Myelodysplastic syndromes

Decitabine shows synergistic effects with arsenic trioxide against myelodysplastic syndrome cells via endoplasmic reticulum stress-related apoptosis

Most of the International Prognostic Scoring System (IPSS) high-risk patients with myelodysplastic syndrome partly responded to hypomethylating therapy even with transient remission, while arsenic trioxide (ATO) had partial effect in patients with MDS. Therefore, we sought to investigate the effects and possible mechanisms of the combination of ATO and decitabine (DAC) in MDS cells. In our study, the MUTZ-1 and SKM-1 cells were treated with ATO, DAC or both. Cell viability, cell apoptosis, levels of reactive oxygen species (ROS) and expressions of the endoplasmicreticulum (ER) stress-associated genes and proteins were examined. Results showed the combination of ATO and DAC synergistically inhibited the proliferation and induced apoptosis of MDS cells. Through the RNA-sequence and GSEA gene function analysis, ER stress-related pathway played an important role in apoptosis of MDS cells induced by the combination of ATO and DAC. ER stress-related genes DNA damage inducible transcript 3, GRP78, and activating transcription factor-6 were significantly highly expressed in combination group than those in single agent groups; proteins were confirmed by western blot. The levels of ROS significantly increased in the combination group. Furthermore, the apoptosis of (ATO+DAC) group MDS cells could be partially reversed by antioxidant agent N-acetylcysteine, accompanied by decreased expression of intracellular ROS and ER stress-related genes. These results suggested that the combination of ATO and DAC synergistically induced the apoptosis of MDS cells by increased ROS-related ER stress in MDS cells.

[Study of iron overload assessment by T2* magnetic resonance imaging in patients with myelodysplastic syndromes]

Objectives: To analyze the cardiac T2* value, liver iron concentration (LIC) , and related laboratory parameters in myelodysplastic syndrome (MDS) with iron overload and evaluate the changes of organ functions after iron chelation therapy. To explore the value of magnetic resonance imaging (MRI) T2* in making early diagnosis and assessing organs iron overload. Methods: Retrospective investigation was used to observe the cardiac T2* value, LIC, iron metabolism parameters and related laboratory parameters of 85 MDS patients from Nov 2014 to Jan 2018. Among them, 7 MDS patients with Low/Int-1 have received iron chelation therapy for 6 months during two MRI examinations. The above parameters were collected before and after iron chelation therapy for comparison. Results: Correlations were found between heart T2* value and age (rs=-0.290, P=0.007) and left ventricular ejection fraction (LVEF) (rs=0.265, P=0.009) . There was a significant negative correlation between heart T2* value and blood transfusion units (rs=-0.701, P<0.001) . There was a significant positive correlation between LIC and serum ferritin (SF) (rs=0.577, P<0.001) . There was also a correlation between LIC and ALT (rs=0.268, P=0.014) and blood transfusion units (rs=0.244, P=0.034) . There was no correlation between heart T2* and pro-BNP, SF (all P>0.05) , and no correlation between LIC and age (P>0.05) . The increase of heart T2* between the normal and abnormal groups was statistically significant (P=0.005) , but the iron overload ratio of the heart T2*<20 ms was not significant between the two groups. There was statistical significance in the proportion of severe liver iron overload (LIC>15 mg/g DW) (P=0.045) . After iron chelation therapy, the values of SF, transferrin saturation, ALT, AST, pro-BNP and LIC of 7 patients were decreased compared with values before iron chelation therapy, and the peripheral blood cell level was increased. However, the changes of LVEF and T2* values after iron chelation were not obvious. Conclusion: MRI T2* may be a predictor of iron overload in patients with MDS in early stage, and may be more valuable compare with LVEF, SF and other laboratory indicators. The safety and repeatability of MRI cardiac T2* examination are recognized, and it can be used as an ideal detection for patients with iron overload.

Clonal hematopoiesis of indeterminate potential-associated mutations and risk of comorbidities in patients with myelodysplastic syndrome

BACKGROUND

Clonal hematopoiesis of indeterminate potential (CHIP)-associated mutations increase the risk of atherosclerotic heart disease. Comorbidities significantly impact the prognosis of patients with myelodysplastic syndromes (MDS). The objective of this study was to determine the association and impact of CHIP mutations with comorbidities in patients with MDS.

METHODS

This retrospective analysis of 566 consecutive patients with MDS was conducted at The University of Texas MD Anderson Cancer Center from August 2013 to December 2016. The 27-item Adult Comorbidity Evaluation (ACE-27) scale was used to assess the severity of comorbid conditions. Next-generation sequencing was used to detect the presence of CHIP mutations in bone marrow aspirates. Spearman correlations and logistic regression analyses were used to determine the association between mutations and comorbidities.

RESULTS

Mutations in the genes tet methylcytosine dioxygenase 2 (TET2), ASXL transcriptional regulator 1 (ASXL1), DNA methyltransferase 3α (DNMT3A), Janus kinase 2 (JAK2), and tumor protein 53 (TP53) were noted in 20%, 18%, 9%, 2%, and 21% of patients, respectively. Patients with DNMT3A and JAK2 mutations had higher likelihoods of a prior history of myocardial infarction (odds ratio, 2.62; P = .03) and veno-occlusive disease (odds ratio, 6.48; P = .02), respectively. TP53 mutation was associated with a prior history of malignancy. Patients with TET2 mutation had no association with any comorbidity. A prognostic model including the revised International Prognostic Scoring System classification, the ACE-27 score, and TP53 mutation status (the I-RAT model) predicted median overall survival.

CONCLUSIONS

In patients with MDS, the presence of CHIP-associated mutations is associated with comorbidities. DNMT3A and JAK2 mutations were associated with higher likelihoods of prior myocardial infarction and thrombotic events. There was no association between comorbidity and TET2 mutation. Incorporating the revised International Prognostic Scoring System classification with the ACE-27 and TP53 mutation status improved outcome prediction in patients with MDS.

Increased opportunity for prolonged survival after allogeneic hematopoietic stem cell transplantation in patients aged 60-69 years with myelodysplastic syndrome

We conducted a nationwide retrospective study to evaluate the outcomes of allogeneic hematopoietic stem cell transplantation (allo-HSCT) in 651 patients aged 60-69 years with de novo myelodysplastic syndrome (MDS). We divided patients into two groups: 152 and 499 patients with an early and advanced disease status, respectively. The 3-year overall survival (OS) rate of patients with an early disease status was 45.9% (95% confidence interval [CI], 37.0 to 54.2%). A multivariate analysis revealed five adverse factors for OS: performance status (PS) 2-4 (hazard ratio [HR] 4.48; P < .001), poor cytogenetic risk group (HR 1.83; P = .041), male recipient (HR 2.58; P = .003), use of HLA-mismatched related grafts (HR 4.75; P = .003), and unrelated cord blood (HR 2.47; P = .023). The 3-year OS rate of patients with an advanced disease status was 37.2% (95% CI 32.4 to 41.9%). Five factors correlated with worse OS: PS 2-4 (HR 1.72; P = .003), poor cytogenetic risk group (HR 1.49; P = .003), use of HLA-mismatched related grafts (HR 1.96; P = .015), unrelated cord blood (HR 2.05; P < .001), and the high number of red blood cell transfusions before transplantation (HR 1.85; P = .018). The present results revealed the more frequent utilization of allo-HSCT for MDS patients aged 60-69 years, which increases the curative potential.

