differences in NRM between MAC and RIC in patients with a low RICE score (training cohort: HR, 0.99; 95% CI, 0.85-1.15; P = .860; validation cohort: HR, 0.81; 95% CI, 0.66-1.01; P = .061). In summary, a new and simple scoring system, the RICE score, appears to be useful for personalizing the conditioning intensity and could improve transplant outcomes in older patients.

Should a matched sibling donor still be considered the primary option for allogeneic hematopoietic cell transplantation in patients over 50 years of age with myelodysplastic syndrome?

Human leukocyte antigen (HLA)-matched sibling donors (MSDs) are the preferred choice for allogeneic hematopoietic cell transplantation (HCT). However, as myelodysplastic syndrome (MDS) is most frequently diagnosed in the elderly, MSDs are also likely to be of advanced age. It is unclear whether an MSD should be considered the primary choice for allogeneic HCT in elderly patients with MDS. We retrospectively compared survival and other outcomes in 1787 patients with MDS over 50 years of age and receiving allogeneic HCT between 2014 and 2020, using either MSD (n = 214), 8/8 allele-matched unrelated donor (MUD) (n = 562), 7/8 allele-MUD (n = 334), or unrelated cord blood (UCB) (n = 677) in Japan. In multivariate analysis, compared to MSD transplants, the risk of relapse was significantly lower following 8/8MUD transplants (hazard ratio [HR], 0.74; P = 0.047), whereas non-relapse mortality was significantly higher following UCB transplants (HR, 1.43; P = 0.041). However, donor type did not determine overall survival, disease-free survival, or graft-versus-host disease (GVHD)-free, relapse-free survival, but chronic GVHD-free, relapse-free survival was better after UCB (HR, 0.80; P = 0.025) and 8/8MUD (HR, 0.81; P = 0.032) compared to MSD transplants. Our study demonstrated that MSDs are not superior to alternative HCT methods, such as 8/8MUD, 7/8MUD, or UCB, in this population.

Development of TCR-T cell therapy targeting mismatched HLA-DPB1 for relapsed leukemia after allogeneic transplantation

Relapsed leukemia after allogeneic hematopoietic stem cell transplantation (allo-HSCT) remains a significant challenge, with the re-emergence of the primary disease being the most frequent cause of death. Human leukocyte antigen (HLA)-DPB1 mismatch occurs in approximately 70% of unrelated allo-HSCT cases, and targeting mismatched HLA-DPB1 is considered reasonable for treating relapsed leukemia following allo-HSCT if performed under proper conditions. In this study, we established several clones restricted to HLA-DPB1*02:01, -DPB1*04:02, and -DPB1*09:01 from three patients who underwent HLA-DPB1 mismatched allo-HSCT using donor-derived alloreactive T cells primed to mismatched HLA-DPB1 in the recipient's body after transplantation. A detailed analysis of the DPB1*09:01-restricted clone 2A9 showed reactivity against various leukemia cell lines and primary myeloid leukemia blasts, even with low HLA-DP expression. T cell receptor (TCR)-T cells derived from clone 2A9 retained the ability to trigger HLA-DPB1*09:01-restricted recognition and lysis of various leukemia cell lines in vitro. Our study demonstrated that the induction of mismatched HLA-DPB1 specific T cell clones from physiologically primed post-allo-HSCT alloreactive CD4⁺ T cells and the redirection of T cells with cloned TCR cDNA by gene transfer are feasible as techniques for future adoptive immunotherapy.

Impact of anti-thymocyte globulin on survival outcomes in female-to-male allogeneic hematopoietic stem cell transplantation

