Shared and distinct mechanisms of UBA1 inactivation across different diseases.

Most cellular ubiquitin signaling is initiated by UBA1, which activates and transfers ubiquitin to tens of E2 enzymes. Clonally acquired UBA1 missense mutations cause an inflammatory-hematologic overlap disease called VEXAS (vacuoles, E1, X-linked, autoinflammatory, somatic) syndrome. Despite extensive clinical investigation into this lethal disease, little is known about the underlying molecular mechanisms. Here, by dissecting VEXAS-causing UBA1 mutations, we discovered that p.Met41 mutations alter cytoplasmic isoform expression, whereas other mutations reduce catalytic activity of nuclear and cytoplasmic isoforms by diverse mechanisms, including aberrant oxyester formation. Strikingly, non-p.Met41 mutations most prominently affect transthioesterification, revealing ubiquitin transfer to cytoplasmic E2 enzymes as a shared property of pathogenesis amongst different VEXAS syndrome genotypes. A similar E2 charging bottleneck exists in some lung cancer-associated UBA1 mutations, but not in spinal muscular atrophy-causing UBA1 mutations, which instead, render UBA1 thermolabile. Collectively, our results highlight the precision of conformational changes required for faithful ubiquitin transfer, define distinct and shared mechanisms of UBA1 inactivation in diverse diseases, and suggest that specific E1-E2 modules control different aspects of tissue differentiation and maintenance.

Personal omics profiling reveals dynamic molecular and medical phenotypes.

Personalized medicine is expected to benefit from combining genomic information with regular monitoring of physiological states by multiple high-throughput methods. Here, we present an integrative personal omics profile (iPOP), an analysis that combines genomic, transcriptomic, proteomic, metabolomic, and autoantibody profiles from a single individual over a 14 month period. Our iPOP analysis revealed various medical risks, including type 2 diabetes. It also uncovered extensive, dynamic changes in diverse molecular components and biological pathways across healthy and diseased conditions. Extremely high-coverage genomic and transcriptomic data, which provide the basis of our iPOP, revealed extensive heteroallelic changes during healthy and diseased states and an unexpected RNA editing mechanism. This study demonstrates that longitudinal iPOP can be used to interpret healthy and diseased states by connecting genomic information with additional dynamic omics activity.

How I reduce and treat posttransplant relapse of MDS.

ABSTRACT: Allogeneic hematopoietic stem cell transplantation (HSCT) is the only potentially curative option for patients with high-risk myelodysplastic syndromes (MDS). Advances in conditioning regimens and supportive measures have reduced treatment-related mortality and increased the role of transplantation, leading to more patients undergoing HSCT. However, posttransplant relapse of MDS remains a leading cause of morbidity and mortality for this procedure, necessitating expert management and ongoing results analysis. In this article, we review treatment options and our institutional approaches to managing MDS relapse after HSCT, using illustrative clinical cases that exemplify different clinical manifestations and management of relapse. We address areas of controversy relating to conditioning regimen intensity, chemotherapeutic bridging, and donor selection. In addition, we discuss future directions for advancing the field, including (1) the need for prospective clinical trials separating MDS from acute myeloid leukemia and focusing on posttransplant relapse, as well as (2) the validation of measurable residual disease methodologies to guide timely interventions.

Molecular Taxonomy of Myelodysplastic Syndromes and its Clinical Implications.