Clinical impact of the loss of chromosome 7q on outcomes of patients with myelodysplastic syndromes treated with allogeneic hematopoietic stem cell transplantation

We conducted a nationwide retrospective study to evaluate the prognostic influence of +1, der(1;7)(q10;p10) [hereafter der(1;7)] and -7/del(7q) after allogeneic hematopoietic stem cell transplantation (allo-HSCT) for de novo myelodysplastic syndromes (MDS). In this database, 69 MDS patients with der(1;7), 75 with -7/del(7q), and 511 with normal karyotype (NK) underwent allo-HSCT at advanced disease status. The 3-year overall survival (OS) and cumulative incidence of relapse (CIR) were 50.4 and 19.4% for those with der(1;7), 36.2 and 38.4% for -7/del(7q), and 51.1 and 20.7% for NK, respectively. In the multivariate analysis, the presence of -7/del(7q) correlated with a significantly shorter OS (HR [95% CI], 1.38 [1.00-1.89]; P = 0.048) and higher CIR (HR, 2.11 [1.36-3.28]; P = 0.001) than those with NK. There were 23 patients with der(1;7), 29 with -7/del(7q), and 347 with NK who underwent allo-HSCT at early disease status. The 3-year OS and CIR were as follows: 47.3 and 9.5% for the der(1;7) group, 70.5 and 13.8% for -7/del(7q), and 70.9 and 5.6% for NK, respectively. No significant differences were observed in OS and CIR among three groups. The impact of the loss of chromosome 7q on OS and CIR may differ based on its type and disease status after allo-HSCT for MDS.

Disruption of erythroid nuclear opening and histone release in myelodysplastic syndromes

Mammalian terminal erythropoiesis involves several characteristic phenomena including chromatin condensation and enucleation. One of the newly identified features of terminal erythropoiesis in mouse is a dynamic nuclear opening and histone release process, which is required for chromatin condensation. However, it is unclear whether the same feature is present in human. Here, we use an in vitro human CD34‐positive hematopoietic stem and progenitor cell culture system and reveal that nuclear openings and histone release are also identified during human terminal erythropoiesis. In contrast to mouse in which each erythroblast contains a single opening, multiple nuclear openings are present in human erythroblast, particularly during the late‐stage differentiation. The nuclear opening and histone release process is mediated by caspase‐3. Inhibition of caspase‐3 blocks nuclear opening, histone release, chromatin condensation, and terminal differentiation. We confirm the finding of histone cytosolic release in paraffin‐embedded human bone marrow in vivo. Importantly, we find that patients with myelodysplastic syndrome (MDS) exhibit significant defects in histone release in the dysplastic erythroblasts. Our results reveal developmentally conserved nuclear envelop and histone dynamic changes in human terminal erythropoiesis and indicate that disruption of the histone release process plays a critical role in the pathogenesis of dyserythropoiesis in MDS.

Myeloid Sarcoma with Megakaryoblastic Differentiation Arising in the Conjunctiva

An 87-year-old woman not known to have either a lymphoma or leukemia developed a left multinodular, fish-flesh superior epibulbar and forniceal mass. A biopsy disclosed a blastic tumor with scattered multinucleated immature megakaryoblasts. Immunophenotyping of bone marrow cells revealed strong positivity for CD7, CD31, CD43, CD45, CD61, and CD117; CD71, myeloperoxidase, and lysozyme were also positive in scattered cells. Forty percent of the neoplastic cells were Ki-67 positive. Cytogenetic studies indicated a trisomy 8 (associated with worse prognosis) and a t(12; 17) translocation. Desmin, smooth muscle actin, pancytokeratin, CAM 5.2, adipophilin, tryptase, S100, SOX10, MART1, and E-cadherin were negative, ruling out a nonhematopoietic tumor. The conjunctival lesion was diagnosed as a myeloid sarcoma with megakaryoblastic differentiation, a rare variant. It probably arose from a myelodysplastic syndrome. This is the first case of its type to develop in the conjunctiva.

Genetics of MDS

Our knowledge about the genetics of myelodysplastic syndromes (MDS) and related myeloid disorders has been dramatically improved during the past decade, in which revolutionized sequencing technologies have played a major role. Through intensive efforts of sequencing of a large number of MDS genomes, a comprehensive registry of driver mutations recurrently found in a recognizable fraction of MDS patients has been revealed, and ongoing efforts are being made to clarify their impacts on clinical phenotype and prognosis, as well as their role in the pathogenesis of MDS. Among major mutational targets in MDS are the molecules involved in DNA methylations, chromatin modification, RNA splicing, transcription, signal transduction, cohesin regulation, and DNA repair. Showing substantial overlaps with driver mutations seen in acute myeloid leukemia (AML), as well as age-related clonal hematopoiesis in healthy individuals, these mutations are presumed to have a common clonal origin. Mutations are thought to be acquired and positively selected in a well-organized manner to allow for expansion of the initiating clone to compromise normal hematopoiesis, ultimately giving rise to MDS and subsequent transformation to AML in many patients. Significant correlations between mutations suggest the presence of functional interactions between mutations, which dictate disease progression. Mutations are frequently associated with specific disease phenotype, drug response, and clinical outcomes, and thus, it is essential to be familiar with MDS genetics for better management of patients. This review aims to provide a brief overview of the recent progresses in MDS genetics.

The leukemia strikes back: a review of pathogenesis and treatment of secondary AML

Secondary AML is associated with a disproportionately poor prognosis, consistently shown to exhibit inferior response rates, event-free survival, and overall survival in comparison with de novo AML. Secondary AML may arise from the evolution of an antecedent hematologic disorder, or it may arise as a complication of prior cytotoxic chemotherapy or radiation therapy in the case of therapy-related AML. Because of the high frequency of poor-risk cytogenetics and high-risk molecular features, such as alterations in TP53, leukemic clones are often inherently chemoresistant. Standard of care induction had long remained conventional 7 + 3 until its reformulation as CPX-351, recently FDA approved specifically for secondary AML. However, recent data also suggests relatively favorable outcomes with regimens based on high-dose cytarabine or hypomethylating agents. With several investigational agents being studied, the therapeutic landscape becomes even more complex, and the treatment approach involves patient-specific, disease-specific, and therapy-specific considerations.

