The 2016 WHO classification and diagnostic criteria for myeloproliferative neoplasms: document summary and in-depth discussion

Myeloid-derived suppressor cells: Implication in myeloid malignancies and immunotherapy

Myeloid malignancies stem from a modified hematopoietic stem cell and predominantly include acute myeloid leukemia, myelodysplastic neoplasms, myeloproliferative malignancies, and chronic myelomonocytic leukemia. Myeloid-derived suppressor cells (MDSCs) exhibit immunoregulatory properties by governing the innate and adaptive immune systems, creating a permissive and supportive environment for neoplasm growth. This review examines the key characteristics of MDSCs in myeloid malignancies, highlighting that an increased MDSC count corresponds to heightened immunosuppressive capabilities, fostering an immune-tolerant neoplasm microenvironment. Also, this review analyzes and describes the potential of combined cancer therapies, focusing on targeting MDSC generation, expansion, and their inherent immunosuppressive activities to enhance the efficacy of current cancer immunotherapies. A comprehensive understanding of the implications of myeloid malignancies may enhance the exploration of immunotherapeutic strategies for their potential application.

Polycythemia Prevalence and Risk Factors in Pilots

INTRODUCTION: Pilots are frequently exposed to thrombotic risk as a result of immobility from air travel. As hypoxemia is associated with secondary polycythemia, and polycythemia increases the risk of thrombosis, intermittent exposure to high-altitude hypoxic environments could escalate the risk of thrombosis in pilots. Our objectives were to find the prevalence of polycythemia in airplane pilots (primary outcome) and to assess associated risk factors of polycythemia (secondary outcome).METHODS: This study is a cross-sectional descriptive study. Data was collected from paper-based and computerized medical records of airplane pilots who applied for Class 1 Aviation Medical Certificate renewal at the Institute of Aviation Medicine, Royal Thai Air Force, Bangkok, Thailand, in 2018. The data was sampled by a simple random sampling technique.RESULTS: A total of 386 paper-based records were sampled. Of those, 29 (7.5%) of the pilots met polycythemia criteria. Spearman's correlation analysis showed a significant positive correlation between Body Mass Index (BMI) and hemoglobin (correlation coefficient = 0.127) and between BMI and hematocrit (correlation coefficient = 0.105). In multivariate logistic regression of each variable on polycythemia as defined by hemoglobin alone, piloting a non-pressurized aircraft was found to be an independent predictor of polycythemia (odds ratio = 4.3).DISCUSSION: The prevalence of polycythemia in airplane pilots was 7.5%. Operating a non-pressurized aircraft was a significant risk factor of polycythemia, and pilots with higher BMI were more likely to have increased red blood cell parameters.Thanapaisan P, Plaingam M, Manyanont S. Polycythemia prevalence and risk factors in pilots. Aerosp Med Hum Perform. 2024; 95(9):683-687.

A randomized, double-blind, placebo-controlled phase 3 study to assess efficacy and safety of ropeginterferon alfa-2b in patients with early/lower-risk primary myelofibrosis

Primary myelofibrosis (PMF) is the most aggressive of the myeloproliferative neoplasms and patients require greater attention and likely require earlier therapeutic intervention. Currently approved treatment options are limited in their selective suppression of clonal proliferation resulting from driver- and coexisting gene mutations. Janus kinase inhibitors are approved for symptomatic patients with higher-risk PMF. Additionally, most ongoing clinical studies focus on patients with higher-risk disease and/or high rates of transfusion dependency. Optimal treatment of early/lower-risk PMF remains to be identified and needs randomized clinical trial evaluations. Pegylated interferon alfa is recommended for symptomatic lower-risk PMF patients based on phase 2 non-randomized studies and expert opinion. Ropeginterferon alfa-2b (ropeg) is a new-generation pegylated interferon-based therapy with favorable pharmacokinetics and safety profiles, requiring less frequent injections than prior formulations. This randomized, double-blind, placebo-controlled phase 3 trial will assess its efficacy and safety in patients with "early/lower-risk PMF", defined as pre-fibrotic PMF or PMF at low or intermediate-1 risk according to Dynamic International Prognostic Scoring System-plus. Co-primary endpoints include clinically relevant complete hematologic response and symptom endpoint. Secondary endpoints include progression- or event-free survival, molecular response in driver or relevant coexisting gene mutations, bone marrow response, and safety. Disease progression and events are defined based on the International Working Group criteria and well-published reports. 150 eligible patients will be randomized in a 2:1 ratio to receive either ropeg or placebo. Blinded sample size re-estimation is designed. Ropeg will be administered subcutaneously with a tolerable, higher starting-dose regimen. The study will provide important data for the treatment of early/lower-risk PMF for which an anti-clonal, disease-modifying agent is highly needed.

Chromosome 9p trisomy increases stem cells clonogenic potential and fosters T-cell exhaustion in JAK2-mutant myeloproliferative neoplasms

JAK2V617F is the most recurrent genetic mutation in Philadelphia-negative chronic Myeloproliferative Neoplasms (MPNs). Since the JAK2 locus is located on Chromosome 9, we hypothesized that Chromosome 9 copy number abnormalities may be a disease modifier in JAK2V617F-mutant MPN patients. In this study, we identified a subset of MPN patients with partial or complete Chromosome 9 trisomy (+9p patients), who differ from JAK2V617F-homozygous MPN patients as they carry three JAK2 alleles as well as three copies of all neighboring gene loci, including CD274, encoding immunosuppressive Programmed death-ligand 1 (PD-L1) protein. Investigation of the clonal hierarchy revealed that the JAK2V617F occurs first, followed by +9p. Functionally, CD34+ cells from +9p MPN patients demonstrated increased clonogenicity, generating a greater number of primitive colonies, due to high OCT4 and NANOG expression, with knock-down of these genes leading to a genotype-specific decrease in colony numbers. Moreover, our analysis revealed increased PD-L1 surface expression in malignant monocytes from +9p patients, while analysis of the T cell compartment unveiled elevated levels of exhausted cytotoxic T cells. Overall, here we identify a distinct novel subgroup of MPN patients, who feature a synergistic interplay between +9p and JAK2V617F that shapes immune escape characteristics and increased stemness in CD34+ cells.

Cytokine-induced killer cells: new insights for therapy of hematologic malignancies

BACKGROUND

Cytokine-induced killer (CIK) cells are a novel subgroup of immune effectors, classified as one of the modified T cell-mediated arms for immunotherapy. These cells exert MHC-unrestricted cytotoxicity against both hematological and solid malignancies with low incidence of treatment-related severe complications. This study reviews the application of CIK cells in treating cases with hematologic malignancies.

MAIN BODY

CIK cells consist of CD3+/CD56+  natural killer (NK) T cells, CD3-/CD56+ NK cells, and CD3+/CD56- cytotoxic T cells. In this regard, the CD3+/CD56+  NK T cells are the primary effectors. Compared with the previously reported antitumor immune cells, CIK cells are characterized by improved in vitro proliferation and amplification, enhanced migration and invasive capacity to tumor region, more significant antitumor activity, and a broader antitumor spectrum. CIK cells can also induce death in tumor cells via numerous pathways and mechanisms. Hence, CIKs-based therapy has been used in various clinical trials and has shown efficacy with a very low graft versus host disease (GVHD) against several cancers, such as hematologic malignancies, even in relapsing cases, or cases not responding to other therapies. Despite the high content of T cells, CIK cells induce low alloreactivity and, thus, pose a restricted threat of GVHD induction even in MHC-mismatched transplantation cases. Phase 1 and 2 clinical trials of CIK cell therapy have also highlighted satisfactory therapeutic advantages against hematologic cancers, indicating the safety of CIK cells even in haploidentical transplantation settings.

CONCLUSION

CIK cells have shown promising results in the treatment of hematologic malignancies, especially in combination with other antitumor strategies. However, the existing controversies in achieving desired clinical responses underscore the importance of future studies.

Potential biomarkers and immune characteristics for polycythemia vera-related atherosclerosis using bulk RNA and single-cell RNA datasets: a combined comprehensive bioinformatics and machine learning analysis

Background

Polycythemia vera (PV) is a myeloproliferative disease characterized by significantly higher hemoglobin levels and positivity for JAK2 mutation. Thrombosis is the main risk event of this disease. Atherosclerosis (AS) can markedly increase the risk of arterial thrombosis in patients with PV. The objectives of our study were to identify potential biomarkers for PV-related AS and to explore the molecular biological association between PV and AS.

