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Measurable residual disease (MRD) monitoring independently predicts long-term outcomes in patients with acute myeloid leukemia (AML). Of the various modalities available, multiparameter flow cytometry-based MRD analysis is widely used and relevant for patients without molecular targets. In the transplant (HCT) setting, the presence of MRD pre-HCT is associated with adverse outcomes. MRD-negative remission status pre-HCT was also associated with longer overall (OS) and progression-free survival and a lower risk of relapse. We hypothesize that the combination of disease risk and MRD at the time of first complete remission (CR1) could identify patients according to the benefit gained from HCT, especially for intermediate-risk patients. We performed a retrospective analysis comparing the outcomes of HCT versus non-HCT therapies based on MRD status in AML patients who achieved CR1. Time-dependent analysis was applied considering time-to-HCT as a time-dependent covariate and compared HCT versus non-HCT outcomes according to MRD status at CR1. Among 336 patients assessed at CR1, 35.1% were MRD positive (MRDpos) post-induction. MRDpos patients benefitted from HCT with improved OS and relapse-free survival (RFS), while no benefit was observed in MRDneg patients. In adverse-risk patients, HCT improved OS (HR for OS 0.55; p = 0.05). In intermediate-risk patients, HCT benefit was not significant for OS and RFS. Intermediate-risk MRDpos patients were found to have benefit from HCT with improved OS (HR 0.45, p = 0.04), RFS (HR 0.46, p = 0.02), and CIR (HR 0.41, p = 0.02). Our data underscore the benefit of HCT in adverse risk and MRDpos intermediate-risk AML patients.
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Trasplante de Células Madre Hematopoyéticas , Leucemia Mieloide Aguda , Humanos , Citometría de Flujo , Estudios Retrospectivos , Trasplante Homólogo , Recurrencia , Neoplasia Residual , Leucemia Mieloide Aguda/diagnóstico , Leucemia Mieloide Aguda/terapia , PronósticoRESUMEN
Nucleophosmin-1 (NPM1)-mutated AML is a molecularly defined subtype typically associated with favorable treatment response and prognosis; however, its prognostic significance in AML evolving from an antecedent chronic myeloid malignancy is unknown. This study's primary objective was to determine the impact of mutated NPM1 on the prognosis of AML evolving from an antecedent chronic myeloid malignancy. We conducted a retrospective chart review including patients with NPM1-mutated de novo and sAML. sAML was defined as those with a preceding chronic-phase myeloid malignancy before diagnosis of AML. Of 575 NPM1-mutated patients eligible for inclusion in our study, 51 (8.9%) patients were considered to have sAML. The median time from diagnosis of NPM1-mutated chronic myeloid malignancy to sAML evolution was 3.6 months (0.5-79.3 months). No significant differences in leukemia-free (2-year LKFS 52.0% vs. 51.2%, p = .9922) or overall survival (2-year OS 56.3% vs. 49.4%, p = .4246) were observed between patients with NPM1-mutated de novo versus sAML. Our study suggests that evolution from a preceding myeloid malignancy is not a significant predictor of poor prognosis in the setting of an NPM1 mutation. Our study demonstrated a short time to progression to sAML in most patients, which further supports the consideration of NPM1 as an AML-defining mutation.
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Acute myeloid leukemia (AML) is an aggressive blood cancer. With low survival rates, new drug targets are needed to improve treatment regimens and patient outcomes. Pseudolaric acid B (PAB) is a plant-derived bioactive compound predicted to interact with cluster of differentiation 147 (CD147/BSG). CD147 is a transmembrane glycoprotein overexpressed in various malignancies with suggested roles in regulating cancer cell survival, proliferation, invasion, and apoptosis. However, the detailed function of PAB in AML remains unknown. In this study, AML cell lines and patient-derived cells were used to show that PAB selectively targeted AML (IC50: 1.59 ± 0.47 µM). Moreover, proliferation assays, flow cytometry, and immunoblotting confirmed that PAB targeting of CD147 resulted in AML cell apoptosis. Indeed, the genetic silencing of CD147 significantly suppressed AML cell growth and attenuated PAB activity. Overall, PAB imparts anti-AML activity through transmembrane glycoprotein CD147.