A diagnosis of discernment: Identifying a novel ATRX mutation in myelodysplastic syndrome with acquired α-thalassemia

Myelodysplastic syndromes (MDS) are a heterogeneous category of myeloid neoplasms that represent the most common class of acquired bone marrow failure syndromes in adults. MDS is typically associated with a hypoproliferative macrocytic anemia, but atypical findings on initial diagnostic evaluations can raise concern for a distinct pathophysiological process and lead to the investigation of alternative etiologies. Here, we report a case of MDS with a concomitant hypoproliferative microcytic and hypochromic anemia that led to the identification of acquired hemoglobin H due to a novel somatic ATRX mutation.

LAMP2 expression dictates azacytidine response and prognosis in MDS/AML

Chaperone-mediated autophagy (CMA) is a highly selective form of autophagy. During CMA, the HSC70 chaperone carries target proteins endowed with a KFERQ-like motif to the lysosomal receptor LAMP2A, which then translocate them into lysosomes for degradation. In the present study, we scrutinized the mechanisms underlying the response and resistance to Azacytidine (Aza) in MDS/AML cell lines and bone marrow CD34⁺ blasts from MDS/AML patients. In engineered Aza-resistant MDS cell lines and some AML cell lines, we identified a profound defect in CMA linked to the absence of LAMP2A. LAMP2 deficiency was responsible for Aza resistance and hypersensitivity to lysosome and autophagy inhibitors. Accordingly, gain of function of LAMP2 in deficient cells or loss of function in LAMP2-expressing cells rendered them sensitive or resistant to Aza, respectively. A strict correlation was observed between the absence of LAMP2, resistance to Aza and sensitivity to lysosome inhibitors. Low levels of LAMP2 expression in CD34⁺ blasts from MDS/AML patients correlated with lack of sensitivity to Aza and were predictive of poor overall survival. We propose that CD34⁺/LAMP2^Low patients at diagnosis or who become CD34⁺/LAMP2^Low during the course of treatment with Aza might benefit from a lysosome inhibitor already used in the clinic.

A Rare Case of Hemophagocytic Lymphohistiocytosis Associated With Myelodysplastic Syndrome and Trisomy 8 in a Pediatric Patient

Hemophagocytic lymphohistiocytosis (HLH) is a rare disease resulting in clinical and biochemical manifestations of extreme inflammation. Myelodysplastic syndrome (MDS) represents a heterogenous group of clonal hematopoietic disorders. The development of MDS is common in children with trisomy of chromosome 8. Here, we report a fatal case of 8-year-old girl who was admitted to the emergency department with status epilepticus, and later diagnosed with HLH associated with MDS and trisomy of chromosome 8. We believe this is the first reported case of HLH associated with MDS and trisomy 8 in a pediatric patient.

Hedgehog/GLI1 activation leads to leukemic transformation of myelodysplastic syndrome in vivo and GLI1 inhibition results in antitumor activity

Myelodysplastic syndromes (MDSs) are stem cell disorders with risk of transformation to acute myeloid leukemia (AML). Gene expression profiling reveals transcriptional expression of GLI1, of Hedgehog (Hh) signaling, in poor-risk MDS/AML. Using a murine model of MDS we demonstrated that constitutive Hh/Gli1 activation accelerated leukemic transformation and decreased overall survival. Hh/Gli1 activation resulted in clonal expansion of phenotypically defined granulocyte macrophage progenitors (GMPs) and acquisition of self-renewal potential in a non-self-renewing progenitor compartment. Transcriptome analysis of GMPs revealed enrichment in gene signatures of self-renewal pathways, operating via direct Gli1 activation. Using human cell lines we demonstrated that in addition to canonical Hh signaling, GLI1 is activated in a Smoothened-independent manner. GLI1 knockdown or inhibition with GANT61 resulted in decreased proliferation and clonogenic potential. Our data suggest that GLI1 activation is frequent in MDS during disease progression and inhibition of GLI1 is an attractive therapeutic target for a subset of patients.

Analysis of genome-wide in cell free DNA methylation: progress and prospect

In this work, we focus on the detection methods of cfDNA methylation based on NGS and the latest progress.

Management of immune thrombocytopenia in elderly patients

Despite the improvement in understanding its pathogenesis and the introduction of novel treatment options, the management of primary immune thrombocytopenia (ITP) still remains challenging. Considering its increased incidence with aging and prolonged life-expectancy, ITP is often diagnosed in elderly patients, a subset that deserves some special precautions. Ensure the diagnosis is a crucial step, and carefully attention must be given in excluding other causes of thrombocytopenia, especially among older people that frequently suffer from many comorbidities. When it comes to treatment decision, it is worth keeping into account that the elderly have an increased risk of bleeding, thrombosis and infections, that they often require many concomitant therapies, including antiplatelet or anticoagulant agents, and that treatment-related toxicities are often increased and sometimes more dangerous that the disease itself. There are not dedicated guidelines, and only few specific studies. Steroids with or without IVIG remain the first-line treatment. Splenectomy is less effective than in youngers and burdened by an increased thrombotic and infectious risk. Rituximab is a good option in non-immunocompromised patients, but long-term remissions are few. Eltrombopag and romiplostim have a good safety and efficacy profile, and have become a prominent drug in this subset, even if they are associated with a possible increased risk of thrombosis, and long-term toxicity is unknown. Other drugs, such as dapsone and danazol, have a well-known efficacy and safety profile, and still represent a valid option among elderly patients.

Dichotomization of the new revised international prognostic scoring system for a better clinical stratification of patients with myelodysplastic syndromes

In clinical practice, patients with myelodysplastic syndromes (MDS) are usually classified in low or high-risk groups to take therapeutic decisions, conservative for low-risk, whereas active for high-risk. Nevertheless, in the Revised International Prognostic Scoring System (IPSS-R) is not well stated which patients are low or high-risk. This study was aimed to ascertain in 364 MDS patients which IPSS-R threshold better dichotomized in low vs. high-risk. The best dichotomization was obtained with an IPSS-R cut-point of 3. Accordingly, 68% patients were classified as low-risk (median OS, 61.3 months) and 32% as high-risk MDS (median OS, 13.9 months) (p < .001). Interestingly, the intermediate IPSS-R risk patients presented an OS more related to the high IPSS-R than to the low IPSS-R risk group. In conclusion, an IPSS-R cut-point of 3 led to a meaningful stratification in low and high-risk that can be helpful for the clinical management of MDS patients.

