Circular mRNA-based TCR-T offers a safe and effective therapeutic strategy for treatment of cytomegalovirus infection.

Circular mRNA (cmRNA) is particular useful due to its high resistance to degradation by exonucleases, resulting in greater stability and protein expression compared to linear mRNA. T cell receptor (TCR)-engineered T cells (TCR-T) represent a promising means of treating viral infections and cancer. This study aimed to evaluate the feasibility and efficacy of cmRNA in antigen-specific-TCR discovery and TCR-T therapy. Using human cytomegalovirus (CMV) pp65 antigen as a model, we found that the expansion of pp65-responsive T cells was induced more effectively by monocyte-derived dendritic cells transfected with pp65-encoding cmRNA compared with linear mRNA. Subsequently, we developed cmRNA-transduced pp65-TCR-T (cm-pp65-TCR-T) that specifically targets the CMV-pp65 epitope. Our results showed that pp65-TCR could be expressed on primary T cells for more than 7 days. Moreover, both in vitro killing and in vivo CDX models demonstrated that cm-pp65-TCR-T cells specifically and persistently kill pp65-and HLA-expressing tumor cells, significantly prolonging the survival of mice. Collectively, our results demonstrated that cmRNA can be used as a more effective technical approach for antigen-specific TCR isolation and identification, and cm-pp65-TCR-T may provide a safe, non-viral, non-integrated therapeutic approach for controlling CMV infection, particularly in patients who have undergone allogeneic hematopoietic stem cell transplantation.

Comparison of long-term outcomes between imatinib and dasatinib prophylaxis after allogeneic stem cell transplantation in patients with Philadelphia-positive acute lymphoblastic leukemia: A multicenter retrospective study.

BACKGROUND: Although the prognosis of Philadelphia-positive acute lymphoblastic leukemia (Ph+ ALL) has improved with the introduction of tyrosine kinase inhibitors (TKIs) and stem cell transplantation, prevention of relapse after transplantation remains a concern. The aim of this study was to compare the impact of TKI prophylaxis with imatinib and dasatinib on long-term outcomes after transplantation. METHODS: Patients with Ph+ ALL who underwent allogeneic hematopoietic stem cell transplantation (allo-HSCT) at first complete remission (CR1) and received TKI prophylaxis after allo-HSCT were included in this retrospective analysis. Two cohorts were established based on the choice of TKI prophylaxis: the imatinib (Ima) and dasatinib (Das) cohorts. The survival and safety outcomes of these cohorts were compared. RESULTS: Ninety-one patients in the Ima cohort and 50 in the Das cohort were included. After a median follow-up of 50.6 months, the 5-year cumulative incidence of relapse, nonrelapse mortality rate, and overall survival in the Ima and Das cohorts were 16.1% and 12.5%, 5.2% and 9.8%, and 86.5% and 77.6%, respectively, with no statistical differences. The cumulative incidence of mild chronic graft-versus-host disease was higher in the Das cohort. The most common adverse event was neutropenia (64.7% vs. 69.5%). The Das cohort had a higher incidence of gastrointestinal bleeding (25.5% vs. 2.3%) and gastrointestinal reaction (48.9% vs. 31.4%) than the Ima cohort. The proportion of patients treated on schedule was significantly lower in the Das cohort than in the Ima cohort, and drug intolerance was the main reason for protocol violation. CONCLUSIONS: For patients with Ph+ ALL undergoing allo-HSCT in CR1, imatinib prophylaxis achieved long-term outcomes similar to those of dasatinib.

The dynamics of B-cell reconstitution post allogeneic hematopoietic stem cell transplantation: A real-world study.

