Definitions and standards in the diagnosis and treatment of the myelodysplastic syndromes: Consensus statements and report from a working conference

Prevalence of massively diluted bone marrow cell samples aspirated from patients with myelodysplastic syndromes (MDS) or suspected of MDS: A retrospective analysis of nationwide samples in Japan

Bone marrow (BM) examination is a key element in the diagnosis and prognostic grading of myelodysplastic syndromes (MDSs), and obtaining adequate BM cell samples is critical for accurate test results. Massive haemodilution of aspirated BM samples is a well-known problem; however, its incidence in patients with MDS has not been well studied. We report the first study to examine the incidence of massive haemodilution in nationwide BM samples aspirated from patients diagnosed with or suspected of MDS in Japan. Among 283 cases available for analysis, BM smears from 92 cases (32.5%) were hypospicular (massively haemodiluted) and, particularly, no BM particles were observed in 52 cases (18.4%). Regarding hypospicular cases, we examined how the doctors in charge interpreted the BM smears of their patients. In only 19 of 92 cases (20.7%), doctors realised that the BM smears were haemodiluted. Furthermore, the BM biopsy, which can help diagnose hypospicular cases, was oftentimes not performed when the haemodilution was overlooked by doctors (not performed in 50 of 73 such cases). These real-world data highlight that not only researchers who are working to improve diagnostic tests but also clinicians who perform and use diagnostic tests must realise this common and potentially critical problem.

Cancer patients with clonal hematopoiesis die from primary malignancy or comorbidities despite higher rates of transformation to myeloid neoplasms

BACKGROUND

The occurrence of somatic mutations in patients with no evidence of hematological disorders is called clonal hematopoiesis (CH). CH, whose subtypes include CH of indeterminate potential and clonal cytopenia of undetermined significance, has been associated with both hematologic cancers and systemic comorbidities. However, CH's effect on patients, especially those with concomitant malignancies, is not fully understood.

METHODS

We performed a retrospective evaluation of all patients with CH at a tertiary cancer center. Patient characteristics, mutational data, and outcomes were collected and analyzed.

RESULTS

Of 78 individuals included, 59 (76%) had a history of cancer and 60 (77%) had moderate to severe comorbidity burdens. DNMT3A, TET2, TP53, and ASXL1 were the most common mutations. For the entire cohort, the 2-year overall survival rate was 79% (95% CI: 70, 90), while the median survival was not reached. Of 20 observed deaths, most were related to primary malignancies (n = 7, 35%), comorbidities (n = 4, 20%), or myeloid neoplasms (n = 4, 20%). Twelve patients (15%) experienced transformation to a myeloid neoplasm. According to the clonal hematopoiesis risk score, the 3-year transformation rate was 0% in low-risk, 15% in intermediate-risk (p = 0.098), and 28% in high-risk (p = 0.05) patients. By multivariate analysis, transformation was associated with variant allele frequency ≥0.2 and hemoglobin <10 g/dL.

CONCLUSIONS

In a population including mostly cancer patients, CH was associated with comorbidities and myeloid transformation in patients with higher mutational burdens and anemia. Nevertheless, such patients were less likely to die of their myeloid neoplasm than of primary malignancy or comorbidities.

Case report: Cytopenias in VEXAS syndrome - a WHO 2022 based approach in a single-center cohort

VEXAS syndrome is an acquired autoinflammatory disease characterized in most cases by cytopenias and macrocytic anemia. Dyshematopoiesis is a frequent finding in chronic inflammatory conditions and therefore, cytopenias are not easily classified in VEXAS patients. Here we report a series of 7 patients affected by VEXAS associated cytopenias, treated at our center. The use of NGS, together with morphological assays, integrated with the WHO 2022 criteria, allowed to identify three subsets of VEXAS associated cytopenias: ICUS (idiopathic cytopenia of uncertain significance), CCUS (clonal cytopenia of uncertain significance) at high risk of clonal evolution, and MDS. This approach could help to better understand the nature of VEXAS associated cytopenias and to guide the use of specific targeted treatments in order to achieve long lasting responses.

Diagnosis and classification of myelodysplastic syndromes

ABSTRACT

Myelodysplastic syndromes (MDSs) are neoplastic myeloid proliferations characterized by ineffective hematopoiesis resulting in peripheral blood cytopenias. MDS is distinguished from nonneoplastic clonal myeloid proliferations by the presence of morphologic dysplasia and from acute myeloid leukemia by a blast threshold of 20%. The diagnosis of MDS can be challenging because of the myriad other causes of cytopenias: accurate diagnosis requires the integration of clinical features with bone marrow and peripheral blood morphology, immunophenotyping, and genetic testing. MDS has historically been subdivided into several subtypes by classification schemes, the most recent of which are the International Consensus Classification and World Health Organization Classification (fifth edition), both published in 2022. The aim of MDS classification is to identify entities with shared genetic underpinnings and molecular pathogenesis, and the specific subtype can inform clinical decision-making alongside prognostic risk categorization. The current MDS classification schemes incorporate morphologic features (bone marrow and blood blast percentage, degree of dysplasia, ring sideroblasts, bone marrow fibrosis, and bone marrow hypocellularity) and also recognize 3 entities defined by genetics: isolated del(5q) cytogenetic abnormality, SF3B1 mutation, and TP53 mutation. It is anticipated that with advancing understanding of the genetic basis of MDS pathogenesis, future MDS classification will be based increasingly on genetic classes. Nevertheless, morphologic features in MDS reflect the phenotypic expression of the underlying abnormal genetic pathways and will undoubtedly retain importance to inform prognosis and guide treatment.

ProGraME: A novel flow cytometry algorithm for the diagnosis of low-risk myelodysplastic syndromes in patients with cytopenia

OBJECTIVES

Flow cytometry (FC) is, together with morphology, genetics, and cytogenetics, used in the diagnostic assessment of cytopenia, as its value in evaluating bone marrow dysplasia been highlighted by several studies. However, despite the development of algorithms and guidelines, there is still a lack of standardization of the FC assessment of bone marrow dysplasia.

METHODS

By combining FC, together with morphological analysis and cytogenetic/molecular assessment in a training cohort of 209 patients, we created a novel score, ProGraME, which includes four parameters, each from a different cell lineage (Progenitor cells, Granulocytes, Monocytes, Erythroid precursors), solely based on relevant population gating. Points for ProGraME were attained for: lymphoid precursors ≤5% of all CD34+ cells (1.5 point); a granulocyte-to-lymphocyte side-scatter ratio ≤6 (1 point); a monocyte CD33-CV% ≥ 63 (2 points), and an erythroid precursor CD36-CV% ≥ 65 (2 points).

RESULTS

Using a cutoff of ≥2 as suggestive of dysplasia, ProGraME showed a sensitivity of 91% and a specificity of 81% in the training cohort and 95% and 75%, respectively, in an independent validation cohort of 159 patients. In addition, ProGraME had a very high negative predictive value of 97.1% and 97.8% in the training and validation cohorts, respectively, offering a useful tool for excluding bone marrow dysplasia. Finally, among the 23 CCUS patients that scored positive for dysplasia with ProGraME in the training cohort, 16 of them (69%) carried high-risk mutations, suggesting that FC might help identify early changes of dysplasia.

CONCLUSIONS

ProGraME can potentially optimize the FC diagnosis of low-risk myelodysplasia without minimal requirements of flow analysis other than accurate population gating.

TNFα induces Caspase-3 activity in hematopoietic progenitor cells CD34+, CD33+, and CD41 + of myelodysplastic syndromes

BACKGROUND

Cytopenia is the primary feature of Myelodysplastic Syndrome, even in the presence of hypercellular bone marrow. TNFα is recognized as both a proinflammatory, and proapoptotic cytokine with a well established role in promoting apoptosis in MDS. Therefore, TNFα has the potential to be a valuable biomarker for predicting the progression of cytopenia in MDS. This study aims to establish the role of TNFα exposure in triggering apoptosis through caspase-3 activity in CD34+, CD33+, and CD41 + cells in MDS.

METHODS

This study is an in vitro comparative experimental research. Bone marrow mononuclear cells were isolated as the source of hematopoietic progenitor cells. Subsequently, CD34+, CD33+, and CD41 + cells were exposed to rhTNFα, and the caspase-3 activity was measured using flowcytometry.