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Apoptosis , Basigina , Proliferación Celular , Diterpenos , Leucemia Mieloide Aguda , Humanos , Basigina/metabolismo , Basigina/genética , Leucemia Mieloide Aguda/tratamiento farmacológico , Leucemia Mieloide Aguda/metabolismo , Leucemia Mieloide Aguda/patología , Proliferación Celular/efectos de los fármacos , Apoptosis/efectos de los fármacos , Línea Celular Tumoral , Diterpenos/farmacología , Supervivencia Celular/efectos de los fármacosRESUMEN
ABSTRACT: Allogeneic double-negative T cells (DNTs) are a rare T-cell subset that effectively target acute myeloid leukemia (AML) without inducing graft-versus-host disease in an allogeneic setting. A phase 1 clinical trial demonstrated the feasibility, safety, and potential efficacy of allogeneic DNT therapy among patients with relapsed AML. However, the molecular mechanisms of DNT-mediated cytotoxicity against AML remain elusive. Thus, we used a flow cytometry-based high throughput screening to compare the surface molecule expression profile on DNTs during their interaction with DNT-susceptible or -resistant AML cells and identified a tumor necrosis factor α (TNFα)-dependent cytotoxic pathway in DNT-AML interaction. TNFα secreted by DNTs, upon encountering susceptible AML targets, sensitized AML cells to DNT-mediated killing, including those otherwise resistant to DNTs. Mechanistically, TNFα upregulated ICAM-1 on AML cells through a noncanonical JAK1-dependent pathway. DNTs then engaged with AML cells more effectively through an ICAM-1 receptor, lymphocyte function-associated antigen 1, leading to enhanced killing. These results reveal a TNFα-JAK1-ICAM-1 axis in DNT-mediated cytotoxicity against AML to improve therapeutic efficacy.
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Molécula 1 de Adhesión Intercelular , Janus Quinasa 1 , Leucemia Mieloide Aguda , Factor de Necrosis Tumoral alfa , Humanos , Leucemia Mieloide Aguda/metabolismo , Molécula 1 de Adhesión Intercelular/metabolismo , Factor de Necrosis Tumoral alfa/metabolismo , Janus Quinasa 1/metabolismo , Citotoxicidad Inmunológica , Transducción de Señal , Línea Celular Tumoral , Subgrupos de Linfocitos T/metabolismo , Subgrupos de Linfocitos T/inmunologíaRESUMEN
Purpose: To compare the accuracy of ultra-low-dose (uLDCT) to standard-of-care low-dose chest CT (LDCT) in the detection of fungal infection in immunocompromised (IC) patients. Method and Materials: One hundred IC patients had paired chest CT scans performed with LDCT followed by uLDCT. The images were independently reviewed by three chest radiologists who assessed the image quality (IQ), diagnostic confidence, and detection of major (macro nodules, halo sign, cavitation, consolidation) and minor (4-10 mm nodules, ground-glass opacity) criteria for fungal disease using a five-point Likert score. Discrepant findings were adjudicated by a fourth chest radiologist. Box-whisker plots were used to analyze IQ and diagnostic confidence. Inter-rater reliability was assessed using interclass correlation coefficients (ICCs). The statistical difference between LDCT and uLDCT results was assessed using Wilcoxon paired test. Results: Lung reconstructions had IQ and diagnostic confidence scores (mean ± std) of 4.52 ± 0.47 and 4.63 ± 0.51 for LDCT and 3.85 ± 0.77 and 4.01 ± 0.88 for uLDCT. The images were clinically acceptable except for uLDCT in obese patients (BMI ≥ 30 kg/m2), which had an IQ ranking from poor to excellent (scores 1 to 5). The accuracy in detecting major and minor radiological findings with uLDCT was 96% and 84% for all the patients. The inter-rater agreements were either moderate, good, or excellent, with ICC values of 0.51-0.96. There was no significant statistical difference between the uLDCT and LDCT ICC values (p = 0.25). The effective dose for uLDCT was one quarter that of LDCT (CTDIvol = 0.9 mGy vs. 3.7 mGy). Conclusions: Thoracic uLDCT, at a 75% dose reduction, can replace LDCT for the detection of fungal disease in IC patients with BMI < 30.0 kg/m2.
