Classification and diagnosis of myeloproliferative neoplasms: the 2008 World Health Organization criteria and point-of-care diagnostic algorithms

Efficacy and safety outcomes in Japanese patients with low-risk polycythemia vera treated with ropeginterferon alfa-2b

Polycythemia vera (PV) is a Philadelphia chromosome-negative myeloproliferative neoplasm characterized by clonal erythrocytosis. A phase 2 study reported that ropeginterferon alfa-2b is a well-tolerated and effective treatment for PV in Japanese patients. This post hoc analysis of the phase 2 data further evaluated outcomes in patients at low risk of thrombosis (low-risk PV). Among 20 patients with low-risk PV, 60.0% (12/20) and 85.0% (17/20) achieved < 45% hematocrit by weeks 24 and 52, respectively. The proportion of responders with complete hematologic response (CHR) was 60.0% (12/20) at week 52, and the median time to response was 11.9 months. The mean JAK2 V617F allele burden decreased from 75.8% at baseline to 53.7% at week 52. No patient experienced thrombosis or bleeding episodes. All patients experienced treatment-emergent adverse events (TEAEs) related to ropeginterferon alfa-2b, but no grade ≥ 3 TEAEs or deaths related to ropeginterferon alfa-2b occurred, and no new safety concerns arose. This analysis indicated that ropeginterferon alfa-2b may be an effective treatment option for Japanese patients with low-risk PV.

Portal vein thrombosis as extraintestinal complications of Crohn's disease: a case report and review of literature

INTRODUCTION

Thrombotic events are more than twice as common in inflammatory bowel disease patients as in the general population. We report an interesting and rare case of portal vein thrombosis as a venous thromboembolic event in the context of extraintestinal manifestations of Crohn's disease. We also conducted a literature review on portal vein thrombosis associated with inflammatory bowel disease, with the following concepts: inflammatory bowel diseases, ulcerative colitis, Crohn's disease, portal vein, and thrombosis.

CASE PRESENTATION

A 24-year-old Syrian female with active chronic Crohn's disease was diagnosed 11 years ago and classified as A1L3B1P according to the Montreal classification. She had no prior surgical history. Her previous medications included azathioprine and prednisolone. Her Crohn's disease activity index was 390 points. Gastroduodenoscopy revealed grade I esophageal varices, a complication of portal hypertension. Meanwhile, a colonoscopy revealed several deep ulcers in the sigmoid, rectum, and descending colon. An investigation of portal vein hypertension revealed portal vein thrombosis. We used corticosteroids to induce remission, followed by tapering; additionally she received ustekinumab to induce and maintain remission. She began on low-molecular-weight heparin for 1 week, warfarin for 3 months, and then apixaban, a novel oral anticoagulant, after excluding antiphospholipid syndrome. Primary prophylaxis for esophageal varices was not required. After 1 year, she achieved clinical, biochemical, and endoscopic remission. Despite 1 year of treatment, a computed tomography scan revealed no improvement in portal vein recanalization.

CONCLUSION

Portal vein thrombosis is a rare and poorly defined complication of inflammatory bowel disease. It is usually exacerbated by inflammatory bowel disease. The symptoms are nonspecific and may mimic a flare-up of inflammatory bowel disease, making the diagnosis difficult. Portal vein Doppler ultrasound for hospital-admitted inflammatory bowel disease patients may contribute to the diagnosis and management of this complication.

ADAMTS13, von Willebrand Factor, Platelet Microparticles, Factor VIII, and Impact of Somatic Mutations in the Pathogenesis of Splanchnic Vein Thrombosis Associated with BCR-ABL-Negative Myeloproliferative Neoplasms

BACKGROUND

Myeloproliferative neoplasms (MPNs) are often associated with splanchnic vein thrombosis (SVT). Not all the factors involved in the thrombotic tendency are currently known.

OBJECTIVES

This study aims to evaluate a possible association between ADAMTS13, von Willebrand factor (VWF), platelet microvesicles (MV), and factor VIII activity (FVIII:C) with thrombotic events in MPN patients.

MATERIALS AND METHODS

In total, 36 consecutive MPN patients with SVT were enrolled. The MPNs were diagnosed based on clinical characteristics and one or more gene mutations among JAK-2, CALR, and MPL. As controls, 50 randomly selected patients with MPN without thrombosis, 50 patients with deep vein thrombosis without MPNs, and 50 healthy blood donors were evaluated. Complete blood count, ADAMTS13, VWF, MV, and FVIII:C in plasma were measured in all the subjects.

RESULTS

The JAK-2 mutation was found in 94% of the patients with SVT, but none were triple-negative for genetic mutations (JAK2 V617F, CALR, MPL, and exon 12). Compared to the normal subjects, in all the MPN patients (with or without SVT), the levels of ADAMTS13 were found to be significantly lower (p < 0.001) and the MV concentrations were significantly higher (p < 0.001). Among the MPN patients, the VWF and FVIII:C levels were significantly higher in the patients with SVT than those without thrombosis (p = 0.007 and p = 0.04, respectively). Splenomegaly was present in 78% of MPN patients with SVT and in 30% of those without SVT (p < 0.001). The ADAMTS13/VWF ratio was reduced in all the patients, but not in the healthy blood donors (p < 0.001).

CONCLUSIONS

The significant increase in circulating MV, VWF, and FVIII:C in the MPN patients and in the patients with thrombosis supports the role of endothelium damage in promoting thrombotic events. In particular, a significant increase in VWF and FVIII:C levels was found in the MPN patients with SVT.

Successful management of VTE with essential thrombocythemia and cavernous transformation of the portal vein in early pregnancy: a case report

Due to the thrombohemorrhagic potential of essential thrombocythemia, pregnancy complicated by essential thrombocythemia should be recognized as a risk factor for obstetric complications. Here, we report the case of a patient with essential thrombocythemia with two significantly different pregnancy outcomes. Her first pregnancy (at 30 years of age) ended with an uneventful term delivery. However, the patient progressed to cavernous transformation of the portal vein in the period between her two pregnancies and subsequently experienced deep venous thrombosis during the first trimester of her second pregnancy (at 36 years of age). The patient's platelet count during pregnancy was within the normal range, so she ignored previous instances of essential thrombocytosis (at 26 years of age). The patient's main symptom was unrelieved pain in her leg. After that, she was successfully treated with anticoagulant throughout her entire pregnancy, resulting in a term vaginal delivery. This case highlights the importance of assessing pregnant patients with essential thrombocythemia according to their risk stratification. Specifically, risk assessments for potential pregnancy complications should take into account advanced maternal age and a previous history of thrombosis. Patients with essential thrombocythemia should be encouraged to participate in preconception counseling for risk assessment and to initiate prophylactic anticoagulation as soon as possible.

The personal impact of living with a myeloproliferative neoplasm

OBJECTIVE

The aim of this study is to gain insight into the physical, psychological and social impact of having a myeloproliferative neoplasm (MPN), a rare type of cancer with an often chronic course.

METHODS

An online survey was conducted among 455 Dutch MPN patients (62.7% female, age M 63) to explore the impact of the disease by measuring the MPN symptom burden (MPN-SAF TSS) and quality of life (QoL) (EORTC QLQ-C30) and its subscales within a hierarchical QoL model. We examined differences in MPN symptom burden and QoL in relation to sociodemographic and disease-related factors. Hierarchical regression analysis was used to explain variances in QoL.

RESULTS

Most patients (97%) experienced MPN-related health complaints, with a significantly higher MPN symptom burden in women (M 31.50) compared to men (M 24.10). Regarding to fatigue and cognitive functioning MPN patients suffered more compared to a reference group of other cancers. MPN subtype or type of treatment did not show significant differences in MPN symptom burden or QoL. However, experiencing side effects, complications or comorbidities significantly negatively affected MPN symptom burden and QoL. 48.8% of patients reported that MPN affected their ability to work. The explained variance in overall QoL was 58%, most importantly by disease progression, comorbidities, MPN symptom burden and role, emotional and social functioning.