Methods

We extracted microarray datasets from the Gene Expression Omnibus (GEO) dataset for PV and AS. Common differentially expressed genes (CGs) were identified by differential expression analysis. Functional enrichment and protein-protein interaction (PPI) networks were constructed from the CG by random forest models using LASSO regression to identify pathogenic genes and their underlying processes in PV-related AS. The expression of potential biomarkers was validated using an external dataset. A diagnostic nomogram was constructed based on potential biomarkers to predict PV-related AS, and its diagnostic performance was assessed using ROC, calibration, and decision curve analyses. Subsequently, we used single-cell gene set enrichment analysis (GSEA) to analyze the immune signaling pathways associated with potential biomarkers. We also performed immune infiltration analysis of AS with "CIBERSORT" and calculated Pearson's correlation coefficients for potential biomarkers and infiltrating immune cells. Finally, we observed the expression of potential biomarkers in immune cells based on the single-cell RNA dataset.

Results

Fifty-two CGs were identified based on the intersection between up-regulated and down-regulated genes in PV and AS. Most biological processes associated with CGs were cytokines and factors associated with chemotaxis of immune cells. The PPI analysis identified ten hub genes, and of these, CCR1 and MMP9 were selected as potential biomarkers with which to construct a diagnostic model using machine learning methods and external dataset validation. These biomarkers could regulate Toll-like signaling, NOD-like signaling, and chemokine signaling pathways associated with AS. Finally, we determined that these potential biomarkers had a strong correlation with macrophage M0 infiltration. Further, the potential biomarkers were highly expressed in macrophages from patients with AS.

Conclusion

We identified two CGs (CCR1 and MMP9) as potential biomarkers for PV-related AS and established a diagnostic model based on them. These results may provide insight for future experimental studies for the diagnosis and treatment of PV-related AS.

SOHO State of the Art Updates and Next Questions | Early Intervention in Myelofibrosis: Where Are We and Does It Matter?

Historically, therapeutic clinical trials in myelofibrosis have predominantly focused on targeting patients with higher-risk disease who are at risk of increased morbidity and mortality. The endpoints have been designed to target regularly measured disease parameters that are of immediate pertinence to patient's welfare including splenic volume reduction and symptom reduction. These efforts have resulted in meaningful and measurable improvements in disease parameters in these high-risk study populations and multiple FDA approved agents. However, they have not tackled specific interventions that may be applied to patients with earlier or less advanced disease state. In this review, we summarize evidence from completed and ongoing clinical trials investigating different aspects of intervention targeted at less advanced disease and advocate for the merit of this approach.

Myeloproliferative Neoplasms Transcriptome Reveals Pro-Inflammatory Signature and Enrichment in Peripheral Blood Monocyte-Related Genes

Myeloproliferative neoplasms (MPN) are hematological diseases associated with genetic driver mutations in the JAK2, CALR, and MPL genes and exacerbated oncoinflammatory status. Analyzing public microarray data from polycythemia vera (n = 41), essential thrombocythemia (n = 21), and primary myelofibrosis (n = 9) patients' peripheral blood by in silico approaches, we found that pro-inflammatory and monocyte-related genes were differentially expressed in MPN patients' transcriptome. Genes related to cell activation, secretion of pro-inflammatory and pro-angiogenic mediators, activation of neutrophils and platelets, coagulation, and interferon pathway were upregulated in monocytes compared to controls. Together, our results suggest that molecular alterations in monocytes may contribute to oncoinflammation in MPN.

The evolving landscape of polycythemia vera therapies

INTRODUCTION

The treatment landscape of polycythemia vera (PV) has seen major advancements within the last decade including approval of ruxolitinib in the second line setting after hydroxyurea, ropegylated interferon-α2b, and advanced clinical development of a novel class of agents called hepcidin mimetics.

AREAS COVERED

We provide a comprehensive review of the evidence discussing the risk stratification, treatment indications, role and limitations of phlebotomy only approach and pivotal trials covering nuances related to the use of interferon-α (IFN-α), ruxolitinib, hepcidin mimetics, and upcoming investigational agents including HDAC and LSD1 inhibitors.

EXPERT OPINION

The research paradigm in PV is slowly shifting from the sole focus on hematocrit control and moving toward disease modification. The discovery of hepcidin mimetics has come as a breakthrough in restoring iron homeostasis, achieving phlebotomy-independence and may lead to improved thrombosis-free survival with stricter hematocrit control. On the other hand, emerging data with IFN- α and ruxolitinib as well as combination of the two agents suggests the potential for achieving molecular remission in a subset of PV patients and long-term follow-up is awaited to validate the correlation of molecular responses with clinically relevant outcomes of progression-free and thrombosis-free survival.

DARS expression in BCR/ABL1-negative myeloproliferative neoplasms and its association with the immune microenvironment

DARS, encoding for aspartyl-tRNA synthetase, is implicated in the pathogenesis of various cancers, including renal cell carcinoma, glioblastoma, colon cancer, and gastric cancer. Its role in BCR/ABL1-negative myeloproliferative neoplasms (MPNs), however, remains unexplored. This study aimed to elucidate the expression of DARS in patients with MPNs (PV 23, ET 19, PMF 16) through immunohistochemical analysis and to examine the profiles of circulating immune cells and cytokines using flow cytometry. Our findings indicate a significant overexpression of DARS in all MPNs subtypes at the protein level compared to controls (P < 0.05). Notably, elevated DARS expression was linked to splenomegaly in MPNs patients. The expression of DARS showed a negative correlation with CD4+ T cells (R = - 0.451, P = 0.0004) and CD4+ T/CD8+ T cell ratio (R = - 0.3758, P = 0.0040), as well as with CD68+ tumor-associated macrophages (R = 0.4037, P = 0.0017). Conversely, it was positively correlated with IL-2 (R = 0.5419, P < 0.001), IL-5 (R = 0.3161, P = 0.0166), IL-6 (R = 0.2992, P = 0.0238), and IFN-γ (R = 0.3873, P = 0.0029). These findings underscore a significant association between DARS expression in MPNs patients and specific clinical characteristics, as well as immune cell composition. Further investigation into the interplay between DARS and the immune microenvironment in MPNs could shed light on the underlying mechanisms of MPNs pathogenesis and immune dysregulation.

Initiating-clone analysis in patients with acute myeloid leukemia secondary to essential thrombocythemia

Most of essential thrombocythemia (ET) patients have the clone harboring a mutation in one of the JAK2, CALR, or MPL gene, and these clones generally acquire additional mutations at transformation to acute myeloid leukemia (AML). However, the proliferation of triple-negative clones has sometimes been observed at AML transformation. To clarify the clonal evolution of ET to AML, we analyzed paired samples at ET and AML transformation in eight patients. We identified that JAK2-unmutated AML clones proliferated at AML transformation in three patients in whom the JAK2-mutated clone was dominant at ET. In two patients, TET2-mutated, but not JAK2-mutated, clones might be common initiating clones for ET and transformed AML. In a patient with JAK2-mutated ET, SMARCC2, UBR4, and ZNF143, but not JAK2, -mutated clones proliferated at AML transformation. Precise analysis using single-cell sorted CD34+/CD38- fractions suggested that ET clone with JAK2-mutated and AML clone with TP53 mutation was derived from the common clone with these mutations. Although further study is required to clarify the biological significance of SMARCC2, UBR4, and ZNF143 mutations during disease progression of ET and AML transformation, the present results demonstrate the possibility of a common initial clone involved in both ET and transformed AML.

Primary polycythaemia: A neglected risk factor

In this case series, we report a 32-year-old male patient with myocardial infarction and 45-year-old female with portal vein thrombosis with splenic infarcts, which were the initial manifestations of polycythaemia vera. The awareness of myeloproliferative disorders as a possible underlying disease-especially in young patients presenting with myocardial infarction and portal venous thrombosis-is crucial for clinical management, as a missed diagnosis can worsen the patients' further prognosis.

Impact of Hydroxyurea to Treat Haematological Disorders on Male Fertility: Two Case Reports and a Systematic Review

PURPOSE

Hydroxyurea (HU) is a cytoreductive agent used as standard treatment option for sickle cell anaemia/disease (SCD), essential thrombocythemia (ET), and polycythaemia vera (PV). Despite its overall good safety profile, its use also in relatively young patients raises an interest on its potential impact on spermatogenesis. To perform a systematic review of all published articles investigating fertility in male patients affected by SCD, ET, and PV and treated with HU. Two paradigmatic case reports of patients affected by PV and ET, respectively, have been also reported.