RESULTS

In MDS CD33 + and CD41 + caspase-3 activity of rhTNFα exposed cells was significantly higher than without exposed cells. The opposite result was found in CD34 + cells, where the caspase-3 activity without rhTNFα exposed cells was significantly higher than rhTNFα exposed cells.

CONCLUSION

rhTNFα exposure led to an elevation in caspase-3 activity in MDS progenitor cells, especially in those that had differentiated into myeloid cell CD33 + and megakaryocyte cell CD41+, as opposed to the early progenitor cells CD34+.

CAR virus receptor mediates erythroid differentiation and migration and is downregulated in MDS

Myelodysplastic syndromes (MDS) are myeloid neoplasms presenting with dysplasia in the bone marrow (BM) and peripheral cytopenia. In most patients anemia develops. We screened for genes that are expressed abnormally in erythroid progenitor cells (EP) and contribute to the pathogenesis of MDS. We found that the Coxsackie-Adenovirus receptor (CAR = CXADR) is markedly downregulated in CD45low/CD105+ EP in MDS patients compared to control EP. Correspondingly, the erythroblast cell lines HEL, K562, and KU812 stained negative for CAR. Lentiviral transduction of the full-length CXADR gene into these cells resulted in an increased expression of early erythroid antigens, including CD36, CD71, and glycophorin A. In addition, CXADR-transduction resulted in an increased migration against a serum protein gradient, whereas truncated CXADR variants did not induce expression of erythroid antigens or migration. Furthermore, conditional knock-out of Cxadr in C57BL/6 mice resulted in anemia and erythroid dysplasia. Finally, decreased CAR expression on EP was found to correlate with high-risk MDS and decreased survival. Together, CAR is a functionally relevant marker that is down-regulated on EP in MDS and is of prognostic significance. Decreased CAR expression may contribute to the maturation defect and altered migration of EP and thus their pathologic accumulation in the BM in MDS.

Patterns of Diagnostic Evaluation and Determinants of Treatment in Older Patients With Non-transfusion Dependent Myelodysplastic Syndromes

BACKGROUND

Older patients with myelodysplastic syndromes (MDS), particularly those with no or one cytopenia and no transfusion dependence, typically have an indolent course. Approximately, half of these receive the recommended diagnostic evaluation (DE) for MDS. We explored factors determining DE in these patients and its impact on subsequent treatment and outcomes.

PATIENTS AND METHODS

We used 2011-2014 Medicare data to identify patients ≥66 years of age diagnosed with MDS. We used Classification and Regression Tree (CART) analysis to identify combinations of factors associated with DE and its impact on subsequent treatment. Variables examined included demographics, comorbidities, nursing home status, and investigative procedures performed. We conducted a logistic regression analysis to identify correlates associated with receipt of DE and treatment.

RESULTS

Of 16 851 patients with MDS, 51% underwent DE. patients with MDS with no cytopenia (n = 3908) had the lowest uptake of DE (34.7%). Compared to patients with no cytopenia, those with any cytopenia had nearly 3 times higher odds of receiving DE [adjusted odds ratio (AOR), 2.81: 95% CI, 2.60-3.04] and the odds were higher for men than for women [AOR, 1.39: 95%CI, 1.30-1.48] and for Non-Hispanic Whites [vs. everyone else (AOR, 1.17: 95% CI, 1.06-1.29)]. The CART showed DE as the principal discriminating node, followed by the presence of any cytopenia for receiving MDS treatment. The lowest percentage of treatment was observed in patients without DE, at 14.6%.

CONCLUSION

In this select older patients with MDS, we identified disparities in accurate diagnosis by demographic and clinical factors. Receipt of DE influenced subsequent treatment but not survival.

Genomic Data Heterogeneity across Molecular Diagnostic Laboratories: A Real-World Connect Myeloid Disease Registry Perspective on Variabilities in Genomic Assay Methodology and Reporting

Genomic data variability from laboratory reports can impact clinical decisions and population-level analyses; however, the extent of this variability and the impact on the data's value are not well characterized. This pilot study used anonymized genetic and genomic test reports from the Connect Myeloid Disease Registry (NCT01688011), a multicenter, prospective, observational cohort study of patients with newly diagnosed myelodysplastic syndromes, acute myeloid leukemia, or idiopathic cytopenia of undetermined significance, to analyze laboratory test variabilities and limitations. Results for 56 randomly selected patients enrolled in the Registry were independently extracted and evaluated (data cutoff, January 2020). Ninety-five reports describing 113 assay results from these 56 patients were analyzed for discrepancies. Almost all assay results [101 (89%)] identified the sequencing technology applied, and 94 (83%) described the test limitations; 95 (84%) described the limits of detection, but none described the limit of blank for detecting false positives. RNA transcript identifiers were not provided for 20 (43%) variants analyzed by next-generation sequencing and reported by the same laboratory. Of 42 variants with variant allele frequencies ≥30%, 16 (38%) of the variants did not have report text indicating that the variants might be germline. Variabilities and lack of standardization present challenges for incorporating this information into clinical care and render data collation ineffective and unreliable for large-scale use in centralized databases for therapeutic discovery.

DHX9-mediated pathway contributes to the malignant phenotype of myelodysplastic syndromes

DHX9 is a member of the DEAH (Asp-Glu-Ala-His) helicase family and regulates DNA replication and RNA processing. DHX9 dysfunction promotes tumorigenesis in several solid cancers. However, the role of DHX9 in MDS is still unknown. Here, we analyzed the expression of DHX9 and its clinical significance in 120 MDS patients and 42 non-MDS controls. Lentivirus-mediated DHX9-knockdown experiments were performed to investigate its biological function. We also performed cell functional assays, gene microarray, and pharmacological intervention to investigate the mechanistic involvement of DHX9. We found that overexpression of DHX9 is frequent in MDS and associated with poor survival and high risk of acute myeloid leukemia (AML) transformation. DHX9 is essential for the maintenance of malignant proliferation of leukemia cells, and DHX9 suppression increases cell apoptosis and causes hypersensitivity to chemotherapeutic agents. Besides, knockdown of DHX9 inactivates the PI3K-AKT and ATR-Chk1 signaling, promotes R-loop accumulation, and R-loop-mediated DNA damage.

A Lower Frequency of Spliceosome Mutations Distinguishes Clonal Cytopenias of Undetermined Significance From Low-Risk Myelodysplastic Syndromes, Despite Inherent Similarities in Genomic, Laboratory, and Clinical Features

Clonal cytopenias of undetermined significance (CCUS) are associated with an increased risk of developing a myelodysplastic syndrome (MDS); however, the mechanism and factors associated with evolution remain unclear. We propose that next-generation sequencing (NGS) of cytopenic cases with equivocal morphologic dysplasia will improve patient clinical care and that serial sequencing of such equivocal cases could identify the factors that predict evolution to MDS. We performed targeted NGS of samples from 193 individuals with confirmed or suspected MDS or MDS/myeloproliferative neoplasm, including sequential investigation for 28 individuals at the time of diagnosis and during follow-up. NGS facilitated the diagnosis of all suspicious cases as myeloid neoplasm (21%), CCUS (34%), or idiopathic cytopenias of undetermined significance (45%) when no variants were detected. We found that there was no significant difference in most measured clinical features or clonal phenotypes, such as cell counts, number of variants, variant allele frequencies, and overall survival, between CCUS and International Prognostic Scoring System-Revised-defined low-risk MDS. However, there was a significant difference in the types of variants between CCUS and low-risk MDS, with a significantly lower number of splicing factor mutations in CCUS cases (P < .001). Moreover, we observed an increased probability of evolution to MDS of individuals with CCUS compared with that in those with idiopathic cytopenias of undetermined significance over the first 5 years (P = .045). Our analyses revealed no conclusive pattern associating clonal expansion or the number of variants with the evolution of CCUS to MDS, perhaps further supporting the similarity of these diseases and the clinical importance of recognizing and formally defining CCUS as a category of precursor myeloid disease state in the next revision of the World Health Organization guidelines.