CONCLUSION

This study revealed that having an MPN has a negative impact on several domains of QoL. Symptom assessment and support should be included in the healthcare management of MPN patients.

Focal Crescentic Glomerulonephritis Superimposed on Myeloproliferative Disease-Related Glomerulopathy in a Case of Myelofibrosis

Proliferative glomerulonephritis in myelofibrosis is a very rare. Mesangial proliferation and sclerosis with changes of chronic thrombotic microangiopathy have been reported, but pauci-immune focal crescentic glomerulonephritis has not been described so far. Herein, we present a 68-year-old male who was a known case of myelofibrosis and presented with rapidly progressive glomerulonephritis and nephrotic range proteinuria. He was diagnosed as anti-neutrophil cytoplasmic antibody (ANCA)-negative focal crescentic glomerulonephritis, and he responded well to a course of intravenous methylprednisolone and cyclophosphamide. Pauci-immune focal crescentic glomerulonephritis may occur in myelofibrosis without ANCA and may be related to unknown pathogenetic mechanisms in myeloproliferative disorders or suggest any superimposed pathology that might respond well to immunosuppressants.

Clinical characteristics and symptom burden of Thai myeloproliferative neoplasm patients

ABSTRACTObjective Patients living with myeloproliferative neoplasms (MPNs) suffer from symptom burden that affect quality of life. Due to the differences in cultures, climates, and genetic background, we aimed to investigate the symptom burden of Thai MPN patients Methods A comprehensive survey using the MPN-10 questionnaire was carried out between September 1, 2014, and September 30, 2017. The scores obtained were then correlated with clinical outcomes.. Results A total of 145 patients were enrolled. Nearly 90% of patients reported being symptomatic. The mean MPN-10 score was 13.6 (SD = 11). The mean MPN-10 score was highest in PMF, whereas the mean score and intensity of individual items were surprisingly low in ET and PV. Notably, the mean MPN-10 score was significantly higher in patients with documented splenomegaly compared to those with a normal-sized spleen. However, there were no correlations between MPN-10 scores and the mutation status, disease complications such as thrombosis and hemorrhage, progression to myelofibrosis or leukemia, and mortality. Patients who needed regular transfusions reported a higher MPN-10 score compared to those who did not. Conclusion The MPN-10 score did not predict survival outcomes among Thai MPN patients. Higher MPN-10 was associated with more transfusion. Thai MPN patients reported lower MPN-10 compared to western population especially PV and ET.

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).

Arterial and Venous Thromboembolic Complications in 832 Patients with BCR-ABL-Negative Myeloproliferative Neoplasms

Arterial (ATE) and venous (VTE) thromboembolic complications are common causes of morbidity and mortality in BCR-ABL-negative myeloproliferative neoplasms (MPNs). However, there are few studies that include all MPN subtypes and focus on both MPN-associated ATE and VTE. In our single-center retrospective study of 832 MPN patients, a total of 180 first thromboembolic events occurred during a median follow-up of 6.6 years (range: 0-37.6 years), of which 105 were VTE and 75 were ATE. The probability of a vascular event at the end of the follow-up period was 36.2%, and the incidence rate for all first ATE/VTE was 2.43% patient/year. The most frequent VTE localizations were deep vein thrombosis with or without pulmonary embolism (incidence rate: 0.59% patient/year), while strokes were the most frequent ATE with an incidence rate of 0.32% patient/year. When comparing the group of patients with ATE/VTE (n = 180) and the group without such an event (n = 652) using multivariate Cox regression analyses, patients with polycythemia vera (hazard ratio [HR]: 1.660; [95% confidence interval [CI] 1.206, 2.286]) had a significantly higher risk of a thromboembolic event than the other MPN subtypes. In contrast, patients with a CALR mutation had a significantly lower risk of thromboembolism compared with JAK2-mutated MPN patients (HR: 0.346; [95% CI: 0.172, 0.699]). In summary, a high incidence of MPN-associated VTE and ATE was observed in our retrospective study. While PV patients or generally JAK2-mutated MPN patients had a significantly increased risk of such vascular events, this risk was reduced in CALR-mutated MPN patients.

Individual with concurrent chest wall tuberculosis and triple-negative essential thrombocythemia: A case report

BACKGROUND

Chest wall tuberculosis (TB) and triple-negative essential thrombocythemia (TN-ET) are rare medical conditions, and their combination is extremely rare globally. Only one case of TB peritonitis with thrombocytosis has been reported, which was identified in 1974.

CASE SUMMARY

Herein, we report the case of a 23-year-old man with concurrent chest wall mass and TN-ET. The patient presented to a local hospital due to having a headache and low-grade fever for 2 d, with their bodily temperature fluctuating at around 36.8 °C. Hematological analysis showed a high platelet count of 1503 × 109/L. Subsequently, the patient visited our hospital for further investigation. Computed tomography of the chest suggested a submural soft tissue density shadow in the left lower chest wall. After surgical resection, the pathological findings of the swelling were reported as TB with massive caseous necrosis. According to the World Health Organization diagnostic criteria, the patient was diagnosed with TN-ET, as they met the requirement of four main criteria or the first three main criteria and one secondary criterion. The patient was eventually diagnosed with chest wall TB with TN-ET, which is extremely rare.

CONCLUSION

Chest wall TB is rare. TN-ET diagnosis requires secondary factor exclusion and satisfaction of primary diagnostic criteria. miRNA, combined with the methylation process, could explain suppressor of cytokine signaling (SOCS) 1 and SOCS3 downregulation in ET-JAK2V617F-negative patients. The miRNA could participate in JAK2 pathway activation. SOCS3 may be a novel MPN biomarker.

Individual with concurrent chest wall tuberculosis and triple-negative essential thrombocythemia: A case report

BACKGROUND

Chest wall tuberculosis (TB) and triple-negative essential thrombocythemia (TN-ET) are rare medical conditions, and their combination is extremely rare globally. Only one case of TB peritonitis with thrombocytosis has been reported, which was identified in 1974.

CASE SUMMARY

Herein, we report the case of a 23-year-old man with concurrent chest wall mass and TN-ET. The patient presented to a local hospital due to having a headache and low-grade fever for 2 d, with their bodily temperature fluctuating at around 36.8 °C. Hematological analysis showed a high platelet count of 1503 × 10⁹/L. Subsequently, the patient visited our hospital for further investigation. Computed tomography of the chest suggested a submural soft tissue density shadow in the left lower chest wall. After surgical resection, the pathological findings of the swelling were reported as TB with massive caseous necrosis. According to the World Health Organization diagnostic criteria, the patient was diagnosed with TN-ET, as they met the requirement of four main criteria or the first three main criteria and one secondary criterion. The patient was eventually diagnosed with chest wall TB with TN-ET, which is extremely rare.

CONCLUSION

Chest wall TB is rare. TN-ET diagnosis requires secondary factor exclusion and satisfaction of primary diagnostic criteria. miRNA, combined with the methylation process, could explain suppressor of cytokine signaling (SOCS) 1 and SOCS3 downregulation in ET-JAK2V617F-negative patients. The miRNA could participate in JAK2 pathway activation. SOCS3 may be a novel MPN biomarker.

Contribution of lowered hemoglobin threshold value in the diagnosis of polycythemia vera: Comparison of 2016 and 2008 WHO criteria

Polycythemia vera (PV) diagnosis remains a difficult task despite various updates in the 2016 World Health Organization (WHO) diagnostic criteria compared to 2008 criteria. This study aimed to examine the biochemical and clinical features of patients diagnosed with PV using the WHO 2016 criteria but would have been missed by the WHO 2008 criteria, and to ascertain the impact of the lowered thresholds on PV diagnosis. A total of 229 patients with suspected myeloproliferative neoplasms were included in this cross sectional study. The study group was divided with regard to hemoglobin values. Group A consisted of 126 patients with hemoglobin values of ≤ 18.5 g/dL in males and ≤ 16.5 g/dL in females. Group B comprised 103 patients with hemoglobin values of > 18.5 g/dL in males and > 16.5 g/dL in females. The number of PV diagnoses increased to 145 from 87 (increased by 66.67%) when the 2016 diagnostic criteria were employed rather that the 2008 criteria. Mean age and the frequency of female subjects were lower in Group A compared to Group B. The groups were similar in terms of chronic obstructive pulmonary disease/obstructive sleep apnea syndrome, spleen status, smoking status, and mean corpuscular volume, white blood count, neutrophil, eosinophil and platelet values. red blood cells and lactate dehydrogenase values were significantly higher, while lymphocyte counts were significantly lower in Group B. With the introduction of WHO 2016 criteria, we found a significant increase in the number of patients who were candidates for PV testing and were ultimately diagnosed with PV. These findings support the diagnostic value of the 2016 WHO criteria, and by extension, the lowered thresholds for detection of patients requiring further analysis.