MATERIALS AND METHODS

PubMed, EMBASE, and Cochrane databases were queried for all the published studies indexed up to November 15th, 2022. A combination of the following keywords was used: "hydroxyurea," "fertility," "male," "sperm," "sickle cell anaemia," "sickle cell disease," "essential thrombocythemia," "polycythaemia vera."

RESULTS

Of 48 articles identified, 8 studies, involving 161 patients, were eligible for inclusion. Overall, the number of spermatogonia per round cross section of seminiferous tubule were decreased in patients with SCD compared to healthy males. HU treatment was always associated with a worsening of semen parameters, even up to azoospermia. Notably, treatment discontinuation was associated with an improvement of semen parameters and a trend toward normalization in the case of PV and ET, with a less clear amelioration in men with SCD. In both our patients with either PV or ET, HU discontinuation was associated with a significant improvement of spermatogenesis with successful spontaneous pregnancies.

CONCLUSIONS

Published evidence do not consistently report normalization of spermatogenesis after HU discontinuation in SCD cases. Conversely, the literature almost consistently reported an improvement of semen parameters at the discontinuation of HU therapy in PV and ET cases. Our real-life two cases confirmed those findings. The willing of fatherhood and the need for effective fertility treatment warrant further research to improve work-up management in men with hematological disorders.

SOHO State of the Art Updates and Next Questions | Diagnosis, Outcomes, and Management of Prefibrotic Myelofibrosis

Prefibrotic primary myelofibrosis (prefibrotic PMF) is a myeloproliferative neoplasm with distinct characteristics comprising histopathological and clinico-biological parameters. It is classified as a subtype of primary myelofibrosis. In clinical practice, it is essential to correctly distinguish prefibrotic PMF from essential thrombocythemia especially but also overt PMF besides other myeloid neoplasms. Risk stratification and survival outcomes for prefibrotic PMF are worse than that of ET but better than that of overt PMF. Rates of progression to overt PMF and blast phase disease are also higher for prefibrotic PMF than ET. In this review we first discuss the historical context to the evolution of prefibrotic PMF as an entity, its presenting features and diagnostic criteria. We emphasize the differences between prefibrotic PMF, ET, and overt PMF with regards to presenting features and disease outcomes including thrombohemorrhagic events and progression to fibrotic and blast phase disease. Next, we discuss the risk stratification models and contextualize these in the setting of clinical management. We share our view of personalizing treatment to address unique patient needs in the context of currently available management options. Lastly, we discuss areas of critical need in clinical research and speculate on the possibility of future disease course modifying therapies in prefibrotic PMF.

Effect of ferric citrate hydrate on fibroblast growth factor 23 and platelets in non-dialysis-dependent chronic kidney disease and non-chronic kidney disease patients with iron deficiency anemia

BACKGROUND

Iron deficiency anemia (IDA) increases levels of C-terminal fibroblast growth factor 23 (cFGF23) and platelet count (PLT), each of which is associated with cardiovascular events. Therefore, we hypothesized that iron replacement with ferric citrate hydrate (FC) would decrease cFGF23 levels and PLT in patients with IDA.

METHODS

In a randomized, open-label, multicenter, 24-week clinical trial, patients with non-dialysis-dependent chronic kidney disease (CKD) and non-CKD complicated by IDA (8.0 ≤ hemoglobin < 11.0 g/dL; and serum ferritin < 50 ng/mL [CKD]; < 12 ng/mL [non-CKD]) were randomized 1:1 to FC-low (500 mg: approximately 120 mg elemental iron/day) or FC-high (1000 mg: approximately 240 mg elemental iron/day). If sufficient iron replacement had been achieved after week 8, further treatment was discontinued.

RESULTS

Seventy-three patients were allocated to FC-low (CKD n = 21, non-CKD n = 15) and FC-high (CKD n = 21, non-CKD n = 16). Regardless of CKD status, FC increased serum ferritin and transferrin saturation, did not change intact FGF23 or serum phosphorus, but decreased cFGF23. In FC-low group, median changes in cFGF23 from baseline to week 8 were -58.00 RU/mL in CKD and -725.00 RU/mL in non-CKD; in FC-high group, the median changes were -66.00 RU/mL in CKD and -649.50 RU/mL in non-CKD. By week 8, FC treatment normalized PLT in all patients with high PLT at baseline (>35.2 × 104/µL; FC-low: 1 CKD, 8 non-CKD; FC-high: 3 CKD, 8 non-CKD).

CONCLUSION

Regardless of CKD status, iron replacement with FC decreased elevated cFGF23 levels and normalized elevated PLT in patients with IDA.

CLINICAL TRIAL REGISTRATION NUMBER

jRCT2080223943.

Primary intradural Extraosseous Ewing's sarcoma of the cauda equina: A case report and literature review

Intradural Extraosseous Ewing sarcoma (IEES) is an infrequent occurrence. We report a case of a 66-year-old male who presented with a 2-month history of low back pain and bilateral S1 sciatica, with acute sphincter dysfunction. Imaging studies revealed an intradural extramedullary lesion in the cauda equina spanning from level L4 to S1. The patient underwent partial removal of the intradural lesion. Histopathological examination showed the presence of small round cells, which were consistent with Ewing Sarcoma. The patient was then treated with targeted radiation therapy and chemotherapy. The rarity of IEES in this specific location underscores the significance of evaluating and managing patients with intradural spinal tumors with careful consideration of this diagnosis. To further investigate this condition, we conducted a thorough review of the literature on IEES involving the lumbar spine and cauda equina. Our analysis revealed that patients with this condition frequently exhibit rapidly progressive neurological symptoms likely attributed to hemorrhagic transformation. This characteristic may serve as a distinguishing factor from other lesion types, particularly benign ones. Our study provides a comprehensive summary that can offer direction for clinical management in comparable uncommon and novel cases.

Overview of dyslipidemia and metabolic syndrome in myeloproliferative neoplasms

Myeloproliferative neoplasms (MPNs) occur due to the abnormal proliferation of one or more terminal myeloid cell lines in peripheral blood. Subjects suffering from MPNs display a high burden of cardiovascular risk factors, and thrombotic events are often the cause of death in this population of patients. Herein, we provide a brief overview of dyslipidemia and metabolic syndrome and their epidemiology in MPNs and examine the common molecular mechanisms between dyslipidemia, metabolic syndrome, and MPNs, with a special focus on cardiovascular risk, atherosclerosis, and thrombotic events. Furthermore, we investigate the impact of dyslipidemia and metabolic syndrome on the occurrence and survival of thrombosis in MPN patients, as well as the management of dyslipidemia in MPNs, and the impact of MPN treatment on serum lipid concentrations, particularly as side/adverse effects reported in the context of clinical trials.

Clinical and Economic Implications of Hydroxyurea Intolerance in Polycythemia Vera in Routine Clinical Practice

Background/Objectives: Polycythemia vera (PV) is a chronic hematologic neoplasm commonly treated with hydroxyurea (HU). We utilized the advanced digitalized database of Maccabi Healthcare Services to retrospectively investigate the clinical and economic implications of HU intolerance in the routine clinical care of PV patients in Israel. Methods: We collected data on demographics, physician visits, hospitalizations, laboratory results, medication purchases, cardiovascular and thrombotic events, mental health, economic outcomes, and mortality. Outcomes included cardiovascular and other thrombotic events, disease progression, mental health events, economic outcomes, and overall mortality. Results: Of the 830 patients studied, 3 (0.4%) were resistant to HU treatment, 318 (38.3%) were intolerant to HU treatment, and 509 (61.3%) were stable on HU treatment. The venous thrombosis rate was significantly higher among HU-intolerant compared to HU-stable patients (1.58 vs. 0.47 per 100 person-years [PY], respectively; p < 0.001). The rate of progression to myelofibrosis was 6 vs. 0.9 per 100 PY in HU-intolerant patients vs. HU-stable patients, respectively (p < 0.001), and the rate of progression to acute myeloid leukemia (AML) was 1.16 vs. 0.2 per 100 PY in HU-intolerant patients vs. HU-stable patients, respectively (p < 0.001). The phlebotomy requirement, mortality rate, and total hospitalization days among HU-intolerant patients were significantly higher than in HU-stable patients (p = 0.049, p < 0.001, p < 0.001, respectively). More mental health-related events were noted in HU-intolerant patients vs. HU-stable patients (p = 0.007), and the total healthcare cost ratio was 2.65 for the HU-intolerant patients compared with HU-stable patients. Conclusions: This study suggests that HU-intolerant patients are more likely to have worse outcomes than HU-stable patients, highlighting the need for the close monitoring of these patients for disease-related complications or progression.