The MDS genomics-prognosis symbiosis

Myelodysplastic syndromes (MDS) are clonal disorders characterized by the accumulation of complex genomic abnormalities that define disease phenotype, prognosis, and the risk of transformation to acute myeloid leukemia. The clinical manifestations and overall outcomes of MDS are very heterogeneous with an overall survival that can be measured in years for some patients to a few months for others. Prognostic scoring systems are important staging tools that aid physicians in their treatment recommendations and decision-making and can help patients understand their disease trajectory and expectations. Several scoring systems have been developed in MDS with the International Prognostic Scoring System and its revised version, the most widely used systems in clinical practice and trial eligibility. These models and others use mainly clinical variables that are obtained from bone marrow biopsy and peripheral blood measurements. Adding molecular data to current models may improve its predictive power but the ultimate method to incorporate this information remains a work in progress. Novel methods to develop a personalized prediction model that provides outcomes that are specific for a patient are currently under way and may change how we think about risk stratification in MDS patients in the future.

From cellular morphology to molecular and epigenetic anomalies of myelodysplastic syndromes

Myelodysplastic syndromes (MDSs) are a myeloid neoplasm with a propensity for natural evolution or transformation to acute leukemias (AL) over time. Mechanisms for MDS transformation to AL remain poorly understood but are related to genomic instability, which affects the production of the different cell lineages. Genomic instability is also generated by dysfunctional telomeres. Indeed telomeres, the protective ends of chromosomes are the backbone of genome stability. Nuclear telomere remodeling is an early indicator of nuclear remodeling preceding the onset of genomic instability and MDS. This review aims to revisit the pathogenesis and pathophysiology of MDS from morphology and cytogenetics to molecular and epigenetic mechanisms. Furthermore, this review will highlight and discuss recent breakthroughs in dysfunctional telomeres and nuclear telomere architecture roles in the pathogenesis and physiopathology of MDS in the global context of genomic instability.

Intragenic hypomethylation of DNMT3A in patients with myelodysplastic syndrome

BACKGROUND

DNMT3A is a DNA methyltransferase that acts in de novo methylation. Aberrant expression of DNMT3A has been reported in several human diseases, including myelodysplastic syndrome (MDS). However, the pattern of DNMT3A methylation remains unknown in MDS.

METHODS

The present study was aimed to investigate the methylation status of DNMT3A intragenic differentially methylated region 2 (DMR2) using real-time quantitative methylation-specific PCR and analyze its clinical significance in MDS.

RESULTS

Aberrant hypomethylation of DNMT3A was found in 57% (51/90) MDS cases. There were no significant differences in age, sex, white blood cell counts, platelet counts, hemoglobin counts and World Health Organization, International Prognostic Scoring System and karyotype classifications between DNMT3A hypomethylated and DNMT3A hypermethylated groups. However, the patients with DNMT3A hypomethylation had shorter overall survival time than those without DNMT3A hypomethylation (11 months vs. 36 months, p=0.033). Multivariate analysis confirmed the independent adverse impact of DNMT3A hypomethylation in MDS.

CONCLUSIONS

Our data suggest that DNMT3A DMR2 hypomethylation may be a negative prognostic hallmark in MDS.

Systematic review and meta-analysis of the effect of iron chelation therapy on overall survival and disease progression in patients with lower-risk myelodysplastic syndromes

The impact of iron chelation therapy (ICT) on overall survival (OS) and progression to acute myeloid leukemia (AML) in patients with iron overload and International Prognostic Scoring System low- or intermediate-risk myelodysplastic syndromes (MDS) is not well understood. We conducted a systematic review and meta-analysis of published studies of ICT in patients with MDS to better elucidate these relationships. We searched PubMed, EMBASE, Cochrane databases, and the World Health Organization Clinical Trial Registry for studies reporting the impact of ICT on OS in patients with low- or intermediate-risk MDS. Studies were examined for demographics, effect measures, and potential bias risk. Fixed and random-effects models were used to calculate adjusted OS and adjusted hazards ratio (aHR) estimates, respectively, among the different studies. Nine observational studies (four prospective and five retrospective) were identified. For patients with MDS, ICT was associated with an overall lower risk of mortality compared with no ICT (aHR 0.42; 95% confidence interval (CI) 0.28-0.62; P < 0.01); however, there was significant heterogeneity across the studies. In studies reporting progression to AML, ICT was not associated with decreased risk of progression (odds ratio 0.68; 95% CI 0.31-1.43; P < 0.030). This systematic review and meta-analysis of nine nonrandomized trials demonstrated significant reduction in risk of mortality in patients with iron overload and low- or intermediate-risk MDS treated with ICT; however, a causal relationship cannot be established. Randomized, controlled trials are needed to more definitively evaluate the relationship between ICT and survival in patients with iron overload and low- or intermediate-risk MDS.

A novel complete blood count-based score to screen for myelodysplastic syndrome in cytopenic patients

The diagnosis of myelodysplastic syndromes (MDS) is often challenging, time- and resource-consuming. A thorough analysis of complete blood count (CBC) parameters could, however, help to screen for MDS among other causes of cytopenia. To test this hypothesis, 109 newly-diagnosed MDS patients and 399 cytopenic patients older than 50 years with confirmed absence of MDS were enrolled in a prospective study. Multiparametric analysis highlighted three CBC parameters that were significantly different between the two cohorts: mean corpuscular volume, absolute neutrophil count and median neutrophil complexity and width of dispersion of the events measured (Ne-WX), which were used to define an MDS-CBC score. This score enables the prediction of MDS with 86% sensitivity and 88% specificity. The MDS-CBC score excluded MDS in 89% of cytopenic controls. Moreover, high score values at MDS diagnosis significantly correlated with decreased event-free (P = 0·02) and overall survival (P = 0·01). The power of this score was confirmed in an independent validation cohort (MDS n = 34, cytopenic controls n = 28). The MDS-CBC score is an easy and fast tool to exclude or suspect MDS in unselected patients with cytopenia of unknown reasons at the time of analysis, by prompting blood smear examination. It may thus improve allocation of further MDS-specific work-up in patients with cytopenia at the time of CBC assessment.