Essential Thrombocythemia in Adolescents and Young Adults: Clinical Aspects, Treatment Options and Unmet Medical Needs

OPINION STATEMENT

Current treatment of essential thrombocythemia (ET) should primarily prevent thrombo-hemorrhagic events, without increasing the rate of fibrotic progression or leukemic evolution, and secondarily control microvascular symptoms. Unlike other classic BCR::ABL1-negative myeloproliferative neoplasms, ET is frequently diagnosed in adolescents and young adults (AYA), defined as individuals aged 15 to 39 years, in up to 20% of patients. However, since the current risk stratification of this disease is based on models, including that of ELN, IPSET-Thrombosis and its revised version, mainly applied to an older patients' population, international guidelines are needed that specifically consider how to evaluate the prognosis of AYAs with ET. Furthermore, although ET is the most frequent MPN among AYA subjects, there is a lack of specific recommendations on how to treat it in this subgroup of patients, as management decisions are typically extrapolated from those for the elderly. Accordingly, since AYAs with ET represent a unique disease subset defined by attenuated genetic risk, more indolent phenotype, and longer survival than their older counterparts, treatment selection requires special attention to specific issues such as the risk of fibrotic/leukemic transformation, carcinogenicity, and fertility. This review article will provide a comprehensive overview of the diagnosis, prognostic stratification, and possible therapeutic approaches for AYA patients with ET, including antiplatelets/anticoagulants and cytoreductive agents, with a focus on pregnancy management in real-life clinical practice.

Thrombocytosis in children

OBJECTIVE

We aimed to investigate the frequency and causes of thrombocytosis in patients admitted to the Department of Pediatric Hematology and Oncology of Elazig Fethi Sekin City Hospital, Elazig, Turkey.

METHODS

Between 2019 and 2021, the laboratory parameters of 2,500 patients admitted to the Hematology Department were studied. During this examination, 319 (12.76%) patients were found to have thrombocytosis. Demographic characteristics (age and gender), hematologic parameters (hemoglobin, white blood cells, and platelets), and ultimate diagnoses ot the cases were recorded from their files.

RESULTS

Of these 319 patients with thrombocytosis, 197 (1.8%) were male and 122 (38.2%) were female, and the mean age was 72.0±69.0 (1-216) months. The median platelet count of the patients was 590.43±280.12/μL (450,000-750,000). The most common cause of secondary thrombocytosis was infection, accounting for 37.9% of all patients. Other common causes were sickle cell anemia (21%), iron deficiency anemia (15.4%), colloid tissue disease (6.6%), hemolytic anemia (5.0%), splenectomy (4.5%), and other causes (9.7%).

CONCLUSION

In our study, infections were the most common cause of thrombocytosis. In addition to infections, sickle cell anemia and iron deficiency anemia should also be considered in the differential diagnosis of thrombocytosis.

Cytological Diagnosis of Classic Myeloproliferative Neoplasms at the Age of Molecular Biology

Myeloproliferative neoplasms (MPN) are clonal hematopoietic stem cell-derived disorders characterized by uncontrolled proliferation of differentiated myeloid cells. Two main groups of MPN, BCR::ABL1-positive (Chronic Myeloid Leukemia) and BCR::ABL1-negative (Polycythemia Vera, Essential Thrombocytosis, Primary Myelofibrosis) are distinguished. For many years, cytomorphologic and histologic features were the only proof of MPN and attempted to distinguish the different entities of the subgroup BCR::ABL1-negative MPN. World Health Organization (WHO) classification of myeloid neoplasms evolves over the years and increasingly considers molecular abnormalities to prove the clonal hematopoiesis. In addition to morphological clues, the detection of JAK2, MPL and CALR mutations are considered driver events belonging to the major diagnostic criteria of BCR::ABL1-negative MPN. This highlights the preponderant place of molecular features in the MPN diagnosis. Moreover, the advent of next-generation sequencing (NGS) allowed the identification of additional somatic mutations involved in clonal hematopoiesis and playing a role in the prognosis of MPN. Nowadays, careful cytomorphology and molecular biology are inseparable and complementary to provide a specific diagnosis and to permit the best follow-up of these diseases.

Retinal oxygen saturation in monoclonal gammopathies patients: A pilot study

PURPOSE

The aim of this pilot study was to assess oxygen saturation in retinal blood vessels in patients with monoclonal gammopathies (MGs).

METHODS

Thirty-one patients with MGs (11 women and 20 men, mean age 65.9 ± 8.9 years) were enrolled during 2016-2020. The patients were diagnosed at the Haemato-Oncology Department and subsequently examined at the Ophthalmology Department before initiating systemic therapy. All patients were subjected to automatic retinal oximetry (Oxymap ehf.) and had their fundus photographed (Topcon TRC-50DX retinal camera). We assessed the association between retinal oxygen saturation (SatO₂ ) - arterial SatO₂ , venous SatO₂ and arterio-venous (AV) difference-and MGs parameters: serum monoclonal immunoglobulin (M-protein) level and serum immunoglobulin-free light chains (FLC kappa and lambda), total protein, serum viscosity, haemoglobin, albumin, lactate dehydrogenase, C-reactive protein, creatinine and serum calcium level. Hyperviscosity-related retinopathy was also evaluated.

RESULTS

Statistical analysis showed a significant positive correlation (r = 0.462; p = 0.009) between the AV difference and the haemoglobin level. A significant, medium strong negative correlation was found between the AV difference and the serum levels of the monoclonal light lambda chains (r = -0.450; p = 0.011). Contrary to expectations, no statistically significant correlation was found between retinal oxygen saturation and the total protein or viscosity.

CONCLUSION

This study found correlation between retinal oxygen saturation and certain parameters in the blood of patients with MGs. Increasing levels of monoclonal immunoglobulin seem to reduce oxygen absorption in retinal arterioles, resulting in a lower AV difference, particularly in patients with a high free light chain level.

Human gene-engineered calreticulin mutant stem cells recapitulate MPN hallmarks and identify targetable vulnerabilities

Calreticulin (CALR) mutations present the main oncogenic drivers in JAK2 wildtype (WT) myeloproliferative neoplasms (MPN), including essential thrombocythemia and myelofibrosis, where mutant (MUT) CALR is increasingly recognized as a suitable mutation-specific drug target. However, our current understanding of its mechanism-of-action is derived from mouse models or immortalized cell lines, where cross-species differences, ectopic over-expression and lack of disease penetrance are hampering translational research. Here, we describe the first human gene-engineered model of CALR MUT MPN using a CRISPR/Cas9 and adeno-associated viral vector-mediated knock-in strategy in primary human hematopoietic stem and progenitor cells (HSPCs) to establish a reproducible and trackable phenotype in vitro and in xenografted mice. Our humanized model recapitulates many disease hallmarks: thrombopoietin-independent megakaryopoiesis, myeloid-lineage skewing, splenomegaly, bone marrow fibrosis, and expansion of megakaryocyte-primed CD41⁺ progenitors. Strikingly, introduction of CALR mutations enforced early reprogramming of human HSPCs and the induction of an endoplasmic reticulum stress response. The observed compensatory upregulation of chaperones revealed novel mutation-specific vulnerabilities with preferential sensitivity of CALR mutant cells to inhibition of the BiP chaperone and the proteasome. Overall, our humanized model improves purely murine models and provides a readily usable basis for testing of novel therapeutic strategies in a human setting.