BACKGROUND: The immune reconstitution after allogeneic hematopoietic stem cell transplantation (allo-HSCT) is crucial for preventing infections and relapse and enhancing graft-versus-tumor effects. B cells play an important role in humoral immunity and immune regulation, but their reconstitution after allo-HSCT has not been well studied. METHODS: In this study, we analyzed the dynamics of B cells in 252 patients who underwent allo-HSCT for 2 years and assessed the impact of factors on B-cell reconstitution and their correlations with survival outcomes, as well as the development stages of B cells in the bone marrow and the subsets in the peripheral blood. RESULTS: We found that the B-cell reconstitution in the bone marrow was consistent with the peripheral blood (p = 0.232). B-cell reconstitution was delayed by the male gender, age >50, older donor age, the occurrence of chronic and acute graft-versus-host disease, and the infections of fungi and cytomegalovirus. The survival analysis revealed that patients with lower B cells had higher risks of death and relapse. More importantly, we used propensity score matching to obtain the conclusion that post-1-year B-cell reconstitution is better in females. Meanwhile, using mediation analysis, we proposed the age-B cells-survival axis and found that B-cell reconstitution at month 12 posttransplant mediated the effect of age on patient survival (p = 0.013). We also found that younger patients showed more immature B cells in the bone marrow after transplantation (p = 0.037). CONCLUSION: Our findings provide valuable insights for optimizing the management of B-cell reconstitution and improving the efficacy and safety of allo-HSCT.

Measurable residual disease monitoring by ddPCR in the early posttransplant period complements the traditional MFC method to predict relapse after HSCT in AML/MDS: a multicenter retrospective study.

BACKGROUND: Droplet digital PCR (ddPCR) is widely applied to monitor measurable residual disease (MRD). However, there are limited studies on the feasibility of ddPCR-MRD monitoring after allogeneic hematopoietic stem cell transplantation (allo-HSCT), especially targeting multiple molecular markers simultaneously. METHODS: Our study collected samples from patients with acute myeloid leukemia (AML) or high-risk myelodysplastic syndrome (MDS) in complete remission after allo-HSCT between January 2018 and August 2021 to evaluate whether posttransplant ddPCR-MRD monitoring can identify patients at high risk of relapse. RESULTS: Of 152 patients, 58 (38.2%) were MRD positive by ddPCR within 4 months posttransplant, with a median variant allele frequency of 0.198%. The detectable DTA mutations (DNMT3A, TET2, and ASXL1 mutations) after allo-HSCT were not associated with an increased risk of relapse. After excluding DTA mutations, patients with ddPCR-MRD positivity had a significantly higher cumulative incidence of relapse (CIR, 38.7% vs. 9.7%, P < 0.001) and lower rates of relapse-free survival (RFS, 55.5% vs. 83.7%, P < 0.001) and overall survival (OS, 60.5% vs. 90.5%, P < 0.001). In multivariate analysis, ddPCR-MRD positivity of non-DTA genes was an independent adverse predictor for CIR (hazard ratio [HR], 4.02; P < 0.001), RFS (HR, 2.92; P = 0.002) and OS (HR, 3.12; P = 0.007). Moreover, the combination of ddPCR with multiparameter flow cytometry (MFC) can further accurately identify patients at high risk of relapse (F+/M+, HR, 22.44; P < 0.001, F+/M-, HR, 12.46; P < 0.001 and F-/M+, HR, 4.51; P = 0.003). CONCLUSION: ddPCR-MRD is a feasible approach to predict relapse after allo-HSCT in AML/MDS patients with non-DTA genes and is more accurate when combined with MFC. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT06000306. Registered 17 August 2023 -Retrospectively registered ( https://clinicaltrials.gov/study/NCT06000306?term=NCT06000306&rank=1 ).

Prediction model for EBV infection following HLA haploidentical matched hematopoietic stem cell transplantation.