Myelodysplastic syndromes/neoplasms (MDS) are clonal hematologic disorders characterized by morphologic abnormalities of myeloid cells and peripheral cytopenias. While genetic abnormalities underlie the pathogenesis of these disorders and their heterogeneity, current classifications of MDS rely predominantly on morphology. We performed genomic profiling of 3,233 patients with MDS or related disorders to delineate molecular subtypes and define their clinical implications. Gene mutations, copy-number alterations (CNAs), and copy-neutral loss of heterozygosity (cnLOH) were derived from targeted sequencing of a 152-gene panel, with abnormalities identified in 91, 43, and 11% of patients, respectively. We characterized 16 molecular groups, encompassing 86% of patients, using information from 21 genes, 6 cytogenetic events, and LOH at the TP53 and TET2 loci. Two residual groups defined by negative findings (molecularly not-otherwise specified, absence of recurrent drivers) comprised 14% of patients. The groups varied in size from 0.5% to 14% of patients and were associated with distinct clinical phenotypes and outcomes. The median bone marrow blast percentage across groups ranged from 1.5 to 10%, and the median overall survival from 0.9 to 8.2 years. We validated 5 well-characterized entities, added further evidence to support 3 previously reported subsets, and described 8 novel groups. The prognostic influence of bone marrow blasts depended on the genetic subtypes. Within genetic subgroups, therapy-related MDS and myelodysplastic/myeloproliferative neoplasms (MDS/MPN) had comparable clinical and outcome profiles to primary MDS. In conclusion, genetically-derived subgroups of MDS are clinically relevant and may inform future classification schemas and translational therapeutic research.

The trajectory of prognostication and risk stratification for patients with myelodysplastic syndromes.

ABSTRACT: Risk stratification and prognostication are crucial for the appropriate management of patients with myelodysplastic syndromes (MDSs) or myelodysplastic neoplasms, for whom the expected survival can vary from a few months to >10 years. For the past 5 decades, patients with MDS have been classified into higher-risk vs lower-risk disease phenotypes using sequentially developed clinical prognostic scoring systems. Factors such as morphologic dysplasia, clinical hematologic parameters, cytogenetics, and, more recently, mutational information have been captured in prognostic scoring systems that refine risk stratification and guide therapeutic management in patients with MDS. This review describes the progressive evolution and improvement of these systems which has led to the current Molecular International Prognostic Scoring System.

Myelodysplastic syndromes, thy name is heterogeneity.

Classification of the heterogeneous spectrum of myelodysplastic syndromes (MDS) requires both morphologic and molecular analysis to effectively subgroup patients. The paper by Zhang et al demonstrated the positive impact of combining the International Consensus Consortium (ICC) morphologic approach with prior clinical (IPSS-R) and mutational (IPSS-M) categorization to provide useful clinical evaluation of MDS patients. Commentary on: Zhang et al. Impact of the International Consensus Classification of Myelodysplastic Syndromes. Br J Haematol 2022 (Online ahead of print). doi: 10.1111/bjh.18628.

Luspatercept in Patients with Lower-Risk Myelodysplastic Syndromes.

BACKGROUND: Patients with anemia and lower-risk myelodysplastic syndromes in whom erythropoiesis-stimulating agent therapy is not effective generally become dependent on red-cell transfusions. Luspatercept, a recombinant fusion protein that binds transforming growth factor ß superfamily ligands to reduce SMAD2 and SMAD3 signaling, showed promising results in a phase 2 study. METHODS: In a double-blind, placebo-controlled, phase 3 trial, we randomly assigned patients with very-low-risk, low-risk, or intermediate-risk myelodysplastic syndromes (defined according to the Revised International Prognostic Scoring System) with ring sideroblasts who had been receiving regular red-cell transfusions to receive either luspatercept (at a dose of 1.0 up to 1.75 mg per kilogram of body weight) or placebo, administered subcutaneously every 3 weeks. The primary end point was transfusion independence for 8 weeks or longer during weeks 1 through 24, and the key secondary end point was transfusion independence for 12 weeks or longer, assessed during both weeks 1 through 24 and weeks 1 through 48. RESULTS: Of the 229 patients enrolled, 153 were randomly assigned to receive luspatercept and 76 to receive placebo; the baseline characteristics of the patients were balanced. Transfusion independence for 8 weeks or longer was observed in 38% of the patients in the luspatercept group, as compared with 13% of those in the placebo group (P<0.001). A higher percentage of patients in the luspatercept group than in the placebo group met the key secondary end point (28% vs. 8% for weeks 1 through 24, and 33% vs. 12% for weeks 1 through 48; P<0.001 for both comparisons). The most common luspatercept-associated adverse events (of any grade) included fatigue, diarrhea, asthenia, nausea, and dizziness. The incidence of adverse events decreased over time. CONCLUSIONS: Luspatercept reduced the severity of anemia in patients with lower-risk myelodysplastic syndromes with ring sideroblasts who had been receiving regular red-cell transfusions and who had disease that was refractory to or unlikely to respond to erythropoiesis-stimulating agents or who had discontinued such agents owing to an adverse event. (Funded by Celgene and Acceleron Pharma; MEDALIST ClinicalTrials.gov number, NCT02631070; EudraCT number, 2015-003454-41.).