The Secondary Myelodysplastic Neoplasms (MDS) Jigsaw

There is a great deal of controversy in the hematologic community regarding the classification of secondary myelodysplastic neoplasms (MDSs). Current classifications are based on the presence of genetic predisposition and MDS post-cytotoxic therapy (MDS-pCT) etiologies. However, since these risk factors are not exclusive for secondary MDSs and there are multiple overlapping scenarios, a comprehensive and definitive classification is yet to come. In addition, a sporadic MDS might arise after a primary tumor fulfills the diagnostic criteria of MDS-pCT without a causative cytotoxicity. In this review, we describe the triggering pieces of a secondary MDS jigsaw: previous cytotoxic therapy, germline predisposition and clonal hematopoiesis. Epidemiological and translational efforts are needed to put these pieces together and ascertain the real weight of each of these pieces in each MDS patient. Future classifications must contribute to understanding the role of secondary MDS jigsaw pieces in different concomitant or independent clinical scenarios associated with the primary tumor.

S100a9 deficiency accelerates MDS-associated tumor escape via PD-1/PD-L1 overexpression

In recent studies, the tolerable safety profile and positive bone marrow (BM) response suggest a beneficial use of anti-PD-1 agents in the treatment of Myelodysplastic Syndromes (MDS), but the underlying mechanism is still unknown. MDS is mainly characterized by ineffective hematopoiesis, which may contribute to inflammatory signaling or immune dysfunction. Our previous studies focused on inflammatory signaling, and the results showed that S100a9 expression was higher in low-risk MDS and lower in high-risk MDS. In this study, we combine the inflammatory signaling and immune dysfunction. SKM-1 cells and K562 cells co-cultured with S100a9 acquire apoptotic features. Moreover, we confirm the inhibitory effect of S100a9 on PD-1/PD-L1. Importantly, PD-1/PD-L1 blockade and S100a9 can both activate the PI3K/AKT/mTOR signaling pathway. The cytotoxicity is higher in lower-risk MDS-lymphocytes than in high-risk MDS-lymphocytes, and S100a9 partially rescues the exhausted cytotoxicity in lymphocytes. Our study demonstrates that S100a9 may inhibit MDS-associated tumor escape via PD-1/PD-L1 blockade through PI3K/AKT/mTOR signaling pathway activation. Our findings indicate the possible mechanisms by which anti-PD-1 agents may contribute to the treatment of MDS. These insights may provide mutation-specific treatment as a supplementary therapy for MDS patients with high-risk mutations, such as TP53, N-RAS or other complex mutations.

Clinical application of flow cytometry in patients with unexplained cytopenia and suspected myelodysplastic syndrome: A report of the European LeukemiaNet International MDS-Flow Cytometry Working Group

This article discusses the rationale for inclusion of flow cytometry (FCM) in the diagnostic investigation and evaluation of cytopenias of uncertain origin and suspected myelodysplastic syndromes (MDS) by the European LeukemiaNet international MDS Flow Working Group (ELN iMDS Flow WG). The WHO 2016 classification recognizes that FCM contributes to the diagnosis of MDS and may be useful for prognostication, prediction, and evaluation of response to therapy and follow-up of MDS patients.

Multicenter prospective evaluation of diagnostic potential of flow cytometric aberrancies in myelodysplastic syndromes by the ELN iMDS flow working group

BACKGROUND

Myelodysplastic syndromes (MDS) represent a diagnostic challenge. This prospective multicenter study was conducted to evaluate pre-defined flow cytometric markers in the diagnostic work-up of MDS and chronic myelomonocytic leukemia (CMML).

METHODS

Thousand six hundred and eighty-two patients with suspected MDS/CMML were analyzed by both cytomorphology according to WHO 2016 criteria and flow cytometry according to ELN recommendations. Flow cytometric readout was categorized 'non-MDS' (i.e. no signs of MDS/CMML and limited signs of MDS/CMML) and 'in agreement with MDS' (i.e., in agreement with MDS/CMML).

RESULTS

Flow cytometric readout categorized 60% of patients in agreement with MDS, 28% showed limited signs of MDS and 12% had no signs of MDS. In 81% of cases flow cytometric readouts and cytomorphologic diagnosis correlated. For high-risk MDS, the level of concordance was 92%. A total of 17 immunophenotypic aberrancies were found independently related to MDS/CMML in ≥1 of the subgroups of low-risk MDS, high-risk MDS, CMML. A cut-off of ≥3 of these aberrancies resulted in 80% agreement with cytomorphology (20% cases concordantly negative, 60% positive). Moreover, >3% myeloid progenitor cells were significantly associated with MDS (286/293 such cases, 98%).

CONCLUSION

Data from this prospective multicenter study led to recognition of 17 immunophenotypic markers allowing to identify cases 'in agreement with MDS'. Moreover, data emphasizes the clinical utility of immunophenotyping in MDS diagnostics, given the high concordance between cytomorphology and the flow cytometric readout. Results from the current study challenge the application of the cytomorphologically defined cut-off of 5% blasts for flow cytometry and rather suggest a 3% cut-off for the latter.

Flow cytometric analysis of myelodysplasia: Pre-analytical and technical issues-Recommendations from the European LeukemiaNet

BACKGROUND

Flow cytometry (FCM) aids the diagnosis and prognostic stratification of patients with suspected or confirmed myelodysplastic syndrome (MDS). Over the past few years, significant progress has been made in the FCM field concerning technical issues (including software and hardware) and pre-analytical procedures.

METHODS

Recommendations are made based on the data and expert discussions generated from 13 yearly meetings of the European LeukemiaNet international MDS Flow working group.

RESULTS

We report here on the experiences and recommendations concerning (1) the optimal methods of sample processing and handling, (2) antibody panels and fluorochromes, and (3) current hardware technologies.

CONCLUSIONS

These recommendations will support and facilitate the appropriate application of FCM assays in the diagnostic workup of MDS patients. Further standardization and harmonization will be required to integrate FCM in MDS diagnostic evaluations in daily practice.

Abnormal platelet immunophenotypes and percentage of giant platelets in myelodysplastic syndrome: A pilot study

OBJECTIVES

Myelodysplastic syndrome (MDS) is a heterogeneous hematopoietic stem cell disorder with thrombocytopenia. Flow cytometric immunophenotyping of blood cells has been instrumental in diagnosis as co-criteria, but the data regarding platelets remains lacking. This study aims to determine if there is a difference in surface antigen levels on platelets by comparing surface antigen levels in MDS patients and healthy control subjects. Concurrently, as flow cytometric gating can reveal the diameter of cells, this study will investigate differences in giant platelet percentage by comparing these percentages in high- and low-risk MDS patients.

STUDY DESIGN

Twenty newly diagnosed MDS patients were enrolled in this study. Platelet surface antigen levels were determined by measuring the binding capacity of antibodies with flow cytometry.

RESULTS

Platelets of MDS patients were shown to have a lower level of CD61 and higher levels of CD31 and CD36 than healthy controls. Judged by forward scatter (FSC), MDS patients' platelets appeared to be larger than those of healthy control subjects, whereas the MFI adjusted by diameter (MFI/FSC ratio) of CD31, CD41a, CD42a, CD42b and CD61 on platelets were lower in MDS patients than in healthy control subjects. There was a significant quantity of giant platelets found in MDS patients, and the high-risk MDS patients tended to have a higher percentage of giant platelets than low-risk patients. Conclusions: All the results indicate that MDS patients exhibit a lower antigen presentation (MFI) adjusted by diameter on platelets than healthy controls and the giant platelets detected by flow cytometry might correlate with the condition of MDS.

Myelodysplastic syndromes

Myelodysplastic syndromes (MDS) are a family of myeloid cancers with diverse genotypes and phenotypes characterized by ineffective haematopoiesis and risk of transformation to acute myeloid leukaemia (AML). Some epidemiological data indicate that MDS incidence is increasing in resource-rich regions but this is controversial. Most MDS cases are caused by randomly acquired somatic mutations. In some patients, the phenotype and/or genotype of MDS overlaps with that of bone marrow failure disorders such as aplastic anaemia, paroxysmal nocturnal haemoglobinuria (PNH) and AML. Prognostic systems, such as the revised International Prognostic Scoring System (IPSS-R), provide reasonably accurate predictions of survival at the population level. Therapeutic goals in individuals with lower-risk MDS include improving quality of life and minimizing erythrocyte and platelet transfusions. Therapeutic goals in people with higher-risk MDS include decreasing the risk of AML transformation and prolonging survival. Haematopoietic cell transplantation (HCT) can cure MDS, yet fewer than 10% of affected individuals receive this treatment. However, how, when and in which patients with HCT for MDS should be performed remains controversial, with some studies suggesting HCT is preferred in some individuals with higher-risk MDS. Advances in the understanding of MDS biology offer the prospect of new therapeutic approaches.