The clinical significance of TAT, PIC, TM, and t-PAIC in vascular events of BCR/ABL-negative myeloproliferative neoplasms

Predicting the likelihood vascular events in patients with BCR/ABL1-negative myeloproliferative neoplasms (MPN) is essential for the treatment of the disease. However, effective assessment methods are lacking. Thrombin-antithrombin complex (TAT), plasmin-α2- plasmininhibitor complex (PIC), thrombomodulin (TM), and tissue plasminogen activator-inhibitor complex (t-PAIC) are the new direct indicators for coagulation and fibrinolysis. The aim of this study was to investigate the changes of these four new indicators in thrombotic and hemorrhagic events in BCR/ABL1-negative MPN. The study cohort of 74 patients with BCR/ABL negative myeloproliferative disorders included essential thrombocythemia, polycythemia vera, and primary myelofibrosis (PMF). A panel of 4 biomarkers, including TAT, PIC, TM, and t-PAIC were determined using Sysmex HISCL5000 automated analyzers, whereas fibrin/fibrinogen degradation products (FDP), D-dimer and Antithrombin III (ATIII) were analyzed using Sysmex CS5100 coagulation analyzer. A total of 24 (32.4%) patients experienced thrombotic events and hemorrhagic events occurred in 8 patients (10.8%). Compared to patients without hemorrhagic-thrombotic events, patients with thrombotic events had higher fibrinogen (FIB) level, FDP level and lower ATIII activity, while patients with hemorrhagic events had lower white blood cell count and hemoglobin level, higher FDP level (P < 0.05). Patients with a JAK2V617F mutation were more likely to experience thrombotic events (P < 0.05). In addtion, patients with thrombotic events had higher TAT, PIC, TM, and t-PAIC levels than patients without hemorrhagic-thrombotic events (P < 0.05), whereas patients with hemorrhagic events had a lower median value in TAT and TM (no statistical difference, P > 0.05). Patients with higher TAT, TM and t-PAIC were more likely to experience thrombotic events (P < 0.05), and only TAT was positively correlated with thrombotic events (Spearman  r =0.287, P = 0.019). TAT, PIC, TM, and t-PAIC combined with ATIII and FDP have a certain value for predicting thrombosis in patients with BCR/ABL1-negative MPN. These 6 parameters are worth further exploration as predictive factors and prognostic markers for early thrombotic events.

Broad Next-Generation Integrated Sequencing of Myelofibrosis Identifies Disease-Specific and Age-Related Genomic Alterations

PURPOSE

Myeloproliferative neoplasms (MPN) are characterized by the overproduction of differentiated myeloid cells. Mutations in JAK2, CALR, and MPL are considered drivers of Bcr-Abl-ve MPN, including essential thrombocythemia (ET), polycythemia vera (PV), prefibrotic primary myelofibrosis (prePMF), and overt myelofibrosis (MF). However, how these driver mutations lead to phenotypically distinct and/or overlapping diseases is unclear.

EXPERIMENTAL DESIGN

To compare the genetic landscape of MF to ET/PV/PrePMF, we sequenced 1,711 genes for mutations along with whole transcriptome RNA sequencing of 137 patients with MPN.

RESULTS

In addition to driver mutations, 234 and 74 genes were found to be mutated in overt MF (N = 106) and ET/PV/PrePMF (N = 31), respectively. Overt MF had more mutations compared with ET/PV/prePMF (5 vs. 4 per subject, P = 0.006). Genes frequently mutated in MF included high-risk genes (ASXL1, SRSF2, EZH2, IDH1/2, and U2AF1) and Ras pathway genes. Mutations in NRAS, KRAS, SRSF2, EZH2, IDH2, and NF1 were exclusive to MF. Advancing age, higher DIPSS, and poor overall survival (OS) correlated with increased variants in MF. Ras mutations were associated with higher leukocytes and platelets and poor OS. The comparison of gene expression showed upregulation of proliferation and inflammatory pathways in MF. Notably, ADGRL4, DNASE1L3, PLEKHGB4, HSPG2, MAMDC2, and DPYSL3 were differentially expressed in hematopoietic stem and differentiated cells.

CONCLUSIONS

Our results illustrate that evolution of MF from ET/PV/PrePMF likely advances with age, accumulation of mutations, and activation of proliferative pathways. The genes and pathways identified by integrated genomics approach provide insight into disease transformation and progression and potential targets for therapeutic intervention.

Association of Higher Hemoglobin Level With Significant Carotid Artery Plaque in the General Population

Objective

Serum hemoglobin (Hb) level affects the viscosity of blood. Several studies have reported that Hb level is associated with adverse cardiovascular outcome. However, there is a paucity of evidence on the association between serum Hb level and the risk of subclinical atherosclerosis. Thus, the objective of this study was to investigate the relationship between Hb level and risk of carotid plaque in a health checkup cohort.

Methods

This retrospective study analyzed a total of 3,805 individuals without history of cardiovascular disease (CVD) who underwent carotid ultrasonography (USG) between January 2016 and June 2018. Participants were divided into 4 groups based on Hb quartiles in each of male and female. Carotid plaque score was calculated based on USG reports. Multivariable logistic regression analysis was performed for each index of quartile groups regarding the risk of carotid plaque.

Results

Of 3,805 individuals (mean age, 52.62±10.25 years; 2,674 [70.28%] males), mean Hb level was 15.11±0.75 g/dL in male and 13.35±0.74 g/dL in female. When the Q1 group was compared to the Q4, increasing quartile of Hb was associated with the presence of significant carotid plaque (plaque score ≥3) in male (adjusted odds ratio [OR], 1.538; 95% confidence interval [CI], 1.182-2.001; p=0.001) and female (adjusted OR, 1.749; 95% CI, 1.058-2.676; p=0.01).

Conclusion

A high Hb level is associated with an increased risk of carotid plaques in individuals without history of CVD. This finding may support the need for early screening of CVD in individuals with high Hb levels.

The Systemic Inflammation Index: A New Candidate Minor Criterion in the Diagnosis of Polycythemia Vera

AIM

To investigate inflammation indices and erythropoietin levels for their potential role in distinguishing polycythemia vera from secondary polycythemia and to compare different parameter combinations in terms of the diagnostic accuracy.

METHODS

This retrospective cohort was created from patients assessed for polycythemia from January 2020 to December 2023. Polycythemia vera diagnosis was made according to the 2016 World Health Organization criteria (n = 145). Those who did not fulfill the criteria were defined as having secondary polycythemia (n = 84).

RESULTS

The neutrophil lymphocyte ratio, platelet lymphocyte ratio and systemic immune-inflammation index were significantly higher in the polycythemia vera group (p < 0.001 for all). Erythropoietin had the highest area under the curve in the analysis to distinguish groups, followed by the systemic immune-inflammation index. The platelet lymphocyte ratio (≥135) had the highest specificity to detect polycythemia vera, followed closely by the systemic immune-inflammation index. The sensitivity for polycythemia vera detection was highest with the erythropoietin and systemic immune-inflammation index combination, followed by erythropoietin and the neutrophil lymphocyte ratio. All the single and combinatory variables exhibited significant performance in predicting polycythemia vera after adjusting for age and sex. However, the erythropoietin and systemic immune-inflammation index combination had the highest odds ratio, followed by erythropoietin alone.

CONCLUSION

These are promising findings supporting the usability of these biomarkers, especially the systemic immune-inflammation index, as minor criteria in the diagnosis of polycythemia vera. It is especially crucial to note that using erythropoietin in combination with these markers may improve diagnostic accuracy.

Evaluation of Absolute Neutrophil, Lymphocyte and Platelet Count and Their Ratios as Predictors of Thrombotic Risk in Patients with Prefibrotic and Overt Myelofibrosis

AIM

To investigate the prognostic contribution of absolute neutrophil (ANC), lymphocyte (ALC), platelet count and their ratios, neutrophil-lymphocyte ratio (NLR) and platelet-lymphocyte ratio (PLR), to thrombotic risk in patients with prefibrotic and overt fibrotic myelofibrosis (MF).

METHODS

We retrospectively analyzed a cohort of 256 patients with prefibrotic (85 patients) and overt fibrotic MF (171 patients) treated in six Croatian hematological centers.

