Current Opinion in Hematology最新文献

Purpose of review: Terminal erythroid differentiation occurs in specialized niches called erythroblastic islands. Since their discovery in 1958, these niches have been described as a central macrophage surrounded by differentiating erythroblasts. Here, we review the recent advances made in the characterization of these islands and the role they could play in anaemia of inflammation.

Recent findings: The utilization of multispectral imaging flow cytometry (flow cytometry with microscopy) has enabled for a more precise characterization of the niche that revealed the presence of maturing granulocytes in close contact with the central macrophage. These erythromyeloblastic islands (EMBIs) can adapt depending on the peripheral needs. Indeed, during inflammation wherein inflammatory cytokines limit erythropoiesis and promote granulopoiesis, EMBIs present altered structures with increased maturing granulocytes and decreased erythroid precursors.

Summary: Regulation of the structure and function of the EMBI in the bone marrow emerges as a potential player in the pathophysiology of acute and chronic inflammation and its associated anaemia.

Purpose of review: This review provides an update on the pathophysiology of sickle cell disease (SCD) with a particular focus on the dysregulation of the von Willebrand factor (VWF) - ADAMTS13 axis that contributes to its pathogenesis. In discussing recent developments, we hope to encourage new and ongoing discussions surrounding therapeutic targets for SCD.

Recent findings: Within the last 5 years, the role of VWF in the pathophysiology of SCD has been further elucidated and is now a target of study in ongoing clinical trials.

Summary: The pathophysiology of SCD is multifaceted, as it involves systemwide vascular activation, altered blood rheology, and the activation of immune responses and coagulative pathways. The presence of VWF in excess in SCD, particularly in its largest multimeric form, greatly contributes to its pathogenesis. Understanding the molecular mechanisms that underly the presence of large VWF multimers in SCD will provide further insight into the pathogenesis of SCD and provide specific targets for therapy.

Purpose of review: Two years after the recognition of VEXAS (for Vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic) syndrome, we propose an extensive review of the current understanding of VEXAS pathophysiology and therapeutic options.

Recent findings: Among the nearly 150 articles published about VEXAS, some have provided determinant insights into VEXAS pathophysiology and treatment. Clinical data from retrospective series support the JAK inhibitor ruxolitinib as the most efficient strategy to control inflammation, and interesting results were also described with azacytidine. Allogeneic stem cell transplantation remains the only curative option, but should be proposed to carefully selected patients.

Summary: Although waiting for more robust evidence from prospective clinical trials, therapeutic options emerge from retrospective studies. We propose a set of criteria that should be systematically reported to harmonize the evaluation of therapeutic outcomes. This will allow the collection of high-quality data and facilitate their subsequent meta-analysis with the overall aim of improving the management of VEXAS patients.

Purpose of review: The aim of this study was to provide insight into how novel next-generation sequencing (NGS) techniques are set to revolutionize clinical practice.

Recent findings: Advances in sequencing technologies have focused on improved capture of mutations and reads and cellular resolution. Both short and long read DNA sequencing technology are being refined and combined in novel ways with other multiomic approaches to gain unprecedented biological insight into disease. Single-cell (sc)DNA-seq and integrated scDNA-seq with immunophenotyping provide granular information on disease composition such as clonal hierarchy, co-mutation status, zygosity, clonal diversity and genotype phenotype correlations. These and other techniques can identify rare cell populations providing the opportunity for increased sensitivity in measurable residual disease monitoring and precise characterization of residual clones permitting distinction of leukemic from pre/nonmalignant clones.

Summary: Increasing genetics-based mechanistic insights and classification of myeloid diseases along with a decrease in the cost of high-throughput NGS mean novel sequencing technologies are closer to being a reality in standard clinical practice. These technologies are poised to improve diagnostics, our ability to monitor treatment response and minimal residual disease and allow the study of premalignant conditions such as clonal haematopoiesis.

Purpose of review: There have been major advances in our understanding of molecular pathogenesis of myeloid neoplasms, which prompt the updates in the classification of myeloid neoplasms in the fifth edition of World Health Organization Classification (WHO-5) and the new International Consensus Classification (ICC). The purpose of this review is to provide an overview of these two classification systems for myeloid neoplasms.

Recent findings: The definition, classification, and diagnostic criteria in many myeloid entities have been refined in WHO-5 and ICC with improved understanding of morphology and integration of new genetic findings. Particularly, molecular and cytogenetic studies have been increasingly incorporated into the classification, risk stratification, and selection of therapy of myeloid neoplasms. Overall, despite some revisions and discrepancies between WHO-5 and ICC, the major categories of myeloid neoplasms remain the same. Further validation studies are warranted to fine-tune and, ideally, integrate these two classifications.

Summary: Integration of clinical information, laboratory parameters, morphologic features, and cytogenetic and molecular studies is essential for the classification of myeloid neoplasms, as recommended by both WHO-5 and ICC.

Purpose of review: The aim of this review is to provide a complete perspective of the evidence that led to the three recent new landmarks of myelodysplastic syndromes (MDS) definition and prognostication: the WHO 2022 and International Consensus Classification (ICC) 2022 classification and the Molecular Intermational Prognostic Scoring System (IPSS-M) score.

Recent findings: The molecular founding lesions of MDS are strongly linked with disease phenotype and prognosis, therefore the genetic assessment have become part of MDS classifications and prognostication.

Summary: The WHO 2022 now recognizes the class 'MDS with defining genetic abnormalities'. It includes 'MDS with SF3B1 mutation', and 'MDS with biallelic TP53 inactivation'. The ICC 2022 further introduces the category 'MDS/acute myeloid leukemia (AML)' emphasizing the biological continuum existing between the diseases, with the aim to expand therapeutic possibilities for MDS patients with more than 10% of blasts; it further identifies 9 MDS-funding lesions, defying the 'MDS/AML with myelodysplasia-related gene mutations' class. In recent years, many efforts have been done in order to specify and weight the role of mutations in disease prognostication; the IPSS-M proposed in 2022 finally integrates the molecular profile of the disease with the clinical and cytogenetic data, providing a better prognostication at patient level compared to IPSS-R.

Purpose of review: Development of hepcidin therapeutics has been a ground-breaking discovery in restoring iron homeostasis in several haematological disorders. The hepcidin mimetic, rusfertide, is in late-stage clinical development for treating polycythemia vera patients with a global phase 3 trial [NCT05210790] currently underway. Rusfertide serves as the first possible noncytoreductive therapeutic option to maintain haematocrit control and avoid phlebotomy in polycythemia vera patients. In this comprehensive review, we discuss the pathobiology of dysregulated iron metabolism in polycythemia vera, provide the rationale for targeting the hepcidin-ferroportin axis and elaborate on the preclinical and clinical trial evidence supporting the role of hepcidin mimetics in polycythemia vera.

Recent findings: Recently, updated results from two phase 2 clinical trials [NCT04057040 & NCT04767802] of rusfertide (PTG300) demonstrate that the drug is highly effective in eliminating the need for therapeutic phlebotomies, normalizing haematological parameters, repleting iron stores and relieving constitutional symptoms in patients with polycythemia vera. In light of these findings, additional hepcidin mimetic agents are also being evaluated in polycythemia vera patients.

Summary: Hepcidin agonists essentially serve as a 'chemical phlebotomy' and are poised to vastly improve the quality of life for phlebotomy requiring polycythemia vera patients.