Pharmacological Modulation of the Crosstalk between Aberrant Janus Kinase Signaling and Epigenetic Modifiers of the Histone Deacetylase Family to Treat Cancer

Hyperactivated Janus kinase (JAK) signaling is an appreciated drug target in human cancers. Numerous mutant JAK molecules as well as inherent and acquired drug resistance mechanisms limit the efficacy of JAK inhibitors (JAKi). There is accumulating evidence that epigenetic mechanisms control JAK-dependent signaling cascades. Like JAKs, epigenetic modifiers of the histone deacetylase (HDAC) family regulate the growth and development of cells and are often dysregulated in cancer cells. The notion that inhibitors of histone deacetylases (HDACi) abrogate oncogenic JAK-dependent signaling cascades illustrates an intricate crosstalk between JAKs and HDACs. Here, we summarize how structurally divergent, broad-acting as well as isoenzyme-specific HDACi, hybrid fusion pharmacophores containing JAKi and HDACi, and proteolysis targeting chimeras for JAKs inactivate the four JAK proteins JAK1, JAK2, JAK3, and tyrosine kinase-2. These agents suppress aberrant JAK activity through specific transcription-dependent processes and mechanisms that alter the phosphorylation and stability of JAKs. Pharmacological inhibition of HDACs abrogates allosteric activation of JAKs, overcomes limitations of ATP-competitive type 1 and type 2 JAKi, and interacts favorably with JAKi. Since such findings were collected in cultured cells, experimental animals, and cancer patients, we condense preclinical and translational relevance. We also discuss how future research on acetylation-dependent mechanisms that regulate JAKs might allow the rational design of improved treatments for cancer patients. SIGNIFICANCE STATEMENT: Reversible lysine-ɛ-N acetylation and deacetylation cycles control phosphorylation-dependent Janus kinase-signal transducer and activator of transcription signaling. The intricate crosstalk between these fundamental molecular mechanisms provides opportunities for pharmacological intervention strategies with modern small molecule inhibitors. This could help patients suffering from cancer.

Mesenchymal stromal cells in tumor microenvironment remodeling of BCR-ABL negative myeloproliferative diseases

Chronic myeloproliferative neoplasms encompass the BCR-ABL1-negative neoplasms polycythemia vera (PV), essential thrombocythemia (ET), and primary myelofibrosis (PMF). These are characterized by calreticulin (CALR), myeloproliferative leukemia virus proto-oncogene (MPL) and the tyrosine kinase Janus kinase 2 (JAK2) mutations, eventually establishing a hyperinflammatory tumor microenvironment (TME). Several reports have come to describe how constitutive activation of JAK-STAT and NFκB signaling pathways lead to uncontrolled myeloproliferation and pro-inflammatory cytokines secretion. In such a highly oxidative TME, the balance between Hematopoietic Stem Cells (HSCs) and Mesenchymal Stromal Cells (MSCs) has a crucial role in MPN development. For this reason, we sought to review the current literature concerning the interplay between HSCs and MSCs. The latter have been reported to play an outstanding role in establishing of the typical bone marrow (BM) fibrotic TME as a consequence of the upregulation of different fibrosis-associated genes including PDGF- β upon their exposure to the hyperoxidative TME characterizing MPNs. Therefore, MSCs might turn to be valuable candidates for niche-targeted targeting the synthesis of cytokines and oxidative stress in association with drugs eradicating the hematopoietic clone.

Bilateral adrenal and pulmonary haemorrhages as an initial presentation of polycythaemia vera

We report a case of a man in his early 60s presenting with bilateral adrenal and pulmonary haemorrhages as an initial presentation of polycythaemia vera (PV). Symptomatology included severe compressive chest pain radiating to epigastrium, with unremarkable physical findings, parameters and ECG. Blood investigations showed an elevated haemoglobin (174 g/L, reference range (RR): 141-172g/L) and haematocrit (55.7%, RR: 40.4%-50.4%) levels.Cross-sectional imaging excluded aortic dissection, but imaging repeated 48 hours after his admission for acute dyspnoea and worsening abdominal pain showed bilateral alveolar and adrenal haemorrhages. Cortisol level was 27 nmol/L (RR: 145-619 nmol/L). Investigations confirming PV included the presence of a Janus kinase 2 (JAK2V617F) gene mutation, hypercellularity with erythroid hyperplasia on bone marrow microscopy and a low serum erythropoietin (2.6 mIU/mL, RR: 4.3-29.0 mIU/mL). Aspirin, hydroxyurea, venesection and cortisol replacement were initiated to get good treatment outcome.

Novel ATM Gene c.5644 C > T (p.Arg1882*) Variant Detected in a Patient with Pancreatic Adenocarcinoma and Two Primary Non-Small Cell Lung Adenocarcinomas: A Case Report

Ataxia-telangiectasia is an autosomal recessive disorder that usually manifests in childhood due to mutations in the Ataxia-Telangiectasia Mutated (ATM) gene. It is believed that there is an association between this gene mutation/polymorphism and cancer risk, including breast, lung, and pancreatic cancers. We report a rare case of a 69-year-old woman who developed three different primary cancers, including non-small cell lung cancer (NSCLC) in both lungs and pancreatic adenocarcinoma, and was later found to have a rarely reported variant mutation in the ATM gene, namely Exon 39, c.5644 C > T. We hypothesize that the ATM gene, c.5644 C > T mutation could be a plausible contributor in the pathogenesis of these three cancers. This hypothesis has yet to be validated by larger studies that focus on a mechanistic approach involving DNA repair genes such as the ATM. More importantly, this paves the way to developing new patient-specific targeted therapies and inaugurating precision medicine as a cornerstone in cancer therapeutics.

Juvenile Myelomonocytic Leukemia in a Child: A Case Report of Palliative Chemotherapy and Literature Review Applied to Limited Resources Centers

Juvenile myelomonocytic leukemia (JMML) is a rare hematopoietic malignancy in children, with an incidence of 1.2 per million children per year. At this moment, we present a case report and a brief literature review of JMML in a child, primarily focused on its applicability in low-middle income countries. A 3.5-year-old male was referred to our tertiary center due to pallor, enlarging abdomen and neck mass, recurrent fever, and chronic diarrhea. Initial laboratory workup showed hemoglobin of 6.4 g/dl, white blood cell of 315.62 × 103/μL, and platelet of 17 × 103/μL. Blood smears showed 10% suspected blasts, 17% myelocytes, and 17% metamyelocytes with thrombocytopenic crisis. The HbF level was 5.8%. BCR-ABL gene tested negative. The patient was diagnosed with juvenile myelomonocytic leukemia. Considering that HSCT could not be done in our center and lack other financial possibilities to seek treatment abroad, the family agreed to do the palliative treatment. The patient was treated with oral 6-mercaptopurine and subcutaneous cytarabine. Four weeks after receiving 6-mercaptopurine, the white blood cell count decreased to 10.6 × 103/μL and the spleen size was half of the original size. The patient continued chemotherapy until week 15, chemotherapy was stopped, but 16 weeks after the diagnosis of JMML, he developed severe thrombocytopenia, endophthalmitis, and sepsis and passed away. As a conclusion, in JMML cases in developing countries without HSCT, palliative chemotherapy is acceptable, and palliative care is an important aspect.

The differences of hemogram, myelogram, and driver gene mutations in classic myeloproliferative neoplasms

The aim of this study was to explore and compare routine blood features and pathological characteristics of bone marrow tissues in essential thrombocythemia (ET), polycythemia vera (PV), primary myelofibrosis, prefibrotic stage (prePMF) and overt fibrotic stage (overtPMF), and the correlation between common driver gene mutations and clinical manifestations of myeloproliferative neoplasms (MPN). Methods: We analyzed 259 MPN patients treated at Tongji Hospital of Huazhong University of Science and Technology from January 2016 to December 2020. Results: Among ET, PV, prePMF, and overtPMF, the median leukocyte counts of PV and prePMF were significantly higher than those of ET. The average hemoglobin level of overtPMF was significantly lower than that of ET, PV, and prePMF. ET and prePMF had higher platelet counts than PV and overtPMF, whereas ET had the lowest platelet distribution width. Regarding hematopoietic tissues in the bone marrow, enlarged megakaryocytes were easily found in ET, PV, and prePMF, whereas the average diameter of megakaryocytes in prePMF was smaller than in ET, and PV showed various sizes of megakaryocytes. An increased M/E ratio and dilation of sinus were seen more frequently in PMF. Additionally, JAK2-positive patients tended to have significantly higher leukocyte counts than CALR-positive patients in ET and PMF.