RESULTS

Prefibrotic compared to overt fibrotic MF patients presented with significantly higher ALC, platelet count and PLR, and experienced longer time to thrombosis (TTT). Among prefibrotic patients, ANC > 8.33 × 109/L (HR 13.08, p = 0.036), ALC > 2.58 × 109/L (HR 20.63, p = 0.049) and platelet count > 752 × 109/L (HR 10.5, p = 0.043) remained independently associated with shorter TTT. Among overt fibrotic patients, ANC > 8.8 × 109/L (HR 4.49, p = 0.004), ALC ≤ 1.43 × 109/L (HR 4.15, p = 0.003), platelet count ≤ 385 × 109/L (HR 4.68, p = 0.004) and chronic kidney disease (HR 9.07, p < 0.001) remained independently associated with shorter TTT.

CONCLUSIONS

Prognostic properties of ANC, ALC and platelet count are mutually independent and exceed those of NLR and PLR regarding thrombotic risk stratification. ALC and platelet count associate in opposite directions with thrombotic risk in prefibrotic and overt fibrotic MF patients.

Effective Management of Polycythemia Vera With Ropeginterferon Alfa-2b Treatment

Background

Polycythemia vera (PV) is a myeloproliferative neoplasm. Ropeginterferon alfa-2b is a new-generation polyethylene glycol-conjugated proline-interferon. It is approved for the treatment of PV at a starting dose of 100 µg (50 µg for patients receiving hydroxyurea (HU)) and dose titrations up to 500 µg by 50 µg increments. The study was aimed at assessing its efficacy and safety at a higher starting dose and simpler intra-patient dose escalation.

Methods

Forty-nine patients with PV having HU intolerance from major hospitals in China were treated biweekly with an initial dose of 250 µg, followed by 350 µg and 500 µg thereafter if tolerated. Complete hematological response (CHR) was assessed every 12 weeks based on the European LeukemiaNet criteria. The primary endpoint was the CHR rate at week 24. The secondary endpoints included CHR rates at weeks 12, 36 and 52, changes of JAK2V617F allelic burden, time to first CHR, and safety assessments.

Results

The CHR rates were 61.2%, 69.4% and 71.4% at weeks 24, 36, and 52, respectively. Mean allele burden of the driver mutation JAK2V617F declined from 58.5% at baseline to 30.1% at 52 weeks. Both CHR and JAK2V617F allele burden reduction showed consistent increases over the 52 weeks of the treatment. Twenty-nine patients (63.0%) achieved partial molecular response (PMR) and two achieved complete molecular response (CMR). The time to CHR was rapid and median time was 5.6 months according to central lab results. The CHRs were durable and median CHR duration time was not reached at week 52. Mean spleen index reduced from 55.6 cm2 at baseline to 50.2 cm2 at week 52. Adverse events (AEs) were mostly mild or moderate. Most common AEs were reversible alanine aminotransferase and aspartate aminotransferase increases, which were not associated with significant elevations in bilirubin levels or jaundice. There were no grade 4 or 5 AEs. Grade 3 AEs were reversible and manageable. Only one AE led to discontinuation. No incidence of thromboembolic events was observed.

Conclusion

The 250-350-500 µg dosing regimen was well tolerated and effectively induced CHR and MR and managed spleen size increase. Our findings demonstrate that ropeginterferon alfa-2b at this dosing regimen can provide an effective management of PV and support using this dosing regimen as a treatment option.

Eosinophilic Myocarditis Resulting in Ventricular Tachycardia Storm

Eosinophilic myocarditis (EM) is a rare but potentially fatal complication of sustained eosinophilia that is characterized by eosinophilic infiltration into myocardial tissue. There are various etiologies of EM that can be classified into general categories: reactive, clonal, and idiopathic. We present a case of EM caused by chronic eosinophilic leukemia, a rare myeloproliferative neoplasm that frequently presents with sustained peripheral eosinophilia. This case displays several serious complications of EM, including recurrent ventricular tachycardia storm, cardiogenic shock, and mural thrombus formation despite anticoagulation. Diagnosis of EM can be difficult as formal diagnosis requires an endomyocardial biopsy. Once EM is suspected, identifying the underlying etiology of eosinophilia is critical for timely implementation of disease-specific therapy.

Newly identified roles for PIEZO1 mechanosensor in controlling normal megakaryocyte development and in primary myelofibrosis

Mechanisms through which mature megakaryocytes (Mks) and their progenitors sense the bone marrow extracellular matrix to promote lineage differentiation in health and disease are still partially understood. We found PIEZO1, a mechanosensitive cation channel, to be expressed in mouse and human Mks. Human mutations in PIEZO1 have been described to be associated with blood cell disorders. Yet, a role for PIEZO1 in megakaryopoiesis and proplatelet formation has never been investigated. Here, we show that activation of PIEZO1 increases the number of immature Mks in mice, while the number of mature Mks and Mk ploidy level are reduced. Piezo1/2 knockout mice show an increase in Mk size and platelet count, both at basal state and upon marrow regeneration. Similarly, in human samples, PIEZO1 is expressed during megakaryopoiesis. Its activation reduces Mk size, ploidy, maturation, and proplatelet extension. Resulting effects of PIEZO1 activation on Mks resemble the profile in Primary Myelofibrosis (PMF). Intriguingly, Mks derived from Jak2V617F PMF mice show significantly elevated PIEZO1 expression, compared to wild-type controls. Accordingly, Mks isolated from bone marrow aspirates of JAK2V617F PMF patients show increased PIEZO1 expression compared to Essential Thrombocythemia. Most importantly, PIEZO1 expression in bone marrow Mks is inversely correlated with patient platelet count. The ploidy, maturation, and proplatelet formation of Mks from JAK2V617F PMF patients are rescued upon PIEZO1 inhibition. Together, our data suggest that PIEZO1 places a brake on Mk maturation and platelet formation in physiology, and its upregulation in PMF Mks might contribute to aggravating some hallmarks of the disease.

Interferons in the treatment of myeloproliferative neoplasms

Interferons are cytokines with immunomodulatory properties and disease-modifying effects that have been used to treat myeloproliferative neoplasms (MPNs) for more than 35 years. The initial use of interferons was limited due to difficulties with administration and a significant toxicity profile. Many of these shortcomings were addressed by covalently binding polyethylene glycol to the interferon structure, which increases the stability, prolongs activity, and reduces immunogenicity of the molecule. In the current therapeutic landscape, pegylated interferons are recommended for use in the treatment of polycythemia vera, essential thrombocythemia, and primary myelofibrosis. We review recent efficacy, molecular response, and safety data for the two available pegylated interferons, peginterferon alfa-2a (Pegasys) and ropeginterferon alfa-2b-njft (BESREMi). The practical management of interferon-based therapies is discussed, along with our opinions on whether to and how to switch from hydroxyurea to one of these therapies. Key topics and questions related to use of interferons, such as their safety and tolerability, the significance of variant allele frequency, advantages of early treatment, and what the future of interferon therapy may look like, will be examined. Pegylated interferons represent an important therapeutic option for patients with MPNs; however, more research is still required to further refine interferon therapy.

Mesenchymal stromal cells in myeloid malignancies: Immunotherapeutic opportunities

Myeloid malignancies are clonal disorders of the progenitor cells or hematopoietic stem cells, including acute myeloid leukemia, myelodysplastic syndromes, myeloproliferative malignancies, and chronic myelomonocytic leukemia. Myeloid neoplastic cells affect the proliferation and differentiation of other hematopoietic lineages in the bone marrow and peripheral blood, leading to severe and life-threatening complications. Mesenchymal stromal cells (MSCs) residing in the bone marrow exert immunosuppressive functions by suppressing innate and adaptive immune systems, thus creating a supportive and tolerant microenvironment for myeloid malignancy progression. This review summarizes the significant features of MSCs in myeloid malignancies, including their role in regulating cell growth, cell death, and antineoplastic resistance, in addition to their immunosuppressive contributions. Understanding the implications of MSCs in myeloid malignancies could pave the path for potential use in immunotherapy.

