Chronic graft-versus-host syndrome in man. A long-term clinicopathologic study of 20 Seattle patients

Incidence and impact of invasive fungal infection comparing post-transplant cyclophosphamide with cyclosporine plus methotrexate GVHD prophylaxis in allogeneic HSCT

BACKGROUND

In recent years, haploidentical hematopoietic stem cell transplantation (haploHSCT) with post-transplant cyclophosphamide (PTCy) has become increasingly prevalent. However, the precise impact of invasive fungal disease (IFD) in relation to graft-versus-host disease (GVHD) prophylaxis and donor type remains to be elucidated.

METHODS

In this study, we analyzed data from 580 HSCT patients, comprising 80 patients who received haploidentical grafts and 500 patients who received grafts from other donor types. PTCy was exclusively administered to haploidentical HSCT recipients, while cyclosporine A (CsA) in combination with short-course methotrexate (scMTX) was used for patients receiving grafts from other donors.

RESULTS

The IFD rate by PTCy and CsA plus scMTX was 15 % and 15.6 %, respectively. At 6 months and 1 year post-transplant, the cumulative incidence of IFD was 9.4 % and 14.8 % for the PTCy group, and 7.9 % and 12.3 % for the CsA plus scMTX group, respectively. Both groups exhibited poor survival outcomes associated with IFD. Identified risk factors for IFD included age ≥ 45 years, disease relapse, and grade III-IV acute GVHD. Aspergillus spp. and Candida spp. were the most commonly isolated pathogens. High rate of cytomegalovirus reactivation was also noticed in PTCy or CsA plus scMTX group, but not a risk factor for IFD.

CONCLUSION

The similar IFD rate between haploHSCT with PTCy and others with CsA plus scMTX was documented, with Aspergillus spp. and Candida spp. as the most common pathogens. Further research is needed to investigate IFD following haploHSCT with PTCy and to explore differences with other types of allogeneic HSCT.

Donor C1 Group KIR-ligand inferiority is linked to increased mortality in haploidentical hematopoietic stem cell transplantation with post-transplant cyclophosphamide

BACKGROUND AIMS

In HLA-identical hematopoietic stem cell transplantation (HSCT), HLA-C1 group killer cell immunoglobulin-like receptor (KIR) ligands have been linked to graft-versus-host disease, whereas C2 homozygosity was associated with increased relapses. The differential impact of the recipients versus the donor's HLA-C KIR ligands cannot be determined in HLA-identical HSCT but may be elucidated in the haploidentical setting, in which HLA-C (including the HLA-C KIR ligand group) mismatching is frequently present.

METHODS

We retrospectively investigated the effect of recipient versus donor C1 ligand content on survival and complications in post-transplant cyclophosphamide (PTCy)-based haploidentical HSCT (n = 170). HSCTs were categorized as donor C1 supremacy (n = 34), C1 balance (n = 98), or donor C1 inferiority (n = 38).

RESULTS

Following HSCT from C1-inferior donors, overall mortality (hazard ratio, 2.84; P = 0.002) and non-relapse mortality (sub-hazard ratio [SHR], 3.86; P = 0.007) were significantly increased. Following HSCT from C1-superior donors, a low 1-year relapse incidence and favorable 1-year progression-free survival were observed. C1 supremacy did not significantly impact acute or chronic graft-versus-host disease, natural killer cell reconstitution, or day 21 chimerism. Infection was a more common cause of death among recipients with a C1-inferior donor compared with C1-superior or C1-balanced donors.

CONCLUSIONS

These findings suggest an increased risk for NRM, particularly infection-related deaths, associated with C1-inferior donors. Upon independent confirmation, C1-inferior donors should be avoided in PTCy-based haploidentical HSCT.

Comparing Comorbidity Indices to Predict Survival After Pediatric Hematopoietic Stem Cell Transplantation for Nonmalignant Disease

BACKGROUND

Hematopoietic stem cell transplantation (HCT) is a potentially curative treatment for children with hematological or immunological disorders. However, treatment-related morbidity and mortality remain concerning. Various comorbidity indices are currently used to assess the risk of complications following pediatric HCT.

PROCEDURE

We compared four comorbidity indices to determine which can most accurately estimate the risk of morbidity and mortality in pediatric nonmalignant HCT. We analyzed 308 pediatric allogeneic nonmalignant HCTs performed between January 2010 and December 2022. Four indices were evaluated: hematopoietic stem cell transplantation-specific comorbidity index (HCT-CI), youth nonmalignant hematopoietic stem cell transplantation comorbidity index (ynHCT-CI), simplified ynHCT-CI, and simplified comorbidity index (SCI). The primary outcome was overall survival (OS). The secondary outcome was graft-versus-host disease (GvHD)-free event-free survival (EFS), defined as acute GvHD Grade 3 or 4, extensive chronic GvHD, retransplantation, or death. The area under the receiver operator characteristic curve (AUC) was calculated per index and outcome at 100 days, 1 year, and 2 years post-HCT.

RESULTS

For OS, AUC values ranged from 0.611 to 0.755. The simplified ynHCT-CI and ynHCT-CI generally had superior discriminative abilities for OS, although no significant difference was found. For EFS, AUC values were between 0.539 and 0.632. The ynHCT-CI performed best for EFS, with AUC values of the simplified ynHCT-CI marginally lower. The ynHCT-CI significantly outperformed the HCT-CI at 100 days post transplantation (p = 0.045).

CONCLUSION

The ynHCT-CI most accurately predicted outcomes after pediatric nonmalignant HCT. We propose the use of ynHCT-CI in future clinical management guidelines in this cohort.

Fludarabine plus myeloablative dose of busulfan regimen was associated with high nonrelapse mortality in allogeneic hematopoietic stem cell transplantation for malignant lymphoma: a propensity score-matched comparison study with fludarabine plus high-dose melphalan

BACKGROUND

In recent years, there have been notable advancements in the treatment of malignant lymphoma. However, a certain percentage of patients are unlikely to achieve a cure through chemotherapy alone. Therefore, allogeneic hematopoietic stem cell transplantation (allo-HSCT) remains a crucial curative treatment for malignant lymphoma.

OBJECTIVE

FluBu4, comprising fludarabine (Flu) combined with a myeloablative dose of intravenous busulfan (Bu; 12.8 mg/kg in total), is a widely used conditioning regimen for allo-HSCT, but its usefulness in malignant lymphoma (ML) has not been fully investigated. The objective of this study was to evaluate the efficacy and safety of FluBu4 in allo-HSCT for lymphoma by comparing the outcomes of two conditioning regimens: FluBu4 and FluMel140.

STUDY DESIGN

We used a Japanese national database from the Transplant Registry Unified Management Program to retrospectively analyze the first allo-HSCT for ML in patients aged ≥16 years. Allo-HSCT cases treated with posttransplant cyclophosphamide were excluded. Two groups, namely FluBu4 and FluMel140 were selected by propensity score matching (PSM) with a case ratio of 1:2.

RESULTS

From 921 cases, 113 were selected by PSM for the FluBu4 group and 226 for the FluMel140 group. The median age was 54 (19-68) years, the median observation period of survivors was 33.8 months, and 145 (42.7%) had a history of autologous HSCT. There were no significant differences in patients' backgrounds between the two groups after PSM. Three-year overall survival (OS) was significantly worse for FluBu4 than for FluMel140 (28.0% vs. 48.6%; P < 0.01). The three-year cumulative relapse rate was comparable for FluBu4 and FluMel140 (40.1% vs. 38.5%; P = 0.65). However, 3-year nonrelapse mortality was significantly higher for FluBu4 than for FluMel140 (35.3% vs. 22.5%; P = 0.02). There was no significant difference between the two treatment groups in the cumulative incidence of acute graft versus host disease (aGVHD) at day 100 after allo-HSCT and the three-year cumulative incidence of chronic GVHD. While the common and major COD was the relapse of lymphoma, aGVHD and noninfectious lung complications were observed more frequently with FluBu4 than with FluMel140. One-year cumulative incidence of interstitial pneumonia was significantly higher for FluBu4 than for FluMel140 (5.3% vs. 0.4%; P = 0.03).

CONCLUSION

FluBu4 use was associated with worse NRM and OS in allo-HSCT for ML compared with FluBu4 and FluMel140 adjusted by PSM. Patients treated with FluBu4 had a higher incidence of noninfectious pulmonary complications and an increased number of associated deaths. A higher rate of NRM in the patients treated with FluBu4 was particularly evident in patients aged ≥60, and its use should be avoided in this patient population.

Comparable outcomes after busulfan- or treosulfan-based conditioning for allo-HSCT in children with ALL: results of FORUM

ABSTRACT

The superiority of total body irradiation (TBI)-based vs chemotherapy conditioning for allogeneic hematopoietic stem cell transplantation (allo-HSCT) in children with acute lymphoblastic leukemia (ALL) has been established in the international, prospective phase-3 FORUM study, randomizing 417 patients aged 4-18 years in complete remission (CR), who received allo-HSCT from HLA-matched sibling or unrelated donors. Because of the unavailability of TBI in some regions and to accommodate individual contraindications, this study reports the prespecified comparison of outcomes of patients receiving busulfan (BU)- or treosulfan (TREO)-based regimens from 2013 to 2018. Overall, 180 and 128 patients received BU/thiotepa (THIO)/fludarabine (FLU) or TREO/THIO/FLU, respectively. Data were analyzed as of February 2023, with a median follow-up of 4.2 years (range, 0.3-9.1). 3-year overall survival was 0.71 (BU, 95% confidence interval [0.64-0.77]) and 0.72 (TREO, [0.63-0.79]) and 3-year event-free survival was 0.60 (BU, [0.53-0.67]) and 0.55 (TREO, [0.46-0.63]). The 3-year cumulative incidence of relapse (BU, 0.31 [0.25-0.38]; TREO, 0.36 [0.27-0.44]); and nonrelapse mortality (BU, 0.08 [0.05-0.13]; TREO, 0.09 [0.05-0.15]) were comparable. One case of fatal veno-occlusive disease occurred in each group. No significant differences in acute and chronic graft-versus-host disease (GVHD) or 3-year GVHD-free and relapse-free survival (BU, 0.48 [0.41-0.55]; TREO, 0.45 [0.37-0.54]) were recorded. Outcomes for patients in first and second CR were similar irrespective of the regimen. In conclusion, BU/THIO/FLU or TREO/THIO/FLU regimens can be an alternative to TBI for patients with ALL aged >4 years with contraindications or lack of access to TBI. This trial was registered at www.ClinicalTrials.gov as #NCT01949129.