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ABSTRACT: The proposed fifth edition of the World Health Organization classification of hematolymphoid tumors (WHO-HAEM5) and International Consensus Classification (ICC) provide different definitions of acute myeloid leukemia with myelodysplasia-related genetics (AML-MR). We conducted a retrospective study which included a cohort of 432 patients, with 354 patients fulfilling WHO-HAEM5 criteria for WHO-AML-MR or 276 patients fulfilling ICC criteria for ICC-AML-MR by gene mutation or cytogenetics (ICC-AML-MR-M/CG). The clinicopathological features were largely similar, irrespective of the classification used, except for higher rates of complex karyotype, monosomy 17, TP53 mutations, and fewer RUNX1 mutations in the WHO-AML-MR group. TP53 mutations were associated with distinct clinicopathological features and dismal outcomes (hazard ratio [HR], 2.98; P < .001). ICC-AML-MR-M/CG group had superior outcome compared with the WHO-AML-MR group (HR, 0.80, P = .032), largely in part due to defining TP53 mutated AML as a standalone entity. In the intensively-treated group, WHO-AML-MR had significantly worse outcomes than AML by differentiation (HR, 1.97; P = .024). Based on ICC criteria, ICC-AML-MR-M/CG had more inferior outcomes compared to AML not otherwise specified (HR, 2.11; P = .048 and HR, 2.55; P = .028; respectively). Furthermore, changing the order of genetic abnormalities defining AML-MR (ie, by gene mutations or cytogenetics) did not significantly affect clinical outcomes. ICC-AML-MR-M/CG showed similar outcomes regardless of the order of assignment. We propose to harmonize the 2 classifications by excluding TP53 mutations from WHO-HAEM5 defined AML-MR group and combining AML-MR defined by gene mutations and cytogenetics to form a unified group.
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Leucemia Mieloide Aguda , Síndromes Mielodisplásicos , Humanos , Estudios Retrospectivos , Consenso , Síndromes Mielodisplásicos/diagnóstico , Síndromes Mielodisplásicos/genética , Síndromes Mielodisplásicos/tratamiento farmacológico , Leucemia Mieloide Aguda/diagnóstico , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/tratamiento farmacológico , Organización Mundial de la SaludRESUMEN
This retrospective report presents the outcomes and adverse events (AEs) observed in 73 patients aged 60 years or older diagnosed with Philadelphia Chromosome-negative Acute Lymphoblastic Leukemia (Ph-negative ALL) treated with a pediatric-inspired protocol incorporating either Pegylated (PEG-ASP) or Native Asparaginase (EC-ASP). Notably, 61% of patients experienced AEs of Grade III-IV severity. The most prevalent AEs included thrombosis (35.6%), febrile neutropenia (38.4%), and transaminitis (34.2%). AEs did not translate into significant differences concerning overall survival, leukemia-free survival, or early mortality. Furthermore, we observed a reduction in early mortality rates (11% vs. 20%) and an increase in median overall survival (54 vs. 48 months) compared to our previous data. These findings suggest that the utilization of a pediatric-inspired chemotherapy protocol, with ASP, is an effective and well-tolerated therapeutic option for older patients with Ph-negative ALL. However, it emphasizes the importance of diligent monitoring and close follow-up throughout treatment.
