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Purpose: Immune cells are capable of eliminating leukemic cells, as evidenced by outcomes in hematopoietic cell transplantation (HCT). However, patients who fail induction therapy will not benefit from HCT due to their minimal residual disease (MRD) status. Thus, we aimed to develop an immunomodulatory agent to reduce MRD by activating immune effector cells in the presence of leukaemia cells via a novel fusion protein that chimerises two clinically tolerated biologics: a CD33 antibody and the IL15Ra/IL15 complex (CD33xIL15). Methods: We generated a set of CD33xIL15 fusion protein constructs with varying configurations and identified those with the best in vitro AML-binding, T cell activation, and NK cell potentiation. Using 89Zr-immunoPET imaging we then evaluated the biodistribution and in vivo tumour retention of the most favourable CD33xIL15 constructs in an AML xenograft model. Ex vivo biodistribution studies were used to confirm the pharmacokinetics of the constructs. Results: Two of the generated fusion proteins, CD33xIL15 (N72D) and CD33xIL15wt, demonstrated optimal in vitro behaviour and were further evaluated in vivo. These studies revealed that the CD33xIL15wt candidate was capable of being retained in the tumour for as long as its parental CD33 antibody, Lintuzumab (13.9 ± 3.1%ID/g vs 18.6 ± 1.1%ID/g at 120 h). Conclusion: This work demonstrates that CD33xIL15 fusion proteins are capable of targeting leukemic cells and stimulating local T cells in vitro and of concentrating in the tumour in AML xenografts. It also highlights the importance of 89Zr-immunoPET to guide the development and selection of tumour-targeted antibody-cytokine fusion proteins. [ABSTRACT FROM AUTHOR]

Myelodysplastic syndromes/neoplasms (MDS) and acute myeloid leukaemia (AML) are neoplastic haematopoietic cell proliferations that are diagnosed and classified based on a combination of morphological, clinical and genetic features. Specifically, the percentage of myeloblasts in the blood and bone marrow is a key feature that has historically separated MDS from AML and, together with several other morphological parameters, defines distinct disease entities within MDS. Both MDS and AML have recurrent genetic abnormalities that are increasingly influencing their definitions and subclassification. For example, in 2022, two new MDS entities were recognised based on the presence of SF3B1 mutation or bi‐allelic TP53 abnormalities. Genomic information is more objective and reproducible than morphological analyses, which are subject to interobserver variability and arbitrary numeric cut‐offs. Nevertheless, the integration of genomic data with traditional morphological features in myeloid neoplasm classification has proved challenging by virtue of its sheer complexity; gene expression and methylation profiling also can provide information regarding disease pathogenesis, adding to the complexity. New machine‐learning technologies have the potential to effectively integrate multiple diagnostic modalities and improve on historical classification systems. Going forward, the application of machine learning and advanced statistical methods to large patient cohorts can refine future classifications by advancing unbiased and robust previously unrecognised disease subgroups. Future classifications will probably incorporate these newer technologies and higher‐level analyses that emphasise genomic disease entities over traditional morphologically defined entities, thus promoting more accurate diagnosis and patient risk stratification. [ABSTRACT FROM AUTHOR]

Acute myeloid leukaemia (AML) is a highly heterogeneous malignancy, with a poor 5-year overall survival rate of approximately 30%. Consequently, the search for novel therapeutic strategies is ongoing, and the identification of new vulnerabilities could accelerate progress. Oxidative stress and metabolic rewiring are established hallmarks of cancer, and recent evidence suggests that NADPH oxidases may regulate metabolism, potentially linking these two processes. Increasing research highlights the importance of NOX2 in AML, particularly its role in metabolic regulation. In this study, we investigated the effects of simultaneously inhibiting NOX2 and glycolysis in AML cells. Dual inhibition of NOX2 and glycolysis—by targeting hexokinase or lactate dehydrogenase (LDH)—significantly reduced cell proliferation, markedly impaired clonogenic potential, and induced extensive cell death in a broad panel of AML cell lines. Importantly, these findings were further validated in primary bone marrow samples derived from AML patients, where combined inhibition triggered similar potent anti-leukemic effects. Furthermore, the combined inhibition of NOX2 and LDH enhanced the efficacy of cytarabine (AraC), suggesting this approach could boost the effectiveness of conventional therapies. In an in vivo AML model, targeting NOX2 and LDH in myeloid progenitor cells delayed the onset of leukaemia and extended survival. In conclusion, our findings propose a novel therapeutic strategy for AML through the dual targeting of NOX2 and glycolysis. [ABSTRACT FROM AUTHOR]

Summary HLA‐haploidentical haematopoietic cell transplantation with post‐transplant cyclophosphamide (PTCy‐haplo) is emerging as an effective alternative due to donor availability and safety. We conducted a nationwide retrospective study comparing the outcomes of PTCy‐haplo with both anti‐thymocyte globulin (ATG)‐free and ATG‐administered matched unrelated donors (MUD) transplantation, using peripheral blood stem cells as the first transplantation for acute myeloid leukaemia (AML). Our study showed a lower and slower haematopoietic recovery and a higher incidence of infection‐related deaths after PTCy‐haplo than after MUD transplantation. In addition, we revealed an increased risk of acute and chronic graft‐versus‐host disease (GVHD) in ATG‐free MUD transplantation in comparison to PTCy‐haplo. For grades III–IV acute GVHD, the hazard ratio (HR) was 2.71 (95% CI, 1.46–5.01), and for extensive chronic GVHD, the HR was 3.11 (95% CI, 2.07–4.68). There was no significant difference regarding overall survival amongst the groups. In addition, GVHD‐free relapse‐free survival (GRFS) was lower in ATG‐free MUD transplantation than in PTCy‐haplo (HR, 1.46; 95% CI, 1.17–1.82). Notably, ATG‐administered MUD transplantation showed no significant difference in GRFS from PTCy‐haplo, negating the advantage of PTCy. Our results suggest that PTCy‐haplo could be viable for AML patients without an HLA‐matched related donor. [ABSTRACT FROM AUTHOR]

Summary Non‐Western immigrant patients (NWIPs) may be a vulnerable population when diagnosed and treated for acute myeloid leukaemia (AML). Here we report selected quality parameters related to diagnosis, treatment, and outcome of newly diagnosed AML among NWIPs (n = 119) and Danish‐born patients (DBPs) (n = 4689). No adjusted differences were observed for time‐to‐diagnosis, time‐to‐treatment, treatment allocation, rates of complete remission, early death, allogeneic stem cell transplantation, and overall survival between NWIPs and DBPs. Among patients allocated for intensive chemotherapy, NWIPs were less likely to participate in clinical trials. The findings highlight equitable AML care but underscore the need to enhance NWIP participation in clinical trials. [ABSTRACT FROM AUTHOR]

Summary: Favourable outcomes with CPX‐351 versus conventional 7 + 3 were demonstrated in the pivotal phase III trial in adults aged 60–75 years with newly diagnosed, highrisk/secondary acute myeloid leukaemia (AML). As a complement to the clinical trial and to address important data gaps, the CPX‐351 Real‐World Effectiveness and SafeTy (CREST‐UK; NCT05169307) study evaluated the use of CPX‐351 in routine clinical practice in the UK, in 147 patients with newly diagnosed therapy‐related AML or AML with myelodysplasia‐related changes. Best response of complete remission or complete remission with incomplete platelet or neutrophil recovery was achieved by 53% of evaluable patients. Kaplan–Meier median overall survival (OS) was 12.8 months (95% confidence interval 9.2–15.3). Fifty (34%) patients proceeded to haematopoietic cell transplantation (HCT); median OS landmarked from the HCT date was not reached. There were no new safety concerns with CPX‐351 identified in CREST‐UK. Patients treated with CPX‐351 in the outpatient setting spent an average of 24.4, 16.7, 28.2, and 27.7 fewer days on the ward compared with inpatients during first induction, second induction, first consolidation, and second consolidation, respectively. The results from CREST‐UK provide valuable insights into the effectiveness, safety, and outpatient delivery of CPX‐351 in routine clinical practice in the UK. [ABSTRACT FROM AUTHOR]