Allogeneic hematopoietic cell transplantation between female donors and male recipients (female-to-male allo-HCT) is a well-established risk factor for inferior survival outcomes due to a higher incidence of graft-versus-host disease (GVHD). However, a clinical significance of anti-thymocyte globulin (ATG) in the female-to-male allo-HCT has not been elucidated. In this study, we retrospectively evaluated male patients who underwent allo-HCT between 2012 and 2019 in Japan. In the female-to-male allo-HCT cohort (n = 828), the use of ATG was not associated with a decreased risk of GVHD (HR of acute GVHD 0.691 [95% CI: 0.461-1.04], P = 0.074; HR of chronic GVHD 1.06 [95% CI: 0.738-1.52], P = 0.76), but was associated with favorable overall survival (OS) and a decreased risk of non-relapse mortality (NRM) (HR of OS 0.603 [95% CI: 0.400-0.909], P = 0.016; HR of NRM 0.506 [95% CI: 0.300-0.856], P = 0.011). The use of ATG in female-to-male allo-HCT resulted in survival outcomes that were almost equivalent to those in the male-to-male allo-HCT group. Therefore, GVHD prophylaxis with ATG might overcome the inferiority of survival outcomes in female-to-male allo-HCT.

Autologous peripheral blood stem cell transplantation for Philadelphia chromosome-positive acute lymphoblastic leukemia is safe but poses challenges for long-term maintenance of molecular remission: Results of the Auto-Ph17 study

Autologous hematopoietic stem cell transplantation (SCT) is not a standard treatment option for Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ALL); however, its position has been reassessed since the introduction of tyrosine kinase inhibitors (TKIs). We prospectively analyzed the efficacy and safety of autologous peripheral blood SCT (auto-PBSCT) for Ph+ALL patients aged between 55 and 70 years who had achieved complete molecular remission. Melphalan, cyclophosphamide, etoposide, and dexamethasone were used for conditioning. A total of 12 courses of maintenance therapy, including dasatinib, were performed. The required number of CD34⁺ cells was harvested in all five patients. No patient died within 100 days after auto-PBSCT, and no unexpected serious adverse events were observed. Although 1-year event-free survival was 100%, hematological relapse was observed in three patients at a median of 801 days (range, 389-1088 days) after auto-PBSCT. Molecular progressive disease was observed in the other two patients, although they maintained their first hematological remission at the last visit. Auto-PBSCT can be safely performed for Ph+ALL with TKIs. A limitation of auto-PBSCT was suggested, despite the increase in the intensity of a single treatment. The development of long-term therapeutic strategies by including new molecular targeted drugs is warranted to maintain long-term molecular remission.

Efficacy and safety of allogeneic hematopoietic cell transplantation in acute myeloid leukemia patients aged > 65 years with unfavorable cytogenetics

Unrelated donor bone marrow transplantation (UR-BMT), unrelated donor cord blood stem cell transplantation (UR-CBT), and haploidentical peripheral blood stem cell transplantation (Haplo-PBSCT) are the main alternative stem cell sources for allogeneic hematopoietic cell transplantation (HCT) in Japan. The present study aimed to identify factors associated with the outcomes of UR-BMT, UR-CBT, and Haplo-PBSCT in older patients with acute myeloid leukemia (AML) and intermediate- or poor-risk cytogenetics to improve the clinical efficacy and safety of allogeneic HCT. We retrospectively analyzed data for 448 AML patients aged > 65 years who received UR-BMT (n = 102), UR-CBT (n = 250), or Haplo-PBSCT (n = 96) between 2014 and 2020. Overall survival (OS) in the UR-BMT group was superior (P = 0.033) to that in the other groups. However, all patients without complete remission (non-CR) who had Karnofsky performance status (KPS) < 80 at HCT and poor-risk cytogenetics died within 1 year after HCT. Multivariate Cox regression analysis identified KPS <80 at HCT and poor-risk cytogenetics as independent predictors of worse OS in non-CR patients. KPS < 80 may be an alternative indicator for non-CR AML patients with poor-risk cytogenetics during the selection of HCT, alternative treatments, or best supportive therapy, and the optimal KPS is important for the success of HCT.

Association between candidemia and non-infectious interstitial pneumonia after allogeneic hematopoietic cell transplantation: JSTCT Transplant Complications Working Group

Background

α-Mannan from Candida albicans reportedly induces Th17-mediated pulmonary graft-versus-host disease (GVHD) in a mouse model. This study aimed to evaluate the association between candidemia and non-infectious interstitial pneumonia (IP) in allogeneic hematopoietic cell transplantation (HCT) recipients.

Methods

By using a Japanese transplant registry database, we analyzed 9,143 pediatric and adult patients with hematological malignancies who underwent their first (n = 7,531) or second (n = 1,612) allogeneic HCT between 2009 and 2019.