Variability of bone marrow biopsy reporting affects accuracy of diagnosis of myeloproliferative neoplasms: data from the ALLG MPN01 registry

The Philadelphia-negative myeloproliferative neoplasms (MPN) are a heterogeneous group of overlapping bone marrow disorders defined by characteristic peripheral blood counts and bone marrow morphological findings in conjunction with recurrent somatic mutations. The accurate diagnosis and subclassification of MPN relies upon careful reporting of bone marrow morphology combined with ancillary information in an integrated pathology report. This co-operative trial group study ALLG MPN01 (ANZCTR:12613000138785), led by the Australasian Leukaemia & Lymphoma Group (ALLG), aimed to describe the current approach to diagnosis of MPN in routine practice. Specifically, we assessed the frequency with which bone marrow biopsies were performed, and the adherence of reporting pathologists to recommendations contained in the revised 2016 WHO classification pertaining to MPN. We reviewed the diagnosis of 152 patients from eight institutions who were enrolled in a national MPN registry of the ALLG between 2010 and 2016. The ALLG MPN01 registry is now closed to recruitment. Key features were extracted from pathology reports provided to the registry. Bone marrow biopsies were performed in 112/152 cases (74%). The pathological information entered was concordant with the stated clinical diagnosis in 75/112 cases (67%). The main reasons for discordant results were incomplete descriptions of megakaryocyte topography and morphology, inconsistent grading of reticulin fibrosis, and failure to integrate the available morphological and ancillary clinicopathological information. In this retrospective audit, 26% of MPN patients did not undergo a diagnostic bone marrow biopsy. In those who did, the specific MPN subtype may not have been reported correctly in 33% of cases, as evidenced by inconsistent features reported or insufficient information to assess. A more standardised approach to bone marrow reporting is required to ensure accuracy of MPN diagnoses and consistent reporting to cancer registries and clinical trials.

Multiomic profiling reveals metabolic alterations mediating aberrant platelet activity and inflammation in myeloproliferative neoplasms

Platelets from patients with myeloproliferative neoplasms (MPNs) exhibit a hyperreactive phenotype. Here, we found elevated P-selectin exposure and platelet-leukocyte aggregates indicating activation of platelets from essential thrombocythemia (ET) patients. Single-cell RNA-seq analysis of primary samples revealed significant enrichment of transcripts related to platelet activation, mTOR, and oxidative phosphorylation in ET patient platelets. These observations were validated via proteomic profiling. Platelet metabolomics revealed distinct metabolic phenotypes consisting of elevated ATP generation accompanied by increases in the levels of multiple intermediates of the tricarboxylic acid cycle, but lower α-ketoglutarate (α-KG) in MPN patients. Inhibition of PI3K/AKT/mTOR signaling significantly reduced metabolic responses and hyperreactivity in MPN patient platelets, while α-KG supplementation markedly reduced oxygen consumption and ATP generation. Ex vivo incubation of platelets from both MPN patients and Jak2 V617F-knockin mice with α-KG supplementation significantly reduced platelet activation responses. Oral α-KG supplementation of Jak2 V617F mice decreased splenomegaly and reduced hematocrit, monocyte, and platelet counts. Finally, α-KG treatment significantly decreased proinflammatory cytokine secretion from MPN CD14+ monocytes. Our results reveal a previously unrecognized metabolic disorder in conjunction with aberrant PI3K/AKT/mTOR signaling that contributes to platelet hyperreactivity in MPN patients.

A case of acute liver failure caused by Budd-Chiari syndrome salvaged by brain-dead donor liver transplantation

A 24-year-old man was admitted to our hospital with abdominal distension. He was found to have acute liver failure and diagnosed with Budd-Chiari syndrome based on angiography and liver biopsy. Liver transplantation was deemed necessary when angiography showed extensive thrombotic occlusion of the hepatic veins and liver biopsy revealed submassive hepatic necrosis. The patient was found to have the JAK2V617F mutation, indicating a myeloproliferative neoplasm as the background disease. He developed hepatic encephalopathy but remained conscious on on-line hemodiafiltration. Brain-dead donor liver transplantation was performed on hospital day 30. Since then, the patient has remained well.

A novel clinical prediction scoring system of high-altitude pulmonary hypertension

Background

High-altitude pulmonary hypertension (HAPH) is a common disease in regions of high altitude where performing right heart catheterization (RHC) is challenging. The development of a diagnostic scoring system is crucial for effective disease screening.

Methods

A total of 148 individuals were included in a retrospective analysis, and an additional 42 residents were prospectively enrolled. We conducted a multivariable analysis to identify independent predictors of HAPH. Subsequently, we devised a prediction score based on the retrospective training set to anticipate the occurrence and severity of HAPH. This scoring system was further subjected to validation in the prospective cohort, in which all participants underwent RHC.

Results

This scoring system, referred to as the GENTH score model (Glycated hemoglobin [OR = 4.5], Echocardiography sign [OR = 9.1], New York Heart Association-functional class [OR = 12.5], Total bilirubin [OR = 3.3], and Hematocrit [OR = 3.6]), incorporated five independent risk factors and demonstrated strong predictive accuracy. In the training set, the area under the curve (AUC) values for predicting the occurrence and severity of HAPH were 0.851 and 0.832, respectively, while in the validation set, they were 0.841 and 0.893. In the validation set, GENTH score model cutoff values of ≤18 or >18 points were established for excluding or confirming HAPH, and a threshold of >30 points indicated severe HAPH.

Conclusions

The GENTH score model, combining laboratory and echocardiography indicators, represents an effective tool for distinguishing potential HAPH patients and identifying those with severe HAPH. This scoring system improves the clinical screening of HAPH diseases and offers valuable insights into disease diagnosis and management.

Hematologic malignancies and hematopoietic stem cell transplantation

Paraneoplastic neurologic syndromes are rarely associated with hematologic malignancies. In their rarity, lymphomas are the diseases with more frequent paraneoplastic neurologic syndrome. High-risk antibodies are absent in most lymphoma-associated paraneoplastic neurologic syndromes, with the exception of antibodies to Tr/DNER in paraneoplastic cerebellar degeneration, mGluR5 in limbic encephalitis, and mGluR1 in some cerebellar ataxias. Peripheral nervous system paraneoplastic neurologic syndromes are rare and heterogeneous, with a prevalence of demyelinating polyradiculoneuropathy in non-Hodgkin lymphoma. Polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy, skin changes (POEMS) is a rare, paraneoplastic syndrome due to an underlying plasma cell disorder. The diagnosis is based on defined criteria, and vascular endothelial growth factor (VEGF), not an antibody, is considered a reliable diagnostic marker that also mirrors therapy response. As with the paraneoplastic neurologic syndromes in solid tumors, therapies rely on cancer treatment associated with immunomodulatory treatment with better response in PNS with antibodies to surface antigens. The best outcome is generally present in Ophelia syndrome/limbic encephalitis with anti-mGluR5 antibodies, with frequent complete recovery. Besides patients with isolated osteosclerotic lesions (where radiotherapy is indicated), hematopoietic stem-cell transplantation is the therapy of choice in patients with POEMS syndrome. In the paraneoplastic neurologic syndromes secondary to immune checkpoint inhibitors, discontinuation of the drug together with immunomodulatory treatment is recommended.

Thrombotic Prediction Model Based on Epigenetic Regulator Mutations in Essential Thrombocythemia Patients Using Survival Analysis in Recurrent Events

INTRODUCTION

Essential thrombocythemia (ET) involves the proliferation of megakaryocytes and platelets and is associated with an increased risk of thrombosis. We aimed to evaluate thrombotic risks in patients with epigenetic regulator mutations and generate a model to predict thrombosis in ET.

MATERIALS AND METHODS

This cohort study enrolled patients aged > 15 years diagnosed with ET at the Songklanakarind Hospital between January 2002 and December 2019. Twenty-five targeted gene mutations, including somatic driver mutations (JAK2, CALR, MPL), epigenetic regulator mutations (TET2, DNMT3A, IDH1, IDH2, TET2, ASXL1, EZH2, SF3B1, SRSF2) and other genes relevant to myeloid neoplasms, were identified using next-generation sequencing. Thrombotic events were confirmed based on clinical condition and imaging findings, and thrombotic risks were analyzed using five survival models with the recurrent event method.

RESULTS

Ninety-six patients were enrolled with a median follow-up of 6.91 years. Of these, 15 patients experienced 17 arterial thrombotic events in total. Patients with JAK2 mutation and IDH1 mutation had the highest frequency of thrombotic events with somatic driver mutations (17.3%) and epigenetic regulator mutations (100%). The 10-year thrombosis-free survival rate was 81.3% (95% confidence interval: 72.0-91.8%). IDH1 mutation was a significant factor for thrombotic risk in the multivariate analysis for all models. The Prentice, William, and Peterson (PWP) gap-time model was the most appropriate prediction model.

CONCLUSIONS

The PWP gap-time model was a good predictive model for thrombotic risk in patients with ET. IDH1 mutation was significant risk factors for thrombosis; however, further studies with a larger sample size should confirm this and provide more insight.