Summary This study compared decitabine exposure when administered IV (DEC‐IV) at a dose of 20 mg/m2 for 5‐days with orally administered decitabine with cedazuridine (DEC‐C), as well as the clinical efficacy and safety of DEC‐C in patients with acute myeloid leukaemia (AML) who were ineligible for intensive induction chemotherapy. In all, 89 patients were randomised 1:1 to DEC‐IV or oral DEC‐C (days 1–5 in a 28‐day treatment cycle), followed by 5 days of the other formulation in the next treatment cycle. All patients received oral DEC‐C for subsequent treatment cycles until treatment discontinuation. Equivalent systemic decitabine exposures were demonstrated (5‐day area under the curve ratio between the two decitabine formulations of 99.64 [90% confidence interval 91.23%, 108.80%]). Demethylation rates also were similar (≤1.1% difference). Median overall survival (OS), clinical response and safety profile with oral DEC‐C were consistent with those previously observed with DEC‐IV. Next‐generation sequencing was performed to identify molecular abnormalities that impact OS and TP53 mutations were associated with a poor outcome. These findings support the use of oral DEC‐C in patients with AML. [ABSTRACT FROM AUTHOR]

ABSTRACT Objectives Methods Results Conclusion Childhood cancer often presents with non‐specific signs and symptoms that might mimic non‐malignant disorders including musculoskeletal diseases, potentially leading to rheumatic and orthopaedic misdiagnoses. We aimed to compare clinical presentation, diagnostic interval and survival in paediatric acute myeloid leukaemia (AML) with and without initial musculoskeletal symptoms.This nationwide retrospective, cohort study reviewed medical records of 144 children below 15 years diagnosed with AML in Denmark from 1996 to 2018.Musculoskeletal symptoms occurred in 29% (42/144) of children with AML and 8% (11/144) received an initial musculoskeletal misdiagnosis, being mainly non‐specific and pain‐related. The children with and without musculoskeletal symptoms did not differ markedly up to the diagnosis of AML and blood counts were affected equally in both groups. However, the children with prior musculoskeletal symptoms were more likely to have elevated levels of LDH and ferritin. Furthermore, they revealed a tendency towards a longer total interval (median 53 days vs. 32 days, p = 0.07), but the overall survival did not differ.AML should be considered as an underlying cause in children with unexplained musculoskeletal symptoms and abnormal blood counts. Concomitant elevation of LDH and ferritin should strengthen the suspicion. [ABSTRACT FROM AUTHOR]

Summary Data on haematological features of telomere biology disorders (TBD) remain scarce. We describe haematological, extra‐haematological characteristics and prognosis of 127 genetically confirmed TBD patients diagnosed after the age of 15. Ninety‐three index cases and 34 affected relatives were included. At diagnosis of TBD, 76.3% of index cases had haematological features, half pulmonary features and a third liver features. At diagnosis, bone marrow failure (BMF) was present in 59 (46.5%), myelodysplastic syndrome (MDS) in 22 (17.3%) and acute myeloid leukaemia (AML) in 2 (1.6%) while 13 (10.2%) developed or worsened bone marrow involvement during follow‐up. At diagnosis, compared to MDS/AML patients, BMF patients were younger (median 23.1 years vs. 43.8, p = 0.007), and had a better outcome (4‐year overall survival 76.3% vs. 31.8%, p < 0.001). While frequencies and burden of cytogenetical and somatic mutations increased significantly in myeloid malignancies, some abnormalities were also observed in patients with normal blood counts and BMF, notably somatic spliceosome variants. Solid cancers developed in 8.7% patients, mainly human papillomavirus‐related cancers and hepatocellular carcinomas. TBD is a multiorgan progressive disease. While BMF is the main haematological disorder, high‐risk myeloid malignancies are common, and are, together with age, the only factors associated with a worse outcome. [ABSTRACT FROM AUTHOR]

Summary: Acute myeloid leukaemia (AML) is a heterogeneous disease characterized by complex molecular and cytogenetic abnormalities. Pro‐oxidant cellular redox status is a common hallmark of AML cells, providing a rationale for redox‐based anticancer strategy. We previously discovered that auranofin (AUF), initially used for the treatment of rheumatoid arthritis and repositioned for its anticancer activity, can synergize with a pharmacological concentration of vitamin C (VC) against breast cancer cell line models. In this study, we observed that this drug combination synergistically and efficiently killed cells of leukaemic cell lines established from different myeloid subtypes. In addition to an induced elevation of reactive oxygen species and ATP depletion, a rapid dephosphorylation of 4E‐BP1 and p70S6K, together with a strong inhibition of protein synthesis were early events in response to AUF/VC treatment, suggesting their implication in AUF/VC‐induced cytotoxicity. Importantly, a study on 22 primary AML specimens from various AML subtypes showed that AUF/VC combinations at pharmacologically achievable concentrations were effective to eradicate primary leukaemic CD34+ cells from the majority of these samples, while being less toxic to normal cord blood CD34+ cells. Our findings indicate that targeting the redox vulnerability of AML with AUF/VC combinations could present a potential anti‐AML therapeutic approach. [ABSTRACT FROM AUTHOR]

Summary: Large amounts of azurophilic granules are considered to be a morphological feature of acute promyelocytic leukaemia (APL). However, a small percentage of acute myeloid leukaemia (AML) patients also have a large number of azurophilic granules. A large cohort of 3210 AML patients in our hospital was screened to identify AML patients who had a large number of azurophilic granules. The clinical parameters of these patients were collected and compared with typical AML patients (control Group 1) and APL patients (control Group 2). The incidence of AML with a large number of azurophilic granules was 1.26%. The fibrinogen and D‐dimer levels of patients in the study group were more similar to those of patients in control Group 2, as was the incidence of bleeding events. Additionally, patients in the study group had higher FLT3‐ITD and NPM1 mutation rates than patients in control Group 1. Finally, patients in the study group had a higher 30‐day mortality rate than those in control Group 2 (24.2% vs. 9.09%) and showed a higher 30‐day mortality trend than those in control Group 1. Therefore, we should pay more attention to the prevention of coagulation dysfunction and bleeding events for these patients. [ABSTRACT FROM AUTHOR]

Acute myeloid leukaemia (AML) is a highly heterogeneous disease, which lead to various findings in transcriptomic research. This study addresses these challenges by integrating 34 datasets, including 26 control groups, 6 prognostic datasets and 2 single‐cell RNA sequencing (scRNA‐seq) datasets to identify 10,000 AML‐related genes (ARGs). We focused on genes with low variability and high consistency and successfully discovered 191 AML signatures (ASs). Leveraging machine learning techniques, specifically the XGBoost model and our custom framework, we classified AML subtypes with both scRNA‐seq and bulk RNA‐seq data, complementing the ELN2022 classification approach. Our research also identified promising treatments for AML through drug repurposing, with solasonine showing potential efficacy for high‐risk AML patients, supported by molecular docking and transcriptomic analyses. To enhance reproducibility and customizability, we developed CSAMLdb, a user‐friendly database platform. It facilitates the reuse and personalized analysis of nearly all results obtained in this research, including single‐gene prognostics, multi‐gene scoring, enrichment analysis, machine learning risk assessment, drug repositioning analysis and literature abstract named entity recognition. CSAMLdb is available at http://www.csamldb.com. [ABSTRACT FROM AUTHOR]

Abstract Acute myeloid leukaemia (AML) is a highly heterogeneous malignancy, with a poor 5-year overall survival rate of approximately 30%. Consequently, the search for novel therapeutic strategies is ongoing, and the identification of new vulnerabilities could accelerate progress. Oxidative stress and metabolic rewiring are established hallmarks of cancer, and recent evidence suggests that NADPH oxidases may regulate metabolism, potentially linking these two processes. Increasing research highlights the importance of NOX2 in AML, particularly its role in metabolic regulation. In this study, we investigated the effects of simultaneously inhibiting NOX2 and glycolysis in AML cells. Dual inhibition of NOX2 and glycolysis—by targeting hexokinase or lactate dehydrogenase (LDH)—significantly reduced cell proliferation, markedly impaired clonogenic potential, and induced extensive cell death in a broad panel of AML cell lines. Importantly, these findings were further validated in primary bone marrow samples derived from AML patients, where combined inhibition triggered similar potent anti-leukemic effects. Furthermore, the combined inhibition of NOX2 and LDH enhanced the efficacy of cytarabine (AraC), suggesting this approach could boost the effectiveness of conventional therapies. In an in vivo AML model, targeting NOX2 and LDH in myeloid progenitor cells delayed the onset of leukaemia and extended survival. In conclusion, our findings propose a novel therapeutic strategy for AML through the dual targeting of NOX2 and glycolysis.