SF3B1-mutant MDS as a distinct disease subtype: a proposal from the International Working Group for the Prognosis of MDS.

The 2016 revision of the World Health Organization classification of tumors of hematopoietic and lymphoid tissues is characterized by a closer integration of morphology and molecular genetics. Notwithstanding, the myelodysplastic syndrome (MDS) with isolated del(5q) remains so far the only MDS subtype defined by a genetic abnormality. Approximately half of MDS patients carry somatic mutations in spliceosome genes, with SF3B1 being the most commonly mutated one. SF3B1 mutation identifies a condition characterized by ring sideroblasts (RS), ineffective erythropoiesis, and indolent clinical course. A large body of evidence supports recognition of SF3B1-mutant MDS as a distinct nosologic entity. To further validate this notion, we interrogated the data set of the International Working Group for the Prognosis of MDS (IWG-PM). Based on the findings of our analyses, we propose the following diagnostic criteria for SF3B1-mutant MDS: (1) cytopenia as defined by standard hematologic values, (2) somatic SF3B1 mutation, (3) morphologic dysplasia (with or without RS), and (4) bone marrow blasts <5% and peripheral blood blasts <1%. Selected concomitant genetic lesions represent exclusion criteria for the proposed entity. In patients with clonal cytopenia of undetermined significance, SF3B1 mutation is almost invariably associated with subsequent development of overt MDS with RS, suggesting that this genetic lesion might provide presumptive evidence of MDS in the setting of persistent unexplained cytopenia. Diagnosis of SF3B1-mutant MDS has considerable clinical implications in terms of risk stratification and therapeutic decision making. In fact, this condition has a relatively good prognosis and may respond to luspatercept with abolishment of the transfusion requirement.

Recent Clinical and Molecular Advances for the Classification of Myelodysplastic Neoplasms.

Several major updates have recently occurred for the NCCN Guidelines for Myelodysplastic Syndromes (MDS) based on a number of prominent articles that have particular clinical and biologic impact for the field. These changes, which have been included in the current iteration of the NCCN Guidelines (Version 1.2023), include the WHO 2022 classification of MDS as well as the ICC suggestions for same. In addition, the molecular underpinning of MDS has been greatly updated with the generation of the Molecular International Prognostic Scoring System (IPSS-M) and an improved understanding to the prognostic implications of mutated TP53 subtypes, which are additive to the revised IPSS (IPSS-R) for stratification and management of patients with MDS. This report emphasizes the major components of the relevant changes to serve as a guide for therapeutic decision-making for patients with MDS.

NCCN Guidelines® Insights: Myelodysplastic Syndromes, Version 3.2022.

The NCCN Guidelines for Myelodysplastic Syndromes (MDS) provide recommendations for the evaluation, diagnosis, and management of patients with MDS based on a review of clinical evidence that has led to important advances in treatment or has yielded new information on biologic factors that may have prognostic significance in MDS. The multidisciplinary panel of MDS experts meets on an annual basis to update the recommendations. These NCCN Guidelines Insights focus on some of the updates for the 2022 version of the NCCN Guidelines, which include treatment recommendations both for lower-risk and higher-risk MDS, emerging therapies, supportive care recommendations, and genetic familial high-risk assessment for hereditary myeloid malignancy predisposition syndromes.

Proposed diagnostic criteria for classical chronic myelomonocytic leukemia (CMML), CMML variants and pre-CMML conditions.