Results

Non-infectious IP was observed in 694 patients at a median of 63 days (range 0-1,292) after HCT. Candidemia occurred in 358 patients at a median of 31 days (range, 0-903 days) after HCT. Candidemia treated as a time-dependent covariate was significantly associated with an increased incidence of non-infectious IP (hazard ratio [HR], 2.51; 95%CI, 1.48-4.25) along with total body irradiation (&gt; 8Gy) (HR, 1.57; 95%CI, 1.18-2.10) and malignant lymphoma (vs. acute myeloid leukemia) (HR, 1.30; 95%CI, 1.004-1.69). On the other hand, prompt platelet recovery (HR, 0.58; 95%CI, 0.45-0.75) and acute lymphoblastic leukemia (vs. acute myeloid leukemia) (HR, 0.68; 95%CI, 0.49-0.94) were associated with a reduced incidence of non-infectious IP. The median survival after the development of non-infectious IP in patients with prior candidemia was significantly shorter than that in those without it (22 days vs. 59 days, P &lt; 0.001).

Conclusions

Candidemia was associated with an increased incidence of non-infectious IP. The prognosis of non-infectious IP after candidemia was extremely poor.

Allogeneic transplantation of bone marrow versus peripheral blood stem cells from HLA-identical relatives in patients with myelodysplastic syndromes and oligoblastic acute myeloid leukemia: a propensity score analysis of a nationwide database

Bone marrow (BM) and granulocyte colony-stimulating factor-mobilized peripheral blood stem cells (PBSC) are used as grafts from HLA-identical-related donors for adults with myelodysplastic syndrome (MDS). To assess the impact of graft sources on post-transplant outcomes in MDS patients, we conducted a retrospective analysis of a nationwide database. A total of 247 and 280 patients underwent transplantation with BM and PBSC, respectively. The inverse probability of treatment weighting (IPTW) methods revealed that overall survival (OS) was comparable between BM and PBSC (P = .129), but PBSC transplantation was associated with worse graft-versus-host disease (GVHD)-free/relapse-free survival (GRFS) (hazard rate [HR], 1.24; 95% confidence intervals [CIs], 1.00-1.53; P = 0.049) and chronic GVHD-free and relapse-free survival (CRFS) (HR, 1.29; 95% CIs, 1.13-1.73; P = 0.002) than BM transplantation. In the propensity score matched cohort (BM, n = 216; PBSC, n = 216), no significant differences were observed in OS and relapse; 3-year OS rates were 64.7% and 60.0% (P = 0.107), while 3-year relapse rates were 27.1% and 23.5% (P = 0.255) in BM and PBSC, respectively. Three-year GRFS rates (36.6% vs. 29.2%; P = 0.006), CRFS rate (37.7% vs. 32.5%; P = 0.003), and non-relapse mortality rates (13.9% vs. 21.1%; P = 0.020) were better in BM than in PBSC. The present study showed that BM transplantation provides a comparable survival benefit with PBSC transplantation and did not identify an enhanced graft-versus-MDS effect to reduce the incidence of relapse in PBSC transplantation.

Age and allogeneic hematopoietic cell transplantation outcomes in acute myeloid leukemia

Although several studies have reported significant effects of patient age on outcomes of allogeneic hematopoietic cell transplantation (HCT), the prognostic relevance of age must be determined separately for myeloablative conditioning (MAC) and reduced-intensity conditioning (RIC). We analyzed Japanese nationwide transplantation registry data of patients aged 20-79 years with acute myeloid leukemia who underwent allogeneic HCT using MAC (n = 7525) or RIC (n = 3154) between 2008 and 2019. Patient were divided into six groups by age, with each group representing a decade, and overall survival (OS), relapse, and non-relapse mortality (NRM) were compared between adjacent age groups. The adverse impact of age on OS increased each decade starting at age 40 among patients receiving MAC, but only differed significantly between patients in their 50s and 60s among those receiving RIC. In patients receiving both MAC and RIC, the detrimental effect of advanced age on OS was accompanied by an increased risk of NRM. These findings show that age affects NRM and OS significantly, but differs depending on conditioning intensity. RIC mitigates the adverse prognostic impact of older age and is thus considered a reasonable option for older patients.