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Asparaginasa , Leucemia-Linfoma Linfoblástico de Células Precursoras , Humanos , Anciano , Asparaginasa/efectos adversos , Estudios Retrospectivos , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamiento farmacológico , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Polietilenglicoles/efectos adversosRESUMEN
PURPOSE: Patients with hematologic malignancy (HM) commonly develop critical illness. Their long-term survival and functional outcomes have not been well described. METHODS: We conducted a prospective, observational study of HM patients admitted to seven Canadian intensive care units (ICUs) (2018-2020). We followed survivors at 7 days, 6 months and 12 months following ICU discharge. The primary outcome was 12-month survival. We evaluated functional outcomes at 6 and 12 months using the functional independent measure (FIM) and short form (SF)-36 as well as variables associated with 12-month survival. RESULTS: We enrolled 414 patients including 35% women. The median age was 61 (interquartile range, IQR: 52-69), median Sequential Organ Failure Assessment (SOFA) score was 9 (IQR: 6-12), and 22% had moderate-severe frailty (clinical frailty scale [CFS] ≥ 6). 51% had acute leukemia, 38% lymphoma/multiple myeloma, and 40% had received a hematopoietic stem cell transplant (HCT). The most common reasons for ICU admission were acute respiratory failure (50%) and sepsis (40%). Overall, 203 (49%) were alive 7 days post-ICU discharge (ICU survivors). Twelve-month survival of the entire cohort was 21% (43% across ICU survivors). The proportion of survivors with moderate-severe frailty was 42% (at 7 days), 14% (6 months), and 8% (12 months). Median FIM at 7 days was 80 (IQR: 50-109). Physical function, pain, social function, mental health, and emotional well-being were below age- and sex-matched population scores at 6 and 12 months. Frailty, allogeneic HCT, kidney injury, and cardiac complications during ICU were associated with lower 12- month survival. CONCLUSIONS: 49% of all HM patients were alive at 7 days post-ICU discharge, and 21% at 12 months. Survival varied based upon hematologic diagnosis and frailty status. Survivors had important functional disability and impairment in emotional, physical, and general well-being.
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Fragilidad , Neoplasias Hematológicas , Humanos , Femenino , Persona de Mediana Edad , Masculino , Estudios Prospectivos , Enfermedad Crítica , Fragilidad/diagnóstico , Canadá/epidemiología , Unidades de Cuidados IntensivosRESUMEN
BACKGROUND: Gene rearrangements affecting KMT2A are frequent in acute myeloid leukemia (AML) and are often associated with a poor prognosis. KMT2A gene fusions are often detected by chromosome banding analysis and confirmed by fluorescence in situ hybridization. However, small intragenic insertions, termed KMT2A partial tandem duplication (KMT2A-PTD), are particularly challenging to detect using standard molecular and cytogenetic approaches. METHODS: We have validated the use of a custom hybrid-capture-based next-generation sequencing (NGS) panel for comprehensive profiling of AML patients seen at our institution. This NGS panel targets the entire consensus coding DNA sequence of KMT2A. To deduce the presence of a KMT2A-PTD, we used the relative ratio of KMT2A exons coverage. We sought to corroborate the KMT2A-PTD NGS results using (1) multiplex-ligation probe amplification (MLPA) and (2) optical genome mapping (OGM). RESULTS: We analyzed 932 AML cases and identified 41 individuals harboring a KMT2A-PTD. MLPA, NGS, and OGM confirmed the presence of a KMT2A-PTD in 22 of the cases analyzed where orthogonal testing was possible. The two false-positive KMT2A-PTD calls by NGS could be explained by the presence of cryptic structural variants impacting KMT2A and interfering with KMT2A-PTD analysis. OGM revealed the nature of these previously undetected gene rearrangements in KMT2A, while MLPA yielded inconclusive results. MLPA analysis for KMT2A-PTD is limited to exon 4, whereas NGS and OGM resolved KMT2A-PTD sizes and copy number levels. CONCLUSIONS: KMT2A-PTDs are complex gene rearrangements that cannot be fully ascertained using a single genomic platform. MLPA, NGS panels, and OGM are complementary technologies applied in standard-of-care testing for AML patients. MLPA and NGS panels are designed for targeted copy number analysis; however, our results showed that integration of concurrent genomic alterations is needed for accurate KMT2A-PTD identification. Unbalanced chromosomal rearrangements overlapping with KMT2A can interfere with the diagnostic sensitivity and specificity of copy-number-based KMT2A-PTD detection methodologies.