Increased Non-Relapse Mortality in Older People With Allogeneic Hematopoietic Stem Cell Transplantation Using Fludarabine and Myeloablative Dose of Busulfan-Based Regimen

Fludarabine and myeloablative busulfan (FluBu4) in allogeneic hematopoietic stem cell transplantation (HSCT) for older people have not been adequately examined. This retrospective study analyzed data from a large-scale, nationwide database in Japan. Adult patients (> 15 years old, y/o) who received their first HSCT with FluBu4 for hematological malignancies were included. They were categorized into the younger (< 60 y/o, N = 1295) and the older group (≥ 60 y/o, N = 993). The 3-year overall survival (OS) rate after HSCT was significantly worse in the older group than in the other (p < 0.01, 39.9% vs. 48.5%). The 3-year non-relapse mortality (NRM) was significantly higher in the older group than in the other (p < 0.01, 30.9% vs. 23.0%), and the 3-year cumulative incidence of relapse was comparable between them. According to the multivariate analysis, age ≥ 60 years was significantly associated with poor OS and high NRM. In a subgroup analysis of the older group, the use of additional chemotherapeutic drugs to FluBu4 was significantly associated with poor OS and high NRM. Total body irradiation was significantly associated with high NRM and 1-year incidence of sinusoidal obstruction syndrome but not with OS. Thus, FluBu4 should be used with caution in older people.

Relationship Between an Interleukin 6 SNP and Relapse After Allogeneic Bone Marrow Transplantation

Background/Objectives: Unrelated bone marrow transplantation (BMT) is a curative treatment for hematological malignancies. While HLA mismatch is a recognized risk factor in unrelated BMT, the significance of non-HLA single nucleotide polymorphisms (SNPs) remains uncertain. Cytokines play key roles in several aspects of unrelated BMT. Although the relationship between cytokine gene SNPs and BMT outcomes has been examined, the findings obtained have been inconsistent; therefore, further investigations in additional cohorts are warranted. Methods: Four SNPs in the IL2, IL6, IFN-gamma, and TGF-beta1 genes were retrospectively genotyped in 822 malignant patients and their corresponding donors who received unrelated BMT through the Japan Marrow Donor Program with compatibility at minimum HLA-A, -B, and -DRB1. The relationships between these SNP genotypes and BMT outcomes were statistically analyzed. Results: The donor interleukin-6 (IL6) SNP, rs1800796, also known as -572G>C and -634C/G, was associated with the relapse of the original disease in both univariable and multivariable regression analyses (minimum p-value = 0.0013), and the cumulative incidence curve analysis identified CC as a risk genotype (p-value = 0.0012). None of these SNPs correlated with overall survival. Conclusions: The donor IL6 SNP, rs1800796, may serve as a useful predictor of tumor relapses if validated.

Impact of First- and Second-Generation Tyrosine Kinase Inhibitors on the Development of Graft-Versus-Host Disease in Individuals with Chronic Myeloid Leukemia: A Retrospective Analysis on Behalf of the Polish Adult Leukemia Group

Background: The implementation of tyrosine kinase inhibitors (TKIs) in the treatment of chronic myeloid leukemia (CML) has brought a significant improvement in the prognosis for CML patients and a decrease in the number of patients requiring allogeneic hematopoietic stem cell transplantation (allo-HCT). Nevertheless, the impact of TKIs on allo-HCT outcomes has not been thoroughly explored. Objectives: The main endpoint of our research was to assess the impact of prior TKI treatment on acute graft-versus-host disease (aGvHD) and chronic graft-versus-host disease (cGvHD). Methods: In our retrospective analysis, we included 240 patients treated between 1993 and 2013 and divided them into three groups according to the therapy administered prior to haploidentical, matched-related, or matched-unrelated donor allo-HCT (imatinib group n = 41, dasatinib/nilotinib group n = 28, TKI-naïve group n = 171). Results: Both the cumulative incidence of aGvHD (p = 0.044) and cGvHD (p < 0.001) in individuals receiving second-generation TKIs (2G-TKIs) prior to allo-HCT were decreased compared to patients receiving no TKIs or imatinib (IMA) (40.7% vs. 61.4% vs. 70.7%, p = 0.044; 25.0% vs. 76.4% vs. 51.2%, p < 0.001, respectively). In the case of the 2G-TKI cohort, the number of low-grade aGvHD and cGvHD was significantly lower compared to the IMA and TKI-naïve groups (p = 0.018, p = 0.004; p < 0.001 versus TKI-naïve, respectively). In terms of 3-year overall survival (OS), there were no important variations between TKI-naïve, IMA, and 2G-TKI (55% vs. 49.9% vs. 69.6%, p = 0.740). Conclusions: The results of our study suggest that TKI treatment prior to allo-HCT may have a protective impact on immune-mediated outcomes.

Post-transplant cyclophosphamide separates graft-versus host disease and graft versus leukemia effects after HLA-matched stem-cell transplantation for acute myeloid leukemia

The association of graft-versus-host disease (GVHD) and graft-versus-leukemia (GVL) effects after allogeneic stem-cell transplantation (SCT) is well-established but was not confirmed in the modern era and following post-transplant cyclophosphamide (PTCy). We assessed GVHD/ GVL association in AML patients following HLA-matched SCT with standard calcineurin-based (n = 12,653, 57% with additional in-vivo T-cell depletion) or PTCy-based (n = 508) GVHD prophylaxis. Following standard prophylaxis, acute GVHD grade II-IV and III-IV, chronic GVHD, and extensive chronic GVHD rates were 23.8%, 7.5%, 37.0%, and 16.3%, respectively. Acute GVHD grade II and III-IV were associated with lower relapse [hazard-ratio (HR) 0.85, P = 0.002; HR 0.76, P = 0.003, respectively)], higher non-relapse mortality (NRM) (HR 1.5, P < 0.001; HR 6.21, P < 0.001) and lower overall survival (OS) (HR 1.49, P < 0.001; HR 6.1, P < 0.001). Extensive chronic GVHD predicted lower relapse (HR 0.69, P < 0.001), higher NRM (HR 2.83, P < 0.001), and lower OS (HR 2.74, P < 0.001). Following PTCy, GVHD rates were 22.8%, 6.2%, 35.5%, and 17.7%, respectively. Acute GVHD was not associated with relapse (HR 1.37, P = 0.15) but predicted higher NRM (HR 3.34, P < 0.001) and lower OS (HR 1.92, P = 0.001). Chronic GVHD was not prognostic for these outcomes. In conclusion, GVHD and GVL are strongly associated with contemporary SCT. However, following PTCy, GVHD is not associated with reduced relapse.

Impact of bone marrow nucleated cell subfractions on transplant outcomes in patients with acute lymphoblastic leukemia

OBJECTIVES

Our previous study showed that a high pre-transplant nucleated cell count in the bone marrow is associated with increased non-relapse mortality (NRM) and decreased overall survival (OS) in patients with acute lymphoblastic leukemia (ALL) in remission. In this retrospective multicenter study, we aimed to examine the association between nucleated cell subfractions and transplant outcomes using the same patient cohort as our previous study.

METHODS

This study included patients with ALL who underwent their first allogeneic hematopoietic stem cell transplantation (allo-HSCT) between 2010 and 2022. The patients were stratified into high and low cell group levels to compare transplant outcomes using cutoff values for predicting OS in each subfraction determined using receiver operating curves.

RESULTS

In the cohort of 134 patients, the median values for myeloid, erythroid, monocyte, and lymphocyte series were 16,860/µL (468-229,296), 15,584/µL (34-246,992), 1,446/µL (70-25,296), and 4,215/µL (90-33,856), respectively.

DISCUSSION

The univariate analysis showed that the groups with high levels of myeloid cells (≥38,000/µL, n = 48), erythroid cells (≥25,000/µL, n = 45), and monocyte cells (≥4,200/µL, n = 44) were all associated with worse 3-year OS and higher NRM than the low-level groups. These findings were confirmed by using multivariate analysis. The high cell count group showed a higher incidence of NRM associated with acute graft-versus-host disease or immunological disorders.

CONCLUSION

High myeloid, erythroid, and monocytic cell levels in the bone marrow before allo-HSCT may independently increase the risk of NRM and reduce OS.

Trends in allogeneic transplantation for favorable risk acute myeloid leukemia in first remission: a longitudinal study of >15 years from the ALWP of the EBMT

We assessed outcomes of allogeneic transplantation (HSCT) in favorable risk AML in CR1 over 3 time periods. 1850 patients were included, 2005 to 2009- 222, 2010 to 2014 -392, and 2015 to 2021-1236; 526 with t (8:21), 625 with inv (16), and 699 with NPM1mutFLT3WT. Patients transplanted in 2015-2021 were older (p < 0.0001) with more patients ≥60 years of age (p < 0.0001). The most frequent diagnosis in 2015-2021 was NPM1mutFLT3WT vs. t (8:21) in the 2 earlier periods, (p < 0001). Haploidentical transplants (Haplo) increased from 5.9% to 14.5% (p < 0.0001). Graft-versus-host disease (GVHD) prophylaxis with post-transplant cyclophosphamide (PTCy) was more frequent in 2015-2021 vs. the other 2 periods (p < 0.0001). On multivariate analysis, incidence of total chronic GVHD was reduced in HSCTs performed ≥2015 vs. those performed in 2005-2009, hazard ratio (HR) = 0.74 (95% CI 0.56-0.99, p = 0.046) and GVHD-free, relapse-free survival (GRFS) improved for patients transplanted from 2010-2014 vs. those transplanted in 2005-2009, HR = 0.74 (95% CI 0.56-0.98, p = 0.037). Other HSCT outcomes did not differ with no improvement ≥2015. LFS, OS, and GRFS were inferior in patients with t (8:21) with HR = 1.32 (95% CI 1.03-1.68, p = 0.026), HR = 1.38 (95% CI 1.04-1.83, p = 0.027) and HR = 01.25 (95% CI 1.02-1.53, p = 0.035), respectively. In conclusion, this retrospective analysis of HSCT in patients with favorable risk AML, transplanted over 16 years showed an increased number of transplants in patients ≥60 years, from Haplo donors with PTCy. Most importantly, 3-year GRFS improved ≥2010 and total chronic GVHD reduced ≥2015, with no significant change in other HSCT outcomes.

Pulmonary Function in Pediatric Stem Cell Transplantation

BACKGROUND

Pediatric hematopoietic stem cell transplantation often results in pulmonary complications, yet limited data exist on pulmonary function in Thailand. This study aims to assess pulmonary function, investigating associated complications and identifying clinical factors linked to pre- and post-transplant pulmonary function defects.

METHODS

In this retrospective cohort study, we focused on children aged 6-18 years who underwent hematopoietic stem cell transplantation between 1999 and 2020, ensuring accessible pulmonary function tests results.

