Correlation between JAK2 allele burden and pulmonary arterial hypertension and hematological parameters in Philadelphia negative JAK2 positive myeloproliferative neoplasms. An Egyptian experience

Association of JAK2V617F allele burden and clinical correlates in polycythemia vera: a systematic review and meta-analysis

Janus kinase 2 (JAK2) V617F mutation is present in most patients with polycythemia vera (PV). One persistently puzzling aspect unresolved is the association between JAK2V617F allele burden (also known as variant allele frequency) and the relevant clinical characteristics. Numerous studies have reported associations between allele burden and both hematologic and clinical features. While there are strong indications linking high allele burden in PV patients with symptoms and clinical characteristics, not all associations are definitive, and disparate and contradictory findings have been reported. Hence, this study aimed to synthesize existing data from the literature to better understand the association between JAK2V617F allele burden and relevant clinical correlates. Out of the 1,851 studies identified, 39 studies provided evidence related to the association between JAK2V617F allele burden and clinical correlates, and 21 studies were included in meta-analyses. Meta-analyses of correlation demonstrated that leucocyte and erythrocyte counts were significantly and positively correlated with JAK2V617F allele burden, whereas platelet count was not. Meta-analyses of standardized mean difference demonstrated that leucocyte and hematocrit were significantly higher in patients with higher JAK2V617F allele burden, whereas platelet count was significantly lower. Meta-analyses of odds ratio demonstrated that patients who had higher JAK2V617F allele burden had a significantly greater odds ratio for developing pruritus, splenomegaly, thrombosis, myelofibrosis, and acute myeloid leukemia. Our study integrates data from approximately 5,462 patients, contributing insights into the association between JAK2V617F allele burden and various hematological parameters, symptomatic manifestations, and complications. However, varied methods of data presentation and statistical analyses prevented the execution of high-quality meta-analyses.

Clinical Phenotype and Outcomes of Pulmonary Hypertension Associated with Myeloproliferative Neoplasms: A Population-based Study

Rationale: Precapillary pulmonary hypertension (PH) is a rare and largely unrecognized complication of myeloproliferative neoplasms (MPNs), including polycythemia vera (PV), essential thrombocythemia (ET), and primary myelofibrosis (MF). Objectives: To describe characteristics and outcomes of MPN-associated PH. Methods: We report clinical, functional, and hemodynamic characteristics, classification, and outcomes of patients with PV, ET, or primary MF in the French PH registry. Measurements and Main Results: Ninety patients with MPN (42 PV, 35 ET, 13 primary MF) presented with precapillary PH with severe hemodynamic impairment, with a median mean pulmonary arterial pressure and pulmonary vascular resistance of 42 mm Hg and 6.7 Wood units, respectively, and impaired clinical conditions, with 71% in New York Heart Association functional classes III/IV and having a median 6-minute-walk distance of 310 m. Half of the patients were diagnosed with chronic thromboembolic PH (CTEPH); the other half were considered to have group 5 PH. MF was preferentially associated with group 5 PH, whereas PV and ET were generally related to CTEPH. Proximal lesions were diagnosed in half of the patients with CTEPH. Thromboendarterectomy was performed in 18 selected patients with high risk of complications (5 early deaths). Overall survival at 1, 3, and 5 years was 67%, 50%, and 34% in group 5 PH and 81%, 66%, and 42% in CTEPH, respectively. Conclusions: PH is a life-threatening condition potentially occurring in MPN. There are multiple mechanisms, with equal diagnoses of CTEPH and group 5 PH. Physicians should be aware that PH strongly affects the burden of patients with MPN, especially in group 5 PH, with unknown pathophysiological mechanisms.

Prevalence and risk factors for Pulmonary Hypertension associated with chronic Myeloproliferative Neoplasms

OBJECTIVES

Pulmonary hypertension (PH) is commonly reported in Philadelphia-chromosome negative myeloproliferative neoplasms (MPNs) including polycythemia vera (PV), essential thrombocythemia (ET), and myelofibrosis (MF). PH may be diagnosed directly by right heart catheterization (RHC) or estimated by transthoracic echocardiography (TTE). Survival is shortened by PH but despite the potential significance of PH to management and prognosis of MPN, estimates of its prevalence in MPNs vary and risk factors for the condition are poorly established. We performed a systematic review and meta-analysis of available studies to fill this void.

METHODS

We searched EMBASE, MEDLINE, and Clinicaltrials.gov for the terms "pulmonary hypertension," "myeloproliferative disorders," "polycythemia vera," "essential thrombocythemia," and "myelofibrosis." We restricted analysis to the 1999-2019 window to improve uniformity of MPN diagnostic criteria. We retrieved 221 records and, after abstract and full-text screening, identified 17 papers meeting criteria for inclusion in our meta-analysis. A modified Newcastle-Ottawa scale was used to assess quality.

RESULTS

Results for 935 patients were available, 309 of these having PH (33%). Using logistic mixed-effect regression, we found that diagnosis mode (RHC vs TTE) and MPN duration influenced PH prevalence. Studies employing predominantly TTE yielded prevalence estimates ~5-fold higher than those using RHC (35% vs 7.2%). We identified MF and duration of MPN as significant risk factors for development of PH.

CONCLUSIONS

Prevalence of PH in MPNs is poorly understood with estimates ranging from 3.8% to 58%. Patients with MF and longer duration of disease seem at particularly high risk and should be carefully monitored for PH.