Clinical Benefit of Low-Dose Antithymocyte Globulin-Thymoglobulin as Graft-versus-Host Disease Prophylaxis in Patients Receiving Allogeneic Peripheral Blood Stem Cell Transplantation from HLA-Identical Donors

Graft-versus-host disease (GVHD) is a major complication of allogeneic peripheral blood stem cell transplantation (PBSCT). Previous randomized studies have already shown that the use of several types of antihuman T lymphocyte immune globulin (ATG) as GVHD prophylaxis can reduce the incidence of acute GVHD and chronic GVHD. However, the efficacy and safety of PBSCT from HLA-identical donors with low-dose ATG remain unclear. This study aimed to clarify the efficacy and safety of PBSCT from HLA-identical donors with low-dose ATG compared with PBSCT from HLA-identical donors without ATG. To do so, we retrospectively analyzed the outcomes of patients who underwent allogeneic PBSCT from HLA-identical donors with low-dose ATG-thymoglobulin (ATG-T; 2.5 mg/kg) versus those who did not receive ATG-T. Patient data were collected retrospectively from the medical records of Anjo Kosei Hospital. This study was conducted from 2009 to the final follow-up in October 2022. Forty-seven of 91 patients received ATG-T between January 2009 and March 2020. ATG-T reduced the incidence rates of moderate-to-severe chronic GVHD (hazard ratio [HR], .15; 95% confidence interval [CI], .057 to .41; P < .0010) and nonrelapse mortality (HR, .21; 95% CI, .0058 to.75, P = .016) without increasing the risk of relapse. Overall survival did not differ significantly between the 2 groups; however, the low-dose ATG-T group had better moderate-to-severe chronic GVHD-free, relapse-free survival rates (HR, .47; 95% CI, .27 to .80, P = .0054) than the non-ATG-T group. In addition, multistate analysis revealed that the low-dose ATG-T group had better current GVHD-free, relapse-free survival at 24 months after transplantation (45% [95% CI, 29% to 63%)] versus 21% [95% CI, 9.1% to 34%]; P = .015). Low-dose ATG-T was not associated with increased incidence of infections or adverse events. Our findings suggest that low-dose ATG-T can be beneficial for patients receiving PBSCT from HLA-identical donors. © 2023 American Society for Transplantation and Cellular Therapy. Published by Elsevier Inc.

Identifying the optimal conditioning intensity for stem cell transplantation in patients with myelodysplastic syndrome: a machine learning analysis

A conditioning regimen is an essential prerequisite of allogeneic hematopoietic stem cell transplantation for patients with myelodysplastic syndrome (MDS). However, the optimal conditioning intensity for a patient may be difficult to establish. This study aimed to identify optimal conditioning intensity (reduced-intensity conditioning regimen [RIC] or myeloablative conditioning regimen [MAC]) for patients with MDS. Overall, 2567 patients with MDS who received their first HCT between 2009 and 2019 were retrospectively analyzed. They were divided into a training cohort and a validation cohort. Using a machine learning-based model, we developed a benefit score for RIC in the training cohort. The validation cohort was divided into a high-score and a low-score group, based on the median benefit score. The endpoint was progression-free survival (PFS). The benefit score for RIC was developed from nine baseline variables in the training cohort. In the validation cohort, the hazard ratios of the PFS in the RIC group compared to the MAC group were 0.65 (95% confidence interval [CI]: 0.48-0.90, P = 0.009) in the high-score group and 1.36 (95% CI: 1.06-1.75, P = 0.017) in the low-score group (P for interaction < 0.001). Machine-learning-based scoring can be useful for the identification of optimal conditioning regimens for patients with MDS.