RESULTS

Among 48 patients, abnormal pulmonary function pre- and post-transplant (2-8 years) included a diffusion defect in 16.7% and 18.8%, a restrictive defect in 20.8% and 8.3%, and an obstructive defect in 4.2% and 10.4%, respectively. Pulmonary complications occurred in 16 patients (33.3%), including 15 infections and 1 case of bronchiolitis obliterans. While pretransplant pulmonary function defects were not significantly associated with specific characteristics, post-transplant pulmonary complications correlated with post-transplant pulmonary function defects (aOR = 4.11, 95% CI = 1.23-13.64, P = .02). Among the 6 patients with pre- and post-transplant follow-up, those with pulmonary complications showed a discernible decline in pulmonary function over time, while those without pulmonary complications remained stable or improved. However, the differences between these groups did not reach statistical significance (P = .13-.76).

CONCLUSIONS

Prevalent pulmonary function defects and complications in pediatric hematopoietic stem cell transplantation highlight the importance of close pulmonary function monitoring. Post-transplant pulmonary complications are associated with defects, suggesting a potential trend of a subsequent decline in lung function, warranting further prospective validation.

Comparing transplant outcomes in ALL patients after myeloablative conditioning in mismatch-related or unrelated donor settings

The optimal myeloablative conditioning regimen for ALL patients undergoing hematopoietic cell transplant (HCT) with an alternative donor is unknown. We analyzed HCT outcomes ALL patients (n = 269) who underwent HCT at our center from 2010 to 2020 in complete remission (CR) after FTBI-etoposide and CNI-based GvHD prophylaxis for matched donor HCT (ETOP-package; n = 196) or FTBI-Fludarabine and post-transplant cyclophosphamide (PTCy)-based prophylaxis for HLA- mismatched (related or unrelated) donors (FLU-package; n = 64). Patients in FLU-package showed a significant delay in engraftment (p < 0.001) and lower cumulative incidence (CI) of any and extensive chronic GVHD (p = 0.009 and 0.001, respectively). At the median follow up of 4.6 years (range 1-12 years); non-relapse mortality, overall or leukemia-free survival and GVHD-free/relapse-free survival were not significantly impacted by the choice of conditioning. However, in patients at CR2 or with measurable residual disease (MRD+), there was a trend towards higher relapse after FLU-package (p = 0.08 and p = 0.07, respectively), while patients at CR1 regardless of MRD status had similar outcomes despite the package/donor type (p = 0.9 and 0.7, respectively). Our data suggests that FLU-package for alternative donors offers comparable outcomes to ETOP-package for matched donor HCT to treat ALL. Disease status and depth of remission at HCT were independent predictors for better outcomes.

Young (<35 years) haploidentical versus old (≥35 years) mismatched unrelated donors and vice versa for allogeneic stem cell transplantation with post-transplant cyclophosphamide in patients with acute myeloid leukemia in first remission: a study on behalf of the Acute Leukemia Working Party of the European Society for Blood and Marrow Transplantation

We compared transplantation (HSCT) outcomes in AML patients undergoing HSCT with post-transplant cyclophosphamide (PTCy) in first complete remission from 1065 young (<35 years) haploidentical (Haplo) donors (yHaplo) vs. 147 old (≥35 years) mismatched unrelated donors (oMMUD) (first comparison) and from 271 young (<35 years) MMUD (yMMUD) vs. 1315 old (≥35 years) Haplo donors (oHaplo) (second comparison). Acute graft-versus-host disease (aGVHD) grades II-IV were significantly lower in the yHaplo vs. oMMUD group (HR = 0.62, p = 0.007). There were no significant differences in chronic GVHD, non-relapse mortality (NRM), relapse incidence, leukemia-free survival, overall survival, and GVHD-free and relapse-free survival. As for the second comparison, more patients in the oHaplo group had de novo AML, 86.6% vs. 81.9% in the yMMUD group (p = 0.044), while myeloablative conditioning was used more frequently in the yMMUD group, 53.3% vs. 46.8% in the oHaplo group (p = 0.049). aGVHD grades II-IV and NRM were significantly lower in the yMMUD vs. oHaplo group (HR = 0.69, p = 0.013 and HR = 0.60, p = 0.022). All other transplant outcomes did not differ. In conclusion, HSCT from young alternative donors (<35 years) results in a lower incidence of grades II-IV aGVHD. In addition, NRM is lower in HSCT from yMMUD compared to HSCT from oHaplo.

Late effects after allogeneic haematopoietic cell transplantation in children and adolescents with non-malignant disorders: a retrospective cohort study

BACKGROUND

Continued advances in haematopoietic cell transplantation (HCT) for children with non-malignant diseases (NMDs) have led to a growing population of survivors in whom late occurring toxic effects remain a challenge. We investigated the incidence of and risk factors for post-transplant toxicities in a contemporary cohort of children and adolescents undergoing HCT for NMDs.

METHODS

In this retrospective cohort study, we extracted data from the Center for International Blood and Marrow Transplantation Research (CIBMTR) database to analyse timing and incidence of effects and risk factors associated with late effects of HCT for treatment of NMDs at age 21 years or younger. Late effects of interest were avascular necrosis, cataracts, congestive heart failure, myocardial infarction, diabetes, gonadal dysfunction, growth hormone deficiency, hypothyroidism, renal failure requiring dialysis, and neurological events (stroke and seizure). Cumulative incidence of each late effect was calculated at 5 years and 7 years after HCT. Risk factors were evaluated in Cox proportional hazards regression analyses. Main exposures were primary NMD, age, sex, ethnicity and race, insurance, donor and graft type, myoablative conditioning, total-body irradiation exposure, graft-versus-host disease (GVHD), and transplant year. Primary outcomes were rates, cumulative incidence probability (95% CI), and risk-factors for organ-specific late effects.

FINDINGS

Between Jan 1, 2000, and Dec 31, 2017, 7785 patients aged 21 years or younger underwent HCT. 1995 patients were ineligible or did not consent to be included. 5790 patients from 171 centres were included in the analysis. 3505 (60·5%) of 5790 patients were male and 2285 (39·5%) were female. 2106 (36·4%) patients were White, 771 (13·3%) were Hispanic, and 773 (12·7%) were Black. 1790 (30·9%) patients were non-USA residents. Median age at HCT was 5·5 years (range 0·0-21·0). 1127 (19%) of 5790 patients had one late effect, and 381 (7%) had at least two. At 7 years post-HCT, the cumulative incidence probability was 1·9 (95% CI 1·5-2·3) for cataracts, 4·9 (4·3-5·6) for diabetes, 2·6 (2·1-3·1) for gonadal dysfunction, 3·2 (2·7-3·8) for hypothyroidism, 5·0 (4·4-5·7) for growth disturbance, 8·1 (7·4-8·9) for renal failure, 1·6 (1·3-2·0) for avascular necrosis, 0·6 (0·4-0·8) for congestive heart failure, 0·2 (0·1-0·3) for myocardial infarction, and 9·4 (8·6-10·2) for neurological effects. Age 10 years or older at HCT, unrelated donor source, total-body irradiation, and GVHD were identified as risk factors for long-term effects.

INTERPRETATION

The findings highlight the need for, and access to, multidisciplinary and lifelong follow-up for children undergoing HCT for NMDs. As more children undergo treatment with cellular therapies for non-malignant conditions, further analyses of post-transplant data could increasingly guide treatment decisions and subsequent long-term surveillance.

FUNDING

National Cancer Institute, National Heart, Lung and Blood Institute, National Institute of Allergy and Infectious Diseases, Health Resources and Services Administration, and Office of Naval Research.

Longitudinal outcome over four decades of allogeneic stem cell transplantation: a single center experience

This 45-year study (1978-2022) at a single institution evaluated HSCT outcomes and complications, emphasizing recent advances, with to provide insights into HSCT's evolving field and ongoing efforts to enhance patient outcomes. Involving 1707 patients, the study revealed an initial phase (1978-1987) with a limited activity that yielded modest outcomes, a nearly three-decade span (1988-2016) with a substantial increase in transplant activity, emphasizing umbilical cord blood transplantation (UCBT) for patients lacking a suitable matched sibling donor. In addition to a gradual increase in recipient age, significant improvement in outcomes emerged in the recent period (2017-2022), marked by UCBT replacement with haploidentical transplants, introduction of PTCY-based GVHD prophylaxis for all type of transplants, and increased use of conditioning regimens with thiotepa, busulfan, and fludarabine. In this period, reductions in GVHD, non-relapse mortality, and relapse rates significantly contributed to improved overall survival, event-free survival, and GVHD-free/relapse-free survival. The study identified specific factors, including GVHD prophylaxis and donor selection changes, associated with these positive trends. This four-decade study provides a unique perspective on allogeneic HSCT, showcasing the dynamic evolution of transplantation practices and their impact on outcomes, offering valuable insights for personalized treatment approaches and emphasizing continual innovation in this critical therapeutic modality.

Clinical characteristics of membranous nephropathy after allogeneic hematopoietic stem cell transplantation: A real-world multicenter study

Membranous nephropathy (MN) is a rare complication that can occur after allogeneic hematopoietic stem cell transplantation (allo-HSCT). MN patients may develop nephrotic syndrome or even kidney failure, which greatly affects their quality of life and prognosis. However, current knowledge regarding MN after allo-HSCT is limited. Thus, a multicenter nested case‒control study was conducted. Patients who had been diagnosed with MN after allo-HSCT were retrospectively identified at 8 HSCT centers. A total of 51 patients with MN after allo-HSCT were included. The median age of MN patients after allo-HSCT was 38 years, and the median duration from HSCT to MN was 18 months. The use of HLA-matched donors (P = 0.0102) and peripheral blood as the graft source (P = 0.0060) were identified as independent predisposing risk factors for the onset of MN after allo-HSCT. Compared to those in the control group, the incidence of extensive chronic graft-versus-host disease was greater in the MN patients (P = 0.0002). A total of 31 patients developed nephrotic syndrome. Patients receiving combination treatments of corticosteroids and immunosuppressants appeared to have better outcomes. In conclusion, MN is a rare but occasionally severe complication following HSCT and may require active treatment.

The efficacy and safety of third-party umbilical blood/umbilical cord mesenchymal stem cell assisted related haploid hematopoietic stem cell transplantation in pediatric patients with acute leukemia: an observational study

Background

There is limited data on third-party umbilical cord blood (UCB) or mesenchymal stem cell (MSC) transplantation-assisted haploidentical hematopoietic stem cell transplantation (haplo-HSCT) in pediatric patients.

Objective

To evaluate the efficacy and safety of UCB and MSC transplantation-assisted haplo-HSCT in pediatric patients with acute leukemia (AL).

Design

Observational study.