The ABNL-MARRO 001 study: a phase 1–2 study of randomly allocated active myeloid target compound combinations in MDS/MPN overlap syndromes

Background

Myelodysplastic/myeloproliferative neoplasms (MDS/MPN) comprise several rare hematologic malignancies with shared concomitant dysplastic and proliferative clinicopathologic features of bone marrow failure and propensity of acute leukemic transformation, and have significant impact on patient quality of life. The only approved disease-modifying therapies for any of the MDS/MPN are DNA methyltransferase inhibitors (DNMTi) for patients with dysplastic CMML, and still, outcomes are generally poor, making this an important area of unmet clinical need. Due to both the rarity and the heterogeneous nature of MDS/MPN, they have been challenging to study in dedicated prospective studies. Thus, refining first-line treatment strategies has been difficult, and optimal salvage treatments following DNMTi failure have also not been rigorously studied. ABNL-MARRO (A Basket study of Novel therapy for untreated MDS/MPN and Relapsed/Refractory Overlap Syndromes) is an international cooperation that leverages the expertise of the MDS/MPN International Working Group (IWG) and provides the framework for collaborative studies to advance treatment of MDS/MPN and to explore clinical and pathologic markers of disease severity, prognosis, and treatment response.

Methods

ABNL MARRO 001 (AM-001) is an open label, randomly allocated phase 1/2 study that will test novel treatment combinations in MDS/MPNs, beginning with the novel targeted agent itacitinib, a selective JAK1 inhibitor, combined with ASTX727, a fixed dose oral combination of the DNMTi decitabine and the cytidine deaminase inhibitor cedazuridine to improve decitabine bioavailability.

Discussion

Beyond the primary objectives of the study to evaluate the safety and efficacy of novel treatment combinations in MDS/MPN, the study will (i) Establish the ABNL MARRO infrastructure for future prospective studies, (ii) Forge innovative scientific research that will improve our understanding of pathogenetic mechanisms of disease, and (iii) Inform the clinical application of diagnostic criteria, risk stratification and prognostication tools, as well as response assessments in this heterogeneous patient population.

Trial registration

This trial was registered with ClinicalTrials.gov on August 19, 2019 (Registration No. NCT04061421).

Abnormal CD13/HLA-DR Expression Pattern on Myeloblasts Predicts Development of Myeloid Neoplasia in Patients With Clonal Cytopenia of Undetermined Significance

OBJECTIVES

Patients with clonal cytopenia of undetermined significance (CCUS) are at increased risk of developing myeloid neoplasia (MN). We evaluated whether a simple flow cytometry immunophenotyping (FCIP) assay could differentiate the risk of development of MN in patients with CCUS.

METHODS

Bone marrow aspirates were assessed by FCIP panel in a cohort of 80 patients identified as having CCUS based on next-generation sequencing or cytogenetics from March 2015 to May 2020, with available samples. Flow cytometric assay included CD13/HLA-DR expression pattern on CD34-positive myeloblasts; CD13/CD16 pattern on maturing granulocytic precursors; and aberrant expression of CD2, CD7, or CD56 on CD34-positive myeloblasts. Relevant demographic, comorbidity, and clinical and laboratory data, including the type and extent of genetic abnormalities, were extracted from the electronic health record.

RESULTS

In total, 17 (21%) patients with CCUS developed MN over the follow-up period (median survival follow-up, 28 months [95% confidence interval, 19-31]). Flow cytometry immunophenotyping abnormalities, including the aberrant pattern of CD13/HLA-DR expression, as detected at the time of the diagnosis of CCUS, were significantly associated with risk of developing MN (hazard ratio, 2.97; P = .006). Additional FCIP parameters associated with the development of MN included abnormal expression of CD7 on myeloblasts and the presence vs absence of any FCIP abnormality.

CONCLUSIONS

A simple FCIP approach that includes assessment of CD13/HLA-DR pattern on CD34-positive myeloblasts can be useful in identifying patients with CCUS at higher risk of developing MN.

Myelodysplastic Syndrome: Diagnosis and Screening

Myelodysplastic syndromes (MDS) are heterogeneous groups of clonal myeloid disorders characterized by unexplained persistent peripheral blood (PB) cytopenia(s) of one or more of the hematopoietic lineages, or bone marrow (BM) morphologic dysplasia in hematopoietic cells, recurrent genetic abnormalities, and an increased risk of progression to acute myeloid leukemia (AML). In the past several years, diagnostic, prognostic, and therapeutic approaches have substantially improved with the development of Next Generation Sequencing (NGS) diagnostic testing and new medications. However, there is no single diagnostic parameter specific for MDS, and correlations with clinical information, and laboratory test findings are needed to reach the diagnosis.

Clonal hematopoiesis of indeterminate potential in patients with acute coronary syndrome undergoing percutaneous coronary intervention in the absence of traditional risk factors

AIMS

To investigate the frequency of clonal hematopoiesis of indeterminate potential (CHIP) and evaluate its impacts on outcomes in patients with acute coronary syndrome (ACS) undergoing percutaneous coronary intervention (PCI) in the absence of traditional cardiovascular risk factors (CVRFs).

METHODS

Whole-exome sequencing was performed to detect the presence of CHIP in 183 patients underwent PCI for the treatment of ACS. The association between CHIP-related mutations and major adverse cardiac or cerebral events (MACCEs, a composite of all-cause mortality, coronary revascularization, myocardial infarction, or stroke) was analyzed in such cohort.

RESULTS

Of 179 patients [median age, 65 years; 84 female (46.9%)] included in this analysis, CHIP-related mutations were detected in 36 (20.1%) patients. The somatic mutations most frequently occurred in the genes DNMT3A (17 mutations), TET2 (6 mutations), and ASXL1 (4 mutations). Clinical outcomes at median 635 follow-up days showed that DNMT3A/TET2/ASXL1-CHIP mutations were associated with significantly higher risk of MACCEs, compared with non-CHIP carriers in the CVRFs-absent ACS cohort (26.1% vs. 4.2%, log-rank P = 0.001). Multivariable regression showed that DNMT3A/TET2/ASXL1-CHIP driver mutations (HR 4.015; 95% CI 1.236-13.046; P = 0.021) were independent predictors of adverse clinical outcomes.

CONCLUSION

The most frequent CHIP-related mutations, DNMT3A, TET2, and ASXL1 are significantly associated with increased risk of recurrent cardiovascular events. Our study may be valuable target to reduce residual risk in patients with ACS carrying specific mutations.

Clinical implications and genetic features of clonal cytopenia of undetermined significance compared to lower-risk myelodysplastic syndrome

Clonal cytopenia of undetermined significance (CCUS) is characterized by persistent cytopenias with genetic aberrations, which do not meet the diagnostic criteria for myelodysplastic syndrome (MDS). We aimed to compare the clinical and genetic characteristics of CCUS with lower-risk MDS and identify patients with CCUS with a high risk of progression. We performed targeted sequencing of bone marrow (BM) samples from patients with idiopathic cytopenia of undetermined significance (ICUS) (n = 139) and MDS (n = 226). Overall survival (OS) of patients with CCUS (n = 78) was worse than non-clonal ICUS (n = 61) and superior to lower-risk MDS (n = 99). Patients with CCUS showed similar characteristics to those with lower-risk MDS, except for higher haemoglobin, lower BM cellularity, and less frequent SF3B1 mutations. Lower haemoglobin, DDX41 (biallelic germline and somatic), ETV6, and RUNX1 mutations were independent prognostic factors for worse OS. Lower haemoglobin and DDX41 mutations were also associated with lower progression-free survival. Patients with CCUS with high-risk features showed similar or worse OS than patients with lower-risk MDS. Our findings suggest that patients with CCUS having certain clinical or genetic features should be regarded and treated as lower-risk MDS despite lacking significant dysplasia or MDS-associated chromosomal abnormalities.