Modeling human RNA spliceosome mutations in the mouse: not all mice were created equal

Myelodysplastic syndromes (MDS) and related myelodysplastic/myeloproliferative neoplasms (MDS/MPNs) are clonal stem cell disorders, primarily affecting patients over 65 years of age. Mapping of the MDS and MDS/MPN genome identified recurrent heterozygous mutations in the RNA splicing machinery, with the SF3B1, SRSF2, and U2AF1 genes being frequently mutated. To better understand how spliceosomal mutations contribute to MDS pathogenesis in vivo, numerous groups have sought to establish conditional murine models of SF3B1, SRSF2, and U2AF1 mutations. The high degree of conservation of hematopoiesis between mice and human and the well-established phenotyping and genetic modification approaches make murine models an effective tool with which to study how a gene mutation contributes to disease pathogenesis. The murine models of spliceosomal mutations described to date recapitulate human MDS or MDS/MPN to varying extents. Reasons for the differences in phenotypes reported between alleles of the same mutation are varied, but the nature of the genetic modification itself and subsequent analysis methods are important to consider. In this review, we summarize recently reported murine models of SF3B1, SRSF2, and U2AF1 mutations, with a particular focus on the genetically engineered modifications underlying the models and the experimental approaches applied.

Mutations and karyotype predict treatment response in myelodysplastic syndromes

We examined the influence of mutations and karyotype on conventional treatment response, specifically hematological improvement in anemia, in primary myelodysplastic syndromes (MDS). Cytogenetic and next generation sequencing (NGS)-derived mutation information was available in 357 patients (median age 74 years; 70% males); the revised international prognostic scoring system risk distribution was very high in 11%, high 15%, intermediate 17%, low 40% and very low 16%. At least one mutation was detected in 81% of patients; most frequent were SF3B1 (32%), ASXL1 (27%), TET2 (24%) and U2AF1 (15%). At median follow-up of 24 months, treatment with hypomethylating agents (HMAs) was documented in 121 (34%) patients, lenalidomide (LEN) in 55 (15%), and erythropoiesis stimulating agents (ESAs) in 136 (38%). ASXL1 mutations adversely affected response to HMAs (27% vs 48%; P = 0.02) and LEN (9% vs 43%; P = 0.04), but not ESAs (P = 0.6). LEN response was also adversely affected by U2AF1 mutations (0% vs 42%; P = 0.02) and high risk karyotype (0% vs 41% in intermediate vs 47% in low risk; P = 0.01). Patients with SF3B1 mutations were more likely to respond to LEN (56% vs 27%; P = 0.04). Contrary to previous reports, we found no association between TET2 mutations and HMA treatment response (40% vs 41%; P = 0.9), even in the absence of ASXL1 mutations (P = 0.4).We conclude that ASXL1 mutations in MDS predict inferior response to treatment with both HMAs and LEN; response to LEN was also compromised by U2AF1 mutations and high risk karyotype; SF3B1 mutations identified patients likely to respond to LEN.

Hidden myelodysplastic syndrome (MDS): A prospective study to confirm or exclude MDS in patients with anemia of uncertain etiology

INTRODUCTION

Diagnosis of myelodysplastic syndromes (MDSs) when anemia is the only abnormality can be complicated. The aim of our study was to investigate the primary causes of anemia and/or macrocytosis of uncertain etiology.

METHODS

We conducted a multicenter, prospective study over 4 months in three hematology laboratories. In step 1, we used an automated informatics system to screen 137 453 hemograms for cases of anemia and/or macrocytosis (n = 2702). In step 2, we excluded all patients whose anemia appeared to be due to a known cause. This left 290 patients had anemia of uncertain etiology. In step 3, we conducted further investigations, including a peripheral blood smear, and analysis of iron, vitamin B12, folate, and thyroid hormone levels.

RESULTS

A differential diagnosis was obtained in 139 patients (48%). The primary causes of anemia were iron deficiency (n = 59) and megaloblastic anemia (n = 39). In total, 25 hematologic disorders were diagnosed, including 14 patients with MDS (56%). The median age of MDS patients was 80 years, 12 had anemia as an isolated cytopenia, and most (n = 10) had lower-risk disease (IPSS-R ≤ 3.5). SF3B1 mutations were most frequent (n = 6) and correlated with the presence of ring sideroblasts (100%) and associated with better prognosis (P = 0.001).

CONCLUSIONS

Our prospective, four-step approach is an efficient and logical strategy to facilitate the diagnosis of MDS on the basis of unexplained anemia and/or macrocytosis, and may allow the early diagnosis of the most serious causes of anemia. Molecular analysis of genes related to MDS could be a promising diagnostic and prognostic approach.

Mayo Alliance Prognostic Model for Myelodysplastic Syndromes: Integration of Genetic and Clinical Information

OBJECTIVE

To develop a new risk model for primary myelodysplastic syndromes (MDS) that integrates information on mutations, karyotype, and clinical variables.

PATIENTS AND METHODS

Patients with World Health Organization-defined primary MDS seen at Mayo Clinic (MC) from December 28, 1994, through December 19, 2017, constituted the core study group. The National Taiwan University Hospital (NTUH) provided the validation cohort. Model performance, compared with the revised International Prognostic Scoring System, was assessed by Akaike information criterion and area under the curve estimates.

RESULTS

The study group consisted of 685 molecularly annotated patients from MC (357) and NTUH (328). Multivariate analysis of the MC cohort identified monosomal karyotype (hazard ratio [HR], 5.2; 95% CI, 3.1-8.6), "non-MK abnormalities other than single/double del(5q)" (HR, 1.8; 95% CI, 1.3-2.6), RUNX1 (HR, 2.0; 95% CI, 1.2-3.1) and ASXL1 (HR, 1.7; 95% CI, 1.2-2.3) mutations, absence of SF3B1 mutations (HR, 1.6; 95% CI, 1.1-2.4), age greater than 70 years (HR, 2.2; 95% CI, 1.6-3.1), hemoglobin level less than 8 g/dL in women or less than 9 g/dL in men (HR, 2.3; 95% CI, 1.7-3.1), platelet count less than 75 × 10⁹/L (HR, 1.5; 95% CI, 1.1-2.1), and 10% or more bone marrow blasts (HR, 1.7; 95% CI, 1.1-2.8) as predictors of inferior overall survival. Based on HR-weighted risk scores, a 4-tiered Mayo alliance prognostic model for MDS was devised: low (89 patients), intermediate-1 (104), intermediate-2 (95), and high (69); respective median survivals (5-year overall survival rates) were 85 (73%), 42 (34%), 22 (7%), and 9 months (0%). The Mayo alliance model was subsequently validated by using the external NTUH cohort and, compared with the revised International Prognostic Scoring System, displayed favorable Akaike information criterion (1865 vs 1943) and area under the curve (0.87 vs 0.76) values.

CONCLUSION

We propose a simple and contemporary risk model for MDS that is based on a limited set of genetic and clinical variables.