Methods

Clinical data of 152 children with AL undergoing haplo-HSCT at the Children's Hospital of Soochow University between January 2020 and June 2022 were collected. The patients were divided into the haplo-HSCT + UCB group (n = 76), haplo-HSCT + MSC group (n = 31), and haplo-HSCT group (n = 45). Hematopoietic reconstruction time, complications within 30 days after transplantation, and survival and recurrence at 3 years after transplantation were compared among the groups.

Results

Multivariate analysis revealed that haplo-HSCT with MSC and human leukocyte antigen (HLA) matching ⩾6/10 were independent factors reducing engraftment syndrome (ES) incidence. There were no significant differences among the groups in the hematopoietic reconstruction time or incidence of complications within 30 days after transplantation (p > 0.05). Overall survival, relapse-free survival, cumulative incidence of relapse, cumulative incidence of hematological relapse, and 3-year transplant-related mortality were not significantly different (p > 0.05). The incidence of adverse reactions in the haplo-HSCT + UCB group was 97.3% within 4 h after UCB infusion, with a particularly high occurrence rate of 94.7% for hypertension. No transfusion-related adverse reactions occurred after the transfusion of umbilical cord MSC in the haplo-HSCT + MSC group.

Conclusion

MSC-assisted haplo-HSCT can reduce ES incidence after transplantation in pediatric patients with AL. UCB infusion is associated with a high incidence of reversible hypertension. However, no adverse reactions were observed in umbilical cord MSC transfusion.

Improved Outcomes in Myelofibrosis after Allogeneic Stem-Cell Transplantation in the Era of Ruxolitinib Pretreatment and Intensified Conditioning Regimen-Single-Center Analysis

(1) Background: Allogeneic hematopoietic stem-cell transplantation (allo-HSCT) is the only treatment with the potential for cure in patients with myelofibrosis (MF). However, the risk of graft rejection, which is particularly high in MF, and the risk of significant non-relapse mortality must be considered. (2) Methods: In this retrospective, single-center study, we compared allo-HSCT outcomes in 36 adult patients with MF transplanted at two-time intervals (2001-2015 versus 2016-2021). (3) Results: The estimated median overall survival was 48.9 months (95%CI 0.00-98.2) in the cohort transplanted before 2016 and not reached in the more recent years (p = 0.04) due to markedly lower non-relapse mortality (p = 0.02). The 3-year relapse incidence was low in both cohorts (11.1% and 12.5%, p > 0.99). When comparing only subgroups within the more recent cohort based on the presence or absence of total body irradiation (TBI) or the use of sequential regimens, OS and PFS were comparable. (4) Conclusion: Pretreatment with ruxolitinib, intensified conditioning, and the preferential use of haploidentical related instead of mismatched unrelated donors for patients lacking an HLA-identical donor are most likely responsible for the improved outcome after allo-HCT in MF in recent years.

Current Approaches for the Prevention and Treatment of Acute and Chronic GVHD

Whereas aGVHD has strong inflammatory components, cGVHD displays autoimmune and fibrotic features; incidence and risk factors are similar but not identical; indeed, the aGVHD is the main risk factor for cGVHD. Calcineurin Inhibitors (CNI) with either Methotrexate (MTX) or Mycophenolate (MMF) still represent the standard prophylaxis in HLA-matched allogeneic stem cell transplantation (HSCT); other strategies focused on ATG, Post-Transplant Cyclophosphamide (PTCy), Abatacept and graft manipulation. Despite the high rate, first-line treatment for aGVHD is represented by corticosteroids, and Ruxolitinib is the standard second-line therapy; investigational approaches include Microbiota transplant and the infusion of Mesenchymal stem cells. GVHD is a pleiotropic disease involving any anatomical district; also, Ruxolitinib represents the standard for steroid-refractory cGVHD in this setting. It is a pleiotropic disease involving any anatomical district; also, Ruxolitinib represents the standard for steroid-refractory cGVHD in this setting. Extracorporeal Photopheresis (ECP) is still an option used for steroid refractoriness or to achieve a steroid-sparing. For Ruxolitinib-refractory cGVHD, Belumosudil and Axatilimab represent the most promising agents. Bronchiolitis obliterans syndrome (BOS) still represents a challenge; among the compounds targeting non-immune effectors, Alvelestat, a Neutrophil elastase inhibitor, seems promising in BOS. Finally, in both aGVHD and cGVHD, the association of biological markers with specific disease manifestations could help refine risk stratification and the availability of reliable biomarkers for specific treatments.

Into the storm: the imbalance in the yin-yang immune response as the commonality of cytokine storm syndromes

There is a continuous cycle of activation and contraction in the immune response against pathogens and other threats to human health in life. This intrinsic yin-yang of the immune response ensures that inflammatory processes can be appropriately controlled once that threat has been resolved, preventing unnecessary tissue and organ damage. Various factors may contribute to a state of perpetual immune activation, leading to a failure to undergo immune contraction and development of cytokine storm syndromes. A literature review was performed to consider how the trajectory of the immune response in certain individuals leads to cytokine storm, hyperinflammation, and multiorgan damage seen in cytokine storm syndromes. The goal of this review is to evaluate how underlying factors contribute to cytokine storm syndromes, as well as the symptomatology, pathology, and long-term implications of these conditions. Although the recognition of cytokine storm syndromes allows for universal treatment with steroids, this therapy shows limitations for symptom resolution and survival. By identifying cytokine storm syndromes as a continuum of disease, this will allow for a thorough evaluation of disease pathogenesis, consideration of targeted therapies, and eventual restoration of the balance in the yin-yang immune response.

Effect of peptide-binding motif on survival of HLA-haploidentical transplantation with post-transplant cyclophosphamide

Peptide-binding motif (PBM) model, a hierarchical clustering of HLA class I based on their binding specificity, was developed to predict immunopeptidome divergence. The effect of PBM mismatches on outcomes is unknown in HLA-haploidentical haematopoietic cell transplantation with post-transplant cyclophosphamide (PTCy-haplo). We therefore conducted a retrospective study using national registry data in PTCy-haplo. Overall, 1352 patients were included in the study. PBM-A bidirectional mismatch was associated with an increased risk of overall mortality in multivariable analysis (hazard ratio, 1.26; 95% confidence interval, 1.06 to 1.50; p = 0.010). None of relapse, non-relapse mortality (NRM) and graft-versus-host disease showed significant differences according to PBM-A bidirectional mismatch status in the entire cohort. The impact of PBM-A bidirectional mismatch on overall survival (OS) was preserved within the HLA-A genotype bidirectional mismatch population, and their lower OS stemmed from higher relapse rate in this population. The worse OS due to high NRM with PBM-A bidirectional mismatch was prominent in lymphoid malignancies receiving reduced-intensity conditioning. The PBM model may predict outcomes more accurately than HLA genotype mismatches. In conclusion, this study demonstrated that the presence of PBM-A bidirectional mismatch elevated the risk of mortality of PTCy-haplo. Avoiding PBM-A bidirectional mismatch might achieve better outcomes in PTCy-haplo.

Unsupervised Clustering Analysis of Regimen and HLA Characteristics in Pediatric Umbilical Cord Blood Transplantation

HLA matching is a critical factor in allogeneic unrelated hematopoietic cell transplantation (HCT) because of its impact on post-transplantation survival and quality of life. Umbilical cord blood transplantation (UCBT) offers unique advantages, but determining the optimal approach to graft selection and immunosuppression remains challenging. Unsupervised clustering, a machine learning technique, has potential for analyzing transplantation outcomes, but its application in investigating leukemia outcomes has been limited. This study aimed to identify optimal combinations of HLA/ killer immunoglobulin receptor (KIR) donor-patient pairing, conditioning, and immunosuppressive regimens in pediatric patients with acute lymphoblastic leukemia (ALL) or acute myeloblastic leukemia (AML) undergoing UCBT. Outcome data for single, unmanipulated UCBT in pediatric AML (n = 708) and ALL (n = 1034) patients from the Eurocord/EBMT registry were analyzed using unsupervised clustering. Resulting clusters were used to inform post hoc competing risks and Kaplan-Meier analyses. In AML, single HLA-C mismatches with other loci fully matched (7/8) were associated with poorer relapse-free survival (RFS) (P = .039), but a second mismatch at any other locus counteracted this effect. In ALL, total body irradiation (TBI) effectively prevented relapse mortality (P = .007). KIR/HLA-C match status affected RFS in AML (P = .039) but not in ALL (P = .8). Administration of antithymocyte globulin (ATG) substantially increased relapse, with no relapses occurring in the 85 patients who did not receive ATG. Our unsupervised clustering analyses generate several key statistical and mechanistic hypotheses regarding the relationships between HLA matching, conditioning regimens, immunosuppressive therapies, and transplantation outcomes in pediatric AML and ALL patients. HLA-C and KIR combinations significantly impact RFS in pediatric AML but not in ALL. ATG use in fully matched pediatric patients is associated with late-stage relapse. TBI regimens appear to be beneficial in ALL, with efficacy largely independent of histocompatibility variables. These findings reflect the distinct genetic and biological profiles of AML and ALL.

Allogeneic stem cell transplant with TBI-based myeloablative conditioning in adolescents and young adults with Philadelphia chromosome-negative ALL treated with pediatric protocols

To investigate the safety of total body irradiation-based myeloablative conditioning (TBI-MAC) in adolescent and young adult (AYA) Philadelphia chromosome (Ph)-negative acute lymphoblastic leukemia (ALL) patients treated with pediatric protocols, treatment outcomes of 106 AYA patients aged 16-39 years old undergoing allogeneic stem cell transplant (allo-SCT) with TBI-MAC in the first remission were compared according to chemotherapy types before transplant. Pediatric and adult protocols were used in 56 and 50 of the patients, respectively. The cumulative incidence (CI) of non-relapse mortality (NRM) and the overall survival (OS) rates were not significantly different between the pediatric-protocol and adult-protocol group (NRM: 4 % vs. 14 % at five years post-transplant, respectively, p = 0.26; OS: 81 % vs. 66 %, respectively, p = 0.14). Multivariate analysis for NRM revealed that a performance status >0 (hazard ratio [HR] = 4.8) and transplant due to chemotherapy toxicities (HR = 3.5) were independent risk factors, but a pediatric protocol was not (HR = 0.48). The CI of NRM and the OS rates were also similar among patients aged over 24 years old. These findings suggested that conventional allo-SCT with TBI-MAC can be performed without increasing NRM in AYA patients with Ph-negative ALL even after pediatric protocols.