Sandip Patil, Xinye Li, Huirong Mai, Ying Wang, Xue Tang, Sixi Liu, Feiqiu Wen Department of Haematology and Oncology, Shenzhen Children’s Hospital, Shenzhen, Guangdong Province, People’s Republic of ChinaCorrespondence: Sixi Liu; Feiqiu Wen, Email tigar467@126.com; fwen62@163.comBackground: This case report underscores the intricate challenges in managing paediatric patients with acute myeloid leukaemia (AML) undergoing intensive chemotherapy, particularly when complicated by the emergence of multidrug-resistant pathogens such as Carbapenem-Resistant Pseudomonas aeruginosa (CRPA).Case Presentation: An 11-year-old male with AML presented with skin purpura and persistent cough. Clinical and laboratory assessments revealed a high-risk AML profile with genetic mutations, leading to the initiation of intensive chemotherapy per the C-HUANA-AML-2015 protocol. Despite successful disease remission after initial chemotherapy courses, the patient experienced unexpected complications. Notably, septic shock, bone marrow failure, and the emergence of CRPA were encountered during the clinical course. Septic shock occurred following Course B3 chemotherapy, marked by a fever unresponsive to initial antibiotic therapy. Despite negative blood cultures, meropenem and vancomycin were initiated, successfully normalizing temperature. Subsequent challenges included persistent bone marrow suppression, perianal dermatitis, and the identification of CRPA in stool cultures, leading to altered antibiotic therapy guided by minimum inhibitory concentration (MIC) considerations. Whole-genome sequencing (WGS) of the CRPA strain revealed a highly virulent clone (ST-970) with numerous resistance and virulence genes.Conclusion: This case report offers new insights into the complexities of pediatric AML management, with a focus on the emergence of CRPA. The discovery of a high-risk CRPA clone with detailed genomic data underscores the growing challenge of antimicrobial resistance in pediatric oncology. The persistent presence of CRPA and ongoing bone marrow failure highlight the difficulties in managing these complications. This case calls for a reassessment of treatment strategies and encourages further research to improve outcomes in pediatric AML, emphasizing the need for a multidisciplinary approach to address infectious complications and antimicrobial resistance.Keywords: acute myeloid leukaemia, carbapenem-resistant Pseudomonas aeruginosa, paediatric oncology, antimicrobial resistance, superbugs

Abstract The aim of this study was to observe the effects of different conditioning regimens on fine immune indices after microtransplantation (MST) in patients with acute myeloid leukaemia (AML). This article discusses the possible immune mechanism of microtransplantation and describes a more optimized conditioning regimen. A total of 55 AML patients who received MST treatment at the Second Hospital of Lanzhou University from August 2015 to October 2023 were included in this study, and 13 AML patients who did not receive MST but directly received the maintenance therapy were included as the control group (C). The MST patients were divided into a conditioning regimen with venetoclax group (A) and a conditioning regimen without venetoclax group (B). The fine immune indices were detected by flow cytometry and cytometric bead array analysis. Changes in the immune indices before and after treatment were observed, and the progression-free survival (PFS) and overall survival (OS) of patients in the MST group were analysed. Compared with those in Group B, patients in Group A had better PFS and OS. The proportion of Treg cells and the expression level of IL-2 were increased, while TNF-α and IFN-α were decreased after MST (P

Despite significant progress in basic and preclinical research into acute myeloid leukaemia (AML), the five-year survival rate for patients with AML remains poor, highlighting the urgent need for new combination therapies. Over the past decade, increased attention has been focused on identifying suitable immunotherapeutic strategies to combat AML, in particular targeting leukaemia cells and their precursors with cytokines. Targeted therapy is also an established approach for the treatment of AML. However, with the increasing number of treatment options, there are challenges in understanding how to select the most effective therapy and how to combine different drugs. Venetoclax is a targeted agent, a potent and highly selective inhibitor of B cell lymphoma protein-2 (BCL-2), one of the cell’s major anti-apoptotic proteins. Research into approaches to improve the treatment of AML remains challenging due to the limitations of experimental models. Despite improvements in ex vivo culture protocols, in vivo models remain the only way to study the inherently heterogeneous nature of AML and the influence of the microenvironment on leukaemia development. In our study, we show that in a xenograft mouse model of acute myeloid leukaemia in mice of the NSG-SGM3 line, there is an increase in serum IL-4 in response to venetoclax therapy. IL-4 has previously been shown to induce apoptosis in AML cells. These data provide new perspectives for the use of strategies based on the synergism of venetoclax and IL-4 in inducing apoptosis. The data also show an increase in serum human MCP-1 levels upon engraftment of OCI-AML-2 leukaemia cells in the serum of xenografted mice, which decreases after venetoclax therapy and may serve as a prognostic marker for the success of ongoing therapy. An obvious advantage of xenograft models in mice was the ability to separate the expression and secretion of murine cytokines and chemokines that determine the microenvironmental response from the cytokine profile of the human tumor cells themselves. Overall, our data suggest additional functional features of venetoclax action on tumor cells through the regulation of cytokine secretion and the prospect of using the immunodeficient mouse line NSG-SGM3 to test new approaches to the treatment of AML.

Summary Aberrant alternative splicing (AS) contributes to leukemogenesis, but reports on the clinical and biological implications of aberrant AS in acute myeloid leukaemia (AML) remain limited. Here, we used RNA‐seq to analyse AS in AML cells from 341 patients, comparing them to healthy CD34+ haematopoietic stem cells (HSCs). Our findings highlight distinct AS patterns in the nuclear transcription factor Y subunit alpha (NFYA) gene, with two main isoforms: NFYA‐L (Long) and NFYA‐S (Short), differing in exon 3 inclusion. Patients with lower NFYA‐L but higher NFYA‐S expression, termed NFYA‐S predominance, displayed more favourable characteristics and better outcomes following intensive chemotherapy, regardless of age and European LeukemiaNet risk classification, compared to those with higher NFYA‐L but lower NFYA‐S expression, termed NFYA‐L predominance. The prognostic effects were validated using The Cancer Genome Atlas cohort. Transcriptome analysis revealed upregulated cell cycle genes in NFYA‐S predominant cases, resembling those of active HSCs, demonstrating relative chemosensitivity. Conversely, NFYA‐L predominant cases, as observed in KMT2A‐rearranged leukaemia, were associated with relative chemoresistance. NFYA‐S overexpression in OCI‐AML3 cells promoted cell proliferation, S‐phase entry and increased cytarabine sensitivity, suggesting its clinical and therapeutic relevance in AML. Our study underscores NFYA AS as a potential prognostic biomarker in AML. [ABSTRACT FROM AUTHOR]

Summary Wilms' tumour 1 (WT1) can function as an oncogene or a tumour suppressor. Our previous clinical cohort studies showed that low WT1 expression at diagnosis independently predicted poor outcomes in acute myeloid leukaemia (AML) with RUNX1::RUNX1T1, whereas it had an opposite role in AML with non‐favourable cytogenetic risk (RUNX1::RUNX1T1‐deficient). The molecular mechanism by which RUNX1::RUNX1T1 affects the prognostic significance of WT1 in AML remains unknown. In the present study, first we validated the prognostic significance of WT1 expression in AML. Then by using the established transfected cell lines and xenograft tumour model, we found that WT1 suppresses proliferation and enhances effect of cytarabine in RUNX1::RUNX1T1(+) AML but has opposite functions in AML cells without RUNX1::RUNX1T1. Furthermore, as a transcription factor, WT1 physically interacts with RUNX1::RUNX1T1 and acts as a co‐factor together with RUNX1::RUNX1T1 to activate the expression of its target gene DUSP6 to dampen extracellular signal‐regulated kinase (ERK) activity. When RUNX1::RUNX1T1‐deficient, WT1 can activate the mitogen‐activated extracellular signal‐regulated kinase/ERK axis but not through targeting DUSP6. These results provide a mechanism by which WT1 together with RUNX1::RUNX1T1 suppresses cell proliferation through WT1/DUSP6/ERK axis in AML. The current study provides an explanation for the controversial prognostic significance of WT1 expression in AML patients. [ABSTRACT FROM AUTHOR]