Phase I study of ruxolitinib in previously treated patients with low or intermediate-1 risk myelodysplastic syndrome with evidence of NF-kB activation

Therapeutic options for patients with lower-risk myelodysplastic syndrome (MDS) who have failed prior therapies are limited particularly after hypomethylating agent. Several studies have indicated that deregulation of innate immunity signaling is critical in the pathogenesis of MDS. This process involves Toll-like receptor stimulation, cytokine overexpression, and nuclear factor-kB (NF-kB) activation. Since ruxolitinib, a JAK1/JAK2 inhibitor, suppresses NF-kB expression, we conducted a phase 1 dose-escalation study to determine the safety and efficacy of ruxolitinib in previously treated lower-risk MDS patients with evidence of NF-kB activation. Nineteen patients, 8 with chronic myelomonocytic leukemia and 11 with MDS, were enrolled. No dose limiting toxicity was observed and the maximum tolerated dose was 20 mg twice daily. Responses were restricted to MDS patients with an overall response rate of 22% [hematological improvement in platelets (HI-P) = 2, hematological improvement in erythrocytes (HI-E) = 1, partial cytogenetic response (PCyR) = 1]. Of these patients, 2 relapsed (HI-P and PCyR) and 2 continue to be in HI-P and HI-E, respectively, with ongoing therapy. Meaningful improvement in bone marrow dysplasia was only seen in a patient who achieved HI-E. Phosphorylated p65 (pp65) decreased in 6 of 15 patients (40%) including the 2 patients with continued response to treatment and increased in a patient who relapsed after a short-lived HI-P. This suggests potential correlation between reduction in pp65 expression and response duration. In conclusion, ruxolitinib was well-tolerated in previously treated lower-risk MDS patients with evidence of NF-kB activation and resulted in low but significant frequency of responses. (NCT01895842).

Drug Shortage Impacts Patient Receipt of Induction Treatment

OBJECTIVE

Examine the impact of the 2011 shortage of the drug cytarabine on patient receipt and timeliness of induction treatment for Acute Myeloid Leukemia (AML).

STUDY DESIGN

A retrospective cohort was utilized to examine odds of receipt of inpatient induction chemotherapy and time to first dose across major (N = 105) and moderate (N = 316) shortage time periods as compared to a nonshortage baseline (N = 1,147).

DATA COLLECTION/EXTRACTION METHODS

De-identified patient data from 2008 to 2011 Surveillance, Epidemiology, and End Results (SEER) were linked to 2007-2013 Medicare claims and 2007-2013 Hospital Characteristics.

PRINCIPAL FINDINGS

Compared to prior nonshortage time period, patients diagnosed during a major drug shortage were 47 percent less likely (p < .05) to receive inpatient chemotherapy within 14 days of diagnosis. Patients who were younger, had a lower Charlson Comorbidity score, and for whom AML was a first primary cancer were prioritized across all periods.

CONCLUSIONS

Period of major shortage of a generic oncolytic, without an equivalent therapeutic substitute, reduced timely receipt of induction chemotherapy treatment. More favorable economic and regulatory policies for generic drug suppliers might result in greater availability of essential, older generic drug products that face prolonged or chronic shortage.

Pathobiological Pseudohypoxia as a Putative Mechanism Underlying Myelodysplastic Syndromes

Myelodysplastic syndromes (MDS) are heterogeneous hematopoietic disorders that are incurable with conventional therapy. Their incidence is increasing with global population aging. Although many genetic, epigenetic, splicing, and metabolic aberrations have been identified in patients with MDS, their clinical features are quite similar. Here, we show that hypoxia-independent activation of hypoxia-inducible factor 1α (HIF1A) signaling is both necessary and sufficient to induce dysplastic and cytopenic MDS phenotypes. The HIF1A transcriptional signature is generally activated in MDS patient bone marrow stem/progenitors. Major MDS-associated mutations (Dnmt3a, Tet2, Asxl1, Runx1, and Mll1) activate the HIF1A signature. Although inducible activation of HIF1A signaling in hematopoietic cells is sufficient to induce MDS phenotypes, both genetic and chemical inhibition of HIF1A signaling rescues MDS phenotypes in a mouse model of MDS. These findings reveal HIF1A as a central pathobiologic mediator of MDS and as an effective therapeutic target for a broad spectrum of patients with MDS.Significance: We showed that dysregulation of HIF1A signaling could generate the clinically relevant diversity of MDS phenotypes by functioning as a signaling funnel for MDS driver mutations. This could resolve the disconnection between genotypes and phenotypes and provide a new clue as to how a variety of driver mutations cause common MDS phenotypes. Cancer Discov; 8(11); 1438-57. ©2018 AACR. See related commentary by Chen and Steidl, p. 1355 This article is highlighted in the In This Issue feature, p. 1333.

Prognostic significance of monosomal karyotype in myelodysplastic syndrome: a meta-analysis

OBJECTIVES

In myelodysplastic syndrome (MDS), the prognostic role of monosomal karyotype (MK), defined as at least two autosomal monosomies or a single monosomy associated with at least one additional structural abnormality, remained controversial. Therefore, we conducted a meta-analysis to address this issue.

METHODS

PubMed, Embase, Web of Science, Medline, and the Cochrane Library were retrieved. We extracted hazard ratios (HRs) and the corresponding 95% confidential intervals (CIs) for overall survival (OS) on patients with MK versus those without, as well as on MK patients with monosomies of chromosome 7 and/or 5 versus those without from the available studies.

RESULTS

Seventeen studies covering 7500 patients were included this meta-analysis. The pooled HRs indicated MK had a negative impact on OS in MDS (pooled HR: 2.484, 95%CI: 2.033-3.036, P < .001), in MDS patients undergoing allogeneic hematopoietic stem cell transplantation (allo-HSCT) (pooled HR: 2.150, 95%CI: 1.861-2.48, P < .001), and in MDS with complex karyotype (CK) (pooled HR: 2.56, 95%CI: 2.032-3.036, P = .01). However, monosomies of chromosome 5 and/or 7 had no impact on OS in MDS with MK (pooled HR: 1.330, 95%CI: 0.827-2.139, P = .240). Meta-regression indicated that therapy was the origin of the heterogeneity (P = .012).

DISCUSSION

Our meta-analysis indicated that MK has a negative impact on OS in MDS, in MDS patients undergoing allo-HSCT, and MDS with CK, but monosomies of chromosome 5 and/or 7 have no impact on OS in MDS with MK. The heterogeneity reflected the biologic and therapeutic heterogeneity of MDS.

CONCLUSION

MK is associated with poor prognosis in MDS, the underlying mechanism needs further exploring.