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Spliceosome machinery mutations are common early mutations in myeloid malignancies; however, effective targeted therapies against them are still lacking. In the current study, we used an in vitro high-throughput drug screen among four different isogenic cell lines and identified RKI-1447, a Rho-associated protein kinase inhibitor, as selective cytotoxic effector of SRSF2 mutant cells. RKI-1447 targeted SRSF2 mutated primary human samples in xenografts models. RKI-1447 induced mitotic catastrophe and induced major reorganization of the microtubule system and severe nuclear deformation. Transmission electron microscopy and 3D light microscopy revealed that SRSF2 mutations induce deep nuclear indentation and segmentation that are apparently driven by microtubule-rich cytoplasmic intrusions, which are exacerbated by RKI-1447. The severe nuclear deformation in RKI-1447-treated SRSF2 mutant cells prevents cells from completing mitosis. These findings shed new light on the interplay between microtubules and the nucleus and offers new ways for targeting pre-leukemic SRSF2 mutant cells.
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ABSTRACT: Transformation of BCR::ABL1-negative myeloproliferative neoplasms (MPN) to an accelerated or blast phase is associated with poor outcomes. The efficacy of acute myeloid leukemia (AML)-type intensive and nonintensive hypomethylating agent-based regimens is not well studied. We therefore performed a retrospective analysis of patients with MPN-AP/BP (N = 138) treated with intensive (N = 81) and nonintensive (N = 57) blast-reduction strategies. We used clinically relatable response criteria developed at the Princess Margaret Cancer Centre. The overall best response, comprising complete remission (CR), complete remission with incomplete hematologic recovery (CRi), and reversion to chronic phase MPN (cMPN), in the intensive and nonintensive groups was 77% (62 of 81) and 39% (21 of 54), respectively. Similar overall best response rates were observed in patients receiving induction with daunorubicin combined with cytarabine arabinoside (daunorubicin + ara-C) (74% [23 of 31]) or FLAG-IDA/NOVE-HiDAC (78% [39 of 50], P = .78). However, patients receiving daunorubicin + ara-C more often required second inductions (29% [9 of 31] vs 4% [2 of 50], P = .002). Most responses in the entire cohort were reversions to cMPN (55 of 83 [66%]). CR and CRi comprised 30% (25 of 83) and 4% (3 of 83) of responses, respectively. Mutations in TP53 (overall response [OR] 8.2 [95% confidence interval [CI] 2.01, 37.1], P = .004) and RAS pathway (OR 5.1 [95%CI 1.2, 23.7], P = .03) were associated with inferior treatment response for intensively treated patients, and poorer performance status (Eastern Cooperative Oncology Group) was associated with inferior treatment response in both intensively (OR 10.4 [95% CI 2.0, 78.5], P = .009) and nonintensively treated groups (OR 12 [95% CI 2.04, 230.3], P = .02). In patients with paired samples before and after therapy (N = 26), there was a significant residual mutation burden remaining irrespective of response to blast-reduction therapy.
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Trastornos Mieloproliferativos , Humanos , Resultado del Tratamiento , Estudios Retrospectivos , Trastornos Mieloproliferativos/genética , Citarabina/uso terapéutico , DaunorrubicinaRESUMEN
CFI-400945 is a selective oral polo-like kinase 4 (PLK4) inhibitor that regulates centriole duplication. PLK4 is aberrantly expressed in patients with acute myeloid leukemia (AML). Preclinical studies indicate that CFI-400945 has potent in vivo efficacy in hematological malignancies and xenograft models, with activity in cells harboring TP53 mutations. In this phase 1 study in very high-risk patients with relapsed/refractory AML and myelodysplastic syndrome (MDS) (NCT03187288), 13 patients were treated with CFI-400945 continuously in dose escalation from 64 mg/day to 128 mg/day. Three of the 9 efficacy evaluable AML patients achieved complete remission (CR). Two of 4 AML patients (50%) with TP53 mutations and complex monosomal karyotype achieved a CR with 1 patient proceeding to allogenic stem cell transplant. A third patient with TP53 mutated AML had a significant reduction in marrow blasts by > 50% with an improvement in neutrophil and platelet counts. Responses were observed after 1 cycle of therapy. Dose-limiting toxicity was enteritis/colitis. A monotherapy and combination therapy study with a newer crystal form of CFI-400945 in patients with AML, MDS and chronic myelomonocytic leukemia (CMML) is ongoing (NCT04730258).