Treatment of anemia in myelofibrosis: focusing on novel therapeutic options

INTRODUCTION

Myelofibrosis is a clonal myeloproliferative neoplasm associated with the proliferation of hematopoietic stem cells, increased bone marrow fibrosis, extramedullary hematopoiesis, hepatosplenomegaly, abnormal cytokine production, and constitutional symptoms. These and many other factors contribute to the development of anemia in myelofibrosis patients.

AREAS COVERED

This review summarizes novel and promising treatments for anemia in myelofibrosis including transforming growth factor-β inhibitors luspatercept and KER-050, JAK inhibitors momelotinib, pacritinib, and jaktinib, BET inhibitors pelabresib and ABBV-744, antifibrotic PRM-151, BCL2/BCL-XL inhibitor navitoclax, and telomerase inhibitor imetelstat.

EXPERT OPINION

Standard approaches to treat myelofibrosis-related anemia have limited efficacy and are associated with toxicity. New drugs have shown positive results in myelofibrosis-associated anemia when used alone or in combination.

Recent advances in the application of induced pluripotent stem cell technology to the study of myeloid malignancies

Acquired myeloid malignancies are a spectrum of clonal disorders known to be caused by sequential acquisition of genetic lesions in hematopoietic stem and progenitor cells, leading to their aberrant self-renewal and differentiation. The increasing use of induced pluripotent stem cell (iPSC) technology to study myeloid malignancies has helped usher a paradigm shift in approaches to disease modeling and drug discovery, especially when combined with gene-editing technology. The process of reprogramming allows for the capture of the diversity of genetic lesions and mutational burden found in primary patient samples into individual stable iPSC lines. Patient-derived iPSC lines, owing to their self-renewal and differentiation capacity, can thus be a homogenous source of disease relevant material that allow for the study of disease pathogenesis using various functional read-outs. Furthermore, genome editing technologies like CRISPR/Cas9 enable the study of the stepwise progression from normal to malignant hematopoiesis through the introduction of specific driver mutations, individually or in combination, to create isogenic lines for comparison. In this review, we survey the current use of iPSCs to model acquired myeloid malignancies including myelodysplastic syndromes (MDS), myeloproliferative neoplasms (MPN), acute myeloid leukemia and MDS/MPN overlap syndromes. The use of iPSCs has enabled the interrogation of the underlying mechanism of initiation and progression driving these diseases. It has also made drug testing, repurposing, and the discovery of novel therapies for these diseases possible in a high throughput setting.

Reduced Proteolipid Protein 2 promotes endoplasmic reticulum stress-related apoptosis and increases drug sensitivity in acute myeloid leukemia

BACKGROUND

The Proteolipid Protein 2 (PLP2), a protein in the Endoplasmic Reticulum (ER) membrane, has been reported to be highly expressed in various tumors. Previous studies have demonstrated that the reduced PLP2 can induce apoptosis and autophagy through ER stress-related pathways, leading to a decreased proliferation and aggressiveness. However, there is no research literature on the role of PLP2 in Acute Myeloid Leukemia (AML).

METHODS

PLP2 expression, clinical data, genetic mutations, and karyotype changes from GEO, TCGA, and timer2.0 databases were analyzed through the R packages. The possible functions and pathways of cells were explored through GO, KEGG, and GSEA enrichment analysis using the clusterProfiler R package. Immuno-infiltration analysis was conducted using the Cibersort algorithm and the Xcell R package. RT-PCR and western blot techniques were employed to identify the PLP2 expression, examine the knockdown effects in THP-1 cells, and assess the expression of genes associated with endoplasmic reticulum stress and apoptosis. Flow cytometry was utilized to determine the apoptosis and survival rates of different groups.

RESULTS

PLP2 expression was observed in different subsets of AML and other cancers. Enrichment analyses revealed that PLP2 was involved in various tumor-related biological processes, primarily apoptosis and lysosomal functions. Additionally, PLP2 expression showed a strong association with immune cell infiltration, particularly monocytes. In vitro, the knockdown of PLP2 enhanced endoplasmic reticulum stress-related apoptosis and increased drug sensitivity in THP-1 cells.

CONCLUSIONS

PLP2 could be a novel therapeutic target in AML, in addition, PLP2 is a potential endoplasmic reticulum stress regulatory gene in AML.

The aetiology and burden of myeloproliferative neoplasms in the United Kingdom: the MyelOproliferative neoplasmS: an In-depth case-control (MOSAICC) study protocol

BACKGROUND

Myeloproliferative neoplasms (MPNs) are a group of haematological malignancies that affect approximately 8 people in every 100,000 individuals in the UK. Little is known about the aetiology of MPNs, as previous studies have been hampered by small sample sizes, thus it is important to understand the cause of MPNs in a larger study to identify prevention strategies and improve treatment strategies. This study aims to determine environmental, lifestyle, genetic and medical causes of MPNs and to assess the relevance of occupational carcinogen exposures and quality of life impacts.

METHODS

A UK-wide case-control study of 610 recently diagnosed MPN patients (within 24 months) receiving clinical care at 21 NHS study sites in Scotland, England, Wales and Northern Ireland and 610 non-blood relative/friend controls is underway. Data on occupational and residential history, medical and environmental factors, and quality of life are being collected from the participants via a structured interview and self-complete questionnaires. Clinical data is being provided by the clinical team. Blood, saliva and toenail samples are also being collected for genetic and elemental analysis. Adjusted odds ratios (ORs) and 95% confidence intervals (95%CI) will be calculated using a p < 0.05 to investigate potential risk factors for the MPN clinical and genetic subtypes, and further analyses will be conducted based on the type of data and outcome of interest at a later stage.

DISCUSSION

The study design is most effective for investigating the aetiology of rare diseases. The study will enable identification of potential causes of MPNs through in-depth assessment of potential risk factors with potential for longer follow-up of a number of outcomes.

Significant heterogeneity in management of calreticulin-mutated essential thrombocythemia and its progression to myelofibrosis: results of a national survey

Despite the recent publication of calreticulin (CALR)-mutated essential thrombocythemia (ET) management guidelines by the European Leukemia Net (ELN), there remains a paucity of data regarding the optimal way to manage this condition. To determine practice around Australia, we constructed a survey asking investigation and treatment questions in a hypothetical case of a young woman with CALR-mutated ET and subsequent progression to myelofibrosis. 51 of 88 hematologists replied. The responses demonstrated significant heterogeneity in specific issues such as the use of aspirin, when to initiate cytoreduction, the preferred type of cytoreduction, and platelet targets. These observations support the ELN acknowledgment that a strong evidence base for many management recommendations is lacking in this disease, and that substantial further research is needed.

Prevalence and diagnostic performance of iron deficiency in polycythemia

INTRODUCTION

Several observations have shown that patients with polycythemia have iron deficiency. Our objectives were to report the prevalence of iron deficiency and to evaluate the diagnostic performance of serum ferritin in polycythemia vera.

PATIENTS AND METHOD

This is a retrospective descriptive and analytical study carried out in the internal medicine department of the Henri Mondor Hospital, Aurillac, France. The study involved 114 patients with polycythemia, followed in the department from January 1, 2010 to December 31, 2021. To evaluate the diagnostic performance, the JAK2 mutation was considered as the gold standard of diagnosis.

RESULTS

Thirty-three patients had polycythemia vera and 76 patients had secondary polycythemia. The mean age of the patients was 61.79 years (±15.44) with a sex ratio of 4.43. The overall prevalence of iron deficiency was 21.05%. The prevalence was 53% in polycythemia vera group and 1.32% in secondary polycythemia group. The risk of iron deficiency was high in polycythemia vera (OR = 115; 95% CI [14.4-918.2], p < 0.0001) and the sensitivity and specificity of serum ferritin were 52.63% and 100% respectively.

CONCLUSION

Assessment of iron deficiency should be part of the initial evaluation of polycythemia. Iron deficiency had a high specificity during polycythemia vera.

The utility of testing erythropoietin level in polycythemia diagnosis

OBJECTIVES

Polycythemia vera (PV) is classically thought to be associated with low erythropoietin (EPO) levels. Here, we present a review of the utility of using EPO levels in diagnosing polycythemia.

METHODS

We conducted a systematic literature review of the Medline data through Pubmed and Google Scholar. We included the articles which described confirmed PV associated with elevated EPO level. Our search strategy included the following terms in Pubmed (((polycythemia vera[MeSH Terms]) OR (jak2 protein tyrosine kinase[MeSH Terms])) OR (Myeloproliferative Disorders[MeSH Terms])) AND (Erythropoietin[MeSH Terms]), and 'polycythemia vera with erythropoietin' in Google Scholar.