The aim of this study was to observe the effects of different conditioning regimens on fine immune indices after microtransplantation (MST) in patients with acute myeloid leukaemia (AML). This article discusses the possible immune mechanism of microtransplantation and describes a more optimized conditioning regimen. A total of 55 AML patients who received MST treatment at the Second Hospital of Lanzhou University from August 2015 to October 2023 were included in this study, and 13 AML patients who did not receive MST but directly received the maintenance therapy were included as the control group (C). The MST patients were divided into a conditioning regimen with venetoclax group (A) and a conditioning regimen without venetoclax group (B). The fine immune indices were detected by flow cytometry and cytometric bead array analysis. Changes in the immune indices before and after treatment were observed, and the progression-free survival (PFS) and overall survival (OS) of patients in the MST group were analysed. Compared with those in Group B, patients in Group A had better PFS and OS. The proportion of Treg cells and the expression level of IL-2 were increased, while TNF-α and IFN-α were decreased after MST (P < 0.05). In Group B, total T cells, CD4+T cells and CD4+/CD8+T cells decreased; NK cells and total B cells increased; and IL-17A first increased and then decreased during the MST (P < 0.05). There were significant differences in total B cells, IL-4 and IFN-γ between Group A and Group B during MST. Moreover, there were significant differences in total T cells, CD4+T cells, Treg cells, IL-17A, IFN-γ and IL-2 between the patients in the MST group and those in the control group (P < 0.05). The MST conditioning regimen containing venetoclax significantly changed the fine immune indices and showed improved efficacy, which is worthy of further study and clinical application. [ABSTRACT FROM AUTHOR]

Introduction: To identify the differentially expressed genes of acute myeloid leukaemia (AML) and construct and verify a survival prognosis model combined with patient survival information. Methods: The TARGET database was searched to identify differentially expressed peripheral blood genes in children with AML and healthy children. A gene set functional analysis and pathway analysis were performed using gene ontology and the KEGG pathway. A prognostic model for children with AML was constructed using univariate Cox, LASSO Cox regression and multivariate Cox regression analyses. Time‐dependent receiver operating characteristic (ROC) curves were adopted to assess the predictive capacity of the prognostic models. Results: In total, 1640 differentially expressed genes were screened (1119 upregulated and 521 downregulated genes). The differentially expressed genes were mainly involved in nutrient metabolism and cytochrome P450 metabolism. Six key genes related to the prognosis of AML, FAM157A, GPR78, IRX5, RP4‐800G7.1, RP11‐179H18.5 and RP11‐61N20.3, were identified. Kaplan–Meier curves indicated that 3‐year and 5‐year overall survival was significantly higher in the low‐risk group than in the high‐risk group. The area under the ROC curve was 0.722. At different stages of AML, FAM157A and RP4‐800G7.1 exhibited significant differences in expression. The expression levels of FAM157A were significantly decreased in AML, whereas the expression levels of GPR78, IRX5, RP4‐800G7.1, RP11‐179H18.5 and RP11‐61N20.3 were significantly increased in AML. Conclusion: A prognosis‐related gene model of AML was successfully constructed, and the expression levels of the model genes varied with AML stage. [ABSTRACT FROM AUTHOR]

Introduction: Despite extensive research, comprehensive characterization of leukaemic stem cells (LSC) and information on their immunophenotypic differences from normal haematopoietic stem cells (HSC) is lacking. Herein, we attempted to unravel the immunophenotypic (IPT) characteristics and heterogeneity of LSC using multiparametric flow cytometry (MFC) and single‐cell sequencing. Materials and Methods: Bone marrow aspirate samples from patients with acute myeloid leukaemia (AML) were evaluated using MFC at diagnostic and post induction time points using a single tube‐10‐colour‐panel containing LSC‐associated antibodies CD123, CD45RA, CD44, CD33 and COMPOSITE (CLL‐1, TIM‐3, CD25, CD11b, CD22, CD7, CD56) with backbone markers that is, CD45, CD34, CD38, CD117, sCD3. Single‐cell sequencing of the whole transcriptome was also done in a bone marrow sample. Results: LSCs and HSCs were identified in 225/255 (88.2%) and 183/255 (71.6%) samples, respectively. Significantly higher expression was noted for COMPOSITE, CD45RA, CD123, CD33, and CD44 in LSCs than HSCs (p < 0.0001). On comparing the LSC specific antigen expressions between CD34+ (n = 184) and CD34‐ LSCs (n = 41), no difference was observed between the groups. More than one sub‐population of LSC was demonstrated in 4.4% of cases, which further revealed high concordance between MFC and single cell transcriptomic analysis in one of the cases displaying three LSC subpopulations by both methods. Conclusion: A single tube‐10‐colour MFC panel is proposed as an easy and reproducible tool to identify and discriminate LSCs from HSCs. LSCs display both inter‐ and intra‐sample heterogeneity in terms of antigen expressions, which opens the facets for single cell molecular analysis to elucidate the role of subpopulations of LSCs in AML progression. [ABSTRACT FROM AUTHOR]

Summary: This retrospective study analysed 106 acute myeloid leukaemia (AML) patients undergoing autologous haematopoietic stem cell transplantation (ASCT) to assess the impact of multiple small‐dose infusions of granulocyte‐colony‐stimulating factor (G‐CSF)‐mobilized haploidentical lymphocytes as post‐ASCT maintenance therapy. Among them, 50 patients received lymphocyte maintenance therapy, 21 received alternative maintenance therapy, and 35 received no maintenance therapy. Patients receiving lymphocyte maintenance therapy demonstrated significantly higher overall survival (OS) and disease‐free survival (DFS) compared to those without maintenance therapy, with 4‐year OS and DFS rates notably elevated. While there were no significant differences in recurrence rates among the three groups, lymphocyte maintenance therapy showcased particular benefits for intermediate‐risk AML patients, yielding significantly higher OS and DFS rates and lower relapse rates compared to alternative maintenance therapy and no maintenance therapy. The study suggests that multiple small‐dose infusions of G‐CSF‐mobilized haploidentical lymphocytes may offer promising outcomes for AML patients after ASCT, particularly for those classified as intermediate‐risk. These findings underscore the potential efficacy of lymphocyte maintenance therapy in reducing disease relapse and improving long‐term prognosis in this patient population. [ABSTRACT FROM AUTHOR]

Introduction: Leukaemia is the most common cancer in children, however, there is still a big gap in knowledge about the genomic alterations in childhood acute myeloid leukaemia (AML) compared to adult AML. Relapsed AML remains as a leading cause of cancer deaths among children. This study aims to understand the molecular mechanisms of relapsed AML by elucidating the mutational landscape before and during relapse. Materials and Methods: Whole genome sequencing was performed on matched samples collected at diagnosis, remission and relapse from three patients of de novo childhood AML. Sanger sequencing was performed for validation in 47 patients' samples, followed by functional analysis. Results: Overall, we identified 312 somatic mutations including synonymous single nucleotide variants (SNVs), missense SNVs, deletions and insertion frameshifts, stopgains and splice sites. After prioritisation, only 46 variants were present at diagnosis (13-17 mutations per patient) and 49 variants at relapse (12-20 mutations per patient). Out of 81 variants, there were 35 new variants detected at relapse but not present at diagnosis. Six potential driver mutations (KIT, CDC73, HNF1A, RBM10, ZMYM4 and ETV6) were identified in predicting relapse for the 3 patients, with recurrent mutations of the ETV6 gene in 2 patients. Functional analysis of the ETV6 mutation showed that ETV6 lost its tumour suppressive function when both mutant ETV6 p.P25fs and ETV6 p.N75fs were tested in vitro. Conclusion: This study has uncovered the mutational landscape in three local childhood AML patients and contributes to a better understanding of the molecular mechanisms of relapsed AML. [ABSTRACT FROM AUTHOR]