Ferritin Light Chain: A Candidate Autoantigen in Immuno-Related Pancytopenia

The characteristic feature of immune-related pancytopenia (IRP) is autoantibody-mediated bone marrow (BM) damage and peripheral blood cytopenia. We found that the potential antigen of IRP was Ferritin light chain (FTL) by SEREX (serological analysis of recombinant cDNA expression libraries) in the previous study. In this study, we tried to explore the antigenic epitopes of FTL and verify its antigenicity in IRP. We found the possible FTL epitope: VNLYLQASYTYLSLG by phage random peptide library. Through ELISPOT, it was found that peptide VNLYLQASYTYLSLG can significantly stimulate the production of interleukin-4 and cannot stimulate the production of interferon-γ, which suggested that the peptide can obviously activate Th2 cells. Peptide-major histocompatibility complex tetramer elicited antigen-specific T cell responses. The expression levels of FTL were significantly increased in the patients with untreated IRP (P < 0.05). In conclusion, we found that FTL is the target antigen for some patients with IRP. The peptide of VNLYLQASYTYLSLG is an epitope of the target antigen. The target antigen is abnormally overexpressed on the membrane of BM cells, especially on the surface of CD34+ BM cells of patients with IRP. In addition, it is related to the severity of disease. These results provide a possible new target for the treatment of IRP in the future.

A predictive model for bone marrow disease in cytopenia based on noninvasive procedures

Bone marrow specimens are the core of the diagnostic work-up of patients with cytopenia. To explore whether next-generation sequencing (NGS) could be used to rule out malignancy without bone marrow specimens, we incorporated NGS in a model to predict presence of disease in the bone marrow of patients with unexplained cytopenia. We analyzed the occurrence of mutations in 508 patients with cytopenia, referred for primary work-up of a suspected hematological malignancy from 2015-2020. We divided patients into a discovery (n = 340) and validation (n = 168) cohort. Targeted sequencing, bone marrow biopsy and complete blood count were performed in all patients. Mutations were identified in 267 (53%) and abnormal bone marrow morphology in 188 (37%) patients. Patients with isolated neutropenia had the lowest frequency of both mutations (21%) and abnormal bone marrow morphology (5%). The median number of mutations per patient was two in patients with abnormal bone marrow morphology, compared to zero in patients with a non-diagnostic bone marrow (P &lt; 0.001). In a multivariable logistic regression, mutations in TET2, SF3B1, U2AF1, TP53 and RUNX1 were significantly associated with abnormal bone marrow morphology. In the validation cohort, a model combining mutational status and clinical data identified 34 patients (20%) without abnormal bone marrow morphology with a sensitivity of 100% (95%-CI: 93%-100%). Overall, we show that NGS combined with clinical data can predict the presence of abnormal bone marrow morphology in patients with unexplained cytopenia and thus can be used to assess the need of a bone marrow biopsy.

Clonal hematopoiesis, myeloid disorders and BAX-mutated myelopoiesis in patients receiving venetoclax for CLL

The BCL2 inhibitor venetoclax has established therapeutic roles in chronic lymphocytic leukemia (CLL) and acute myeloid leukemia (AML). As BCL2 is an important determinant of survival of both myeloid progenitor and B cells, we investigated whether clinical and molecular abnormalities arise in the myeloid compartment during long-term continuous venetoclax treatment of CLL in 89 patients (87 with relapsed/refractory CLL). Over a median follow-up of 75 (range 21-98) months, persistent cytopenias (≥1 of neutropenia, thrombocytopenia, anemia) lasting ≥4 months and unrelated to CLL occurred in 25 patients (28%). Of these patients, 20 (80%) displayed clonal hematopoiesis, including 10 with therapy-related myeloid neoplasms (t-MNs). t-MNs occurred exclusively in patients previously exposed to fludarabine-alkylator combination therapy with a cumulative 5-year incidence of 10.4% after venetoclax initiation, consistent with rates reported for patients exposed to fludarabine-alkylator combination therapy without venetoclax. To determine whether the altered myelopoiesis reflected the acquisition of mutations, we analyzed samples from patients with no or minimal bone marrow CLL burden (n = 41). Mutations in the apoptosis effector BAX were identified in 32% (13/41). In cellular assays, C-terminal BAX mutants abrogated outer mitochondrial membrane localization of BAX and engendered resistance to venetoclax killing. BAX-mutated clonal hematopoiesis occurred independently of prior fludarabine-alkylator combination therapy exposure and was not associated with t-MNs. Single-cell sequencing revealed clonal co-occurrence of mutations in BAX with DNMT3A or ASXL1. We also observed simultaneous BCL2 mutations within CLL cells and BAX mutations in the myeloid compartment of the same patients, indicating lineage-specific adaptation to venetoclax therapy.

When are idiopathic and clonal cytopenias of unknown significance (ICUS or CCUS)?

Rapid advances in sequencing technology have led to the identification of somatic mutations that predispose a significant subset of the aging population to myeloid malignancies. Recently recognized myeloid precursor conditions include clonal hematopoiesis of indeterminate potential (CHIP) and clonal cytopenia of unknown significance (CCUS). These conditions can present diagnostic challenges and produce unwarranted anxiety in some instances. While the risk of progression to myeloid malignancies is very low in CHIP, true CCUS confers an exponential increase in risk. Idiopathic cytopenia of unknown significance (IDUS) lacks the predisposing genetic mutations and has a variable course. In this review we define the early myeloid precursor conditions and their risk of progression. We present our diagnostic approach to patients with unexplained cytopenias and discuss the clinical consequences of CHIP and CCUS.

A comprehensive analysis of cytopenias and bone marrow morphology in patients with a history of bariatric and metabolic surgery

INTRODUCTION

Following bariatric and metabolic surgery (BMS), patients may develop persistent cytopenia(s) despite adequate micronutrient levels. A comprehensive analysis of laboratory and hematopathologic findings in BMS patients with unexplained cytopenia(s) has not been previously described.

METHODS

We reviewed the clinical and laboratory data, bone marrow histology, and used ancillary testing to characterize patients with a history of BMS who had subsequent bone marrow biopsies due to unexplained cytopenia(s).

RESULTS

All patients had anemia and 59% (23/39) had additional cytopenias. Myelodysplastic syndrome (MDS) and clonal cytopenia of unknown significance (CCUS) were diagnosed in 8% (3/39) and 10% (4/39), respectively. Remaining cases were classified as idiopathic cytopenia of unknown significance (ICUS) with anemia alone (ICUS-A) in 47% (15/32) or multiple cytopenias (ICUS-PAN) in 53% (17/32). Time since surgery, age, or amount of weight loss was not associated with a specific diagnosis. No patient was vitamin B12 or folate deficient. However, vitamin B6 and zinc were decreased in 47% (5/11) and 29% (9/29), respectively. Examination of bone marrow aspirates revealed slight erythroid dyspoiesis affecting <10% of precursors in 60% (9/15) ICUS-A and 59% (10/17) ICUS-PAN.

CONCLUSION

Bone marrow findings in patients with unexplained cytopenia(s) after BMS are not specific in the majority of cases, and caution is advised when interpreting dyserythropoiesis. Levels of micronutrients and vitamins other than iron, folate and vitamin B12 are frequently disturbed in this patient cohort and warrant correction and close clinical follow-up.

Peripheral blood cytopenias in the aging general population and risk of incident hematological disease and mortality

Peripheral blood cytopenias may precede the development of hematological malignancies and frequently pose clinical challenges in the older population. The natural course of (mild) cytopenias during aging and their association with hematological disorders in community-dwelling individuals are not well studied. Within the population-based Lifelines cohort (n = 167729), we studied changes in peripheral blood counts, occurrence of cytopenias, and associated hematological outcomes in the context of aging. Development of hematological malignancies and (cause-specific) mortality were evaluated by linkage to nationwide registries. Anemia and thrombocytopenia emerged with older age, in line with a general age-related decline in these blood counts. For neutropenia, no increase in prevalence with older age was observed. Using standard reference limits to define cytopenias, anemia (hazard ratio [HR], 1.84; 95% confidence interval [CI], 1.59-2.12), thrombocytopenia (HR, 1.58; 95% CI, 1.32-1.89), and, especially the concomitant presence of anemia and thrombocytopenia (HR, 4.75; 95% CI, 2.98-7.55) were associated with inferior overall survival. Only a minor proportion of deaths was explained by diagnosed hematological malignancies, with the majority attributable to other causes. Neutropenia, either isolated (HR, 0.88; 95% CI, 0.73-1.06) or combined with another cytopenia, did not affect overall survival. For individuals aged ≥60 years, 5-year cumulative incidence of hematological malignancies was 0.60% (95% CI, 0.50-0.70), with higher incidences among those with anemia (P < .001) or thrombocytopenia (P < .001) but not neutropenia (P = .201). Highest cumulative incidences of diagnoses and mortality from hematological malignancies were observed in individuals with >1 cytopenia. We conclude that anemia and thrombocytopenia, but not neutropenia, are associated with inferior overall survival of community-dwelling individuals. Hematological malignancies develop in a small fraction of these cases.