Chronic myelomonocytic leukemia (CMML) is a myeloid neoplasm characterized by dysplasia, abnormal production and accumulation of monocytic cells and an elevated risk of transforming into acute leukemia. Over the past two decades, our knowledge about the pathogenesis and molecular mechanisms in CMML has increased substantially. In parallel, better diagnostic criteria and therapeutic strategies have been developed. However, many questions remain regarding prognostication and optimal therapy. In addition, there is a need to define potential pre-phases of CMML and special CMML variants, and to separate these entities from each other and from conditions mimicking CMML. To address these unmet needs, an international consensus group met in a Working Conference in August 2018 and discussed open questions and issues around CMML, its variants, and pre-CMML conditions. The outcomes of this meeting are summarized herein and include diag nostic criteria and a proposed classification of pre-CMML conditions as well as refined minimal diagnostic criteria for classical CMML and special CMML variants, including oligomonocytic CMML and CMML associated with systemic mastocytosis. Moreover, we propose diagnostic standards and tools to distinguish between 'normal', pre-CMML and CMML entities. These criteria and standards should facilitate diagnostic and prognostic evaluations in daily practice and clinical studies in applied hematology.

Time-dependent changes in mortality and transformation risk in MDS.

In myelodysplastic syndromes (MDSs), the evolution of risk for disease progression or death has not been systematically investigated despite being crucial for correct interpretation of prognostic risk scores. In a multicenter retrospective study, we described changes in risk over time, the consequences for basal prognostic scores, and their potential clinical implications. Major MDS prognostic risk scoring systems and their constituent individual predictors were analyzed in 7212 primary untreated MDS patients from the International Working Group for Prognosis in MDS database. Changes in risk of mortality and of leukemic transformation over time from diagnosis were described. Hazards regarding mortality and acute myeloid leukemia transformation diminished over time from diagnosis in higher-risk MDS patients, whereas they remained stable in lower-risk patients. After approximately 3.5 years, hazards in the separate risk groups became similar and were essentially equivalent after 5 years. This fact led to loss of prognostic power of different scoring systems considered, which was more pronounced for survival. Inclusion of age resulted in increased initial prognostic power for survival and less attenuation in hazards. If needed for practicability in clinical management, the differing development of risks suggested a reasonable division into lower- and higher-risk MDS based on the IPSS-R at a cutoff of 3.5 points. Our data regarding time-dependent performance of prognostic scores reflect the disparate change of risks in MDS subpopulations. Lower-risk patients at diagnosis remain lower risk whereas initially high-risk patients demonstrate decreasing risk over time. This change of risk should be considered in clinical decision making.

Myelodysplastic Syndromes, Version 2.2017, NCCN Clinical Practice Guidelines in Oncology.

The myelodysplastic syndromes (MDS) comprise a heterogenous group of myeloid disorders with a highly variable disease course. Diagnostic criteria to better stratify patients with MDS continue to evolve, based on morphology, cytogenetics, and the presence of cytopenias. More accurate classification of patients will allow for better treatment guidance. Treatment encompasses supportive care, treatment of anemia, low-intensity therapy, and high-intensity therapy. This portion of the guidelines focuses on diagnostic classification, molecular abnormalities, therapeutic options, and recommended treatment approaches.

Hematopoietic stem cell and progenitor cell mechanisms in myelodysplastic syndromes.

Myelodysplastic syndromes (MDS) are a group of disorders characterized by variable cytopenias and ineffective hematopoiesis. Hematopoietic stem cells (HSCs) and myeloid progenitors in MDS have not been extensively characterized. We transplanted purified human HSCs from MDS samples into immunodeficient mice and show that HSCs are the disease-initiating cells in MDS. We identify a recurrent loss of granulocyte-macrophage progenitors (GMPs) in the bone marrow of low risk MDS patients that can distinguish low risk MDS from clinical mimics, thus providing a simple diagnostic tool. The loss of GMPs is likely due to increased apoptosis and increased phagocytosis, the latter due to the up-regulation of cell surface calreticulin, a prophagocytic marker. Blocking calreticulin on low risk MDS myeloid progenitors rescues them from phagocytosis in vitro. However, in the high-risk refractory anemia with excess blasts (RAEB) stages of MDS, the GMP population is increased in frequency compared with normal, and myeloid progenitors evade phagocytosis due to up-regulation of CD47, an antiphagocytic marker. Blocking CD47 leads to the selective phagocytosis of this population. We propose that MDS HSCs compete with normal HSCs in the patients by increasing their frequency at the expense of normal hematopoiesis, that the loss of MDS myeloid progenitors by programmed cell death and programmed cell removal are, in part, responsible for the cytopenias, and that up-regulation of the "don't eat me" signal CD47 on MDS myeloid progenitors is an important transition step leading from low risk MDS to high risk MDS and, possibly, to acute myeloid leukemia.