Summary Our observational study analysed fungal infection frequency within cohorts with versus without antifungal prophylaxis (AFP) among newly diagnosed first‐line venetoclax and azacitidine (VEN + AZA)‐treated acute myeloid leukaemias in Czech, Austrian and Slovak haematology centres. Among 186 patients, 85 (46%) received antifungal prophylaxis, while 101 (54%) received no prophylaxis. Fungal infections occurred in 1/85 patients with prophylaxis (1%) and 5/101 patients without prophylaxis (5%) (p = 0.222). No significant difference was recorded between cohorts with and without AFP in terms of death rate (p = 0.296) and overall survival (p = 0.844). In conclusion, most infections were not severe, developing during the first treatment‐cycle and did not affect patients' overall outcome. [ABSTRACT FROM AUTHOR]

Mastocytosis is a rare disorder due to the abnormal proliferation of clonal mast cells. Mast cells exist in most tissues, mature in situ from hematopoietic stem cells and develop unique characteristics of local effector cells. It manifests as two main categories: cutaneous mastocytosis and systemic mastocytosis (SM). Patients presenting with SM-acute myeloid leukaemia (AML) often have the worst outcome. Here we present a patient with the simultaneous diagnosis of SM associated with t (8;21) (q22;q22) acute myeloid leukaemia,M2 subtype in theFrench-American-British (FAB) classification, carrying a population ofimmature mast cell precursors. Initially, she was diagnosed with AML with t (8;21) (q22;q22) and was started on induction chemotherapy. Subsequent trephine biopsy evaluation post-induction chemotherapy showed no increase in blast cells. However, abnormal mast cells were seen distributed throughout the marrow spaces, which expressed mast cell tryptase, CD117 and CD68. She was then diagnosed as SM associated with t(8;21) (q22;q22) AML. Unfortunately, she succumbed to death due to severe neutropenic sepsis postinduction chemotherapy. By sharing the knowledge, hopefully it will help the clinicians as the diagnosis of SM is difficult to establish because the associated malignancy may obscure the morphological features of SM. However, a reduction in blast cell percentage at the time of a post-induction marrow evaluation helps in diagnosis. [ABSTRACT FROM AUTHOR]

Summary: For patients with relapsed or refractory AML, sequential conditioning prior to allogeneic stem cell transplantation (alloSCT) is an established and potentially curative treatment option. Early response to treatment during conditioning indicates chemotherapy‐responsive disease and may have prognostic value. We retrospectively evaluated blast clearance on day 5 after melphalan, administered 11 days prior to alloSCT as part of a sequential conditioning in 176 patients with active AML. Overall survival (OS) was 52% (95% confidence interval [CI] 45%–60%), and relapse‐free survival (RFS) was 47% (95% CI 40%–55%) at 3 years. Patients who achieved early blast clearance did not show a significant improvement in OS and RFS (OS, hazard ratio [HR] HR 0.75, p 0.19; RFS, HR 0.71, p 0.09, respectively), but had a significantly lower non‐relapse mortality rate (HR 0.46, p 0.017). HLA‐mismatched donor, older age, adverse genetic risk and higher comorbidity scores were associated with inferior survival outcomes. A high initial blast count was only associated with inferior prognosis in patients receiving chemotherapy‐only compared to total body irradiation containing conditioning therapy. These results indicate that for patients transplanted with active AML, sensitivity to chemotherapy might be of less importance, compared to other disease‐ and transplant‐related factors. [ABSTRACT FROM AUTHOR]

Summary: The treatment landscape of acute myeloid leukaemia (AML) is evolving rapidly. Venetoclax in combination with intensive chemotherapy or doublets or triplets with targeted or immune therapies is the focus of numerous ongoing trials. The development of mutation‐targeted therapies has greatly enhanced the treatment armamentarium, with FLT3 inhibitors and isocitrate dehydrogenase inhibitors improving outcomes in frontline and relapsed/refractory (RR) AML, and menin inhibitors showing efficacy in RR NPM1mut and KMT2A‐rearranged AML. With so many new drugs approved, the number of potential combinatorial approaches to leverage the maximal benefit of these agents has increased dramatically, while at the same time introducing clinical challenges, such as key preclinical and clinical data supporting the development of combinatorial therapy, how to optimally combine or sequence these novel agents, how to optimise dose and duration to maintain safety while enhancing efficacy, the optimal duration of therapy and the role of measurable residual disease in decision‐making in both intensive and low‐intensity therapy settings. In this review, we will outline the evidence leading to the approval of key agents in AML, their on‐label current approvals and how they may be optimally combined in a safe and deliverable fashion to further improve outcomes in AML. [ABSTRACT FROM AUTHOR]

Acute myeloid leukemia (AML) patients with DNA methyltransferase 3A (DNMT3A) mutation display poor prognosis, and targeted therapy is not available currently. Our previous study identified increased expression of Exportin1 (XPO1) in DNMT3AR882H AML patients. Therefore, we further investigated the therapeutic effect of XPO1 inhibition on DNMT3AR882H AML. Three types of DNMT3AR882H AML cell lines were generated, and XPO1 was significantly upregulated in all DNMT3AR882H cells compared with the wild-type (WT) cells. The XPO1 inhibitor selinexor displayed higher potential in the inhibition of proliferation, promotion of apoptosis, and blockage of the cell cycle in DNMT3AR882H cells than WT cells. Selinexor also significantly inhibited the proliferation of subcutaneous tumors in DNMT3AR882H AML model mice. Primary cells with DNMT3A mutations were more sensitive to selinexor in chemotherapy-naive AML patients. RNA sequencing of selinexor treated AML cells revealed that the majority of metabolic pathways were downregulated after selinexor treatment, with the most significant change in the glutathione metabolic pathway. Glutathione inhibitor L-Buthionine-(S, R)-sulfoximine (BSO) significantly enhanced the apoptosis-inducing effect of selinexor in DNMT3AWT/DNMT3AR882H AML cells. In conclusion, our work reveals that selinexor displays anti-leukemia efficacy against DNMT3AR882H AML via downregulating glutathione pathway. Combination of selinexor and BSO provides novel therapeutic strategy for AML treatment. [ABSTRACT FROM AUTHOR]

Cytomegalovirus reactivation (CMVr) and bloodstream infections (BSI) are the most common infectious complications in patients after allogeneic haematopoietic stem cell transplantation (allo-HSCT). Both are associated with great high morbidity whilst the BSI is the leading cause of mortality. This retrospective study evaluated the incidence of CMVr and BSI, identified associated risk factors, assessed their impact on survival in allo-HSCT recipients during the first 100 days after transplantation. The study comprised 500 allo-HSCT recipients who were CMV DNA-negative and CMV IgG-positive before allo-HSCT. Amongst them, 400 developed CMVr and 75 experienced BSI within 100 days after allo-HSCT. Multivariate regression revealed that graft failure and acute graft-versus-host disease were significant risk factors for poor prognosis, whereas CMVr or BSI alone were not. Amongst all 500 patients, 56 (14%) developed both CMVr and BSI in the 100 days after HSCT, showing significantly reduced 6-month overall survival (p = 0.003) and long-term survival (p = 0.002). Specifically, in the initial post-transplant phase (within 60 days), BSI significantly elevate mortality risk, However, patients who survive BSI during this critical period subsequently experience a lower mortality risk. Nevertheless, the presence of CMVr in patients with BSI considerably diminishes their longterm survival prospects. This study provides real-world data on the impact of CMVr and BSI following transplantation on survival, particularly in regions such as China, where the prevalence of CMV IgG-positivity is high. The findings underscore the necessity for devising and executing focused prevention and early management strategies for CMVr and BSI to enhance outcomes for allo-HSCT recipients. [ABSTRACT FROM AUTHOR]