Clonal hematopoiesis and myeloid malignancies: clonal dynamics and clinical implications

PURPOSE OF REVIEW

Clinical and experimental studies have uncovered relevant clinical implications of clonal hematopoiesis. However, the true magnitude of this process, clonal dynamics over time and mechanisms of progression into overt malignancy remain to be largely elucidated. In this article, the consequences of clonal hematopoiesis, its significance in the context of cytopenia, and its implications in the clinical management of patients with myeloid malignancies are reviewed and discussed.

RECENT FINDINGS

Clonal hematopoiesis has been associated with higher risk of hematologic cancers, as well as of death from cardiovascular causes. Clonal hematopoiesis has been proven clinically relevant in the context of disorders characterized by peripheral blood cytopenia, including aplastic anemia, cytopenia of undetermined significance, as well as unexplained anemia of the elderly.

SUMMARY

The available evidence has been proving the utility of somatic mutational analysis in patients with unexplained cytopenia, as well as in those receiving a diagnosis of myeloid neoplasm, enabling more accurate diagnosis, risk assessment, effective therapeutic strategies and residual disease monitoring. The access to a minimally invasive assessment is paving the way for screening programs of clonal hematopoiesis in individuals with absent or mild hematologic phenotype, as well as for therapeutic targeting of preleukemia cells.

Myelodysplastic syndrome and immunotherapy novel to next in-line treatments

Patients with Myelodysplastic syndromes (MDS) have few therapy options for sustainable responses in the frontline setting, and even less after hypomethylating agent (HMA) failure in relapsed and refractory setting. The only potential cure is an allogeneic hematopoietic stem cell transplant which is an unrealistic option for the majority of MDS patients. Immunotherapy with checkpoint inhibition, CAR-T cells, and vaccine therapy few have shown promise in a variety cancer and have now been tested in patients with MDS. Most trials have focused on AML patients and included small numbers of MDS patients. Until now, a dedicated review of immunotherapy outcomes in MDS patients has been lacking. Thus, herein we review outcomes of MDS patients after immunotherapies on a variety of clinical trials reported to date.

The utility of a single tube 10-color flow cytometry for quantitative and qualitative analysis in myelodysplastic syndrome- a pilot study

INTRODUCTION

Assessment of myelodysplasia (MDS) by flow cytometry (FCM) includes elaborate panels, and interpretation is observer-dependent. This study evaluates single tube 10-color FCM in a test cohort of clinically suspected MDS patients.

METHODS

We analyzed fifty-six bone marrow (BM) samples from clinically suspected MDS patients in a morphology-blinded manner along with controls using a 10-color single tube flow cytometry. We analyzed the reproducibility of Ogata score and modified FCM scores, additionally incorporating the proportion of CD15, CD11b, CD56, and CD38MFI on CD34+CD19-cluster for each patient. Patients were grouped as proven-MDS, suspected-MDS, and non-MDS groups based on morphology and cytogenetics. Optimized multi-axial radar-plots were also used to analyze maturation patterns in the granulocytic, monocytic, and blast progenitor compartments of proven-MDS cases and controls.

RESULTS

Flow cytometric abnormalities ≥3 were present in proven-MDS (n = 23) with a sensitivity and specificity of 78 % and 94 %, respectively, as per Ogata score. The addition of CD38 MFI to the score yielded sensitivity and specificity of 82 % and 88 %, respectively. Additional analysis of aberrant expression of CD15, CD11b, and CD56 increased the diagnostic power of the FCM score. A qualitative analysis of data also showed differences in maturation patterns in proven-MDS compared to the control group.

CONCLUSION

Single tube 10-color FCM scoring, including Ogata score, modified-FCM scores, and radar plots pattern analysis, showed significant abnormalities in proven-MDS cases in this pilot study. Large databases, including FCM-scoring and pattern-based analysis for normal BM maturation, could be further validated and standardized for screening MDS.

U2AF1 mutation promotes tumorigenicity through facilitating autophagy flux mediated by FOXO3a activation in myelodysplastic syndromes

Mutations in the U2 small nuclear RNA auxiliary factor 1 (U2AF1) gene are the common feature of a major subset in myelodysplastic syndromes (MDS). However, the genetic landscape and molecular pathogenesis of oncogenic U2AF1^S34F mutation in MDS are not totally understood. We performed comprehensive analysis for prognostic significance of U2AF1 mutations in acute myeloid leukemia (AML) cohort based on The Cancer Genome Atlas (TCGA) database. Functional analysis of U2AF1^S34F mutation was performed in vitro. Differentially expressed genes (DEGs) and significantly enriched pathways were identified by RNA sequencing. The forkhead box protein O3a (FOXO3a) was investigated to mediate the function of U2AF1^S34F mutation in cell models using lentivirus. Chromatin immunoprecipitation, immunoblotting analyses, and immunofluorescence assays were also conducted. U2AF1 mutations were associated with poor prognosis in MDS and AML samples, which significantly inhibited cell proliferation and induced cellular apoptosis in cell models. Our data identified that U2AF1-mutant cell lines undergo FOXO3a-dependent apoptosis and NLRP3 inflammasome activation, which induces pyroptotic cell death. Particularly, an increase in the level of FOXO3a promoted the progression of MDS in association with restored autophagy program leading to NLRP3 inflammasome activation in response to U2AF1^S34F mutation. Based on the result that U2AF1^S34F mutation promoted the transcriptional activity of Bim through upregulating FOXO3a with transactivation of cell cycle regulators p21^Cip1 and p27^Kip1, FOXO3a, a potentially cancer-associated transcription factor, was identified as the key molecule on which these pathways converge. Overall, our studies provide new insights that U2AF1^S34F mutation functions the crucial roles in mediating MDS disease progression via FOXO3a activation, and demonstrate novel targets of U2AF1 mutations to the pathogenesis of MDS.

Incidence and Prognosis of Clonal Hematopoiesis in patients with Chronic Idiopathic Neutropenia

The incidence and prognosis of clonal hematopoiesis in patients with isolated neutropenia among patients with idiopathic cytopenia of undetermined significance (ICUS), known as ICUS-N or chronic idiopathic neutropenia (CIN) patients, is poorly defined. In the present study we sought to investigate the frequency and clinical significance of mutations of genes implicated in myeloid malignancies using next generation sequencing, in CIN patients (n=185) with a long follow-up. We found that 21/185 patients (11.35%) carried totally 25 somatic mutations in 6 genes with median variant allele frequency (VAF) 12.75%. The most frequently mutated genes were DNMT3A and TET2 involving more than 80% of patients followed by IDH1/2, SRSF2 and ZRSR2. The frequency of transformation to a myeloid malignancy was low in the total group of patients (5/185 patients; 2.70%). However, from the transformed patients four belonged to the clonal (4/21; 19.05%) and one to the non-clonal (1/164; 0.61%) group, indicating that the presence of mutation(s) confers a relative risk for transformation 31.24 (P = 0.0017). The VAF of the mutant clones in the transformed patients was higher than 10% in all cases and the genes most frequently associated with malignant transformation were the SRSF2 and IDH1. No significant differences were identified between clonal and non-clonal groups in the severity of neutropenia. Patients with clonal disease were older compared to non-clonal patients. These data contribute to the better understanding of the heterogeneous entities underlying ICUS and highlight the importance of the mutation analysis for the diagnosis and prognosis of patients with unexplained neutropenias.