Comparable relapse incidence after unrelated allogeneic stem cell transplantation with post-transplant cyclophosphamide versus conventional anti-graft versus host disease prophylaxis in patients with acute myeloid leukemia: A study on behalf of the Acute Leukemia Working Party of the European Society for Blood and Marrow Transplantation

We compared relapse incidence (RI) post-unrelated transplantation with post-transplant cyclophosphamide (PTCy) versus no PTCy graft-versus-host disease (GVHD) prophylaxis, in 7049 acute myeloid leukemia (AML) patients in remission, 707 with PTCy, and 6342 without (No PTCy). The patients in the PTCy group were younger, 52.7 versus 56.6 years (p < .001). There were more 9/10 donors in the PTCy group, 33.8% versus 16.4% (p < .001), and more received myeloablative conditioning, 61.7% versus 50.2% (p < .001). In the No PTCy group, 87.7% of patients received in vivo T-cell depletion. Neutrophil and platelet engraftment were lower in the PTCy versus No PTCy group, 93.8% and 80.9% versus 97.6% and 92.6% (p < .001). RI was not significantly different in the PTCy versus the No PTCy group, hazard ratio (HR) of 1.11 (95% confidence interval [CI] 0.9-1.37) (p = .31). Acute GVHD grades II-IV and III-IV, were significantly lower in the PTCy versus the No PTCy group, HR of 0.74 (95% CI 0.59-0.92, p = .007) and HR = 0.56 (95% CI 0.38-0.83, p = .004), as were total and extensive chronic GVHD, HRs of 0.5 (95% CI 0.41-0.62, p < .001) and HR = 0.31 (95% CI 0.22-0.42, p < .001). Non-relapse mortality (NRM) was significantly lower with PTCy versus the No PTCy group, HR of 0.67 (95% CI 0.5-0.91, p = .007). GVHD-free, relapse-free survival (GRFS) was higher in the PTCy versus the No PTCy group, HR of 0.69 (95% CI 0.59-0.81, p = .001). Leukemia-free survival (LFS) and overall survival (OS) did not differ between the groups. In summary, we observed comparable RI, OS, and LFS, significantly lower incidences of GVHD and NRM, and significantly higher GRFS in AML patients undergoing unrelated donor-hematopoietic stem cell transplantation with PTCy versus No PTCy GVHD prophylaxis.

Allogeneic stem cell transplantation for inherited metabolic disorders: 35 years' experience at a single institution

Hematopoietic stem cell transplants for inherited metabolic disorders performed at Tokai University Hospital between June 5, 1986, and May 28, 2021, were analyzed and compared between the period before 2007 and the period from 2007 onward based on availability of medical resources. Transplants were performed for 38 patients with mucopolysaccharidosis, 33 with adrenoleukodystrophy, and 16 with another disorder. Before 2007, oral busulfan-based regimens were mainly used. From 2007 onward, intravenous busulfan-based regimens or 4 Gy of thoracoabdominal irradiation (TAI), fludarabine, and melphalan (Mel)/treosulfan were adopted. Between 2002 and 2010, adrenoleukodystrophy was treated with 12 Gy of TAI and Mel. HLA-identical sibling bone marrow was used in 43% of cases before 2007 and 15% from 2007 onward, while alternative donors were selected for other transplants. Overall survival and event-free survival (EFS) before 2007 and from 2007 onward were 76% and 62%, and 97% and 85%, respectively (P = 0.006 and 0.017). Transplant era predicted superior overall survival and EFS, while myeloablative conditioning also predicted EFS. The incidence of primary graft failure decreased from 2007 onward, especially in cord blood transplant when 4 Gy of TAI with 150 mg/m2 fludarabine and 180 mg/m2 Mel or 42 g/m2 treosulfan were used as conditioning.

Cutaneous Chronic Graft-Versus-Host Disease: Clinical Manifestations, Diagnosis, Management, and Supportive Care

Cutaneous chronic graft-versus-host disease (cGVHD) is associated with morbidity, mortality, and impaired quality of life after hematopoietic stem cell transplantation. The clinical features of cutaneous cGVHD are heterogeneous but can be broadly classified into nonsclerotic or sclerotic presentations. This review provides an overview of clinical presentation, diagnosis and differential diagnosis, grading, and treatment of cutaneous cGVHD. Particular attention is given to cutaneous cGVHD in skin of color, which can have unique features and is generally underrepresented in the literature leading to delays in diagnosis. Finally, an overview of long-term skin care for patients with cutaneous cGVHD is provided in order to support patients from a dermatologic perspective as they recover from cGVHD. Multidisciplinary care with frequent communication between transplant specialists and dermatologists is critical to effectively managing cutaneous cGVHD.

Associations between acute and chronic graft-versus-host disease

ABSTRACT

Chronic graft-versus-host disease (GVHD) is 1 of the major complications after allogeneic hematopoietic cell transplantation (allo-HCT). Although various risk factors for chronic GVHD have been reported, limited data are available regarding the impact of acute GVHD on chronic GVHD. We examined the association between acute and chronic GVHD using a Japanese registry data set. The landmark point was set at day 100 after allo-HCT, and patients who died or relapsed before the landmark point were excluded. In total, 14 618 and 6135 patients who underwent allo-HCT with bone marrow or peripheral blood (BM/PB) and with umbilical cord blood (UCB), respectively, were analyzed. In the BM/PB cohort, the risk for chronic GVHD that requires systemic steroids increased with each increase in acute GVHD grade from 0 to 2 (grade 0 vs 1 [hazard ratio (HR), 1.32; 95% confidence interval (CI), 1.19-1.46; P < .001]; grade 1 vs 2 [HR, 1.41; 95% CI, 1.28-1.56; P < .001]), but the risk was similar between acute GVHD grade 2 and grade 3 to 4 (HR, 1.02; 95% CI, 0.91-1.15; P = 1.0). These findings were confirmed in the UCB cohort. We further observed that the risk for severe chronic GVHD increased with each increment in the grade of acute GVHD, even between acute GVHD grade 2 and grade 3 to (grade 2 vs 3-4: HR, 1.70; 95% CI, 1.12-2.58; P = .025). In conclusion, the preceding profiles of acute GVHD should help to stratify the risk for chronic GVHD and its severity, which might be useful for the development of risk-adopted preemptive strategies for chronic GVHD.

Haploidentical transplantation in primary refractory/relapsed secondary vs de novo AML: from the ALWP/EBMT

ABSTRACT

We compared the outcomes of haploidentical stem cell transplantation (haplo-HSCT) with posttransplant cyclophosphamide (PTCy) in 719 patients with primary refractory (PR) or first relapse (Rel) secondary acute myeloid leukemia (sAML; n = 129) vs those with de novo AML (n = 590), who received HSCT between 2010 and 2022. A higher percentage of patients with sAML vs de novo AML had PR disease (73.6% vs 58.6%; P = .002). In 81.4% of patients with sAML , the antecedent hematological disorder was myelodysplastic syndrome. Engraftment was 83.5% vs 88.4% in sAML and de novo AML, respectively (P = .13). In multivariate analysis, haplo-HSCT outcomes did not differ significantly between the groups: nonrelapse mortality hazard ratio (HR), 1.38 (95% confidence interval [CI], 0.96-1.98; P = .083), relapse incidence HR, 0.68 (95% CI, 0.4.7.-1.00; P = .051). The HRs for leukemia-free survival, overall survival, and graft-versus-host disease (GVHD)-free, and GVHD and relapse-free survival were 0.99 (95% CI, 0.76-1.28; P = .94), 0.99 (95% CI, 0.77-1.29; P = .97), and 0.99 (95% CI, 0.77-1.27; P = .94), respectively. We conclude that outcomes of haplo-HSCT with PTCy are not different for PR/Rel sAML in comparison with PR/Rel de novo AML, a finding of major clinical importance.

Total body irradiation versus thiotepa/busulfan-based conditioning regimens for myeloablative allogeneic stem cell transplantation in adults with acute lymphoblastic leukemia

Total body irradiation (TBI)-based conditioning regimens are generally recommended for allogeneic HSCT (allo-HSCT) in patients with acute lymphoblastic leukemia (ALL). Recent evidence suggests that modern chemotherapy-based regimens may be as effective. This multicenter retrospective study compared the clinical outcomes of myeloablative allo-HSCT with thiotepa, busulfan, and cyclophosphamide/fludarabine (TTB) to TBI-based conditioning. Between 2002 to 2018, 63 and 114 patients received TTB- and TBI-based conditioning regimens, respectively. The 5-year cumulative incidence of relapse was lower in the TBI cohort compared to the TTB cohort (30% [95% CI, 22-38] versus 47% [95% CI, 36-59]; P = 0.03). Multivariate analysis identified T-ALL, Ph-negative B-ALL, and measurable residual disease associated with a higher relapse risk. The 5-year cumulative incidence of non-relapsed mortality (NRM) was significantly lower with TTB (12% [95% CI, 5-20]) compared to TBI (25% [95% CI, 18-33]) (P = 0.001). Multivariate analysis found TBI conditioning, older age, and advanced stages of ALL at transplantation associated with a higher NRM. No statistical difference was seen in overall survival (49% [95% CI, 40-58] and 46% [95% CI, 35-60]) in the TBI and TTB groups, respectively; P = 0.9). The study suggests that TTB-based conditioning may be a promising option for ALL patients undergoing allo-HSCT, as it resulted in similar OS and lower NRM than TBI-based conditioning.

Cyclophosphamide and horse anti-thymocyte globulin versus fludarabine, reduced cyclophosphamide and rabbit anti-thymocyte globulin conditioning regimen for allogeneic hematopoietic stem cell transplantation from matched sibling donors in patients with acquired aplastic anemia

BACKGROUND

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is a potentially curative treatment for acquired aplastic anemia (acquired AA) in young patients. The objective of the study was to compare patient outcomes after Cyclophosphamide and horse antithymocyte globulin (Cy-hATG) versus Fludarabine-cyclophosphamide and rabbit ATG (Flu-Cy-rATG) as part of conditioning regimen in allo-HSCT for acquired AA.

RESEARCH DESIGN AND METHODS

Descriptive retrospective study conducted on patients with acquired AA who received allo-HSCT from HLA-matched sibling donors between January 2008 and August 2022 after conditioning regimen with Cy-hATG or Flu-Cy-rATG.

RESULTS

A total of 121 patients were enrolled. Cumulative incidence of graft failure was 11.2% in Cy-hATG and 5.3% Flu-Cy-rATG group. There were no significant differences between the two groups in terms of acute GVHD, chronic GVHD, and transplant related mortality. Flu-Cy-rATG group was associated with significantly higher CMV and EBV reactivation(s) compared to Cy-hATG group (p = 0.008 and 0.035, respectively). After a median follow-up of 58 months, estimated overall survival, event-free survival, and graft rejection-free survival were not statistically different between the two groups.

CONCLUSIONS

In high-risk population, Flu-Cy-rATG is associated with comparable outcomes to Cy-hATG in allo-HSCT from MSD. However, it seems to be associated with significant risk of viral infections.