Background and Aims Patients with acute myeloid leukaemia (AML) suffer from severe myocardial injury during daunorubicin (DNR)-based chemotherapy and are at high risk of cardiac mortality. The crosstalk between tumour cells and cardiomyocytes might play an important role in chemotherapy-related cardiotoxicity, but this has yet to be demonstrated. This study aimed to identify its underlying mechanism and explore potential therapeutic targets. Methods Cardiac tissues were harvested from an AML patient after DNR-based chemotherapy and were subjected to single-nucleus RNA sequencing. Cardiac metabolism and function were evaluated in AML mice after DNR treatment by using positron emission tomography, magnetic resonance imaging, and stable-isotope tracing metabolomics. Plasma cytokines were screened in AML mice after DNR treatment. Genetically modified mice and cell lines were used to validate the central role of the identified cytokine and explore its downstream effectors. Results In the AML patient, disruption of cardiac metabolic homeostasis was associated with heart dysfunction after DNR-based chemotherapy. In AML mice, cardiac fatty acid utilization was attenuated, resulting in cardiac dysfunction after DNR treatment, but these phenotypes were not observed in similarly treated tumour-free mice. Furthermore, tumour cell-derived interleukin (IL)-1α was identified as a primary factor leading to DNR-induced cardiac dysfunction and administration of an anti-IL-1α neutralizing antibody could improve cardiac functions in AML mice after DNR treatment. Conclusions This study revealed that crosstalk between tumour cells and cardiomyocytes during chemotherapy could disturb cardiac energy metabolism and impair heart function. IL-1α neutralizing antibody treatment is a promising strategy for alleviating chemotherapy-induced cardiotoxicity in AML patients. [ABSTRACT FROM AUTHOR]

Background: Bloodstream infection (BSI) represent a prevalent complication in haematological malignancies (HMs). Typically, Patients with BSI usually undergo empirical treatment pending pathogen identification. The timely and effective management of BSIs significantly influences patient prognosis. However, pathogen distribution in BSIs exhibits regional variation. In this study, we investigated the clinical characteristics, pathogen spectrum, drug resistance, risk factors of short-term prognosis and long-term prognostic factors of acute myeloid leukemia (AML) patients with BSI at Zhejiang Provincal People's Hospital. Methods: From 2019 to 2021, a total of 56 AML patients with BSI were treated in the Department of Haematology at Zhejiang Province People's Hospital. Data regarding pathogen spectrum and drug resistance were collected for analysis. The patients were stratified into non-survivor cohort and survivor cohort within 30 days after BSI, and the predictors of 30-days mortality were identified through both univariate and multivariate Logistic regression analyses. Furthermore, Kaplan-Meier survival analysis and Cox regression analysis were employed to ascertain the risk factors associated with poor prognosis in AML patients complicated by BSI. Results: A total of 70 strains of pathogenic bacteria were isolated from 56 AML patients with BSI. Gram-negative bacteria constituted the predominant pathogens (71.4%), with Klebsiella pneumoniae being the most prevalent (22.9%). Gram-positive bacteria and fungi accounted for 22.9% and 5.7%, respectively. Univariate and multivariate analyses revealed significant differences in total protein, albumin levels, and the presence of septic shock between the non-survivor cohort and the survior cohort 30 days post-BSI. COX regression analysis showed that agranulocytosis duration exceeding 20 days (HR:3.854; 95% CI: 1.451-10.242) and septic shock (HR:3.788; 95% CI: 1.729-8.299) were independent risk factors for poor prognosis in AML patients complicated by BSI. Notably, the mortality rate within 30 days after Stenotrophomonas maltophilia infection was up to 71.4%. Conclusions: In this study, Gram-negative bacteria, predominantly Klebsiella pneumoniae, constituted the primary pathogens among AML patients with BSIs. Serum albumin levels and the presence of septic shock emerged as independent risk factors for mortality within 30 days among AML patients with BSI. In terms of long-term prognosis, extended agranulocytosis duration exceeding 20 days and septic shock were associated with elevated mortality rates in AML patients with BSI. Additionally, in our centre, Stenotrophomonas maltophilia infection was found to be associated with a poor prognosis. Early intervention for Stenotrophomonas maltophilia infection in our centre could potentially improve patient outcomes. [ABSTRACT FROM AUTHOR]

Summary: Acute myeloid leukaemia (AML) is a highly heterogeneous disease, exhibiting diverse subtypes according to the characteristics of tumour cells. The immunophenotype is one of the aspects acquired routinely through flow cytometry in the diagnosis of AML. Here, we characterized the antigen expression in paediatric AML cases across both morphological and molecular genetic subgroups. We discovered a subgroup of patients with unfavourable prognosis that can be immunologically characterized, irrespective of morphological FAB results or genetic aberrations. Cox regression analysis unveiled key antigens influencing the prognosis of AML patients. In terms of underlying genotypes, we observed that the antigenic profiles and outcomes of one specific group, primarily composed of CBFA2T3::GLIS2 and FUS::ERG, were analogous to the reported RAM phenotype. Overall, our data highlight the significance of immunophenotype to tailor treatment for paediatric AML. [ABSTRACT FROM AUTHOR]

Summary: The interaction of acute myeloid leukaemic (AML) blasts with the bone marrow (BM) microenvironment is a major determinant governing disease progression and resistance to treatment. The constitutive expression of E‐selectin in the vascular compartment of BM, a key endothelial cell factor, directly mediates chemoresistance via E‐selectin ligand/receptors. Despite the success of hypomethylating agent (HMA)‐containing regimens to induce remissions in older AML patients, the development of primary or secondary resistance is common. We report that following treatment with 5‐azacitidine, promoter regions regulating the biosynthesis of the E‐selectin ligands, sialyl Lewis X, become further hypomethylated. The resultant upregulation of these gene products, in particular α(1,3)‐fucosyltransferase VII (FUT7) and α(2,3)‐sialyltransferase IV (ST3GAL4), likely causes functional E‐selectin binding. When combined with the E‐selectin antagonist uproleselan, the adhesion to E‐selectin is reversed and the survival of mice transplanted with AML cells is prolonged. Finally, we present clinical evidence showing that BM myeloid cells from higher risk MDS and AML patients have the potential to bind E‐selectin, and these cells are more abundant in 5‐azacitidine‐non‐responsive patients. The collective data provide a strong rationale to evaluate 5‐azacitidine in combination with the E‐selectin antagonist, uproleselan, in this patient population. [ABSTRACT FROM AUTHOR]

Summary: Allogeneic stem cell transplantation is a centrally important curative strategy in adults with acute myeloid leukaemia; however, relapse occurs in a significant proportion of patients and remains the leading cause of treatment failure. The prognosis for patients who relapse post‐transplant remains poor, and the development of new strategies with the ability to reduce disease recurrence without increasing transplant toxicity remains a priority. In this review, within the context of our understanding of disease biology and the graft‐versus‐leukaemia (GVL) effect, we will discuss established, evolving and novel approaches for increasing remission rates, decreasing measurable residual disease pretransplant, future methods to augment the GVL effect and the opportunities for post‐transplant maintenance. Future progress depends upon the development of innovative trials and networks, which will ensure the rapid assessment of emerging therapies in prospective clinical trials. [ABSTRACT FROM AUTHOR]

Summary: Background: Acute myeloid leukaemia (AML) is a bone marrow malignancy with poor prognosis. One of several treatments for AML is midostaurin combined with intensive chemotherapy (MIC), currently approved for FLT3 mutation-positive (FLT3-MP) AML. However, many patients carrying FLT3 mutations are refractory or experience an early relapse following MIC treatment, and might benefit more from receiving a different treatment. Development of a stratification method that outperforms FLT3 mutational status in predicting MIC response would thus benefit a large number of patients. Methods: We employed mass spectrometry phosphoproteomics to analyse 71 diagnosis samples of 47 patients with FLT3-MP AML who subsequently received MIC. We then used machine learning to identify biomarkers of response to MIC, and validated the resulting predictive model in two independent validation cohorts (n = 20). Findings: We identified three distinct phosphoproteomic AML subtypes amongst long-term survivors. The subtypes showed similar duration of MIC response, but different modulation of AML-implicated pathways, and exhibited distinct, highly-predictive biomarkers of MIC response. Using these biomarkers, we built a phosphoproteomics-based predictive model of MIC response, which we called MPhos. When applied to two retrospective real-world patient test cohorts (n = 20), MPhos predicted MIC response with 83% sensitivity and 100% specificity (log-rank p