AIMS: Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is an effective treatment for hematological malignancies. However, viral infections, particularly EBV infection, frequently occur following allo-HSCT and can result in multi-tissue and organ damage. Due to the lack of effective antiviral drugs, these infections can even progress to post-transplant lymphoproliferative disorders (PTLD), thereby impacting the prognosis. In light of this, our objective is to develop a prediction model for EBV infection following allo-HSCT. METHODS: A total of 466 patients who underwent haploidentical hematopoietic stem cell transplantation (haplo-HSCT) between September 2019 and December 2020 were included in this study. The patients were divided into a development cohort and a validation cohort based on the timing of their transplantation. Our aim was to develop and validate a grading scale using these cohorts to predict the risk of EBV infection within the first year after haplo-HSCT. Additionally, single-cell RNA sequencing (sc-RNAseq) data from the bone marrow of healthy donors were utilized to assess the impact of age on immune cells and viral infection. RESULTS: In the multivariate logistic regression model, four predictors were retained: donor age, female-to-male transplant, graft MNC (mononuclear cell) dose, and CD8 dose. Based on these predictors, an EBV reactivation predicting score system was constructed. The scoring system demonstrated good calibration in both the derivation and validation cohorts, as confirmed by the Hosmer-Lemeshow test (p > 0.05). The scoring system also exhibited favorable discriminative ability, as indicated by the C statistics of 0.72 in the derivation cohort and 0.60 in the validation cohort. Furthermore, the clinical efficacy of the scoring system was evaluated using Kaplan-Meier curves based on risk ratings. The results showed significant differences in EBV reactivation rates between different risk groups, with p-values less than 0.001 in both the derivation and validation cohorts, indicating robust clinical utility. The analysis of sc-RNAseq data from the bone marrow of healthy donors revealed that older age had a profound impact on the quantity and quality of immune subsets. Functional enrichment analysis highlighted that older age was associated with a higher risk of infection. Specifically, CD8 + T cells from older individuals showed enrichment in the pathway of "viral carcinogenesis", while older CD14 + monocytes exhibited enrichment in the pathway of "regulation of viral entry into host cell." These findings suggest that older age may contribute to an increased susceptibility to viral infections, as evidenced by the altered immune profiles observed in the sc-RNAseq data. CONCLUSION: Overall, these results demonstrate the development and validation of an effective scoring system for predicting EBV reactivation after haplo-HSCT, and provide insights into the impact of age on immune subsets and viral infection susceptibility based on sc-RNAseq analysis of healthy donors' bone marrow.

Reconstituted CD74+ NK cells trigger chronic graft versus host disease after allogeneic bone marrow transplantation.

Chronic graft-versus-host disease (cGVHD) is the most common long-term complication after allogeneic hematopoietic stem cell transplantation (allo-HSCT). The patients with pulmonary cGVHD in particular have a very poor prognosis. NK cells are the first reconstituted lymphocyte subset after allo-HSCT; however, the impact of reconstituted NK cells on cGVHD is unclear. Here, we found allogeneic recipients showed obvious pulmonary cGVHD. Surprisingly, deletion of reconstituted NK cells resulted in maximal relief of pulmonary cGVHD. Mechanistically, reconstituted NK cells with donor profiles modulated the pulmonary inflammatory microenvironment to trigger cGVHD. Reconstituted NK cells secreted IFN-γ and TNF-α to induce CXCL10 production by epithelial cells, which recruited macrophages and CD4+ T cells to the lungs. Then macrophages and CD4+ T cells were activated by the inflammatory microenvironment, thereby mediating lung injury. Through assessment of differences in cellular energy, we found that CD74+ NK cells with high mitochondrial potential and pro-inflammatory activity triggered pulmonary cGVHD. Furthermore, targeted elimination of CD74+ NK cells using the anti-CD74 antibody significantly alleviated pulmonary cGVHD but preserved the CD74- NK cells to exert graft-versus-leukemia (GVL) effects. Data from human samples corroborated our findings in mouse models. Collectively, our results reveal that reconstituted CD74+ NK cells trigger pulmonary cGVHD and suggest that administration of CD74 antibody was a potential therapeutic for patients with cGVHD.

CD56bright NK cell expansion correlated with EBV reactivation control post allogeneic hematopoietic stem cell transplantation.

Natural killer (NK) cells are equipped with anti-Epstein-Barr virus (EBV) function, however, whether EBV infection will affect NK cells reconstitution after allogeneic hematopoietic stem cell transplantation (allo-HSCT) remains unclear. To identify the characteristics of NK cells, we prospectively enrolled 11 patients who occurred EBV reactivation post allo-HSCT and 11 patients without EBV infection as control. We found that that EBV infection induced the expansion of CD56bright and NKG2A+KIR- NK subsets,and decreased the cytotoxicity function of NK cells. The frequency of NKG2A+KIR- NK cells were higher in patients who progressed into post-transplant lymphoproliferative disorder (PTLD) than EBV viremia patients, which also correlated with decreased proliferation and cytotoxic function. By screening the activation receptors of NK cells, we found the DNAM-1+CD56bright NK cells is significantly increased after EBV stimulation, further we demonstrated that DNAM-1 is essential for EBV induced NK cells activation as the cytokine release against EBV-transformed lymphoblastoid cell lines(EBV-LCLs) of CD56bright NK cells were significantly decreased after DNAM-1 blockade. NK cells infusion suppressed the progression of EBV-related tumor mice model. A prospective cohort indicated that old donor age was an independent risk factor for EBV infection. Rapid CD56bri expansion and high expression of DNAM-1 on CD56bri NK cells in response to EBV reactivation correlated with rapid EBV clearance post allo-HSCT in patients with younger donors. In summary, our data showed that high expression of DNAM-1 receptors on NK cell may participate protective CD56bri NK cells response to EBV infection after allo-HSCT.