Response to hypomethylating agents improves long-term outcomes for lower-risk patients with myelodysplastic syndrome in case-matched cohorts

Predictive factors for initiating hypomethylating agents' (HMAs) treatment and the survival benefit of HMAs for lower-risk myelodysplastic syndrome (LR-MDS) are still unknown. This study evaluated the factors affecting the use of HMAs and compared long-term outcomes between best supportive care (BSC) and HMA groups after matching baseline clinical factors. Data of 353 patients diagnosed with LR-MDS by International Prognostic Scoring System between October 1992 and July 2013 were retrospectively analyzed. HMAs were administered continuously until a clinical response or progression. HMAs were administered to 243 patients with median 45 days (range 0-7078 days) after diagnosis, while 110 patients were treated with BSC. HMAs were administered over a median of 5 cycles and overall response was achieved in 104 patients (42.8%). The cumulative incidence of HMA treatment increased in higher-risk groups by other risk scoring systems. Three-year overall survival (OS) rate was higher in BSC group (69.1%) than HMA responders (47.4%, p = 0.065) or HMA non-responders (46.3%, p = 0.005). Among 162 case-matched cohorts, 3-year OS rates were comparable between the BSC group (67.1%) and HMA responders (58.1%, p = 0.914), while that of HMA non-responder was low (32.2%, p < 0.001). In the case-matched cohorts, HMA non-responder were associated with inferior OS rate in the multivariate analysis (hazard ratio 3.01, p = 0.001). Higher-risk groups by other clinical risk scoring systems among IPSS lower-risk patients showed an increased incidence of using HMAs. The OS rate of HMA responders among case-matched cohorts showed an improved OS rate similar to the BSC group.

Haploidentical Donor Bone Marrow Transplantation for Severe Aplastic Anemia

Hematopoietic stem cell transplantation (bone marrow transplantation [BMT]) is the only curative treatment of severe aplastic anemia. BMT from an human leukocyte antigen (HLA)-matched sibling donor is the standard of care for young patients; immunosuppressive therapy is used for older patients or those lacking matched sibling donors. Patients with refractory or relapsed disease are increasingly treated with HLA haploidentical BMT. Historically, haploidentical BMT led to high rates of graft rejection and graft-versus-host disease. High-dose post transplant cyclophosphamide, which mitigates the risk of graft-versus-host disease, is a major advance. This article provides an overview of the haploidentical BMT approach in severe aplastic anemia.

Gastric carcinoma subsequent to myelodysplastic syndrome with t (1; 19) chromosome translocation: A rare case report and its potential mechanisms

RATIONALE

Myelodysplastic syndrome (MDS) is a heterogeneous malignant hematologic disease with median overall survival ranging from six months to more than ten years. Solid tumor rarely occurs in combination with MDS and the underlying pathogenesis and prognostic significance still remain controversial.

PATIENT CONCERNS

Here we report a relative low risk myelodysplastic syndrome-refractory cytopenia with multilineage dysplasia (MDS-RCMD) patient, with a rare t(1; 19)chromosome translocation. This patient also suffered from gastric carcinoma.

DIAGNOSES

Gastric carcinoma, Myelodysplastic syndrome with t (1; 19) chromosome translocation.

INTERVENTIONS

This patient received radical operation for gastric carcinoma and erythropoietin infusion.

OUTCOMES

The patient took follow up visits every 2 to 3 months in past years and now he is in stable disease without further treatment.

LESSONS

We reviewed the mechanism of MDS complicated by solid tumor and concluded the potential mechanisms of this patient. The interactions between potential factors may play a role in oncogenesis which, however, need an in-depth study of its operating mechanism.

Impact of spliceosome mutations on RNA splicing in myelodysplasia: dysregulated genes/pathways and clinical associations

SF3B1, SRSF2, and U2AF1 are the most frequently mutated splicing factor genes in the myelodysplastic syndromes (MDS). We have performed a comprehensive and systematic analysis to determine the effect of these commonly mutated splicing factors on pre-mRNA splicing in the bone marrow stem/progenitor cells and in the erythroid and myeloid precursors in splicing factor mutant MDS. Using RNA-seq, we determined the aberrantly spliced genes and dysregulated pathways in CD34⁺ cells of 84 patients with MDS. Splicing factor mutations result in different alterations in splicing and largely affect different genes, but these converge in common dysregulated pathways and cellular processes, focused on RNA splicing, protein synthesis, and mitochondrial dysfunction, suggesting common mechanisms of action in MDS. Many of these dysregulated pathways and cellular processes can be linked to the known disease pathophysiology associated with splicing factor mutations in MDS, whereas several others have not been previously associated with MDS, such as sirtuin signaling. We identified aberrantly spliced events associated with clinical variables, and isoforms that independently predict survival in MDS and implicate dysregulation of focal adhesion and extracellular exosomes as drivers of poor survival. Aberrantly spliced genes and dysregulated pathways were identified in the MDS-affected lineages in splicing factor mutant MDS. Functional studies demonstrated that knockdown of the mitosis regulators SEPT2 and AKAP8, aberrantly spliced target genes of SF3B1 and SRSF2 mutations, respectively, led to impaired erythroid cell growth and differentiation. This study illuminates the effect of the common spliceosome mutations on the MDS phenotype and provides novel insights into disease pathophysiology.

Evaluation of Parameters Related to the Probability of Leukemic Progression in Patients With Lower-Risk Myelodysplastic Syndrome

BACKGROUND

The prognosis of patients with lower-risk myelodysplastic syndrome (LR-MDS) is very heterogeneous. In addition to survival estimates, identification of factors related to the probability of leukemic progression might help prognosis assessment.

PATIENTS AND METHODS

The present study is a retrospective analysis of 409 patients with primary LR-MDS. The probability of leukemic progression was estimated in the competing risk framework by the cumulative incidence method considering death without acute myeloid leukemia (AML) as a competing event.

RESULTS

Sixty-six patients (16.1%) progressed to AML. The following covariates influenced the probability of leukemic progression in a multivariate competing risk regression model: intermediate karyotype versus diploid or chromosome 5 deletion, 5% to 9% bone marrow blast percentage, platelet count <50 × 10e⁹/L and age younger than 75 years.

CONCLUSION

According to these, a predictive model is proposed, which categorizes patients with different probability of leukemic progression (P < .001). Validation of these results might help prognostic refinement of patients with LR-MDS.

Myelodysplastic syndromes current treatment algorithm 2018

Myelodysplastic syndromes (MDS) include a group of clonal myeloid neoplasms characterized by cytopenias due to ineffective hematopoiesis, abnormal blood and marrow cell morphology, and a risk of clonal evolution and progression to acute myeloid leukemia (AML). Because outcomes for patients with MDS are heterogeneous, individual risk stratification using tools such as the revised International Prognostic Scoring System (IPSS-R) is important in managing patients-including selecting candidates for allogeneic hematopoietic stem cell transplantation (ASCT), the only potentially curative therapy for MDS. The IPSS-R can be supplemented by molecular genetic testing, since certain gene mutations such as TP53 influence risk independent of established clinicopathological variables. For lower risk patients with symptomatic anemia, treatment with erythropoiesis-stimulating agents (ESAs) or lenalidomide (especially for those with deletion of chromosome 5q) can ameliorate symptoms. Some lower risk patients may be candidates for immunosuppressive therapy, thrombopoiesis-stimulating agents, or a DNA hypomethylating agent (HMA; azacitidine or decitabine). Among higher risk patients, transplant candidates should undergo ASCT as soon as possible, with HMAs useful as a bridge to transplant. Non-transplant candidates should initiate HMA therapy and continue if tolerated until disease progression. Supportive care with transfusions and antimicrobial drugs as needed remains important in all groups.