Fedratinib, the first selective JAK2 inhibitor approved for treatment of myelofibrosis - an option beyond ruxolitinib

Introduction: Myelofibrosis, a life shortening clonal disorder, presents with a constellation of features: bone marrow fibrosis, abnormal blood counts, extramedullary hematopoiesis, splenomegaly, thrombohemorrhagic complications and constitutional symptoms. Until recently Ruxolitinib, a JAK1 and 2 inhibitor, has been the only targeted therapy available for transplant-ineligible patients requiring treatment for splenomegaly and disease related symptoms. However, most patients discontinue Ruxolitinib after 3-5 years, mostly due to loss of response. There has been an unmet need for this patient group. In August 2019 Fedratinib (INREBIC® capsules, Impact Biomedicines, Inc., a wholly owned subsidiary of Bristol Meyer Squibb), a JAK2 inhibitor, was approved by US FDA for treatment of myelofibrosis in both JAK inhibitor naïve and pre-treated patients for the management of symptoms and splenomegaly.Areas covered: Here, we discuss the development, evidence base to date for Fedratinib. Including early and late phase, and ongoing trials, safety issues, potential role and current position of Fedratinib in the treatment of myelofibrosis, as well as future direction of targeted therapy in myelofibrosis.Expert opinion: Fedratinib presents a much needed option of treatment, particularly, for patients failing Ruxolitinib, with response rates that are quite similar. Nonetheless, there remain important questions including sequencing and options for combining therapy.

TGF-β signaling in myeloproliferative neoplasms contributes to myelofibrosis without disrupting the hematopoietic niche

Myeloproliferative neoplasms (MPNs) are associated with significant alterations in the bone marrow microenvironment that include decreased expression of key niche factors and myelofibrosis. Here, we explored the contribution of TGF-β to these alterations by abrogating TGF-β signaling in bone marrow mesenchymal stromal cells. Loss of TGF-β signaling in Osx-Cre-targeted MSCs prevented the development of myelofibrosis in both MPLW515L and Jak2V617F models of MPNs. In contrast, despite the absence of myelofibrosis, loss of TGF-β signaling in mesenchymal stromal cells did not rescue the defective hematopoietic niche induced by MPLW515L, as evidenced by decreased bone marrow cellularity, hematopoietic stem/progenitor cell number, and Cxcl12 and Kitlg expression, and the presence of splenic extramedullary hematopoiesis. Induction of myelofibrosis by MPLW515L was intact in Osx-Cre Smad4fl/fl recipients, demonstrating that SMAD4-independent TGF-β signaling mediates the myelofibrosis phenotype. Indeed, treatment with a c-Jun N-terminal kinase (JNK) inhibitor prevented the development of myelofibrosis induced by MPLW515L. Together, these data show that JNK-dependent TGF-β signaling in mesenchymal stromal cells is responsible for the development of myelofibrosis but not hematopoietic niche disruption in MPNs, suggesting that the signals that regulate niche gene expression in bone marrow mesenchymal stromal cells are distinct from those that induce a fibrogenic program.

TGF-β signaling in myeloproliferative neoplasms contributes to myelofibrosis without disrupting the hematopoietic niche

Myeloproliferative neoplasms (MPNs) are associated with significant alterations in the bone marrow microenvironment that include decreased expression of key niche factors and myelofibrosis. Here, we explored the contribution of TGF-β to these alterations by abrogating TGF-β signaling in bone marrow mesenchymal stromal cells. Loss of TGF-β signaling in Osx-Cre-targeted MSCs prevented the development of myelofibrosis in both MPLW515L and Jak2V617F models of MPNs. In contrast, despite the absence of myelofibrosis, loss of TGF-β signaling in mesenchymal stromal cells did not rescue the defective hematopoietic niche induced by MPLW515L, as evidenced by decreased bone marrow cellularity, hematopoietic stem/progenitor cell number, and Cxcl12 and Kitlg expression, and the presence of splenic extramedullary hematopoiesis. Induction of myelofibrosis by MPLW515L was intact in Osx-Cre Smad4fl/fl recipients, demonstrating that SMAD4-independent TGF-β signaling mediates the myelofibrosis phenotype. Indeed, treatment with a c-Jun N-terminal kinase (JNK) inhibitor prevented the development of myelofibrosis induced by MPLW515L. Together, these data show that JNK-dependent TGF-β signaling in mesenchymal stromal cells is responsible for the development of myelofibrosis but not hematopoietic niche disruption in MPNs, suggesting that the signals that regulate niche gene expression in bone marrow mesenchymal stromal cells are distinct from those that induce a fibrogenic program.

Case Report: Free-Floating Intracoronary Thrombus: Who Is the Convict?

In young patients, especially with no traditional coronary risk factors, hypercoagulable states may always be considered as an alternative cause of acute coronary syndromes. The concomitant thrombotic and bleeding risk associated with myeloproliferative disorders complicates the decision-making, particularly regarding long-term dual antiplatelet therapy. The chosen therapy may need to be frequently revisited, depending on the patient's bleeding complications. We reported the case of a 49-year-old woman with acute myocardial infarction with no traditional risk factors for coronary artery disease where a myeloproliferative neoplasm was diagnosed.

JAK2V617F Is a Risk Factor for TIA/Stroke in Young Patients

The objective of this study was to assess the risk of arterial thrombosis in patients who harbor the JAK2V617F allele burden ≥1% detected during workup for myeloproliferative neoplasms (MPNs). We conducted a large cross-sectional analysis consisted of 5,220 patients who were tested for JAK2V617F and 1,047,258 people matched in age from health care insurance provider, taking into account age, sex, hypertension, diabetes, atrial fibrillation. Compared with noncarriers, mutation carriers were older, less likely to be current or past smokers and had lower body mass index. There was no significant difference between the groups regarding myocardial infarction and peripheral vascular disease. However, JAK2V617F ≥1% at age 34 to 54 years was associated with eightfold more likely to have transient ischemic attack (TIA)/stroke history unrelated to hypertension, diabetes, or atrial fibrillation. Association of JAK2V617F with TIA/stroke was also observed in the older age group, albeit a weaker association and not statistically significant. Prevalence of TIA/stroke was higher in patients with JAK2V617F negative, with odds ratio of 3.93 when compared with the general population after confounder adjustments. Further research is warranted to verify the relation between allele burden of JAK2V617F mutation and TIA/stroke and the role of JAK2V617F per se as a risk factor for arterial thrombosis in the absence of overt MPN. Also, consideration should be paid to the screened group with JAK2V617F negative due to the high incidence of TIA/stroke among them in comparison to the general population.

Cerebrovascular Accident in a Patient with Polycythemia: a Case Report

Polycythemia vera is not only a clonal disease that causes hematopoietic stem cells, but also a pathology that often leads to thrombotic complications. Thrombosis can have different localization and is clinically manifested by stroke, myocardial infarction, deep vein thrombosis of the lower extremities, pulmonary embolism, thrombosis of the veins of internal organs and other conditions. One of the most formidable thrombotic complications is acute cerebrovascular accident. The heterogeneity of the possible causes of acute cerebrovascular accident requires a careful approach to differential diagnosis for timely diagnosis and individual, pathogenetically grounded selection of means of long-term antithrombotic therapy. The presented clinical case of the development of cerebrovascular accident in a patient with polycythemia vera demonstrates the importance of an informal approach to diagnosis, as well as interdisciplinary interaction for finding the true cause of the development of acute cerebrovascular accident and the appointment of pathogenetically based treatment, aimed, among other things, at the prevention of repeated episodes of acute cerebrovascular accident and others. thrombotic complications.