Exploration of ETV6::ABL1-positive AML with concurrent NPM1 and FLT3-ITD mutations.

ETV6::ABL1 is a rare fusion gene that found in MPN, ALL, and AML. It has a complex and diverse formation mechanism due to the reciprocal orientations of the ETV6 and ABL1 genes relative to the centromeres. NPM1 is frequently mutated in adult AML, often accompanied by FLT3-ITD, which suggests molecular synergisms in AML pathogenesis. Previous reports on ETV6::ABL1 mostly focus on FLT3-ITD. In this study, we present a case of AML with ETV6::ABL1, along with NPM1 and FLT3-ITD. The patient showed a rapid increase in primitive cells at the initial stage, along with the presence of immature granulocytes and erythrocytes. Through cytogenetic analysis, fluorescence in situ hybridization (FISH), and RNA-seq, we elucidated the mechanism behind the formation of the ETV6::ABL1 fusion gene. Despite conventional chemotherapy failure and rapid tumor proliferation, we attempted to add FLT3 inhibitor sorafenib to the treatment, along with chemotherapy bridging to haploidentical transplantation. After haplo-HSCT, a combination of sorafenib and dasatinib was administered as maintenance therapy. The patient achieved complete remission (CR) and maintained it for 11 months. The intricate genetic landscape observed in this case presents diagnostic dilemmas and therapeutic challenges, emphasizing the importance of a comprehensive understanding of its implications for disease classification, risk stratification, and treatment selection.

Efficacy and prognostic factors of allogeneic hematopoietic stem cell transplantation treatment for adolescent and adult Tlymphoblastic leukemia /lymphoma: a large cohort multicenter study in China.

T lymphoblastic leukemia /lymphoma (T-ALL/LBL) is a rare and highly aggressive neoplasm of lymphoblasts. We evaluated 195 T-ALL/LBL adolescent and adult patients who received ALL-type chemotherapy alone (chemo,n = 72) or in combination with autologous hematopoietic stem cell transplantation(auto-HSCT,n = 23) or allogeneic hematopoietic stem cell transplantation(allo-HSCT,n = 100) from January 2006 to September 2020 in three Chinese medical centers. 167 (85.6%) patients achieved overall response (ORR) with 138 complete response (CR) patients (70.8%) and 29 partial response (PR) patients (14.8%). Until October 1, 2023, no difference was found in 5-year overall survival (5-OS) and 5-year progression free survival(5-PFS) between allo-HSCT and auto-HSCT (5-OS 57.9% vs. 36.7%, P = 0.139, 5-year PFS 49.4% vs. 28.6%, P = 0.078) for patients who achieved CR, for patients who achieved PR, allo-HSCT recipients had higher 5-OS compared with chemo alone recipients (5-OS 23.8% vs. 0, P = 0.042). For patients undergoing allo-HSCT, minimal residual disease (MRD) negative population showed better 5-OS survival compared with MRD positive patients (67.8% vs. 19.6%, p = 0.000). There were no significant differences between early T-cell precursor (ETP), NON-ETP patients with or without expression of one or more myeloid-associated or stem cell-associated (M/S+) markers (NON-ETP with M/S+, NON-ETP without M/S+) groups in allo-HSCT population for 5-OS. (62.9% vs. 54.5% vs.48.4%, P > 0.05). Notch mutations were more common in patients with non-relapsed/refractory disease than relapsed/refractory disease (χ² =4.293, P = 0.038). In conclusion, Allo-HSCT could be an effective consolidation therapy not just for patients with CR, but also for those who achieved PR. The prognosis is significantly improved by obtaining MRD negative prior to allogeneic transplantation.

Impact of prior COVID-19 infection on allogeneic hematopoietic stem cell transplantation outcomes.