Intensified conditioning regimens improved disease-free survival and engraftment after unrelated single-unit cord blood transplantation but not after matched sibling or matched unrelated donor allogeneic hematopoietic cell transplantation

The impact of conditioning intensity on different donor groups has been unclear in allogeneic transplantation. The objective of this study was to clarify the effect of conditioning intensity on disease-free survival (DFS), relapse, non-relapse mortality (NRM), neutrophil engraftment, and graft-versus-host disease for each donor type. We retrospectively evaluated the effect of conditioning intensity on transplant outcomes for patients with acute leukemia or myelodysplastic syndrome aged between 16 and 60 years in Japan using the transplant conditioning intensity (TCI) scoring system. A total of 8526 patients who received first allogeneic transplantation from 6/6 antigen-matched sibling donor (MSD, n = 2768), 8/8 allele-matched unrelated donor (MUD, n = 2357), and unrelated single-cord blood (UCB, n = 3401) were eligible for the analyses. Compared to conditioning with TCI score 4.0, which was corresponds to conventional myeloablative conditioning, including cyclophosphamide with total body irradiation 12 Gy or busulfan 12.8 mg, and was considered as the reference group in the multivariate analyses, intensified conditioning with TCI score ≥4.5 improved DFS (hazard ratio [HR],0.81, P < 0.001) and relapse rate (HR, 0.70, P < 0.001) but only after UCB transplants and not MSD and MUD transplants. In contrast, NRM was higher after intensified conditioning with TCI score ≥4.5 for MSD (HR, 1.39, P = 0.008) and MUD (HR, 1.47, P = 0.002) transplants but not UCB transplants (HR, 1.12, P = 0.240). Neutrophil engraftment was also significantly higher after intensified conditioning with TCI score ≥4.5 but only for UCB transplants (HR, 1.24, P < 0.001), whereas it was significantly lower after reduced-intensity conditioning with TCI score ≤3.5 for MSD transplants only (HR, 0.82, P < 0.001). These data demonstrated that an intensified conditioning regimen improved survival and engraftment rate only after a UCB transplants. Therefore, TCI scoring system could enable the optimization of conditioning intensity according to donor type, particularly in terms of survival and engraftment.

Effect of the COVID-19 pandemic on allogeneic stem cell transplantation in Japan

The coronavirus disease 2019 (COVID-19) pandemic affected healthcare quality and access worldwide and may also have negatively affected the frequency and outcomes of allogeneic hematopoietic stem cell transplantation (HSCT). We evaluated the effect of the pandemic on allogeneic HSCT in Japan. Our subjects were patients who received allogeneic HSCT during January 2018-December 2020 in Japan. We assessed differences in yearly number of allogeneic HSCTs and 1-year outcomes in 2020 versus both 2019 and 2018. The total number of patients who received allogeneic HSCT increased from 3621 patients in 2018 and 3708 patients in 2019 to 3865 patients in 2020. Some following changes in allogeneic HSCT methods were observed: patients were older, fewer patients received bone marrow transplantation, fewer patients received transplants from unrelated donors, fewer patients received transplants from matched donors, more patients received reduced-intensity conditioning, and fewer patients received anti-thymocyte globulin in 2020 compared with previous years. HSCT outcomes were not affected, as 1-year overall survival was not significantly different (65.8% in 2020, vs. 66.5% in 2019 and 66.4% in 2018). Our results suggest that we can maintain transplant care during the pandemic by controlling the spread of COVID-19 and modifying HSCT methods.

Adenovirus disease after hematopoietic cell transplantation: A Japanese transplant registry analysis

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, survival, and treatment details, among 25 233 patients who underwent autologous HCT and 48 380 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 patients age ≥50 years, male patients, lymphoma, HCT-specific comorbidity index ≥3, human leukocyte antigen-mismatched or haploidentical donors, cord blood, in vivo T-cell depletion, HCT from 2005 to 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 the 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.