Eosinophilic Myocarditis: When Allergies Attack the Heart!

Eosinophilic myocarditis is a clinical condition whereby myocardial injury is mediated by eosinophilic infiltration. A number of underlying causes, including reactive, clonal, or idiopathic hypereosinophilic syndrome, may trigger eosinophilia. Disease presentation may vary from mild subclinical variants to fulminant myocarditis with thromboembolic complications, and in some cases, endomyocardial and valvular fibrosis may be seen. A detailed examination coupled with the use of multimodality imaging, and endomyocardial biopsy may help establish diagnosis. Treatment is aimed at symptomatic management and treating the underlying cause of eosinophilia, such as withdrawal of implicated drugs, antihelminthic therapy for infection, immunosuppression for autoimmune conditions, and targeted therapy with tyrosine kinase inhibitors in cases with clonal myeloid disorders.

rs779805 Von Hippel-Lindau Gene Polymorphism Induced/Related Polycythemia Entity, Clinical Features, Cancer Association, and Familiar Characteristics

Increased red blood cell count may result from primary erythrocytosis (polycythemia vera), but it is often due to secondary causes with increased erythropoietin levels. Secondary erythrocytosis may also be congenital due to different gene mutations of hemoglobin, hemoglobin stabilization proteins, EPO receptors, or oxygen sensing pathways. Von Hippel- Lindau gene mutation causes altered tissue oxygen sensation in VHL disease, usually with normal hemoglobin. Germline VHL mutations associate with classical VHL disease and represent genetic susceptibility for pheochromocytoma. VHL polymorphisms are mostly considered an innocent phenomenon. Still, some data indicate that these polymorphisms are not always harmless and can occur with prostate, renal, and colon cancer or even with isolated erythrocytosis. Seventy-eight patients referred to our department with elevated hemoglobin were screened for VHL mutations. There were no classical somatic VHL mutations. However, we found heterozygous (GA) or homozygous (AA) rs779805 VHL c.-195G>A polymorphism accompanied by erythrocytosis. These patients are Jak-2 negative, with normal or elevated EPO levels, sometimes with family accumulations and often phlebotomy needs, and in some cases with malignancies in the family. No other cause of erythrocytosis was found. We use phlebotomy regularly, and for those with cardiovascular risk factors, we recommend aspirin.

Tumor models in various Drosophila tissues

The development of cancer is a complex multistage process. Over the past few decades, the model organism Drosophila melanogaster has been crucial in identifying cancer-related genes and pathways and elucidating mechanisms underlying growth regulation in development. Investigations using Drosophila has yielded new insights into the molecular mechanisms involved in tumor initiation and progression. In this review, we describe various tumor models that have been developed in recent years using different Drosophila tissues, such as the imaginal tissue, the neural tissue, the gut, the ovary, and hematopoietic cells. We discuss underlying genetic alterations, cancer-like characteristics, as well as similarities and key differences among these models. We also discuss how disruptions in stem cell division and differentiation result in tumor formation in diverse tissues, and highlight new concepts developed using the fly model to understand context-dependent tumorigenesis. We further discuss the progress made in Drosophila to explore tumor-host interactions that involve the innate immune response to tumor growth and the cachexia wasting phenotype. This article is categorized under: Cancer > Genetics/Genomics/Epigenetics Cancer > Stem Cells and Development Cancer > Molecular and Cellular Physiology.

Targeting CD123 in BPDCN: an emerging field

INTRODUCTION

Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare and aggressive hematologic malignancy with historically poor outcomes for patients, often refractory to traditional chemotherapy. Recent research has focused on targeted therapy to improve responses and limit potential toxicity.

AREAS COVERED

CD123 (also known as IL-3 Rα) is a cell surface marker and attractive therapeutic target for many myeloid malignancies, particularly BPDCN, whose cells ubiquitously overexpress CD123. We review the history of CD123 research regarding BPDCN, recent advances including FDA approval of tagraxofusp (formerly SL-401) for BPDCN, and ongoing clinical studies utilizing novel therapeutic strategies to target CD123.

EXPERT OPINION

The approval of tagraxofusp for the treatment of BPDCN in December 2018 drastically changed the treatment landscape for patients with this rare neoplasm. While tagraxofusp is better tolerated than traditional multi-agent chemotherapy regimens, it requires close monitoring and sound clinical judgment by providers to prevent and mitigate severe treatment-related complications with special attention to the recognition and management of capillary leak syndrome (CLS). Several other promising strategies for targeting CD123 in BPDCN are currently under investigation, including antibody-drug conjugates, T-cell engagers, and CAR-T cellular therapeutics. These CD123 targeted approaches may soon become standard of care for patients with this difficult to treat malignancy.

Kidney Dysfunction Is Associated with Thrombosis and Disease Severity in Myeloproliferative Neoplasms: Implications from the German Study Group for MPN Bioregistry

Simple Summary

In patients with myeloproliferative neoplasms (MPN) and in patients with kidney dysfunction, a higher rate of thrombosis has been reported compared with the general population. Furthermore, MPN patients are more prone to develop kidney dysfunction. In our study, we assessed the importance of specific risk factors for kidney dysfunction and thrombosis in MPN patients. We found that the rate of thrombosis is correlated with the degree of kidney dysfunction, especially in myelofibrosis. Significant associations for kidney dysfunction included arterial hypertension, MPN treatment, and increased inflammation, and those for thrombosis comprised arterial hypertension, non-excessive platelet counts, and antithrombotic therapy. The identified risk factor associations varied between MPN subtypes. Our data suggest that kidney dysfunction in MPN patients is associated with an increased risk of thrombosis, mandating closer monitoring, and, possibly, early thromboprophylaxis.

Abstract

Inflammation-induced thrombosis represents a severe complication in patients with myeloproliferative neoplasms (MPN) and in those with kidney dysfunction. Overlapping disease-specific attributes suggest common mechanisms involved in MPN pathogenesis, kidney dysfunction, and thrombosis. Data from 1420 patients with essential thrombocythemia (ET, 33.7%), polycythemia vera (PV, 38.5%), and myelofibrosis (MF, 27.9%) were extracted from the bioregistry of the German Study Group for MPN. The total cohort was subdivided according to the calculated estimated glomerular filtration rate (eGFR, (mL/min/1.73 m²)) into eGFR1 (≥90, 21%), eGFR2 (60–89, 56%), and eGFR3 (<60, 22%). A total of 29% of the patients had a history of thrombosis. A higher rate of thrombosis and longer MPN duration was observed in eGFR3 than in eGFR2 and eGFR1. Kidney dysfunction occurred earlier in ET than in PV or MF. Multiple logistic regression analysis identified arterial hypertension, MPN treatment, increased uric acid, and lactate dehydrogenase levels as risk factors for kidney dysfunction in MPN patients. Risk factors for thrombosis included arterial hypertension, non-excessive platelet counts, and antithrombotic therapy. The risk factors for kidney dysfunction and thrombosis varied between MPN subtypes. Physicians should be aware of the increased risk for kidney disease in MPN patients, which warrants closer monitoring and, possibly, early thromboprophylaxis.