There are limited data on outcomes of allogeneic hematopoietic stem cell transplantation (allo-HSCT) in recipients with prior COVID-19 infection. This single-center retrospective study included 54 adult patients who received allo-HSCT from July 2020 to September 2021 after previous COVID-19 infection and 122 control group patients without a history of COVID-19 who underwent HSCT during the same period, with a median follow-up of 17 months. Median time from COVID-19 to allo-HSCT was 211 days. The incidence of main complications in the post-transplant period was not significantly different between the two groups: deep vein thrombosis (p = .85), TMA (p = .8), VOD (p = .25), bloodstream infections (p = .21), pneumonia of any etiology (p = .41), viral infections (p = .85), invasive fungal disease (p = .08). The 2-year non-relapse mortality, relapse incidence, overall survival, and progression-free survival also were comparable in the study and the control groups: 22% (95% CI 10.5-36.2) versus 26.3% (95% CI 18.7-34.6) p = .4; 15.6% (95% CI 7.3-26.9) versus 23.6% (95% CI 16.0-32.3) p = .39; 67.9% (95% CI 50.4-80.3) versus 59.8% (95% CI 50.2-68.1) p = .24 and 62.3% (95% CI 45.5-75.3) versus 49.9% (95% CI 40.0-59.1) p = .18, respectively. The history of previous COVID-19 infection did not affect the results of allo-HSCT.

Second line extracorporeal photopheresis for cortico-resistant acute and chronic GVHD after allogeneic hematopoietic cell transplantation for hematological malignancies: Long-term results from a real-life study.

BACKGROUND & OBJECTIVES: The primary objective of this observational study was to perform an exhaustive description concerning patients receiving extracorporeal photopheresis (ECP) as second line treatment after steroid resistance for either acute or chronic GVHD following allo-HCT, secondary objectives were to evaluate the efficacy and long-term outcomes. STUDY DESIGN: A total of 106 patients were included, 65 (61%) males and 41 (39%) females with a median age at transplantation of 52 years (range: 20-67). ECP was initiated after transplantation either for acute GVHD [N = 25 (24%), 12 grade III and 13 grade IV] affecting skin alone (N = 5), gut alone (N = 12), gut and liver (N = 8), or chronic GVHD [N = 81 (76%), 15 (14%) limited and 66 (62%) extensive]. RESULTS: Among the 25 patients treated for acute GHVD, 67% were responders and among the 81 patients with chronic GVHD, 78% were responders. Patients with acute GVHD had a median OS of 6 months with a survival probability at 2 years of 35% [95%CI: 14-56]. Patients with chronic GVHD had a median OS of 72 months with a survival probability at 2 years of 68% [95%CI: 56-78]. There was a significant difference in terms of survival for patients responding to ECP compared to non-responders in both acute and chronic GVHD forms. Acute GVHD grade III-IV, negatively impacted on OS (HR=7.77, 95%CI: 1.7-34), p = 0.007 and on disease relapse HR= 5.88, 95%CI: 1.7-20, p = 0.005. CONCLUSION: We demonstrated that ECP is an effective treatment for GVHD in a good proportion of patients with high overall response rate.

Clofarabine Preconditioning followed by Allogeneic Transplant Using TBI and Post-Transplant Cyclophosphamide for Relapsed Refractory Leukemia.

Acute myeloid leukemia patients with induction failure or relapsed refractory disease have minimal chance of achieving remission with subsequent treatments. Several trials have shown the feasibility of clofarabine-based conditioning in allogeneic stem cell transplants (allo-HSCT) for non-remission AML patients. Pre-transplant conditioning with clofarabine followed by reduced-intensity allo-HSCT has also demonstrated a potential benefit in those patients with human leukocyte antigen (HLA)-identical donors, but it is not commonly used in haploidentical and mismatched transplants. In this case report, we describe our experience of seven cases of non-remission AML who received clofarabine preconditioning followed by an allo-HSCT with PTCy. The 2-year overall survival and disease-free survival was 83.3% (95% confidence interval (CI): 27.3-97.9%) and 85.7% (95% CI: 33.4-97.9%). Median days of neutrophil and platelet recovery were 16 (range of 13-23) and 28 (range of 17-75), respectively. The cumulative incidence of grade II-IV acute graft-versus-host disease (GVHD) at day 100 and chronic GVHD at 1-year showed 28.6% (95% CI: 8-74.2%) and 28.6% (95% CI: 3-63.9%), respectively. The two-year relapse rate was 14.3% (95% CI: 2.14-66.6%). One-year GVHD-free relapse-free survival (GFRS) at 1-year was 71.4% (95% CI: 25.8-92%). Our patients showed successful outcomes with clofarabine preconditioning to reduce the leukemic burden at the pre-transplant period followed by PTCy to reduce GVHD resulting in lower relapsed rate and better GFRS in these patients.