Investigation of biomarkers to predict outcomes in allogeneic hematopoietic stem cell transplantation

BACKGROUND

Various biomarkers have been developed and evaluated to predict the prognosis and complications of allogeneic hematopoietic cell transplantation (HCT). Most previous studies conducted on different biomarkers evaluated single effects such as those associated with inflammation, immunology, iron metabolism, and nutrition, and only a few studies have comprehensively analyzed markers.

OBJECTIVE

The study aimed to survey comprehensive multiple markers prior to HCT and extract those that significantly predict the outcomes.

STUDY DESIGN

A prospective multicenter observational study was performed. (UMIN000013506) Patients undergoing HCT for hematologic diseases were consecutively enrolled. Besides the usual clinical biomarkers, serum samples for extra-clinical biomarkers were collected and cryopreserved before starting the conditioning regimen. A total of 32 candidate biomarkers were selected, 23 from hematology, biochemistry, immunology, nutrition, and iron metabolism, and 9 from composite markers. Based on the area under the curve (AUC) values for survival, promising biomarkers was extracted. Internal validation for these markers was applied based on bootstrap methods. Setting the cut-off values for them, log-rank test was applied and outcomes including overall survival (OS), relapse, and non-relapse mortality (NRM) were evaluated using multivariate analyses. Furthermore, detailed analysis including transplant-related complications and external validation were conducted focusing on C-reactive protein (CRP) to platelet (Plt) ratio.

RESULTS

A total of 152 patients with hematologic malignancies were enrolled from April 2014 to March 2017. CRP, soluble interleukin-2 receptor (IL2R), CRP to albumin (Alb) ratio, CRP to Plt ratio, Plt to IL2R ratio, and IL2R to Alb ratio were identified as promising markers. Internal validation successfully confirmed their reliability of AUC and multivariate analysis demonstrated the statistical significance between the higher and the lower markers. Above all, a higher CRP to Plt ratio was significantly associated with a lower OS (hazard ratio [HR] 2.77; 95% confidence interval [CI] 1.30-5.91; P = 0.008) and higher non-relapse mortality rates (HR 2.79; 95%CI 1.14-6.80; P = 0.024) at 180 days. Furthermore, univariate analysis showed that a higher CRP to Plt ratio was significantly associated with a higher incidence of sinusoidal obstructive syndrome (P < 0.001) and bloodstream infection (P = 0.027). An external validation test confirmed the significance of the CRP to Plt ratio for these outcomes.

CONCLUSION

The multicenter prospective observational study successfully identified significant biomarkers in patients with hematologic malignancies who received HCT. In particular, CRP to Plt ratio was identified as a novel and useful biomarker for predicting transplant outcomes. Further investigations are needed to validate the novel markers, analysis of the pathophysiology, and application to treatment settings other than HCT.

Reduced intensity versus myeloablative conditioning for MDS: long-term results of an EBMT phase III study (RICMAC)

Short-term outcome of myeloablative (MAC) and reduced intensity (RIC) conditioning in the prospective randomized international EBMT RICMAC study in patients with myelodyplastic syndrome (MDS) was comparable but longer follow up is lacking. Patients with MDS aged 18-65 years were randomized to receive MAC (N = 64) with busulfan/cyclophosphamide or RIC (n = 65) with busulfan/fludarabine followed by stem cell transplantation -(HCT) from HLA matched or mismatched donor. After a median follow-up of 6.2 (0.4-12.5) years, 10-year OS and RFS were 54.0% and 43.9% for RIC and 44.4% and 44.2% for MAC (p = 0.15 and p = 0.78), respectively. Since the first report, 6 patients died on NRM, 4 after RIC, and 2 after MAC. Similarly, 8 patients relapsed (4 in each arm), increasing the number of relapsed patients to 28. The second HCT was performed in 18 pts, 8 in the MAC, and 10 in the RIC arm. In a multivariate analysis, ECOG status and chemotherapy prior to HCT were independent risk factors for OS and RFS, ECOG and low cytogenetic risk for NRM and chemotherapy prior to HCT for RI. Patients with low cytogenetic risk had better OS [p = 0.002], RFS [p = 0.02], and NRM (p = 0.015) after RIC as compared to MAC.

Significance of absolute neutrophil count before allogeneic hematopoietic stem cell transplantation in adult patients with aplastic anemia

The impact of absolute neutrophil count (ANC) before allogenic hematopoietic stem cell transplantation (HSCT) on the outcomes for patients with aplastic anemia (AA) remains unclear. We retrospectively evaluated the relationship between ANC before transplantation and patient outcomes, involving 883 adult Japanese patients with AA who underwent allogeneic HSCT as their first transplantation between 2008 and 2020. Patients were divided into three groups based on ANC: 0/µL (n = 116); 1-199 (n = 210); and ≥ 200 (n = 557). In the low ANC groups (ANC < 200), patient age was higher, previous anti-thymocyte globulin (ATG) treatments were infrequent, duration from diagnosis to transplantation was shorter, hematopoietic cell transplantation-comorbidity index (HCT-CI) was higher, ATG-based conditioning was used infrequently, and peripheral blood stem cell from related donor and cord blood were used frequently. In multivariate analysis, patient age, previous ATG treatment, HCT-CI, stem cell source, and ANC before transplantation were significantly associated with 5-year overall survival (OS) ("ANC ≥ 200": 80.3% vs. "ANC 1-199": 71.7% vs. "ANC 0": 64.4%). The cumulative incidence of bacterial infection, invasive fungal disease, and early death before engraftment were significantly higher in the low ANC groups. Among patients with ANC of zero before transplantation, younger patient age, shorter duration from diagnosis to transplantation, HCT-CI of 0, and bone marrow from related donor as stem cell source were significantly associated with better OS. Consequently, ANC before allogeneic HSCT was found to be a significant prognostic factor in adult patients with AA. Physicians should pay attention to ANC before transplantation.

Alternative donor transplantation for severe aplastic anemia: a comparative study of the SAAWP EBMT

ABSTRACT

Selecting the most suitable alternative donor becomes challenging in severe aplastic anemia (SAA) when a matched sibling donor (MSD) is unavailable. We compared outcomes in patients with SAA undergoing stem cell transplantation (SCT) from matched unrelated donors (MUD) (n = 1106), mismatched unrelated donors (MMUD) (n = 340), and haploidentical donors (Haplo) (n = 206) registered in the European Society for Blood and Marrow Transplantation database (2012-2021). For Haplo SCT, only those receiving posttransplant cyclophosphamide for graft-versus-host disease (GVHD) prophylaxis were included. Median age was 20 years, and the median time from diagnosis to transplantation 8.7 months. Compared with MUD, MMUD (hazard ratio [HR], 2.93; 95% confidence interval [CI], 1.52-5.6) and Haplo (HR, 5.15; 95% CI, 2.5-10.58) showed significantly higher risks of primary graft failure. MUD had lower rates of acute GVHD compared with MMUD and Haplo (grade 2-4: 13%, 22%, and 19%, respectively; P < .001; grade 3-4: 5%, 9%, and 7%, respectively; P = .028). The 3-year nonrelapse mortality rate was 14% for MUD, 19% for MMUD, and 27% for Haplo (P < .001), whereas overall survival and GVHD and relapse-free survival (GRFS) rates were 81% and 73% for MUD, 74% and 65% for MMUD, and 63% and 54% for Haplo, respectively (P < .001). In addition to donor type, multivariable analysis identified other factors associated with GRFS such as patient age, performance status, and interval between diagnosis and transplantation. For patients with SAA lacking an MSD, our findings support MUDs as the preferable alternative donor option. However, selecting between an MMUD and Haplo donor remains uncertain and requires further exploration.

Immune reconstitution after single-unit umbilical cord blood transplantation using anti-thymoglobulin and myeloablative conditioning in adults with hematological malignancies

This study aimed to investigate the kinetics of immune recovery following umbilical cord blood transplantation (UCBT) in adults who received a myeloablative conditioning (MAC) regimen and antithymocyte globulin (ATG). While the immune recovery kinetics has been extensively studied in pediatric UCBT recipients, limited data exist for adults. We conducted a comprehensive analysis of 221 consecutive adult patients who underwent UCBT with MAC and ATG at a single institution. Our objective was to evaluate the influence of patient, disease, and transplant factors, along with acute graft-versus-host disease (aGVHD), on immune reconstitution and overall survival. Our findings confirm a delayed recovery of T cells, while B and NK cell reconstitution exhibited rapid progress, with NK cell counts reaching normal levels within 3 months post-transplantation and B cells within 6 months. Within CD3+ T cells, CD8+ T cells also experienced a delayed recovery (12 months), but to a lesser extent compared to CD4+ T cells (18 months). Delayed immune recovery of T-cell subsets was associated with the development of aGVHD grade II-IV, older age, CMV negativity, and a female donor. Patients with lymphoproliferative diseases showed slower NK cell recovery. Our study demonstrates that adult patients undergoing MAC with ATG and receiving a single unit UCBT for hematologic malignancies experienced rapid reconstitution of NK and B cells. However, T cell recovery, particularly CD4+ T cells, was significantly delayed. To enhance T cell recovery, it may be crucial to consider UCB units with higher cellularity and optimize ATG doses in conditioning.

Post-transplant cyclophosphamide, calcineurin inhibitor, and mycophenolate mofetil compared to anti-thymocyte globulin, calcineurin inhibitor, and methotrexate combinations as graft-versus-host disease prophylaxis post allogeneic stem cell transplantation from sibling and unrelated donors in patients with acute myeloid leukemia: a study on behalf of the Acute Leukemia Working Party of the European Society for Blood and Marrow Transplantation

Post-transplant cyclophosphamide plus calcineurin inhibitor (CNI)(tacrolimus or cyclosporine A) plus mycophenolate mofetil (PTCy/TAC or CSA/MMF) and anti-thymocyte globulin plus CNI (tacrolimus or cyclosporine A) plus methotrexate (ATG/TAC or CSA/MTX) are common graft-versus-host disease (GVHD) prophylaxis regimens. We compared the two regimens in patients with acute myeloid leukemia (AML) undergoing allogeneic transplantation from matched siblings or unrelated donors. 402 received PTCy/TAC or CSA/MMF and 5648 received ATG/TAC or CSA/MTX. Patients in the PTCy-based group were younger (48.7 vs. 51.5 years, p = 0.024) and there was a higher frequency of patient cytomegalovirus seropositivity and female donor to male patient combination in this group (77.8% vs. 71.8%, p = 0.009 and 18.4% vs. 14.4%, p = 0.029, respectively). More patients in the PTCy-based group received reduced-intensity conditioning (51.5% vs. 41%, p < 0.0001). No differences were observed in the incidence of acute GVHD grade II-IV and III-IV (21.2% vs. 20.4%, p = 0.92 and 8.1% vs. 6%, p = 0.1) or 2-year total and extensive chronic GVHD (33.7% vs. 30%, p = 0.09 and 10.7% vs. 11.2%, p = 0.81) between the groups. In the multivariate analysis, all transplant outcomes did not differ between the groups. PTCy/CNI/MMF and ATG/CNI/MTX are alternative regimens for GVHD prophylaxis in AML patients.