Comparison of the effects between MPL and JAK2V617F on thrombosis and peripheral blood cell counts in patients with essential thrombocythemia: a meta-analysis

To assess the effects between MPL and JAK2V617F on the thrombosis risk and peripheral blood cell counts in patients with essential thrombocythemia (ET), we identified eligible studies from PubMed, Embase, and the Cochrane Library. Seven studies were ultimately included in this meta-analysis. All studies reported the peripheral blood cell counts of ET patients, and three of them reported the eligible thrombotic events. In comparing the effect of MPL versus JAK2V617F on thrombosis, 1257 ET patients (73 MPL + and 1184 JAK2V617F +) were included. MPL-positive (MPL +) ET patients had a higher risk of thrombosis than JAK2V617F-positive (JAK2V617F +) ET patients [RR = 1.80 (1.08-3.01), P = 0.025]. And 3453 ET patients (138 MPL + and 3315 JAK2V617F +) were included in the comparison of peripheral blood cell counts. Platelet counts of MPL + ET patients were higher than that of JAK2V617F + ET patients [WMD = 81.18 (31.77-130.60), P = 0.001]. MPL + ET patients had lower hemoglobin [WMD =  - 11.66 (- 14.32 to - 9.00), P = 0.000] and white blood cell counts [WMD =  - 1.01 (- 1.47 to - 0.56), P = 0.000] than JAK2V617F + ET patients. These findings indicate that the MPL mutation is a high-risk factor for thrombosis in ET patients, and it may be rational to include MPL mutation in the revised IPSET as a criterion for thrombosis prediction scores. And given the differences in peripheral blood, it is necessary to further study whether MPL + ET patients differ from JAK2V617F + ET patients in bleeding and survival.

Direct oral anticoagulants (DOAC) for prevention of recurrent arterial or venous thromboembolic events (ATE/VTE) in myeloproliferative neoplasms

In patients with BCR-ABL-negative myeloproliferative neoplasms (MPN), arterial or venous thromboembolic events (ATE/VTE) are a major burden. In order to control these complications, vitamin K antagonists (VKA) are widely used. There is no robust evidence supporting the use of direct oral anticoagulants (DOAC) in MPN patients. We therefore compared the efficacy and safety of both anticoagulants in 71 cases from a cohort of 782 MPN patients. Seventy-one of 782 MPN patients (9.1%) had ATE/VTE with nine ATE (12.7%) and 62 VTE (87.3%). Forty-five of 71 ATE/VTE (63.4%) were treated with VKA and 26 (36.6%) with DOAC. The duration of anticoagulation therapy (p = 0.984), the number of patients receiving additional aspirin (p = 1.0), and the proportion of patients receiving cytoreductive therapy (p = 0.807) did not differ significantly between the VKA and DOAC groups. During anticoagulation therapy, significantly more relapses occurred under VKA (n = 16) compared to DOAC treatment (n = 0, p = 0.0003). However, during the entire observation period of median 3.2 years (0.1-20.4), ATE/VTE relapse-free survival (p = 0.2) did not differ significantly between the two anticoagulants. For all bleeding events (p = 0.516) or major bleeding (p = 1.0), no significant differences were observed between VKA and DOAC. In our experience, the use of DOAC was as effective and safe as VKA, possibly even potentially beneficial with a lower number of recurrences and no increased risk for bleedings. However, further and larger studies are required before DOAC can be routinely used in MPN patients.

Co-occurrence of cohesin complex and Ras signaling mutations during progression from myelodysplastic syndromes to secondary acute myeloid leukemia

Myelodysplastic syndromes (MDS) are hematological disorders at high risk of progression to secondary acute myeloid leukemia (sAML). However, the mutational dynamics and clonal evolution underlying disease progression are poorly understood at present. To elucidate the mutational dynamics of pathways and genes occurring during the evolution to sAML, next generation sequencing was performed on 84 serially paired samples of MDS patients who developed sAML (discovery cohort) and 14 paired samples from MDS patients who did not progress to sAML during follow-up (control cohort). Results were validated in an independent series of 388 MDS patients (validation cohort). We used an integrative analysis to identify how mutations, alone or in combination, contribute to leukemic transformation. The study showed that MDS progression to sAML is characterized by greater genomic instability and the presence of several types of mutational dynamics, highlighting increasing (STAG2) and newly-acquired (NRAS and FLT3) mutations. Moreover, we observed cooperation between genes involved in the cohesin and Ras pathways in 15-20% of MDS patients who evolved to sAML, as well as a high proportion of newly acquired or increasing mutations in the chromatin-modifier genes in MDS patients receiving a disease-modifying therapy before their progression to sAML.

IRF4 and IRF8 expression are associated with clinical phenotype and clinico-hematological response to hydroxyurea in essential thrombocythemia

The morbidity and mortality of myeloproliferative neoplasms (MPNs) are primarily caused by arterial and venous complications, progression to myelofibrosis, and transformation to acute leukemia. However, identifying molecular-based biomarkers for risk stratification of patients with MPNs remains a challenge. We have previously shown that interferon regulatory factor-8 (IRF8) and IRF4 serve as tumor suppressors in myeloid cells. In this study, we evaluated the expression of IRF4 and IRF8 and the JAK2V617F mutant allele burden in patients with MPNs. Patients with decreased IRF4 expression were correlated with a more developed MPN phenotype in myelofibrosis (MF) and secondary AML (sAML) transformed from MPNs versus essential thrombocythemia (ET). Negative correlations between the JAK2V617F allele burden and the expression of IRF8 (P < 0.05) and IRF4 (P < 0.001) and between white blood cell (WBC) count and IRF4 expression (P < 0.05) were found in ET patients. IRF8 expression was negatively correlated with the JAK2V617F allele burden (P < 0.05) in polycythemia vera patients. Complete response (CR), partial response (PR), and no response (NR) were observed in 67.5%,10%, and 22.5% of ET patients treated with hydroxyurea (HU), respectively, in 12 months. At 3 months, patients in the CR group showed high IRF4 and IRF8 expression compared with patients in the PR and NR groups. In the 12-month therapy period, low IRF4 and IRF8 expression were independently associated with the unfavorable response to HU and high WBC count. Our data indicate that the expression of IRF4 and IRF8 was associated with the MPN phenotype, which may serve as biomarkers for the response to HU in ET.

The Prevalence of TET2 Gene Mutations in Patients with BCR-ABL-Negative Myeloproliferative Neoplasms (MPN): A Systematic Review and Meta-Analysis

Multiple recurrent somatic mutations have recently been identified in association with myeloproliferative neoplasms (MPN). This meta-analysis aims to assess the pooled prevalence of TET2 gene mutations among patients with MPN. Six databases (PubMed, Scopus, ScienceDirect, Google Scholar, Web of Science and Embase) were searched for relevant studies from inception till September 2020, without language restrictions. The eligibility criteria included BCR-ABL-negative MPN adults with TET2 gene mutations. A random-effects model was used to estimate the pooled prevalence with 95% confidence intervals (CIs). Subgroup analyses explored results among different continents and countries, WHO diagnostic criteria, screening methods and types of MF. Quality assessment was undertaken using the Joanna Briggs Institute critical appraisal tool. The study was registered with PROSPERO (CRD42020212223). Thirty-five studies were included (n = 5121, 47.1% female). Overall, the pooled prevalence of TET2 gene mutations in MPN patients was 15.5% (95% CI: 12.1-19.0%, I2 = 94%). Regional differences explained a substantial amount of heterogeneity. The prevalence of TET2 gene mutations among the three subtypes PV, ET and MF were 16.8%, 9.8% and 15.7%, respectively. The quality of the included studies was determined to be moderate-high among 83% of the included studies. Among patients with BCR-ABL-negative MPN, the overall prevalence of TET2 gene mutations was 15.5%.

Clinicopathological spectrum of BCR-ABL-Negative myeloproliferative neoplasms with correlation with janus-associated kinase 2 mutation

Background: Non chronic myelogenous leukemia (non-CML)/BCR-ABL-negative myeloproliferative neoplasms (MPNs) include essential thrombocythemia (ET), polycythemia vera (PV), and primary myelofibrosis (PMF) (apart from chronic neutrophilic leukemia and chronic eosinophilic leukemia, which are rare). They are uncommon clonal disorders of adults, with an incidence ranging from 0.5 to 3/100,000 persons, BCR-ABL negative, and characterized by the activation of Janus-associated kinase 2 (JAK2). Very few studies have been reported from India. Aims and Objectives: The aims and objectives of this study were to analyze the clinicopathological spectrum and to determine the frequency of JAK2 mutation in patients of non-CML/BCR-ABL negative MPNs. Materials and Methods: Clinical and morphological features and frequency of JAK2 mutation in patients with PV, ET, and PMF were studied at a tertiary care hospital. The material was retrieved from the hematopathology records and reviewed. Results: JAK2V617F mutation was found in 10 of 14 cases (71%) of MPNs, 100% in PV, 50% in ET, and 71% of idiopathic myelofibrosis. The presence of JAK2V617F mutation was associated with a higher hemoglobin level (P < 0.05), a higher TLC (P < 0.05), and higher age (P < 0.05). Results showed that there are morphologic differences, and megakaryocytic morphology represents a useful clue for the differential diagnosis of these three BCR-ABL-negative MPN subtypes. Conclusion: The JAK2 V617F mutation was detected in 71% of patients with MPN disorders. Peripheral blood mutation screening for JAK2 V617F should be incorporated into the initial evaluation of patients suspected to have MPNs. Differences in megakaryocytic morphology provide the histomorphological hallmark of BCR-ABL-negative MPN subtypes.