A Primed Neutrophil Subset Predicts the Risk of Bloodstream Infections in Allogeneic Hematopoietic Stem-Cell Transplant Patients: A Prospective Study.

BACKGROUND: Bloodstream infections (BSIs) are the most common infectious complication in patients who receive allogeneic hematopoietic stem-cell transplants (allo-HSCTs). Polymorphonuclear neutrophils (PMNs) are quantified to monitor the susceptibility to BSIs; however, their degree of activation is not. We previously identified a population of primed PMNs (pPMNs) with distinct markers of activation representing approximately 10% of PMNs in circulation. In this study, we investigate whether susceptibility to BSIs is related to the proportion of pPMNs rather than strictly PMN counts. METHODS: In this prospective observational study, we used flow cytometry to assess pPMNs in blood and oral rinse samples collected from patients receiving an allo-HSCT over the course of their treatment. We used the proportion of pPMNs in the blood on day 5 post-transplant to categorize patients into a high- or a low-pPMN group (>10% or <10% pPMNs). These groups were then used as a predictor of BSIs. RESULTS: A total of 76 patients were enrolled in the study with 36 in the high-pPMN group and 40 in the low-pPMN group. Patients in the low-pPMN group had lower expression of PMN activation and recruitment markers and displayed a delay in PMN repopulation of the oral cavity after the transplant. These patients were more susceptible to BSIs compared with patients in the high-pPMN group with an odds ratio of 6.5 (95% confidence interval, 2.110-25.07; P = .002). CONCLUSIONS: In patients who receive an allo-HSCT, having <10% pPMNs early in the post-transplant phase can be an independent predictor of BSI in allo-HSCT patients.

Molecular disparity of HLA-DPB1 is associated with the development of subsequent solid cancer after allogeneic hematopoietic stem cell transplantation.

BACKGROUND: An increased incidence of subsequent solid cancers (SSCs) has been reported in long-term survivors of allogeneic hematopoietic stem cell transplantation (allo-HSCT), and SSC is associated with inferior mortality and morbidity. Previous studies showed that the incidence of SSC is significantly higher in those who underwent allo-HSCT from HLA-mismatched donors, suggesting that persistent alloimmunity may predispose patients to SSCs. It was recently reported that, in a cohort of patients who received allo-HSCT from an unrelated donor matched at HLA-A, -B, -C, -DRB1/3/4/5, and -DQB1 loci, HLA-DPB1 alloimmunity determined by high mismatched eplets (MEs) and Predicted Indirectly Recognizable HLA Epitopes (PIRCHE) score (PS), was associated with relapse protection and increased risk of acute graft-versus-host disease (GVHD). METHODS: In the present study, the impact of HLA-DPB1 alloimmunity assessed by molecular mismatch algorithms on the development of SSCs in a cohort of 1514 patients who underwent allo-HSCT for hematologic malignancies was further investigated. ME load at the HLA-DPB1 locus was measured using the HLAMatchmaker module incorporated in HLA Fusion software, and the PS for mismatched HLA-DPB1 was calculated using the HSCT module from the PIRCHE online matching service. RESULTS: In multivariable analysis after adjusting for baseline risk factors, higher ME, PS-I, and PS-II in the GVH direction, but not in the HVG direction, were associated with an increased risk of SSCs (ME: subdistribution hazard ratio [SHR] 1.58, p = .01; PS-I: SHR 1.59, p = .009; PS-II: SHR 1.71, p = .003). In contrast, nonpermissive HLA-DPB1 mismatches defined by the conventional T-cell epitope algorithm were not predictive of the risk of SSCs. Moreover, posttransplant cyclophosphamide-based GVHD prophylaxis was associated with a reduced risk of subsequent solid cancer (SHR 0.34, p = .021). CONCLUSIONS: These results indicate for the first time that increased GVH alloreactivity could contribute to the development of SSCs in allo-HSCT survivors.

Disparities in receiving disease-directed therapy, allogeneic stem cell transplantation in non-Hispanic Black patients with TP53-mutated acute myeloid leukemia.