Novel spontaneous myelodysplastic syndrome mouse model

Background

Myelodysplastic syndrome (MDS) is a group of disorders involving hemopoietic dysfunction leading to leukemia. Although recently progress has been made in identifying underlying genetic mutations, many questions still remain. Animal models of MDS have been produced by introduction of specific mutations. However, there is no spontaneous mouse model of MDS, and an animal model to simulate natural MDS pathogenesis is urgently needed.

Methods

In characterizing the genetically diverse mouse strains of the Collaborative Cross (CC) we observed that one, designated JUN, had abnormal hematological traits. This strain was thus further analyzed for phenotypic and pathological identification, comparing the changes in each cell population in peripheral blood and in bone marrow.

Results

In a specific-pathogen free environment, mice of the JUN strain are relatively thin, with healthy appearance. However, in a conventional environment, they become lethargic, develop wrinkled yellow hair, have loose and light stools, and are prone to infections. We found that the mice were cytopenic, which was due to abnormal differentiation of multipotent bone marrow progenitor cells. These are common characteristics of MDS.

Conclusions

A mouse strain, JUN, was found displaying spontaneous myelodysplastic syndrome. This strain has the advantage over existing models in that it develops MDS spontaneously and is more similar to human MDS than genetically modified mouse models. JUN mice will be an important tool for pathogenesis research of MDS and for evaluation of new drugs and treatments.

Genetic Heterogeneity in Chronic Myeloid Leukemia: How Clonal Hematopoiesis and Clonal Evolution May Influence Prognosis, Treatment Outcome, and Risk of Cardiovascular Events

Chronic myeloid leukemia (CML) has long been considered as a model of cancer caused by a single-driver genetic lesion (BCR/ABL1 rearrangement) that codes for a unique, gain-of-function, deregulated protein. However, in the last decade, high-throughput sequencing technologies have shed light on a more complex genetic landscape, in which additional mutations may be found in different disease phases, including diagnosis. These genetic lesions may even precede the occurrence of the Philadelphia (Ph) chromosome, pointing to an antecedent premalignant state of clonal hematopoiesis (CH) at least in some patients. Preliminary data support the hypothesis that the most frequent CH-associated mutations (DNMT3A, TET2, and ASXL1) may be associated with a risk of vascular event, but a definitive answer for this topic is still lacking. Moreover, several recent studies have linked a much more complex genetic background in chronic-phase CML, including signs of clonal evolution over time, with depth of treatment responses or with patient survival. In the present review, we address the current state of the art on age-related CH, its association with cardiovascular risk, and its pathophysiology; review the current knowledge on CH that precedes the acquisition of the Ph chromosome in CML patients; and discuss available evidence on the prognostic and predictive value of additional mutations in chronic-phase CML, either as a sign of clonal dynamics under treatment or as markers of an antecedent CH.

Expression of mRNA TNFα and level of protein TNFα after exposure sCD40L in bone marrow mononuclear cells of myelodysplastic syndromes

Background

Cytopenia is the primary phenomenon in myelodysplastic syndrome (MDS) amidst hypercellular bone marrow. The soluble CD40 ligand (sCD40L) is considered as a cytokine that can trigger synthesis of tumor necrosis factor α (TNFα) that promotes apoptosis. The objective of this study is to prove that recombinant human sCD40L (rh-sCD40L) exposure on bone marrow mononuclear cells (BMMC) MDS increases TNFα expression at mRNA level and at protein level.

Methods

BMMC from MDS patients whom diagnosed and classified using the WHO 2008 criteria, were exposed to rh-sCD40L and antiCD40L. The expressions of TNFα mRNAs were quantified by qRT-PCR, level of TNFα were measured using the ELISA method.

Results

Exposure of rh-sCD40L significantly increased the expression of TNFα mRNA. The similar exposure also significantly increased the level of TNFα compared to controls. TNFα mRNA expression on BMMC in MDS samples exposed to rh-sCD40L is 3.32 times compared to TNFα mRNA expression without exposure. level of TNFα in supernatant media exposed to rh-sCD40L in MDS samples was higher than that of control samples which were 44.44 and 4.85 pg/mL, P=0.018.

Conclusions

The sCD40L plays a role in increasing the synthesis of TNFα in mRNA level and protein level in BMMC MDS.

AHR signaling pathway reshapes the metabolism of AML/MDS cells and potentially leads to cytarabine resistance

Emerging evidence suggests that aryl hydrocarbon receptor (AHR) promotes the initiation, invasion, progression, and metastasis of cancer cells. However, its effects in patients with myelodysplastic syndrome/acute myeloid leukemia (MDS/AML) remain undefined. In this study, we aimed to investigate the effects of AHR activation on malignant cells in patients with MDS/AML. We found that AHR was expressed aberrantly in patients with MDS/AML. Further studies demonstrated that inhibiting AHR decreased the mitochondrial dehydrogenase content and the mitochondrial membrane potential (MMP) in MDS/AML cells. Activating AHR with L-kynurenine (Kyn) increased AHR expression, which was accompanied by an increase in mitochondrial dehydrogenase content and MMP in MDS/AML cells. Moreover, the expression level of mitochondria-associated mitochondrial transcription factor A was increased after activating AHR with L-Kyn when compared with that in the control group but decreased after inhibiting the AHR signal. Activating AHR in MDS/AML cells enhanced the resistance to cytarabine. These findings indicated that activating the AHR signaling pathway reshaped the metabolism in MDS/AML cells, thus contributing to the resistance to cytarabine.

Diagnosis and prognosis are supported by integrated assessment of next-generation sequencing in chronic myeloid malignancies. A real-life study

Next-generation sequencing (NGS) is used to investigate the presence of somatic mutations. The utility of incorporating routine sequencing to guide diagnosis and therapeutic decisions remains unclear. We report the findings of an observational, multicenter study that aimed to assess the impact of somatic mutation testing by NGS in a reallife setting of chronic myeloid malignancies. A total of 177 patients were enrolled, partitioned into two overlapping groups. In group A (n=94), the indication was to search for clonal hematopoiesis, in a context of suspected myelodysplastic syndrome or myeloproliferative neoplasia. In group B (n=95), the theranostic impact of somatic mutations was studied. A panel of 34 genes was used on DNA extracted from blood or bone marrow samples. Within group A, the detection of clonal hematopoiesis supported the diagnosis of chronic myeloid malignancies for 31 patients while the absence of clonal hematopoiesis ruled out the suspected diagnosis in 47 patients. Within group B, NGS identified prognostically relevant somatic mutations in 32 patients, which had a therapeutic impact in 18 cases. By determining the presence or absence of somatic mutations, the application of NGS in daily practice was found to be useful for an integrated final diagnosis in 83% of the patients. Moreover, the search for somatic mutations had a prognostic impact that led to treatment modification in 19% of the cases. This study outlines the fact that adequate implementation of new investigations may have a significant positive medico-economic impact by enabling appropriate management of patients.

Unique ethnic features of DDX41 mutations in patients with idiopathic cytopenia of undetermined significance, myelodysplastic syndrome, or acute myeloid leukemia

DDX41 mutations are associated with hematologic malignancies including myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML), but the incidence in idiopathic cytopenia of undetermined significance (ICUS) is unknown. We investigated the incidence, genetic characteristics, and clinical features of DDX41 mutations in Korean patients with ICUS, MDS, or AML. We performed targeted deep sequencing of 61 genes including DDX41 in 457 patients with ICUS (n=75), MDS (n=210), or AML (n=172). The germline DDX41 mutations with causality were identified in 28 (6.1%) patients, of whom 27 (96.4%) had somatic mutations in the other position of DDX41. Germline origins of the DDX41 mutations were confirmed in all of the 11 patients who performed germline-based testing. Of the germline DDX41 mutations, p.V152G (n=10) was most common, followed by p.Y259C (n=8), p.A500fs (n=6), and p.E7* (n=3). Compared with non-mutated patients, DDX41-mutated patients showed male predominance, old age, normal karyotype, low leukocyte count, and hypocellular marrow at diagnosis. Three of the 4 ICUS patients with germline DDX41 mutations progressed to MDS. DDX41 mutations in Korean patients showed a high incidence and distinct mutation patterns, in that p.V152G was a unique germline variant. ICUS harboring germline DDX41 mutations may be regarded as a hereditary myeloid neoplasm. Germline DDX41 mutations are not uncommon and should be explored when treating the patients with myeloid malignancies.