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Indazoles , Indoles , Leucemia Mieloide Aguda , Leucemia Mielomonocítica Crónica , Síndromes Mielodisplásicos , Humanos , Leucemia Mieloide Aguda/genética , Síndromes Mielodisplásicos/genética , Leucemia Mielomonocítica Crónica/tratamiento farmacológico , Supervivencia sin Enfermedad , Proteínas Serina-Treonina Quinasas/genéticaRESUMEN
Despite early optimism, therapeutics targeting oxidative phosphorylation (OxPhos) have faced clinical setbacks, stemming from their inability to distinguish healthy from cancerous mitochondria. Herein, we describe an actionable bioenergetic mechanism unique to cancerous mitochondria inside acute myeloid leukemia (AML) cells. Unlike healthy cells which couple respiration to the synthesis of ATP, AML mitochondria were discovered to support inner membrane polarization by consuming ATP. Because matrix ATP consumption allows cells to survive bioenergetic stress, we hypothesized that AML cells may resist cell death induced by OxPhos damaging chemotherapy by reversing the ATP synthase reaction. In support of this, targeted inhibition of BCL-2 with venetoclax abolished OxPhos flux without impacting mitochondrial membrane potential. In surviving AML cells, sustained polarization of the mitochondrial inner membrane was dependent on matrix ATP consumption. Mitochondrial ATP consumption was further enhanced in AML cells made refractory to venetoclax, consequential to downregulations in both the proton-pumping respiratory complexes, as well as the endogenous F1-ATPase inhibitor ATP5IF1. In treatment-naive AML, ATP5IF1 knockdown was sufficient to drive venetoclax resistance, while ATP5IF1 overexpression impaired F1-ATPase activity and heightened sensitivity to venetoclax. Collectively, our data identify matrix ATP consumption as a cancer-cell intrinsic bioenergetic vulnerability actionable in the context of mitochondrial damaging chemotherapy.
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ABSTRACT: Advancements in genomics are transforming the clinical management of chronic myeloid leukemia (CML) toward precision medicine. The impact of somatic mutations on treatment outcomes is still under debate. We studied the association of somatic mutations in epigenetic modifier genes and activated signaling/myeloid transcription factors (AS/MTFs) with disease progression and treatment failure in patients with CML after tyrosine kinase inhibitor (TKI) therapy. A total of 394 CML samples were sequenced, including 254 samples collected at initial diagnosis and 140 samples taken during follow-up. Single-molecule molecular inversion probe (smMIP)-based next-generation sequencing (NGS) was conducted targeting recurrently mutated loci in 40 genes, with a limit of detection of 0.2%. Seventy mutations were detected in 57 diagnostic samples (22.4%), whereas 64 mutations were detected in 39 of the follow-up samples (27.9%). Carrying any mutation at initial diagnosis was associated with worse outcomes after TKI therapy, particularly in AS/MTF genes. Patients having these mutations at initial diagnosis and treated with imatinib showed higher risks of treatment failure (hazard ratio, 2.53; 95% confidence interval, 1.13-5.66; P = .0239). The adverse prognostic impact of the mutations was not clear for patients treated with second-generation TKIs. The multivariate analysis affirmed that mutations in AS/MTF genes independently serve as adverse prognostic factors for molecular response, failure-free survival, and progression risk. Additionally, there was an observable nonsignificant trend indicating a heightened risk of progression to advanced disease and worse overall survival. In conclusion, mutations in the AS/MTF genes using smMIP-based NGS can help identify patients with a potential risk of both treatment failure and progression and may help upfront TKI selection.