PPARγ agonists promote the resolution of myelofibrosis in preclinical models

Myelofibrosis (MF) is a non-BCR-ABL myeloproliferative neoplasm associated with poor outcomes. Current treatment has little effect on the natural history of the disease. MF results from complex interactions between (a) the malignant clone, (b) an inflammatory context, and (c) remodeling of the bone marrow (BM) microenvironment. Each of these points is a potential target of PPARγ activation. Here, we demonstrated the therapeutic potential of PPARγ agonists in resolving MF in 3 mouse models. We showed that PPARγ agonists reduce myeloproliferation, modulate inflammation, and protect the BM stroma in vitro and ex vivo. Activation of PPARγ constitutes a relevant therapeutic target in MF, and our data support the possibility of using PPARγ agonists in clinical practice.

Erythrocytosis in the general population: clinical characteristics and association with clonal hematopoiesis

Erythrocytosis is a common reason for referral to hematology services and is usually secondary in origin. The aim of this study was to assess clinical characteristics and clonal hematopoiesis (CH) in individuals with erythrocytosis in the population-based Lifelines cohort (n = 147 167). Erythrocytosis was defined using strict (World Health Organization [WHO] 2008/British Committee for Standards in Hematology) and wide (WHO 2016) criteria. Individuals with erythrocytosis (strict criteria) and concurrent leukocytosis and/or thrombocytosis were 1:2 matched with individuals with isolated erythrocytosis and analyzed for somatic mutations indicative of CH (≥5% variant allele frequency). One hundred eighty five males (0.3%) and 223 females (0.3%) met the strict criteria, whereas 4868 males (7.6%) and 309 females (0.4%) met the wide criteria. Erythrocytosis, only when defined using strict criteria, was associated with cardiovascular morbidity (odds ratio [OR], 1.8; 95% confidence interval [CI], 1.2-2.6), cardiovascular mortality (hazard ratio [HR], 2.2; 95% CI, 1.0-4.6), and all-cause mortality (HR, 1.7; 95% CI, 1.2-2.6), independent of conventional risk factors. Mutations were detected in 51 of 133 (38%) evaluable individuals, with comparable frequencies between individuals with and without concurrent cytosis. The JAK2 V617F mutation was observed in 7 of 133 (5.3%) individuals, all having concurrent cytosis. The prevalence of mutations in BCOR/BCORL1 (16%) was high, suggesting aberrant epigenetic regulation. Erythrocytosis with CH was associated with cardiovascular morbidity (OR, 9.1; 95% CI, 1.2-68.4) in a multivariable model. Our data indicate that only when defined using strict criteria erythrocytosis is associated with cardiovascular morbidity (especially in the presence of CH), cardiovascular mortality, and all-cause mortality.

Low JAK2 V617F Allele Burden in Ph-Negative Chronic Myeloproliferative Neoplasms Is Associated with Additional CALR or MPL Gene Mutations

JAK2 (Janus kinase 2) V617F, CALR (Calreticulin) exon 9, and MPL (receptor for thrombopoietin) exon 10 mutations are associated with the vast majority of Ph-negative chronic myeloproliferative neoplasms (MPNs). These mutations affect sequential stages of proliferative signal transduction and therefore, after the emergence of one type of mutation, other types should not have any selective advantages for clonal expansion. However, simultaneous findings of these mutations have been reported by different investigators in up to 10% of MPN cases. Our study includes DNA samples from 1958 patients with clinical evidence of MPN, admitted to the National Research Center for Hematology for genetic analysis between 2016 and 2019. In 315 of 1402 cases (22.6%), CALR mutations were detected. In 23 of these 315 cases (7.3%), the JAK2 V617F mutation was found in addition to the CALR mutation. In 16 from 24 (69.6%) cases, with combined CALR and JAK2 mutations, V617F allele burden was lower than 1%. A combination of JAK2 V617F with MPL W515L/K was also observed in 1 out of 1348 cases, only. JAK2 allele burden in this case was also lower than 1%. Additional mutations may coexist over the low background of JAK2 V617F allele. Therefore, in cases of detecting MPNs with a low allelic load JAK2 V617F, it may be advisable to search for other molecular markers, primarily mutations in exon 9 of CALR. The load of the combined mutations measured at different time points may indicate that, at least in some cases, these mutations could be represented by different clones of malignant cells.

JAK2V617F, CALR and MPL515L/K mutations and plateletcrit in essential thrombocythemia: A single centre's experience

AIMS

JAK2V617F (JAK2), calreticulin (CALR) and MPL515L/K (MPL) mutations are important in essential thrombocythemia (ET) and may be associated with various clinical consequences of the disease. This study aimed to compare the clinical and haematological parameters of ET patients regarding the mentioned mutations and the role of plateletcrit (PCT).

METHODS

Seventy patients who were diagnosed with ET between 2005 and 2017 in a single centre were included in this descriptive study. The initial symptoms and clinical findings were retrieved from the electronic database. JAK2 gene V617F mutations, MPL gene exon 10 mutations and CALR gene exon 9 DNA sequence analyses were performed. Forty-one healthy volunteers were included to perform ROC curve analysis for interpreting PCT value.

RESULTS

The distributions of patients according to the mutations were as follows: Thirty-seven (52.9%) patients were JAK2-positive, 15 (21.4%) were CALR-positive, 2 (2.8%) patients were positive for both CALR and JAK2, and 1 (1.4%) was only MPL-positive. Fifteen (21.4%) patients were triple-negative. The ET patients with JAK2 mutation showed a higher level of haemoglobin at the time of diagnosis. The ET patients with CALR mutation presented with higher platelet and LDH levels (P = .002 and P = .001, respectively). The PCT level was higher in the CALR-positive group when compared to the others (P = .026). A sensitivity value of 97.6% and specificity value of 98.6% were determined regarding PCT% at a cut-off value of 0.37 in ET patients. In CALR-positive patients, the sensitivity and specificity values were 100% for the PCT at a cut-off value of 0.42%.

CONCLUSION

We determined that the platelet count and blood LDH level was high in the ET patient group with CALR mutation. Besides, we found that the blood haemoglobin level was higher in the ET patient group with JAK2 mutation. Additionally, the PCT level was higher in the CALR group when compared to the other patient groups.

Rare case of plasmablastic myeloma diagnosed on lung biopsy

Plasmablastic myeloma is a rare variant of multiple myeloma characterised by neoplastic proliferation of single clone of plasma cells producing monoclonal immunoglobulins. A 60-year-old man presented to hospital with a 6-week history of chest pain, back pain, leg weakness and numbness. Imaging revealed a 75 mm left lobular lung mass with chest wall invasion, metastatic bony and soft-tissue deposits and spinal cord compression at T5 level. Lung biopsy, for suspected metastatic lung cancer, surprisingly showed features of plasmablastic myeloma. Protein electrophoresis demonstrated 2 g/L of IgG lambda paraproteinaemia and an increase in lambda light chains with reduced kappa/lambda ratio of 0.01. Bone marrow biopsy did not show evidence of infiltration by disease. The patient received radiotherapy to the spine; responded to third-line chemotherapy and received autologous stem cell transplant. This case adds to the rare causes of lung mass and is the first reported case of plasmablastic myeloma diagnosed on lung biopsy.