The treatment of acute myeloid leukaemia (AML) has changed fundamentally in the last decade with many new targeted therapies entering clinics. Some of the most interesting agents under development are Menin inhibitors which interfere with the interaction of Menin with wild‐type (wt) KMT2A or a KMT2A‐fusion protein and thereby downregulate the leukaemic gene expression (MEIS1, PBX3, HOX) in NPM1 mutant or KMT2A‐rearranged leukaemia. Other HOX and MEIS1 expressing leukaemias may also be sensitive to Menin inhibition. Following the encouraging results as monotherapy in refractory and relapsed AML, the combination of Menin inhibitors with chemotherapeutic agents and other targeted drugs is being investigated clinically. [ABSTRACT FROM AUTHOR]

Abstract Background and Objective Acute myeloid leukemia (AML) is an aggressive, heterogenous hematopoetic malignancies with poor long-term prognosis. T-cell mediated tumor killing plays a key role in tumor immunity. Here, we explored the prognostic performance and functional significance of a T-cell mediated tumor killing sensitivity gene (GSTTK)-based prognostic score (TTKPI). Methods Publicly available transcriptomic data for AML were obtained from TCGA and NCBI-GEO. GSTTK were identified from the TISIDB database. Signature GSTTK for AML were identified by differential expression analysis, COX proportional hazards and LASSO regression analysis and a comprehensive TTKPI score was constructed. Prognostic performance of the TTKPI was examined using Kaplan–Meier survival analysis, Receiver operating curves, and nomogram analysis. Association of TTKPI with clinical phenotypes, tumor immune cell infiltration patterns, checkpoint expression patterns were analysed. Drug docking was used to identify important candidate drugs based on the TTKPI-component genes. Results From 401 differentially expressed GSTTK in AML, 24 genes were identified as signature genes and used to construct the TTKPI score. High-TTKPI risk score predicted worse survival and good prognostic accuracy with AUC values ranging from 75 to 96%. Higher TTKPI scores were associated with older age and cancer stage, which showed improved prognostic performance when combined with TTKPI. High TTKPI was associated with lower naïve CD4 T cell and follicular helper T cell infiltrates and higher M2 macrophages/monocyte infiltration. Distinct patterns of immune checkpoint expression corresponded with TTKPI score groups. Three agents; DB11791 (Capmatinib), DB12886 (GSK-1521498) and DB14773 (Lifirafenib) were identified as candidates for AML. Conclusion A T-cell mediated killing sensitivity gene-based prognostic score TTKPI showed good accuracy in predicting survival in AML. TTKPI corresponded to functional and immunological features of the tumor microenvironment including checkpoint expression patterns and should be investigated for precision medicine approaches.

Summary: Recursive partitioning of healthy consortia led to the development of the Clonal Hematopoiesis Risk Score (CHRS) for clonal haematopoiesis (CH); however, in the practical setting, most cases of CH are diagnosed after patients present with cytopenias or related symptoms. To address this real‐world population, we characterize the clinical trajectories of 94 patients with CH and distinguish CH harbouring canonical DNMT3A/TET2/ASXL1 mutations alone ('sole DTA') versus all other groups ('non‐sole DTA'). TET2, rather than DNMT3A, was the most prevalent mutation in the real‐world setting. Sole DTA patients did not progress to myeloid neoplasm (MN) in the absence of acquisition of other mutations. Contrastingly, 14 (20.1%) of 67 non‐sole DTA patients progressed to MN. CHRS assessment showed a higher frequency of high‐risk CH in non‐sole DTA (vs. sole DTA) patients and in progressors (vs. non‐progressors). RUNX1 mutation conferred the strongest risk for progression to MN (odds ratio [OR] 10.27, 95% CI 2.00–52.69, p = 0.0053). The mean variant allele frequency across all genes was higher in progressors than in non‐progressors (36.9% ± 4.62% vs. 24.1% ± 1.67%, p = 0.0064). This analysis in the post‐CHRS era underscores the natural history of CH, providing insight into patterns of progression to MN. [ABSTRACT FROM AUTHOR]

Central nervous system (CNS) lesions, especially invasive fungal diseases (IFDs), in immunocompromised patients pose a great challenge in diagnosis and treatment. We report the case of a 48-year-old man with acute myeloid leukaemia and probable pulmonary aspergillosis, who developed hyposthenia of the left upper limb, after achieving leukaemia remission and while on voriconazole. Magnetic resonance imaging (MRI) showed oedematous CNS lesions with a haemorrhagic component in the right hemisphere with lepto-meningitis. After 2 weeks of antibiotics and amphotericin-B, brain biopsy revealed chronic inflammation with abscess and necrosis, while cultures were negative. Clinical recovery was attained, he was discharged on isavuconazole and allogeneic transplant was postponed, introducing azacitidine as a maintenance therapy. After initial improvement, MRI worsened; brain biopsy was repeated, showing similar histology; and 16S metagenomics sequencing analysis was positive (Veilonella, Pseudomonas). Despite 1 month of meropenem, MRI did not improve. The computer tomography and PET scan excluded extra-cranial infectious–inflammatory sites, and auto-immune genesis (sarcoidosis, histiocytosis, CNS vasculitis) was deemed unlikely due to the histological findings and unilateral lesions. We hypothesised possible IFD with peri-lesion inflammation and methyl-prednisolone was successfully introduced. Steroid tapering is ongoing and isavuconazole discontinuation is planned with close follow-up. In conclusion, the management of CNS complications in immunocompromised patients needs an interdisciplinary approach. [ABSTRACT FROM AUTHOR]

Spontaneous remissions (SRs) in blastic plasmacytoid dendritic cell neoplasms (BPDCNs) are infrequent, poorly documented, and transient. We report a 40-year-old man presenting with bycitopenia and soft tissue infection. The bone marrow exhibited 3% abnormal cells. Immunophenotyping of these cells revealed the antigens CD45+ (dim), CD34+, CD117+, CD123+ (bright), HLA-DR+ (bimodal), CD56+ (bright), CD33+, CD13+, CD2+, and CD22+ (dim) and the partial expression of the CD10+, CD36+, and CD7+ antigens. All other myeloid, monocytic, and lymphoid antigens were negative. Genetic studies showed a complex karyotype and mutations in the TP53R337C and KRASG12D genes. On hospital admission, the patient showed a subcutaneous nodule on the right hand and left lower limb. Flow cytometry multiparameter (FCM) analysis showed the presence of 29% abnormal cells with the previously described immunophenotype. The patient was diagnosed with BPDCN. The patient was treated with broad-spectrum antibiotics for soft tissue infection, which delayed therapy for BPDCN. No steroids or chemotherapeutic or hypomethylating agents were administered. His blood cell counts improved and skin lesions disappeared, until the patient relapsed five months after achieving spontaneous remission. About 60% of abnormal cells were identified. No changes in immunophenotype or the results of genetic studies were observed. The patient underwent a HyperCVAD chemotherapy regimen for six cycles. Consolidation therapy was performed via allogeneic bone marrow transplantation with an HLA-unrelated donor. One year after the bone marrow transplant, the patient died due to the progression of his underlying disease, coinciding with a respiratory infection caused by SARS-CoV-2. In the available literature, SRs are often linked to infections or other stimulators of the immune system, suggesting that powerful immune activation could play a role in controlling the leukemic clone. Nevertheless, the underlying mechanism of this phenomenon is not clearly understood. We hypothesize that the immune system would force the leukemic stem cell (LSC) to undergo a state of quiescence. This loss of replication causes the LSC progeny to die off, resulting in the SR of BPDCN. [ABSTRACT FROM AUTHOR]

Acute myeloid leukaemia (AML) is a fatal and refractory haematologic cancer that primarily affects adults. It interferes with bone marrow cell proliferation. Patients have a 5 years survival rate of less than 30% despite the availability of several treatments, including chemotherapy, allogeneic haematopoietic stem cell transplantation (Allo‐HSCT), and receptor antagonist drugs. Allo‐HSCT is the mainstay of acute myeloid leukaemia treatment. Although it does work, there are severe side effects, such as graft‐versus‐host disease (GVHD). In recent years, chimeric antigen receptor (CAR)‐T cell therapies have made significant progress in the treatment of cancer. These engineered T cells can locate and recognize tumour cells in vivo and release a large number of effectors through immune action to effectively kill tumour cells. CAR‐T cells are among the most effective cancer treatments because of this property. CAR‐T cells have demonstrated positive therapeutic results in the treatment of acute myeloid leukaemia, according to numerous clinical investigations. This review highlights recent progress in new targets for AML immunotherapy, and the limitations, and difficulties of CAR‐T therapy for AML. [ABSTRACT FROM AUTHOR]