BACKGROUND: Although the clinical outcomes of patients with TP53-mutated acute myeloid leukemia (AML) are dismal, subsets of patients eligible for curative-intent therapies may fare better. Because racial disparities are known to affect outcome in hematologic malignancies, the authors sought to explore disparities among patients with TP53-mutated AML. METHODS: A multicenter, retrospective study was conducted in a cohort of 340 patients who had TP53-mutated AML (275 non-Hispanic White [NHW] and 65 non-Hispanic Black [NHB]) to analyze differences in treatment and outcome among NHW and NHB patients. RESULTS: The median patient age was comparable between NHW and NHB patients (p = .76). A higher proportion of NHB patients had therapy-related AML (31% vs. 20%; p = .08) and had co-mutations (74% vs. 61%; p = .06). A higher proportion of NHW patients received intensive chemotherapy compared with NHB patients (47% vs. 31%; p = .02). Conversely, a higher proportion of NHB patients received low-intensity chemotherapy (9% vs. 5.5%; p = .02) or best supportive care (22% vs. 7%; p < .001). The complete response rate (including complete responses with or without complete count recovery) was 31% versus 24.5% (p = .39) in NHW and NHB patients, respectively. Only 5% of NHB patients received allogeneic stem cell transplantation compared with 15.5% of NHW patients (p = .02). The proportion of patients who were event-free (18.5% vs. 8.5%; p = .49) or who remained alive (24.9% vs. 8.3%; p = .13) at 18 months was numerically higher in NHW versus NHB patients, respectively, but was not statistically significant. CONCLUSIONS: The current study highlights disparities between NHW and NHB patients with TP53-mutated AML. Efforts are warranted to eliminate treatment disparities in minority populations.

Predicting short-term and long-term mortalities from sepsis in patients who receive allogeneic haematopoietic stem cell transplantation.

Patients who receive allogeneic haematopoietic stem cell transplantation (allo-HSCT) may develop sepsis, which result in a highly intensive care unit admission rate and mortality. Therefore, short-term and long-term prognostic models for sepsis after allo-HSCT are urgently needed. We enrolled patients receiving allo-HSCT who developed sepsis after allo-HSCT at Peking University People's Hospital between 2012 and 2021, including 287 patients who received allo-HSCT in 2018-2021 in the derivation cohort, and 337 patients in 2012-2017 in the validation cohort. Multivariate logistic regression analysis was used to identify prognostic factors, and these identified factors were incorporated into two scoring models. Seven independent factors (acute graft-versus-host disease (GVHD), chronic GVHD (cGVHD), total bilirubin, lactate dehydrogenase (LDH) and organ dysfunction [renal, lung and heart]) were included in the 6-month prognostic model, and six factors (cGVHD, C-reactive protein, LDH, organ dysfunction [lung, neurologic and coagulation]) were included in the 14-day prognostic model. The area under the receiver operating characteristic curves, calibration plots and decision curve analysis demonstrated the robust predictive performance of the models, better than the Sequential Organ Failure Assessment score. Early identification of patients with high risk of 6-month and 14-day death may allow clinicians to provide timely treatments and improve the therapeutic effects.

Outcomes of allogeneic or autologous stem cell transplantation followed by maintenance chemotherapy in adult patient with B-ALL in CR1 with no detectable minimal residual disease.

Autologous haematopoietic stem cell transplantation (auto-HSCT) as a treatment for B-cell acute lymphoblastic leukaemia (B-ALL) has been rigorously debated in recent years. We retrospectively analysed the outcomes of 355 adult patients with B-ALL in first complete remission who had received auto-HSCT or allogeneic HSCT (allo-HSCT) in our centre. The treatment efficacy was evaluated from a model stratified on the risk classification and minimal residue disease (MRD) status after three chemotherapy cycles. Auto-HSCT demonstrated comparable 3-year overall survival (OS) (72.7% vs. 68.5%, p = 0.441) and leukaemia-free survival rates (62.8% vs. 56.1%, p = 0.383) compared to allo-HSCT for patients with negative MRD, while the advantage of lower non-relapse mortality (1.5% vs. 25.1%, p < 0.001) was offset by a higher cumulative incidence of relapse (CIR) rates (35.7% vs. 18.9%, p = 0.018), especially in high-risk patients. For patients at high risk and with positive MRD, there was a lower trend of 3-year OS (50.0% vs. 66.0%, p = 0.078) and significantly higher CIR rates (71.4% vs. 39.1%, p = 0.018) in auto-HSCT. However, no significant interaction was observed in the tests. In conclusion, auto-HSCT appears to be an attractive treatment for patients with negative MRD after three chemotherapy cycles. For MRD-positive patients, allo-HSCT may be a more effective treatment.