Post-allogeneic Hematopoietic Stem Cell Transplantation Portal Hypertension Not Associated with Liver Cirrhosis, Veno-occlusive Disease, or Graft-versus-host Disease

We herein report a rare case of idiopathic portal hypertension (IPH)-like disease that developed after allogeneic hematopoietic stem cell transplantation (allo-HSCT). A 53-year-old woman who underwent allo-HSCT for acute myeloid leukemia showed portal hypertension with radiological and histopathological findings consistent with IPH, distinct from veno-occlusive disease (VOD) and graft-versus-host disease (GVHD) of the liver. This case highlights the importance of considering IPH-like disease as a potential cause of portal hypertension after allo-HSCT. Awareness of this complication can aid in the early diagnosis and appropriate management of patients post allo-HSCT.

The role of donor type and pre-transplant immunosuppression on outcomes of hematopoietic stem cell transplantation in children and young adults with severe aplastic anemia

BACKGROUND

The goal of this study was to assess the effect of donor type and pre-transplant immunotherapy (IST) on outcomes of hematopoietic stem cell transplantation (HSCT) for children and young adults with severe aplastic anemia (SAA).

METHODS

This retrospective, multi-center study included 52 SAA patients, treated in 5 pediatric transplant programs in Florida, who received HSCT between 2010 and 2020 as the first- or second-line treatment.

RESULTS

The median age at HSCT for all 52 patients was 15 years (range 1-25). The 3-year overall survival (OS) by donor type were as follows: 95% [95% CI 85.4-99] for matched related donors (MRD) (N = 24), 84% [95% CI 63.5-99] for haploidentical (N = 13), and 71% [95% CI 36-99] for matched unrelated donors (MUD) (N = 7). The 3-year OS was 81% [95% CI 69.7-99] for all patients, 90.5% [95% CI 79.5-99] for non-IST patients (N = 27), and 70% [95% CI 51-99] for IST patients (N = 24) (log-rank p = .04). Survival of haploidentical HSCT (haplo-HSCT) recipients with post-transplant cyclophosphamide (PTCy) (N = 13) was excellent for both groups: 100% for non-IST patients (N = 3) and 80% for IST patients (N = 10). The 3-year OS for patients with previous IST by donor type in groups where >5 patients were available was 78.8% [95% CI 52.3-99] for haplo-HSCT (N = 10) and 66.7% [95% CI 28.7-99] for MUD (N = 6). Although it appears that patients receiving HSCT ≥6 months after the start of IST had worse survival, the number of patients in each category was small and log-rank was not significant(p = .65).

CONCLUSIONS

Patients receiving MUD and haplo-HSCT with PTCy had similar outcomes, suggesting that haplo-HSCT with PTCy could be included in randomized trials of upfront IST versus alternative donor HSCT.

Impact of early cyclosporine A levels on acute graft-versus-host disease in allogeneic hematopoietic stem cell transplantation using in vivo T-cell depletion

BACKGROUND AIMS

Cyclosporin A (CsA) remains a major component of immunosuppressive regimens applied in allogeneic hematopoietic stem cell transplantation (HSCT). The impact of CsA trough levels during the first weeks after HSCT has not yet been investigated specifically in anti-T-lymphocyte globulin (ATLG)-based HSCT from matched related and unrelated donors.

METHODS

To address this issue, we have retrospectively examined 307 consecutive matched related (n = 145) and unrelated (n = 162) HSCTs, using peripheral blood stem cells or bone marrow. HSCTs for active, uncontrolled malignancies were excluded. The initial three weeks' average mean CsA trough levels were analyzed in landmark and multi-state models, using a cut-off of 200 ng/mL.

RESULTS

CsA levels >200 ng/mL were associated with a reduced risk of acute graft-versus-host disease (GVHD) grade 3-4 at the first-week landmark (subdistribution hazard ratio [SHR] 0.59, P = 0.03) and the second-week landmark (SHR 0.48, P = 0.004), whereas there was no impact at the third-week landmark (HR 0.87, P = 0.69). This was supported by a multi-state model, in which week 1 (hazard ratio [HR] 0.53, P = 0.006) and week 2 (HR 0.48, P = 0.003), but not week 3 (HR 0.80, P = 0.44) CsA levels >200 ng/mL were associated with a reduced acute GVHD 3-4 risk. Relapse incidence was not significantly affected by week 1 through 3 CsA levels. Despite ATLG's inherent GVHD-preventive properties, week 1 CsA trough levels >200 ng/mL following ATLG-based HSCT (n = 220) were associated with a significantly reduced risk of non-relapse mortality (SHR 0.52, P = 0.02) and improved overall survival (HR 0.61, P = 0.02).

CONCLUSIONS

Our findings emphasize the continuing importance of ensuring CsA levels ≥200 ng/mL immediately post-transplant in the setting of ATLG-based HSCT.

Allogeneic hematopoietic cell transplantation is effective for p47phox chronic granulomatous disease: A Primary Immune Deficiency Treatment Consortium study

BACKGROUND

P47phox (neutrophil cytosolic factor-1) deficiency is the most common cause of autosomal recessive chronic granulomatous disease (CGD) and is considered to be associated with a milder clinical phenotype. Allogeneic hematopoietic cell transplantation (HCT) for p47phox CGD is not well-described.

OBJECTIVES

We sought to study HCT for p47phox CGD in North America.

METHODS

Thirty patients with p47phox CGD who received allogeneic HCT at Primary Immune Deficiency Treatment Consortium centers since 1995 were included.

RESULTS

Residual oxidative activity was present in 66.7% of patients. In the year before HCT, there were 0.38 CGD-related infections per person-years. Inflammatory diseases, predominantly of the lungs and bowel, occurred in 36.7% of the patients. The median age at HCT was 9.1 years (range 1.5-23.6 years). Most HCTs (90%) were performed after using reduced intensity/toxicity conditioning. HCT sources were HLA-matched (40%) and -mismatched (10%) related donors or HLA-matched (36.7%) and -mismatched (13.3%) unrelated donors. CGD-related infections after HCT decreased significantly to 0.06 per person-years (P = .038). The frequency of inflammatory bowel disease and the use of steroids also decreased. The cumulative incidence of graft failure and second HCT was 17.9%. The 2-year overall and event-free survival were 92.3% and 82.1%, respectively, while at 5 years they were 85.7% and 77.0%, respectively. In the surviving patients evaluated, ≥95% donor myeloid chimerism at 1 and 2 years after HCT was 93.8% and 87.5%, respectively.

CONCLUSIONS

Patients with p47phox CGD suffer from a significant disease burden that can be effectively alleviated by HCT. Similar to other forms of CGD, HCT should be considered for patients with p47phox CGD.

ATG or post-transplant cyclophosphamide to prevent GVHD in matched unrelated stem cell transplantation?

There is a high risk of GVHD and non-relapse mortality (NRM) after allogeneic stem cell transplantations (alloSCT) from unrelated donors. Prophylaxis with rabbit anti-thymocyte globulin (rATG) is standard in Europe but post-transplantation Cyclophosphamide (PTCy) is an emerging alternative. We analyzed outcomes of rATG (n = 7725) vs. PTCy (n = 1039) prophylaxis in adult patients with hematologic malignancies undergoing peripheral blood alloSCT from 10/10 antigen-matched unrelated donors (MUD) between January 2018 and June 2021 in the EBMT database. The provided P-values and hazard ratios (HR) are derived from multivariate analysis. Two years after alloSCT, NRM in the PTCy group was 12.1% vs. 16.4% in the rATG group; p = 0.016; HR 0.72. Relapse was less frequent after PTCy vs. rATG (22.8% vs. 26.6%; p = 0.046; HR 0.87). Overall survival after PTCy was higher (73.1% vs. 65.9%; p = 0.001, HR 0.82). Progression free survival was better after PTCy vs. rATG (64.9% vs. 57.2%; p < 0.001, HR 0.83). The incidence of chronic GVHD was lower after PTCy (28.4% vs. rATG 31.4%; p = 0.012; HR 0.77), whereas the incidence and severity of acute GVHD were not significantly different. GVHD-free relapse-free survival was significantly higher in the PTCy arm compared to the rATG arm (2 y incidence: 51% vs. 45%; HR: 0.86 [95% CI 0.75-0.99], p = 0.035). In the absence of evidence from randomized controlled trials, our findings support a preference for the use of PTCy in adult recipients of peripheral blood alloSCTs from MUD.

Post-Transplant Cyclophosphamide versus Anti-Thymocyte Globulin in Patients with Hematological Malignancies Treated with Allogeneic Hematopoietic Stem Cell Transplantation from Haploidentical and Matched Unrelated Donors: A Real-Life Experience

Background: Post-transplant cyclophosphamide (PTCY) is widely used as graft versus host disease (GvHD) prophylaxis in allogeneic hematopoietic stem cell transplant (HSCT) recipients, with reported clinical benefits in patients who underwent transplant from a matched unrelated donor (MUD). However, real-life data on clinical efficacy and safety of PTCY in haploidentical and MUD transplantations are still poor. Methods: In our real-life retrospective observational study, we included a total of 40 consecutive adult patients who underwent haploidentical or MUD HSCT for various hematological malignancies and who received PTCY (n = 24) or ATG (n = 16) as GvHD prophylaxis at Hematology Units from hospitals of Salerno and Avellino, Italy, and clinical outcomes were compared. Results: We showed protective effects of PTCY against disease relapse with the relapse rate after transplantation of 16% versus 50% in the ATG arm (p = 0.02). All-cause mortality was lower (36% vs. 75%; p = 0.02) and the 2-year overall survival was slightly superior in patients administered PTCY (61% vs. 42%; p = 0.26). Conclusions: We support the use of PTCY, even in a real-life setting; however, the optimization of this protocol should be further investigated to better balance relapse prevention and GvHD prophylaxis.