Prognostic significance of SRSF2 mutations in myelodysplastic syndromes and chronic myelomonocytic leukemia: a meta-analysis

OBJECTIVE

Serine/arginine-rich splicing factor 2 (SRSF2) mutations were detected frequently in myelodysplastic syndrome (MDS) and chronic myelomonocytic leukemia (CMML) patients. However, its prognostic value has not yet been fully clarified.

METHODS

In this meta-analysis, Hazard Ratio (HR) and 95% confidence interval (CI) for overall-survival (OS) were chosen to evaluate the prognostic impact of SRSF2 mutations and to compare SRSF2 mutations to those with wild-type.

RESULTS

A total of 2056 patients from 12 studies were obtained. The pooled HRs for OSsuggested that patients with MDS had a poorer prognosis (HR = 1.780, 95% CI (1.410-2.249)), while analysis on SRSF2 mutations revealed no significant effect on the prognosis of CMML patients (HR = 1.091, 95% CI (0.925-1.286)). The frequency of SRSF2 mutations was found to be 11.5% and 39.8% in patients with MDS and CMML, respectively.

DISCUSSION

This meta-analysis suggests that SRSF2 has a poor prognosis in patients with MDS, but no prognosis impact on patients with CMML.

CONCLUSION

In conclusion, SRSF2 mutations were significantly related to the shorter OS in patients with MDS which may consider as an adverse prognostic risk factor. Whereas, analysis did not show any prognostic effect on OS of CMML patients with SRSF2 mutations.

Prognostic role of TET2 deficiency in myelodysplastic syndromes: A meta-analysis

Tet methylcytosine dioxygenase2 gene (TET2) is one of the most frequently mutated gene in myeloid neoplasm, but the prognostic role of TET2 aberrations in myelodysplastic syndromes (MDS) remains unclear. Therefore, we performed a meta-analysis. Fourteen eligible studies with 1983 patients were included in this meta-analysis. Among these, 2 studies evaluated the impact that the TET2 expression level had on the prognosis. The combined hazard ratios (HR) estimated for overall survival (OS) was 1.00 (95%CI: 0.74 to 1.37; p=0.989) when comparing those with TET2 mutations with those without. Among the patients treated with hypomethylating agents (HMAs) or hematopoietic stem cell transplantation (HSCT), the pooled HR for OS was 1.02 (95% CI: 0.77-1.35, p=0.89) and 1.54 (95%CI: 0.69 to 3.44; p=0.29), respectively. We also conducted an analysis of the response rate to HMAs, and the OR was 1.73 (95%CI: 1.11 to 2.70; p=0.016). Additionally, subgroup analyses showed the pooled HR for OS was 0.93(95%CI: 0.44 to 1.98; P=0.849) in WHO-classified CMML patients and 1.02(95%CI: 1.02 to 3.46; p=0.042) in studies evaluated TET2 expression level. The analysis suggested TET2 mutations had no significant prognostic value on MDS. However, the response rates to HMAs were significantly different between those with and without TET2 mutations, and the low expression level of TET2 gene was significantly associated with a poor OS in MDS patients.

Distinct mutation profile and prognostic relevance in patients with hypoplastic myelodysplastic syndromes (h-MDS)

Myelodysplastic syndromes (MDS) are a heterogeneous group of hematologic malignancies. Although most MDS patients have normal or increased BM cellularity (NH-MDS), some have hypocellular BM (h-MDS). The reports concerning the differences in genetic alterations between h-MDS and NH-MDS patients are limited. In this study, 369 MDS patients diagnosed according to the WHO 2008 criteria were recruited. h-MDS patients had lower PB white blood cell and blast counts, and lower BM blast percentages, than those with NH-MDS. h-MDS was closely associated with lower-risk MDS, defined by the International Prognostic Scoring System (IPSS) and revised IPSS (IPSS-R). IPSS-R could properly predict the prognosis in h-MDS (P<0.001) as in NH-MDS patients. The h-MDS patients had lower incidences of RUNX1, ASXL1, DNMT3A, EZH2 and TP53 mutations than NH-MDS patients. The cumulated incidence of acute leukemic transformation at 5 years was 19.3% for h-MDS and 40.4% for NH-MDS patients (P= 0.001). Further, the patients with h-MDS had longer overall survival (OS) than those with NH-MDS (P= 0.001), and BM hypocellularity remains an independent favorable prognostic factor for OS irrespective of age, IPSS-R, and gene mutations. Our findings provide evidence that h-MDS indeed represent a distinct clinico-biological subgroup of MDS and can predict better leukemia-free survival and OS.

DNA Methyltransferase Inhibition Promotes Th1 Polarization in Human CD4+CD25high FOXP3+ Regulatory T Cells but Does Not Affect Their Suppressive Capacity

Regulatory T cells (Treg) can show plasticity whereby FOXP3 expression, the master transcription factor for Treg suppressor function, is lost and proinflammatory cytokines are produced. Optimal FOXP3 expression strongly depends on hypomethylation of the FOXP3 gene. 5-Azacytidine (Aza) and its derivative 5-aza-2'-deoxycytidine (DAC) are DNA methyltransferase inhibitors (DNMTi) that are therapeutically used in hematological malignancies, which might be an attractive strategy to promote Treg stability. Previous in vitro research primarily focused on Treg induction by DAC from naïve conventional CD4⁺ T cells (Tconv). Here, we examined the in vitro effect of DAC on the stability and function of FACS-sorted human naturally occurring CD4⁺CD25^high FOXP3⁺ Treg. We found that in vitro activation of Treg in the presence of DAC led to a significant inhibition of Treg proliferation, but not of Tconv. Although Treg activation in the presence of DAC led to increased IFNγ expression and induction of a Thelper-1 phenotype, the Treg maintained their suppressive capacity. DAC also induced a trend towards increased IL-10 expression. In vivo studies in patients with hematological malignancies that were treated with 5-azacytidine (Vidaza) supported the in vitro findings. In conclusion, despite its potential to increase IFNγ expression, DAC does preserve the suppressor phenotype of naturally occurring Treg.