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Leucemia Mielógena Crónica BCR-ABL Positiva , Mutación , Humanos , Leucemia Mielógena Crónica BCR-ABL Positiva/genética , Leucemia Mielógena Crónica BCR-ABL Positiva/tratamiento farmacológico , Leucemia Mielógena Crónica BCR-ABL Positiva/mortalidad , Leucemia Mielógena Crónica BCR-ABL Positiva/diagnóstico , Masculino , Persona de Mediana Edad , Femenino , Adulto , Anciano , Transducción de Señal , Inhibidores de Proteínas Quinasas/uso terapéutico , Pronóstico , Factores de Transcripción/genética , Resultado del Tratamiento , Secuenciación de Nucleótidos de Alto Rendimiento , Adulto Joven , Anciano de 80 o más Años , Progresión de la EnfermedadRESUMEN
FMS-like tyrosine kinase 3 (FLT3) mutations are detected in approximately 20-30% of patients with acute myeloid leukemia (AML), with the presence of a FLT3 internal tandem duplication (FLT3-ITD) mutation being associated with an inferior outcome. Assessment of FLT3 mutational status is now essential to define optimal upfront treatment in both newly diagnosed and relapsed AML, to support post-induction allogeneic hematopoietic stem cell transplantation (alloSCT) decision-making, and to evaluate treatment response via measurable (minimal) residual disease (MRD) evaluation. In view of its importance in AML diagnosis and management, the Canadian Leukemia Study Group/Groupe canadien d'étude sur la leucémie (CLSG/GCEL) undertook the development of a consensus statement on the clinical utility of FLT3 mutation testing, as members reported considerable inter-center variability across Canada with respect to testing availability and timing of use, methodology, and interpretation. The CLSG/GCEL panel identified key clinical and hematopathological questions, including: (1) which patients should be tested for FLT3 mutations, and when?; (2) which is the preferred method for FLT3 mutation testing?; (3) what is the clinical relevance of FLT3-ITD size, insertion site, and number of distinct FLT3-ITDs?; (4) is there a role for FLT3 analysis in MRD assessment?; (5) what is the clinical relevance of the FLT3-ITD allelic burden?; and (6) how should results of FLT3 mutation testing be reported? The panel followed an evidence-based approach, taken together with Canadian clinical and laboratory experience and expertise, to create a consensus document to facilitate a more uniform approach to AML diagnosis and treatment across Canada.
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Trasplante de Células Madre Hematopoyéticas , Leucemia Mieloide Aguda , Humanos , Canadá , Tirosina Quinasa 3 Similar a fms/genética , Leucemia Mieloide Aguda/genética , MutaciónRESUMEN
Initial classification of acute leukemia involves the assignment of blasts to cell states within the hematopoietic hierarchy based on morphological and immunophenotypic features. Yet, these traditional classification approaches lack precision, especially at the level of immature blasts. Single-cell RNA-sequencing (scRNA-seq) enables precise determination of cell state using thousands of markers, thus providing an opportunity to re-examine present-day classification schemes of acute leukemia. Here, we developed a detailed reference map of human bone marrow hematopoiesis from 263,519 single-cell transcriptomes spanning 55 cellular states. Cell state annotations were benchmarked against purified cell populations, and in-depth characterization of gene expression programs underlying hematopoietic differentiation was undertaken. Projection of single-cell transcriptomes from 175 samples spanning acute myeloid leukemia (AML), mixed phenotype acute leukemia (MPAL), and acute erythroid leukemia (AEL) revealed 11 subtypes involving distinct stages of hematopoietic differentiation. These included AML subtypes with notable lymphoid or erythroid lineage priming, challenging traditional diagnostic boundaries between AML, MPAL, and AEL. Quantification of lineage priming in bulk patient cohorts revealed specific genetic alterations associated with this unconventional lineage priming. Integration of transcriptional and genetic information at the single-cell level revealed how genetic subclones can induce lineage restriction, differentiation blocks, or expansion of mature myeloid cells. Furthermore, we demonstrate that distinct cellular hierarchies can co-exist within individual patients, providing insight into AML evolution in response to varying selection pressures. Together, precise mapping of hematopoietic cell states can serve as a foundation for refining disease classification in acute leukemia and understanding response or resistance to emerging therapies.