Feasibility of trimethoprim/sulfamethoxazole desensitization therapy in hematological diseases

The effectiveness and safety of trimethoprim/sulfamethoxazole (TMP/SMX) desensitization therapy is insufficiently evaluated in hematological diseases. From 2002 to 2019, we retrospectively analyzed 112 patients with hematological diseases who underwent desensitization therapy after TMP/SMX prophylaxis withdrawal due to adverse events. They orally started TMP/SMX at 0.4 mg/2 mg, which was then increased daily to 80 mg/400 mg for 5 or 9 days. Eighty-eight patients (79%) had complete desensitization, and the major reason for failure was rash seen in 21 cases (19%). The cause of desensitization and reasons for failure matched in 22 cases (92%). Pneumocystis pneumonia was not observed throughout the study. In the failure group, the number of eosinophils and alanine aminotransferase (ALT) levels were significantly increased after desensitization. In particular in the failure group, the slight increase in eosinophils was seen through the beginning to halfway during desensitization (36/μL (0-900/μL) and 48/μL (0-2560/μL), respectively, p = 0.025). These data show that TMP/SMX desensitization therapy is effective and safe in hematological diseases. The recurrence of adverse events could help predict desensitization success.

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

BACKGROUND AIMS

In allogeneic stem cell transplantation, unrelated donors are chosen in cases where appropriate related donors are not available. Peripheral blood stem cells (PBSCs) are more often selected as a graft source than bone marrow (BM). However, the prognostic benefits of PBSCs versus BM transplants from unrelated donors have not been carefully examined in patients with acute myeloid leukemia (AML). This study compared outcomes of adult AML patients who underwent unrelated PBSC and BM transplantation, evaluating post-transplant complications, including engraftment, graft-versus-host disease (GVHD) and infections, and determined subgroups of patients who are most likely to benefit from unrelated PBSCs compared with BM transplants.

METHODS

The authors analyzed 2962 adult AML patients who underwent unrelated PBSC or BM transplants between 2011 and 2018 (221 PBSC and 2741 BM) using the Japanese nationwide registry database, in which graft source selection is not skewed toward PBSCs.

RESULTS

In 49.7% of patients, disease status at transplantation was first complete remission (CR1). In 57.1% of cases, HLA-matched donors were selected. Myeloablative conditioning was performed in 75.1% of cases, and anti-thymocyte globulin (ATG) was added to conditioning in 10.5%. Multivariate analyses showed a trend toward favorable non-relapse mortality (NRM) in PBSC recipients compared with BM recipients (hazard ratio [HR], 0.731, P = 0.096), whereas overall survival (OS) (HR, 0.959, P = 0.230) and disease-free survival (DFS) (HR, 0.868, P = 0.221) were comparable between PBSC and BM recipients. Although the rate of chronic GVHD (cGVHD) was significantly higher in PBSC patients (HR, 1.367, P = 0.016), NRM was not increased, mainly as a result of significantly reduced risk of bacterial infections (HR, 0.618, P = 0.010), reflecting more prompt engraftments in PBSC recipients. Subgroup analyses revealed that PBSC transplantation was advantageous in patients transplanted at CR1 and in those without ATG use. PBSC recipients experienced significantly better OS and/or DFS compared with BM recipients in this patient group.

CONCLUSIONS

The authors' results confirmed the overall safety of unrelated PBSC transplantation for adult AML patients and suggested an advantage of PBSCs, especially for those in CR1. Further optimization of the prophylactic strategy for cGVHD is required to improve the overall outcome in transplantation from unrelated PBSC donors.

Ideal body weight is useful for predicting neutrophil engraftment and platelet recovery for overweight and obese recipients in single-unit cord blood transplantation

BACKGROUND

Since cord blood (CB) units are usually selected based on the cell dose /kg, overweight (25 kg/m² ≤ body mass index (BMI) < 30 kg/m²) and obese (30 kg/m² ≤ BMI) recipients tend to have difficulty in getting appropriate CB units. In general, actual body weight (ABW) is used for CB unit selection. However, ideal body weight (IBW) has been reported to be more closely correlated with successful engraftment after autologous, allogeneic bone marrow, and peripheral blood stem cell transplantation than ABW.

OBJECTIVES

We conducted this analysis to clarify the threshold of CD34⁺ cell doses based on ideal body weight (CD34^IBW) and to compare the outcomes among the groups stratified by the threshold according to actual body weight (CD34^ABW) and CD34^IBW for overweight and obese recipients in cord blood transplantation (CBT).