Transcriptional noise is proposed to participate in cell fate changes, but contributions to mammalian cell differentiation systems, including cancer, remain associative. Cancer evolution is driven by genetic variability, with modulatory or contributory participation of epigenetic variants. Accumulation of epigenetic variants enhances transcriptional noise, which can facilitate cancer cell fate transitions. Acute myeloid leukaemia (AML) is an aggressive cancer with strong epigenetic dependencies, characterized by blocked differentiation. It constitutes an attractive model to probe links between transcriptional noise and malignant cell fate regulation. Gcn5/KAT2A is a classical epigenetic transcriptional noise regulator. Its loss increases transcriptional noise and modifies cell fates in stem and AML cells. By reviewing the analysis of KAT2A-depleted pre-leukaemia and leukaemia models, I discuss that the net result of transcriptional noise is diversification of cell fates secondary to alternative transcriptional programmes. Cellular diversification can enable or hinder AML progression, respectively, by differentiation of cell types responsive to mutations, or by maladaptation of leukaemia stem cells. KAT2A-dependent noise-responsive genes participate in ribosome biogenesis and KAT2A loss destabilizes translational activity. I discuss putative contributions of perturbed translation to AML biology, and propose KAT2A loss as a model for mechanistic integration of transcriptional and translational control of noise and fate decisions. This article is part of a discussion meeting issue 'Causes and consequences of stochastic processes in development and disease'. [ABSTRACT FROM AUTHOR]

Acute myeloid leukaemia (AML) management remains a significant challenge in oncology due to its low survival rates and high post-treatment relapse rates, mainly attributed to treatment-resistant leukaemic stem cells (LSCs) residing in bone marrow (BM) niches. This review offers an in-depth analysis of AML progression, highlighting the pivotal role of extracellular vesicles (EVs) in the dynamic remodelling of BM niche intercellular communication. We explore recent advancements elucidating the mechanisms through which EVs facilitate complex crosstalk, effectively promoting AML hallmarks and drug resistance. Adopting a temporal view, we chart the evolving landscape of EV-mediated interactions within the AML niche, underscoring the transformative potential of these insights for therapeutic intervention. Furthermore, the review discusses the emerging understanding of endothelial cell subsets' impact across BM niches in shaping AML disease progression, adding another layer of complexity to the disease progression and treatment resistance. We highlight the potential of cutting-edge methodologies, such as organ-on-chip (OoC) and single-EV analysis technologies, to provide unprecedented insights into AML–niche interactions in a human setting. Leveraging accumulated insights into AML EV signalling to reconfigure BM niches and pioneer novel approaches to decipher the EV signalling networks that fuel AML within the human context could revolutionise the development of niche-targeted therapy for leukaemia eradication. [ABSTRACT FROM AUTHOR]

Background and Objective: Acute myeloid leukemia (AML) is an aggressive, heterogenous hematopoetic malignancies with poor long-term prognosis. T-cell mediated tumor killing plays a key role in tumor immunity. Here, we explored the prognostic performance and functional significance of a T-cell mediated tumor killing sensitivity gene (GSTTK)-based prognostic score (TTKPI). Methods: Publicly available transcriptomic data for AML were obtained from TCGA and NCBI-GEO. GSTTK were identified from the TISIDB database. Signature GSTTK for AML were identified by differential expression analysis, COX proportional hazards and LASSO regression analysis and a comprehensive TTKPI score was constructed. Prognostic performance of the TTKPI was examined using Kaplan–Meier survival analysis, Receiver operating curves, and nomogram analysis. Association of TTKPI with clinical phenotypes, tumor immune cell infiltration patterns, checkpoint expression patterns were analysed. Drug docking was used to identify important candidate drugs based on the TTKPI-component genes. Results: From 401 differentially expressed GSTTK in AML, 24 genes were identified as signature genes and used to construct the TTKPI score. High-TTKPI risk score predicted worse survival and good prognostic accuracy with AUC values ranging from 75 to 96%. Higher TTKPI scores were associated with older age and cancer stage, which showed improved prognostic performance when combined with TTKPI. High TTKPI was associated with lower naïve CD4 T cell and follicular helper T cell infiltrates and higher M2 macrophages/monocyte infiltration. Distinct patterns of immune checkpoint expression corresponded with TTKPI score groups. Three agents; DB11791 (Capmatinib), DB12886 (GSK-1521498) and DB14773 (Lifirafenib) were identified as candidates for AML. Conclusion: A T-cell mediated killing sensitivity gene-based prognostic score TTKPI showed good accuracy in predicting survival in AML. TTKPI corresponded to functional and immunological features of the tumor microenvironment including checkpoint expression patterns and should be investigated for precision medicine approaches. [ABSTRACT FROM AUTHOR]

Acute myeloid leukaemia (AML) is a complex haematological malignancy characterised by diverse genetic alterations leading to abnormal proliferation of myeloid precursor cells. One of the most significant genetic alterations in AML involves mutations in the FLT3 gene, which plays a critical role in haematopoiesis and haematopoietic homeostasis. This review explores the current understanding of FLT3 gene mutations and isoforms and the importance of the FLT3 protein in AML. FLT3 mutations, including internal tandem duplications (FLT3-ITD) and point mutations in the tyrosine kinase domain (FLT3-TKD), occur in 25–30% in AML and are associated with poor prognosis. FLT3-ITD mutations lead to constitutive activation of the FLT3 signalling pathway, promoting cell survival and proliferation. FLT3-TKD mutations affect the tyrosine kinase domain and affect AML prognosis in various ways. Furthermore, FLT3 isoforms, including shorter variants, contribute to the complexity of FLT3 biology. Additionally, nonpathological polymorphisms in FLT3 are being explored for their potential impact on AML prognosis and treatment response. This review also discusses the development of molecular treatments targeting FLT3, including first-generation and next-generation tyrosine kinase inhibitors, highlighting the challenges of resistance that often arise during therapy. The final chapter describes FLT3 protein domain rearrangements and their relevance to AML pathogenesis. [ABSTRACT FROM AUTHOR]

Acute myeloid leukaemia (AML) is a prevalent haematological malignancy in which various immune and stromal cells in the bone marrow microenvironment have instrumental roles and substantially influence its progression. KIR2DL is a member of the immunoglobulin‐like receptor family and a natural killer (NK) cell surface‐specific receptor. However, its impact on immune infiltration regarding AML has not been addressed. We aimed to explore molecular markers associated with the immune microenvironment and prognosis of AML with a particular focus on KIR2DL family members. Analysis of data from The Cancer Genome Atlas and Genotype‐Tissue Expression databases revealed that KIR2DL1, KIR2DL3 and KIR2DL4 expression were significantly upregulated in AML and associated with decreased overall survival (OS). Moreover, univariate Cox analysis implicated KIR2DL genes as independent prognostic markers of OS. Functional enrichment analysis revealed that KIR2DL genes were associated with immune cells, the immune microenvironment and NK cell‐mediated cytotoxicity. Additionally, immune infiltration analyses revealed that KIR2DL upregulation was associated with stronger immune infiltration. Finally, we performed drug sensitivity profiling of KIR2DL genes using the Cellminer database. Collectively, our findings suggest that KIR2DL1, KIR2DL3 and KIR2DL4 have critical roles in AML and may represent novel biomarker genes for disease prognosis and immune infiltration. [ABSTRACT FROM AUTHOR]

In recent years, technology developments and increase in knowledge have led to profound changes in the diagnostics of haematologic neoplasms, particularly myeloid neoplasms. Therefore an updated, fifth edition of the World Health Organization (WHO) classification of haematolymphoid neoplasms (WHO-HAEM5) will be issued in 2024. In this context, we present a practical guide for analysing the genetic aspects of clonal haematopoiesis of indeterminate potential (CHIP), clonal cytopenia of undetermined significance (CCUS), myelodysplastic neoplasms (MDS), and acute myeloid leukaemia (AML) based on WHO-HAEM5. This guide navigates through the genetic abnormalities underlying myeloid neoplasms which are required to be detected for classification according to WHO-HAEM5 and provides diagnostic algorithms. [ABSTRACT FROM AUTHOR]