RESULTS

Our research yielded four cases of PV with elevated EPO levels. The most common symptom was a headache. Thrombotic phenomena happened in a single case in the form of Budd-Chiari syndrome. The mean Hb level was 20.2 gm/dl, and the EPO level was 213 mlU/mL.

DISCUSSION

Although PV is usually associated with low EPO levels, high levels do not exclude this diagnosis. Workup should include testing for JAK2 mutation and bone marrow biopsy in the presence of suggestive signs and symptoms. Novel biomarkers are also being proposed to aid in the diagnosis.

CONCLUSION

Although elevated EPO levels suggest secondary causes of polycythemia, cases where elevated EPO levels were associated with an underlying PV are reported in the literature, and we have summarized a review of them. Workup for polycythemia should include JAK2 mutation testing if signs and symptoms suggest PV even if EPO is elevated.

Molecular landscape of the JAK2 gene in chronic myeloproliferative neoplasm patients from the state of Amazonas, Brazil

JAK2V617F (dbSNP: rs77375493) is the most frequent and most-studied variant in BCR::ABL1 negative myeloproliferative neoplasms and in the JAK2 gene. The present study aimed to molecularly characterize variants in the complete coding region of the JAK2 gene in patients with BCR::ABL1 negative chronic myeloproliferative neoplasms. The study included 97 patients with BCR::ABL1 negative myeloproliferative neoplasms, including polycythemia vera (n=38), essential thrombocythemia (n=55), and myelofibrosis (n=04). Molecular evaluation was performed using conventional PCR and Sanger sequencing to detect variants in the complete coding region of the JAK2 gene. The presence of missense variants in the JAK2 gene including rs907414891, rs2230723, rs77375493 (JAK2V617F), and rs41316003 were identified. The coexistence of variants was detected in polycythemia vera and essential thrombocythemia. Thus, individuals with high JAK2V617F variant allele frequency (≥50% VAF) presented more thrombo-hemorrhagic events and manifestations of splenomegaly compared with those with low JAK2V617F variant allele frequency (<50% VAF). In conclusion, individuals with BCR::ABL1 negative neoplasms can display >1 variant in the JAK2 gene, especially rs2230722, rs2230724, and rs77375493 variants, and those with high JAK2V617F VAF show alterations in the clinical-laboratory profile compared with those with low JAK2V617F VAF.

Management of classical Philadelphia chromosome-negative myeloproliferative neoplasms in Asia: consensus of the Asian Myeloid Working Group

Myeloproliferative neoplasms (MPN) are a heterogeneous group of clonal hematopoietic stem cell disorders characterized clinically by the proliferation of one or more hematopoietic lineage(s). The classical Philadelphia-chromosome (Ph)-negative MPNs include polycythemia vera (PV), essential thrombocythemia (ET) and primary myelofibrosis (PMF). The Asian Myeloid Working Group (AMWG) comprises representatives from fifteen Asian centers experienced in the management of MPN. This consensus from the AMWG aims to review the current evidence in the risk stratification and treatment of Ph-negative MPN, to identify management gaps for future improvement, and to offer pragmatic approaches for treatment commensurate with different levels of resources, drug availabilities and reimbursement policies in its constituent regions. The management of MPN should be patient-specific and based on accurate diagnostic and prognostic tools. In patients with PV, ET and early/prefibrotic PMF, symptoms and risk stratification will guide the need for early cytoreduction. In younger patients requiring cytoreduction and in those experiencing resistance or intolerance to hydroxyurea, recombinant interferon-α preparations (pegylated interferon-α 2A or ropeginterferon-α 2b) should be considered. In myelofibrosis, continuous risk assessment and symptom burden assessment are essential in guiding treatment selection. Allogeneic hematopoietic stem cell transplantation (allo-HSCT) in MF should always be based on accurate risk stratification for disease-risk and post-HSCT outcome. Management of classical Ph-negative MPN entails accurate diagnosis, cytogenetic and molecular evaluation, risk stratification, and treatment strategies that are outcome-oriented (curative, disease modification, improvement of quality-of-life).

Engagement of Mesenchymal Stromal Cells in the Remodeling of the Bone Marrow Microenvironment in Hematological Cancers

Mesenchymal stromal cells (MSCs) are a subset of heterogeneous, non-hematopoietic fibroblast-like cells which play important roles in tissue repair, inflammation, and immune modulation. MSCs residing in the bone marrow microenvironment (BMME) functionally interact with hematopoietic stem progenitor cells regulating hematopoiesis. However, MSCs have also emerged in recent years as key regulators of the tumor microenvironment. Indeed, they are now considered active players in the pathophysiology of hematologic malignancies rather than passive bystanders in the hematopoietic microenvironment. Once a malignant event occurs, the BMME acquires cellular, molecular, and epigenetic abnormalities affecting tumor growth and progression. In this context, MSC behavior is affected by signals coming from cancer cells. Furthermore, it has been shown that stromal cells themselves play a major role in several hematological malignancies' pathogenesis. This bidirectional crosstalk creates a functional tumor niche unit wherein tumor cells acquire a selective advantage over their normal counterparts and are protected from drug treatment. It is therefore of critical importance to unveil the underlying mechanisms which activate a protumor phenotype of MSCs for defining the unmasked vulnerabilities of hematological cancer cells which could be pharmacologically exploited to disrupt tumor/MSC coupling. The present review focuses on the current knowledge about MSC dysfunction mechanisms in the BMME of hematological cancers, sustaining tumor growth, immune escape, and cancer progression.

An overlooked mimic? Autoimmune myelofibrosis-A scoping review of the literature

BACKGROUND AND OBJECTIVES

Autoimmune myelofibrosis (AIMF) is a rare cause of bone marrow fibrosis (BMF) occurring in the presence or absence of a defined autoimmune disease (secondary or primary AIMF, sAIMF/pAIMF, respectively). Unlike primary myelofibrosis (PMF), AIMF responds well to immunosuppressive therapy with a benign clinical course. Diagnostic criteria for AIMF in opposition to PMF have been lacking, though recent work has helped better characterise molecular and pathological features of AIMF, improving diagnostic precision.

METHODS

Using a modern clinical and pathophysiological understanding of AIMF, we apply scoping review methodology and rigorous case-criteria to retrospectively analyse the case literature. We examine its patient-population, describing patient-associated factors, presentation, bone marrow pathology, genetics, treatment and outcomes.

RESULTS

Fifty-five studies were identified, describing 139 AIMF patients. Patients were mostly young females (~4:1 ratio female:male, median age 40.8 years) and typically presented with cytopenias. Splenomegaly was rare. sAIMF was more common than pAIMF (~3:1 ratio), and most cases responded well to immunosuppressive therapy.

CONCLUSIONS

Our results strengthen the emerging picture of AIMF's patient population, natural history and response to treatment. Further work should continue to use reproducible diagnostic criteria, and explore AIMF's pathophysiology, response to different therapies, and sequelae over larger timescales, as well as differences between pAIMF, sAIMF and PMF.

Upregulated SPAG6 correlates with increased STAT1 and is associated with reduced sensitivity of interferon-α response in BCR::ABL1 negative myeloproliferative neoplasms

Sperm-associated antigen 6 (SPAG6) has been identified as an oncogene or tumor suppressor in various types of human cancer. However, the role of SPAG6 in BCR::ABL1 negative myeloproliferative neoplasms (MPNs) remains unclear. Herein, we found that SPAG6 was upregulated at the mRNA level in primary MPN cells and MPN-derived leukemia cell lines. The SPAG6 protein was primarily located in the cytoplasm around the nucleus and positively correlated with β-tubulin expression. In vitro, forced expression of SPAG6 increased cell clone formation and promoted G1 to S cell cycle progression. Downregulation of SPAG6 promoted apoptosis, reduced G1 to S phase transition, and impaired cell proliferation and cytokine release accompanied by downregulated signal transducer and activator of transcription 1 (STAT1) expression. Furthermore, the inhibitory effect of interferon-α (INF-α) on the primary MPN cells with high SPAG6 expression was decreased. Downregulation of SPAG6 enhanced STAT1 induction, thus enhancing the proapoptotic and cell cycle arrest effects of INF-α both in vitro and in vivo. Finally, a decrease in SPAG6 protein expression was noted when the STAT1 signaling was blocked. Chromatin immunoprecipitation assays indicated that STAT1 protein could bind to the SPAG6 promoter, while the dual-luciferase reporter assay indicated that STAT1 could promote the expression of SPAG6. Our results substantiate the relationship between upregulated SPAG6, increased STAT1, and reduced sensitivity to INF-α response in MPN.