The diagnostic and prognostic significance of flow cytometric bone marrow assessment in myelodysplastic syndromes according to the European LeukemiaNet recommendations in single-centre real-life experience

INTRODUCTION

This analysis attempts to determine the diagnostic and prognostic value of bone marrow (BM) evaluation by multiparameter flow cytometry in patients with myelodysplastic syndrome (MDS).

MATERIALS AND METHODS

The study group consisted of patients who underwent diagnostic process in the years 2008-2017 due to cytopenia and finally were diagnosed with MDS (n = 71). The comparative group included patients with cytopenia diagnosed in the same period, whose definitive diagnosis was other than MDS (n = 39). Flow cytometric evaluation of BM was performed following the recommendations of the European LeukemiaNet (ELN) in all patients.

RESULTS

The median number of immunophenotypic abnormalities found on granulocytes in the MDS group was significantly higher compared to the comparative group [2 (range 0-5) vs 0 (range 0-2); P < .0001]. Similarly, the median Ogata score was significantly higher in the MDS group [2 (range 0-4) vs 1 (range 0-3); P < .0001]. Since the disturbances of the CD11b/HLA-DR and CD11b/CD13 on granulocytes were significantly more common in MDS patients, the Ogata score was extended by these abnormalities, what resulted in its higher diagnostic sensitivity (82%) while preserving high specificity (87%). The positive correlation was found between risk score determined by the Revised International Prognostic Scoring System and the number of the BM immunophenotypic abnormalities (P = .017).

CONCLUSIONS

Our results indicate that the diagnostic usefulness of the Ogata score may be increased by including the abnormal expression of CD11b/HLA-DR and CD11b/CD13 on granulocytes. Moreover, our findings suggest the prognostic significance of the number of BM cytometric abnormalities in MDS.

From Clonal Hematopoiesis to Therapy-Related Myeloid Neoplasms: The Silent Way of Cancer Progression

Simple Summary

In the last decades the improved management of cancer patients and the overall prolonged life expectancy contributed to the increased number of patients at risk of late clonal events such as therapy-related myeloid neoplasms (t-MN). The discovery of clonal hematopoiesis of indeterminate potential (CHIP) in normal individuals has shed light on the pathophysiologic mechanism behind the process of myeloid evolution, defining CHIP carriers at higher risk of progression. Moreover, different patterns of clonal evolution have been identified in case of t-MN development after anti-cancer treatment exposure. The growing body of evidence in this field allowed the creation of dedicated cancer survivorship programs and “CHIP-Clinics” in order to specifically address the issue of CHIP in patients undergoing anti-cancer treatment and develop measure of early detection possibly guiding tumor surveillance.

Abstract

Clonal hematopoiesis (CH) has been recognized as a predisposing factor for the development of myeloid malignancies. Its detection has been reported at different frequencies across studies, based on the type of genome scanning approach used and the population studied, but the latest insights recognize its virtual ubiquitous presence in older individuals. The discovery of CH in recent years paved the way for a shift in the paradigm of our understanding of the biology of therapy-related myeloid malignancies (t-MNs). Indeed, we moved from the concept of a treatment-induced lesion to a model where CH precedes the commencement of any cancer-related treatment in patients who subsequently develop a t-MN. Invariant patterns of genes seem to contribute to the arising of t-MN cases, with differences regarding the type of treatment received. Here, we review the principal studies concerning CH, the relationship with myeloid progression and the mechanisms of secondary t-MN development.

Identification of latent core genes and pathways associated with myelodysplastic syndromes based on integrated bioinformatics analysis

Background: Myelodysplastic syndromes (MDS) are relatively common hematological malignancies characterized by dysplastic hematopoiesis in one or more of the lineages of the bone marrow. This study aimed to identify critical pathogenic biomarkers associated with the carcinogenesis and progression of MDS. Methods: To explore the candidate genes, the expression profiles of GSE2779, GSE4619, and GSE19429 were downloaded from the Gene Expression Omnibus (GEO) database, which contained CD34+ cells isolated from MDS patients and normal controls. The three microarray datasets were integrated to obtain differentially expressed genes (DEGs) and were deeply analyzed by bioinformatics methods. The construction of protein-protein interaction (PPI) network together with module analysis was performed based on Cytoscape software and the Search Tool for the Retrieval of Interacting Genes (STRING) database. Results: Our study identified 114 DEGs, which were highly enriched in various key pathways, including forkhead box protein O (FoxO) signaling pathway, the primary immunodeficiency, and hematopoietic cell lineage. Twelve core genes, such as FOXO1, PAX5 and CXCR4 were identified with a high degree of connectivity. It is plausible that FoxO signaling pathway plays an important role in MDS, and the dysregulation of FOXO1 was significantly associated with TGFβ, IL2/STAT5, Notch signaling and apoptosis pathways. Conclusion: The current study for the first time identified twelve latent indicators and their downstream targets, which might become significant biomarkers for worse clinical characteristics in MDS.

Human hematopoiesis: aging and leukemogenic risk

PURPOSE OF REVIEW

Our understanding of the effects of aging on human hematopoiesis has advanced significantly in recent years, yet the full ramifications of these findings are not fully understood. This review summarizes these findings and discusses their implication as they relate to malignant hematopoiesis.

RECENT FINDINGS

With human aging there is an impaired immune response, loss of hematopoietic stem cell (HSC) function, increase in clonal hematopoiesis, and higher frequency of myeloid malignancies. Although murine models have implicated abnormalities in DNA damage repair, autophagy, metabolism, and epigenetics, studies in primary human specimens are more limited. The development of age-related clonal hematopoiesis and the risk associated with this is one of the major findings in the field of recent years. This is accompanied by changes in bone marrow stem and progenitor composition, changes in the epigenetic program of stem cells and an inflammatory milieu in the bone marrow. The precise consequences of these changes for the development of age-related malignancies are still unclear.

SUMMARY

Advances in the field have begun to reveal the mechanisms driving human HSC loss of function with age. It will be critical to delineate between normal and malignant aging in order to better prevent age-associated myeloid malignancies.

Cytogenetic characteristics of 665 patients with myelodysplastic syndrome in China: A single-center report

The karyotype is highly important for diagnosis and prognosis in myelodysplastic syndrome (MDS). The objective of the present study was to investigate the cytogenetic characteristics of patients with MDS in China. The karyotypes of 665 Chinese patients with MDS were analyzed, and it was identified that 298 cases (298/665, 44.8%) had abnormal karyotypes. Among the 298 patients with abnormal karyotypes, the 75 patients with trisomy 8 (+8) constituted the most common subset (75/298, 25.2%). The incidence of abnormal karyotypes was significantly higher in patients who were ≥51 years old compared with those <51 years old, (54.8 vs. 34.7%, respectively; P<0.05). Based on World Health Organization (WHO) classification-based Prognostic Scoring System (WPSS) criteria, the incidence of poor-prognosis karyotypes was significantly higher (17.4 vs. 5.4%; P<0.05) in the older patient group, and based on the Revised International Prognostic Scoring System (IPSS-R) criteria, the incidence of poor-/very poor-prognosis karyotypes was also significantly higher (17.4 vs. 6.6%; P<0.05) in patients ≥51 years old compared with younger ones. Based on the WHO classification of MDS subtypes, the incidence of abnormal karyotypes in patients with high percentages of bone marrow (BM) blasts [excess blasts (EB)-I + EB-II, ≥5% blasts] was significantly higher than that in patients with low percentages of BM blasts (those with single lineage dysplasia + multilineage dysplasia, <5% blasts) (62.5 vs. 36.0%; P<0.05). The incidence of poor-prognosis karyotypes based on WPSS criteria was significantly higher in patients with high percentages of BM blasts than those with low percentages (22.0 vs. 6.9%, respectively; P<0.05), and the incidence of poor-/very poor-prognosis karyotypes based on IPSS-R criteria was also significantly higher (23.0 vs. 7.4%, respectively; P<0.05). These results demonstrate that +8 is the most common abnormal karyotype in Chinese patients with MDS. Age and the percentage of BM blasts are associated with the incidence of both abnormal karyotypes and karyotypes with poor prognosis. The results of cytogenetic abnormalities in this study will supplement the data on patients of MDS in China.