Efficacy of haematopoietic stem cell boost as a rescue for poor graft function after haematopoietic stem cell transplantation: A multicentre retrospective study on behalf of the Francophone Society of Bone Marrow Transplantation and Cellular Therapy (SFGM-TC).

Haematopoietic stem cell reinjection may be a curative option for poor graft function after haematopoietic stem cell transplantation; however, literature supporting its use remains limited. We conducted a multicentre retrospective study on behalf of the Francophone Society of Bone Marrow Transplantation and Cellular Therapy, including 55 patients. We demonstrated response rates of nearly 40% and two-year survival of more than 60% in the context of an otherwise deadly complication and we observed that the timing of injection and the degree of cytopenia are strongly associated with outcomes. This study shows the feasibility of the procedure informing on its epidemiology, outcomes and prognostic factors, setting the stage for future guidelines.

Acute megakaryoblastic leukaemia shows high frequency of chromosome 1q aberrations and dismal outcome.

Acute megakaryoblastic leukaemia (AMKL) is associated with poor prognosis. Limited information is available on its cytogenetics, molecular genetics and clinical outcome. We performed genetic analyses, evaluated prognostic factors and the value of allogeneic haematopoietic stem cell transplantation (allo-HSCT) in a homogenous adult AMKL patient cohort. We retrospectively analysed 38 adult patients with AMKL (median age: 58 years, range: 21-80). Most received intensive treatment in AML Cooperative Group (AMLCG) trials between 2001 and 2016. Cytogenetic data showed an accumulation of adverse risk markers according to ELN 2017 and an unexpected high frequency of structural aberrations on chromosome arm 1q (33%). Most frequently, mutations occurred in TET2 (23%), TP53 (23%), JAK2 (19%), PTPN11 (19%) and RUNX1 (15%). Complete remission rate in 33 patients receiving intensive chemotherapy was 33% and median overall survival (OS) was 33 weeks (95% CI: 21-45). Patients undergoing allo-HSCT (n = 14) had a superior median OS (68 weeks; 95% CI: 11-126) and relapse-free survival (RFS) of 27 weeks (95% CI: 4-50), although cumulative incidence of relapse after allo-HSCT was high (62%). The prognosis of AMKL is determined by adverse genetic risk factors and therapy resistance. So far allo-HSCT is the only potentially curative treatment option in this dismal AML subgroup.

DNTT activation, TdT-aided gene length mutation, and better prognosis in ATG-based regimen allo-HSCT in AML.

This study aimed to investigate the relationship between anomalous DNA nucleotidylexotransferase (DNTT) activation and the mutagenesis of gene length mutations (LMs) in acute myeloid leukemia (AML), and the relevance of their prognosis in antithymocyte globulin (ATG)-based regimen allogeneic hematopoietic stem cell transplantation (allo-HSCT). A cohort of 578 AML cases was enrolled. Next-generation sequencing was performed to screen mutations of 86 leukemia driver genes. RNA-seq was used to analyze gene expression. Prognostic analysis was investigated in 239 AML cases who underwent ATG-based regimen allo-HSCT. We report a refined subtyping algorithm of LMs (type I-IV) based on sequence anatomy considering the TdT-aided mutagenesis mechanism. GC content adjacent to LM junctions, inserted nontemplate nucleotide bases, and DNTT expression analysis supported the DNTT activation and TdT-aided mutagenesis in type II/III LMs in the total AML cohort. Both single-variate and multivariate analyses showed a better overall survival of FLT3 type III compared to type I in a subset of ATG-based regimen allo-HSCT cases. The novel LM subtyping algorithm not only deciphers the etiology of the mutagenesis of LMs but also helps to fine-tune prognosis differentiation in AML. The possible prognostic versatility of this novel LM subtyping algorithm in terms of chemotherapy, targeted therapy, and allo-HSCT merits further investigation.