STUDY DESIGN

We retrospectively analyzed 650 overweight and obese recipients who received single-unit CBT. To focus on the recipients who received a low CD34⁺ cell dose /kg, those who received 1.5×10⁵ CD34⁺ cells /ABW or more were excluded. Using a cut-off of 0.8×10⁵ CD34⁺ cells/kg, we compared the outcomes in 3 groups with low CD34^ABW and low CD34^IBW (CD34^Low/Low), low CD34^ABW but high CD34^IBW (CD34^Low/High), and high CD34^ABW and high CD34^IBW (CD34^High/High).

RESULTS

Hematopoietic recoveries were significantly delayed in the CD34^Low/Low group compared with those in the CD34^Low/High group (hazard ratio (HR) 0.67 for neutrophil, P < 0.001; HR 0.72 for platelet, P = 0.014), while those were comparable in the CD34^Low/High and CD34^High/High groups (HR 1.22 for neutrophil, P = 0.16; HR 1.29 for platelet, P = 0.088). Moreover, the CD34^Low/High group demonstrated longer overall survival than the CD34^Low/Low group (HR 1.48, P = 0.011) and comparable survival to the CD34^High/High group (HR 0.93, P = 0.68).

CONCLUSIONS

This finding may address the lack of availability of CB units for some overweight and obese recipients for whom suitable donors are unavailable. Further investigations are warranted to evaluate the appropriateness of ABW and IBW.

HLA 1-3 antigen-mismatched related peripheral blood stem cells transplantation using low-dose antithymocyte globulin versus unrelated cord blood transplantation

Little information is available regarding whether unrelated cord blood transplantation (CBT) or an HLA 1-3 antigen-mismatched related donor peripheral blood stem-cell transplantation (PBSCT) using low-dose anti-thymocyte globulin (ATG) is superior as an alternative transplantation for patients who lack an HLA-matched sibling or unrelated donor. Therefore, we evaluated 7861 patients with hematologic malignancies (aged 0 to 70 years) who received either a CBT without ATG (CBT-no ATG, n = 7034) or an HLA 1-3 antigen-mismatched related donor PBSCT using low-dose ATG (PBSCT-ATG, n = 827). CBT-no ATG was associated with significantly better overall survival (OS) than the use of a PBSCT-ATG (hazard ratio [HR], 0.77; p < .001), although PBSCT-ATG patients with an HLA 1 antigen-mismatch showed OS comparable to that in the CBT-no ATG group. Neutrophil and platelet engraftment was significantly delayed, whereas the incidences of nonrelapse mortality, and severe graft-versus-host disease (GVHD) were significantly lower in the CBT-no ATG group. The incidences of relapse and chronic GVHD were comparable between these donors. In conclusion, CBT-no ATG may be a better alternative than HLA-mismatched related donor PBSCT using low-dose ATG. Notably, HLA 2-3 antigen mismatch-related transplantation with low-dose ATG had significant adverse effects on transplantation outcomes.

Exposure to aerosol extract from heated tobacco products causes a drastic decrease of glutathione and protein carbonylation in human lung epithelial cells

Heated tobacco products (HTPs) are an emerging class of tobacco goods that claim to have lower health risks than those of smoking combustible tobacco products. In this study, we exposed human lung epithelial cell lines to extracts prepared from HTP aerosols and combustible cigarette smoke to compare cytotoxicity. We focused on the effects of aldehydes present in the aerosols of HTPs at levels close to those in combustible cigarette smoke. Significant toxicity was confirmed for the HTP extract, albeit to a lesser extent than that with the combustible cigarette extract. When redox balance was evaluated by the oxidative loss of low-molecular-weight thiols in the cells, we found that total glutathione (GSH) contents and low-molecular-weight thiol levels were significantly decreased after exposure to the aerosol extract of HTPs. These results indicated that GSH is rapidly consumed during the detoxification of xenobiotics, such as aldehydes from tobacco extracts. Accordingly, exposure to the aerosol extract of HTPs resulted in the enhanced carbonylation of many proteins. In a simple comparison, the results for HTPs were significantly different from those obtained with combustible cigarette smoke, suggesting reduced toxicity of HTPs. However, we found significant and harmful effects after exposing lung epithelial cells to the aerosol extract of HTPs. Thus, a further comprehensive study is needed to clarify the lung damage induced via the long-term inhalation of aerosols from HTPs.