Frequency of del(12p) is commonly underestimated in myelodysplastic syndromes: Results from a German diagnostic study in comparison with an international control group.

In myelodysplastic syndromes (MDS), deletion of the short arm of chromosome 12 (del(12p)) is usually a small abnormality, rarely detected as a single aberration by chromosome banding analysis (CBA) of bone marrow metaphases. Del(12p) has been described in 0.6 to 5% of MDS patients at initial diagnosis and is associated with a good to intermediate prognosis as a sole anomaly according to current scoring systems. Here, we present the results of a systematic del(12p) testing in a German prospective diagnostic study (clinicaltrials.gov: NCT01355913) on 367 MDS patients in whom CD34+ peripheral blood cells were analysed for the presence of del(12p) by sequential fluorescence in situ hybridization (FISH) analyses. A cohort of 2,902 previously published MDS patients diagnosed by CBA served as control. We demonstrate that, using a sensitive FISH technique, 12p deletion occurs significantly more frequently in MDS than previously described (7.6% by CD34+ PB-FISH vs. 1.6% by CBA, P < 0.001) and is often associated with other aberrations (93% by CD34+ PB-FISH vs. 60% by CBA). Additionally, the detection rate can be increased by repeated analyses in a patient over time which is important for the patient´s prognosis to distinguish a sole anomaly from double or complex aberrations. To our knowledge, this is the first study to screen for 12p deletions with a suitable probe for ETV6/TEL in 12p13. Our data suggest that the supplement of a probe for the detection of a 12p deletion to common FISH probe panels helps to avoid missing a del(12p), especially as part of more complex aberrations.

Validation of cytogenetic risk groups according to International Prognostic Scoring Systems by peripheral blood CD34+FISH: results from a German diagnostic study in comparison with an international control group.

International Prognostic Scoring Systems are used to determine the individual risk profile of myelodysplastic syndrome patients. For the assessment of International Prognostic Scoring Systems, an adequate chromosome banding analysis of the bone marrow is essential. Cytogenetic information is not available for a substantial number of patients (5%-20%) with dry marrow or an insufficient number of metaphase cells. For these patients, a valid risk classification is impossible. In the study presented here, the International Prognostic Scoring Systems were validated based on fluorescence in situ hybridization analyses using extended probe panels applied to cluster of differentiation 34 positive (CD34(+)) peripheral blood cells of 328 MDS patients of our prospective multicenter German diagnostic study and compared to chromosome banding results of 2902 previously published patients with myelodysplastic syndromes. For cytogenetic risk classification by fluorescence in situ hybridization analyses of CD34(+) peripheral blood cells, the groups differed significantly for overall and leukemia-free survival by uni- and multivariate analyses without discrepancies between treated and untreated patients. Including cytogenetic data of fluorescence in situ hybridization analyses of peripheral CD34(+) blood cells (instead of bone marrow banding analysis) into the complete International Prognostic Scoring System assessment, the prognostic risk groups separated significantly for overall and leukemia-free survival. Our data show that a reliable stratification to the risk groups of the International Prognostic Scoring Systems is possible from peripheral blood in patients with missing chromosome banding analysis by using a comprehensive probe panel (clinicaltrials.gov identifier:01355913).

Myelodysplastic syndromes, version 2.2015.

The NCCN Guidelines for Myelodysplastic Syndromes (MDS) comprise a heterogeneous group of myeloid disorders with a highly variable disease course that depends largely on risk factors. Risk evaluation is therefore a critical component of decision-making in the treatment of MDS. The development of newer treatments and the refinement of current treatment modalities are designed to improve patient outcomes and reduce side effects. These NCCN Guidelines Insights focus on the recent updates to the guidelines, which include the incorporation of a revised prognostic scoring system, addition of molecular abnormalities associated with MDS, and refinement of treatment options involving a discussion of cost of care.