Development of an umbilical cord blood transplantation-specific nonrelapse mortality risk assessment score

ABSTRACT

Higher rate of nonrelapse mortality (NRM) remains yet to be resolved in umbilical cord blood transplantation (UCBT). Considering that UCBT has some unique features compared with allogeneic hematopoietic cell transplantation from other graft sources, a UCBT-specific NRM risk assessment system is required. Thus, in this study, we sought to develop a UCBT-specific NRM Risk Assessment (CoBRA) score. Using a nationwide registry database, we retrospectively analyzed 4437 recipients who had received their first single-unit UCBT. Using the backward elimination method, we constructed the CoBRA score in a training cohort (n = 2687), which consisted of recipients age ≥55 years (score 2), hematopoietic cell transplantation-specific comorbidity index ≥3 (score 2), male recipient, graft-versus-host disease prophylaxis other than tacrolimus in combination with methotrexate, performance status (PS) 2 to 4, HLA allele mismatch ≥ 2, refined Disease Risk Index high risk, myeloablative conditioning, and CD34+ cell doses < 0.82 × 105/kg (score 1 in each). The recipients were categorized into 3 groups: low (0-4 points), intermediate (5-7 points), and high (8-11 points) groups according to the CoBRA score. In the validation cohort (n = 1750), the cumulative incidence of NRM at 2 years was 14.9%, 25.5%, and 47.1% (P < .001), and 2-year overall survival (OS) was 74.2%, 52.7%, and 26.3% (P < .001) in the low, intermediate, and high groups, respectively. In summary, the CoBRA score could predict the NRM risk as well as OS after UCBT. Further external validation will be needed to confirm the significance of the CoBRA score.

Impacts of Posttransplant Cyclophosphamide Dose on Graft-versus-Leukemia Effects via HLA-B Leader in HLA-Haploidentical Peripheral Blood Stem Cell Transplantation

INTRODUCTION

The graft-versus-leukemia effect of HLA-B leader dimorphism, i.e., methionine (M) or threonine (T) at position -21 of the leader sequence, has been observed in HLA-haploidentical hematopoietic cell transplantation with posttransplant cyclophosphamide (PTCy-haplo). However, the biological mechanism has been unclear, and the contributions of HLA-B leader genotype to risk reduction of relapse might be dependent on posttransplant cyclophosphamide (PTCy) doses.

METHODS

To investigate whether the effect of HLA-B leader dimorphism was modified by the PTCy dose, we retrospectively analyzed 99 patients who received PTCy-haplo.

RESULTS

In the low-dose PTCy group, the patient M+ HLA-B leader genotype did not significantly affect the cumulative incidence of relapse (CIR) but negatively impacted the overall survival (OS) compared to the M- genotype. In contrast, in the high-dose PTCy group, patients with the M+ genotype had a decreased CIR, but no significant difference in the OS was observed between patients with the M+ and M- genotypes. Regardless of PTCy doses, the patient M+ genotype had detrimental effects on nonrelapse mortality.

CONCLUSION

Our findings suggest that the effect of the patient HLA-B leader genotype is modified by the PTCy dose, providing immunological insight into the PTCy dosage and supporting further studies to investigate the underlying mechanisms.

Peripheral Blood Haploidentical Allogeneic Stem Cell Transplantation in Older Adults with Acute Myeloid Leukemia and Myelodysplastic Syndromes Demonstrates Long Term Survival, Results from Australia and New Zealand Transplant and Cellular Therapies

There is a limited body of evidence for haploidentical hematopoietic stem cell transplantation (haplo-HSCT) in older patients. Previous studies have used a high proportion of bone marrow-derived grafts and a variety of conditioning regimens. In Australia and New Zealand, haplo-HCST is predominantly performed using peripheral blood (PB) with universal use of post-transplantation cyclophosphamide (PTCy). To characterize the outcomes of older recipients undergoing haplo-HSCT for acute myeloid leukemia (AML) and myelodysplastic syndromes (MDS). Data were collected through the Australasian Bone Marrow Transplant Recipient Registry (ABMTRR) for patients aged 65 or older receiving a PB haplo-HSCT for AML/MDS between January 2010 and July 2020. A total of 44 patients were included in the analysis. The median follow-up time was 377 days. The median age was 68 (range 65-74) with a median Karnofsky performance status of 90. Thirty patients (68.2%) had AML, whereas 14 (31.8%) had MDS. The median donor age was 40. The most common conditioning regimen was nonmyeloablative fludarabine, cyclophosphamide, and total body irradiation (75%); the remainder of the patients received either melphalan- or busulfan-based regimens, and the majority were reduced intensity, with only 2 patients undergoing myeloablative conditioning. All patients received post-transplantation cyclophosphamide and mycophenolate mofetil, with the majority also receiving tacrolimus (90.5%) and the remainder receiving cyclosporine (9.5%). No patients received anti-thymocyte globulin. Neutrophil engraftment was achieved in 97.6% of patients at a median of 18 days, whereas platelet engraftment was achieved in 92.7% of patients at a median of 28 days. The cumulative incidences of cytomegalovirus (CMV) reactivation and CMV disease were 52.5% and 5.1% at 1 year. The incidence of grade 2-4 acute Graft Versus Host Disease (GVHD) was 18.2%. The incidence of chronic GVHD at 2 years was 40.7%, with extensive chronic GVHD occurring in 17.7% of patients. The incidences of relapse and non-relapse mortality (NRM) at 2 years were 8.8% and 20.7% respectively. The leading causes of death were infection (64.7%) followed by relapse (14.2%). The 2-year overall survival was 74%. Relapse free survival and GVHD free, relapse free survival at 2 years was 70% and 48%. Haplo-HSCT using a peripheral blood graft and PTCy GVHD prophylaxis demonstrates long-term disease control with acceptable rates of NRM for older patients with AML/MDS.

Lower overall survival in male patients with advanced disease undergoing allogeneic hematopoietic stem cell transplantation is associated with CYP1B1 Leu432Val polymorphism

Human cytochrome P450 1B1 (CYP1B1) is an extrahepatic key enzyme involved in estrogen metabolism, steroid synthesis, and pro-carcinogen activation. In a single-center retrospective study, 382 patients who underwent allogeneic hematopoetic stem cell transplantation and their donors were genotyped for CYP1B1 C432G polymorphism by reverse transcription polymerase chain reaction. One hundred and sixty-nine patients (44%) were homozygous wild-type (wt) gene CC, 157 (41%) heterozygous CG and 56 (15%) homozygous gene mutated GG. Of interest, mutated CYP1B1 was more common in male (62%) than in female patients (48%) P=0.006, unlike in donors. Five-year estimate for overall survival (OS) was 58±4% (CC) versus 48±3% (CG and GG), P=0.048. Surprisingly, this difference was only evident in males (P=0.024): OS 58±6% versus 42±4%, whereas it was virtually absent in females. Importantly, this difference was only evident in male patients with advanced disease (AD) (n=118, P=0.002): OS 44±8% (CC) versus 32±6% (CG) versus 6±6% (GG), whereas it was virtually absent in male patients with early disease. One-year non-relapse mortality in male patients with AD was 8±4% (CC) versus 21±5% (CG) versus 50±12% (GG), P=0.002. Three-year relapse rate in male patients with AD was 31±7% (wt) versus 42±6% (mut), P=0.04. Multivariate analysis for OS in male patients with AD revealed CYP1B1 polymorphism as the only prognostic factor: RR 1.78, P=0.001. In conclusion, these results suggest that male patients with AD and mutant CYP1B1 polymorphism have lower OS after allogeneic hematopoetic stem cell transplantation due to a higher non-relapse mortality and a higher relapse rate.

The clinical outcomes of haploidentical stem cell transplantation (haplo-HSCT) for patients with therapy-related myelodysplastic syndrome: comparable to de novo myelodysplastic syndrome

Therapy-related myelodysplastic syndrome (t-MDS) is defined as a complication in patients with cancer following exposure to chemotherapy and/or radiotherapy and has an inferior outcome compared with de novo myelodysplastic syndrome (de novo MDS). This study aimed to estimate and compare the clinical outcomes of haploidentical stem cell transplantation (haplo-HSCT) for t-MDS and de novo MDS. We retrospectively analyzed 96 patients with MDS who received haplo-HSCT between January 2015 and December 2021. Eleven patients with t-MDS and 85 patients with de novo MDS were matched using the case-pair method in a 1:8 ratio with the following pairing criteria: (1) sex, (2) age (± 5 years), (3) year of haplo-HSCT (± 2 years), and (4) blast cell counts (≥ 5% or not). The 3-year overall survival and disease-free survival after haplo-HSCT for t-MDS versus de novo MDS patients were 72.7% versus 75.1% (P = 0.99) and 54.5% versus 67.0% (P = 0.50), respectively. The 3-year cumulative incidence of relapse was 36.4% versus 15.5% (P = 0.08), respectively. In multivariate analysis, there was no difference in relapse between t-MDS and de novo MDS. The 3-year cumulative non-relapse mortality rates were 9.1% versus 17.6% (P = 0.45), respectively. This study confirmed the comparable clinical outcomes of haplo-HSCT on the prognosis of t-MDS and de novo MDS.

Lack of RBC transfusion independence by Day 30 following allogeneic hematopoietic stem cell transplant strongly predicts inferior survival and high non-relapse mortality in acute myeloid leukemia patients

BACKGROUND

Studies have suggested that acute myeloid leukemia (AML) patients with incomplete hematologic recovery undergoing allogeneic stem cell transplantation (allo-HSCT) had inferior overall survival (OS).

STUDY DESIGN AND METHODS

This single-center, retrospective study of AML patients evaluated the relationship between red blood cell (RBC) and platelet (PLT) transfusion requirements during the first 30 days and long-term outcomes after allo-HSCT through multivariate analyses.

RESULTS

A total of 692 AML patients received peripheral blood stem cells (89.2%), marrow (5.6%), or umbilical cord (5.2%) from matched related (37.4%), unrelated (49.1%), or haploidentical (8.2%) donors in 2011-2017. Transfusion requirements during the first 30 days for RBC (89.5% transfused, median 3, range 1-18 units) or PLT (98.2% transfused, median 6, range 1-144 units) were variable. By Day 30, 56.7% (95% confidence interval [CI]: 52.8-60.3%) and 86.1% (95% CI: 83.2-88.5%) had achieved RBC and PLT transfusion independence, respectively. Median follow-up among survivors (n = 307) was 7.1 years (range: 2.7-11.8). Lack of RBC transfusion independence by Day 30 was strongly and independently associated with worse 5-year OS (39.2% vs. 59.6%, adjusted hazard ratio [HR] 1.83, 95% CI: 1.49-2.25), leukemia-free survival (35.8% vs. 55.5%, HR = 1.75, 95% CI: 1.43-2.14), and NRM (29.7% vs. 13.7%, HR = 2.05, 95% CI: 1.45-2.89) (p < .001). There was no difference in relapse rates among patients who achieved or did not achieve RBC (p = .34) or PLT (p = .64) transfusion independence.

CONCLUSION

Prolonged RBC dependence predicted worse survival and NRM rates, but not increased relapse. Posttransplant surveillance of such patients should be adjusted with more attention to non-relapse complications.