Diagnostic and prognostic markers and treatment of connective tissue disease-associated pulmonary arterial hypertension: current recommendations and recent advances

INTRODUCTION

Pulmonary arterial hypertension (PAH), also referred to as group 1 pulmonary hypertension, occurs either primarily or in association with other diseases such as connective tissue diseases (CTD). Of CTD, systemic sclerosis (SSc), systemic lupus erythematosus and mixed connective tissue disease are commonly accompanied with PAH. It is of note that SSc-PAH is associated with distinctive histopathology, an unfavorable outcome, and a blunted responsiveness to modern PAH therapies.

AREAS COVERED

The data in articles published until May 2020 in peer-reviewed journals, covered by PubMed databank, are discussed. The current review introduces recent advances over the past years which have moved our understanding of CTD-PAH forward and discusses what we are currently able to do and what will be necessary in the future to overcome the yet unsatisfactory situation in the management of CTD-PAH, particularly in that of SSc-PAH.

EXPERT OPINION

A multifaceted and integrated approach would be crucial to improve the outcome of patients with SSc-PAH. The authors also propose a possible algorithm to classify and treat SSc patients with suspicion of pulmonary vascular disease.

BCR-ABL1-Negative Chronic Myeloproliferative Neoplasms and Pulmonary Hypertension: A Prospective Long-Term Follow-up Study of the Impact of Pulmonary Hypertension on Survival

PURPOSE

To assess the prevalence of PHT in patients with BCR-ABL1-negative CMPN and to evaluate impact of PHT on survival during long-term follow-up.

PATIENTS AND METHODS

A total of 122 patients with BCR-ABL1-negative CMPN underwent transthoracic echocardiographic (TTE) evaluation at the beginning of study. Patients undergoing PHT on TTE examination were also evaluated by a pulmonologist. Patients were divided into 3 groups. Group A comprised patients with CMPN-related PHT; group B, patients with no PHT; and group C, patients with PHT due to secondary causes. Patients were evaluated again every 3 to 6 months.

RESULTS

PHT was detected in 33 (27%) of 122 patients. Eight (6.5%) had CMPN-related PHT and the remaining 25 (20.5%) had non-CMPN-related PHT. Positivity for JAK2 V617F mutation in the study population was 72.9%. Groups were similar with respect to hematologic parameters and gender. Follow-up times were as follows: median (range) time from diagnosis to TTE and study end were 34 (1-158) months and 107 (16-251) months, respectively, and from TTE to study end was 88 (7-110) months. No significant differences found among the groups in terms of median time from diagnosis to TTE, follow-up, and overall survival.

CONCLUSION

BCR-ABL1-negative CMPN patients had a lower prevalence of PHT compared to earlier studies. There was no statistically significant difference in median overall survival between patients with or without PHT. This may be because patients with PHT were asymptomatic and PHT was mild. The impact of PHT on survival was negligible.

Prevalence and risk factors of high echocardiographic probability of pulmonary hypertension in myeloproliferative neoplasms patients

Pulmonary hypertension (PH) is emerging as a complication of myeloproliferative neoplasms (MPNs). This was a prospective study conducted at Chiang Mai University Hospital. The primary objective was to determine the prevalence of high echocardiographic probability of PH in MPNs patients. The secondary objectives were to determine risk factors of PH and the correlation between risk factors and peak tricuspid regurgitation velocity (TRV_max). All MPNs patients aged over 18 years, including polycythemia vera (PV), essential thrombocythemia (ET), and primary myelofibrosis (PMF), were enrolled. All eligible patients underwent echocardiography for evaluation of the probability of PH in line with the 2015 European Society of Cardiology (ESC) and the European Respiratory Society (ERS) Guidelines. Sixty-six patients with a median age of 59 years were enrolled. There were 35 PV, 25 ET, and 6 PMF patients included. The prevalence of high echocardiographic probability of PH was 4.55% (2 ET and 1 PMF). Risk factors associated with high echocardiographic probability of PHT were not analyzed. There were three risk factors associated with increased TRV_max, specifically lower hemoglobin, older age, and the presence of JAK2V617F mutation. The prevalence of high echocardiographic probability of PH in MPNs patients was 4.55%.

Pulmonary hypertension in patients with Philadelphia-negative myeloproliferative neoplasms: a single-center retrospective analysis of 225 patients

Background

The prevalence of pulmonary hypertension (PH) in myeloproliferative neoplasms (MPNs) varies among studies. We analyzed the prevalence of PH in Korean patients with Philadelphia-negative (Ph^-) MPNs.

Methods

Medical records of patients with Ph^- MPNs [essential thrombocythemia (ET), polycythemia vera (PV), or primary myelofibrosis (PMF)] visiting a single hospital between 1993 and 2019 were reviewed retrospectively. Transthoracic echocardiographic examination (TTE) results were reviewed and PH was diagnosed according to established guidelines.

Results

Of the 320 MPN (179 ET, 107 PV, and 34 PMF) patients, 225 (121 ET, 83 PV, and 21 PMF) underwent TTE. Of these 225 MPN patients, 19 of 121 (15.7%) ET, 9 of 83 (10.8%) PV, and 6 of 21 (28.6%) PMF patients had PH. PV patients with PH were older [71 (42‒85) vs. 61.5 (26‒91) yr, respectively; P=0.049], predominantly female (male:female ratio, 0.29 vs. 1.96, respectively; P=0.010), had lower hemoglobin levels (15.9±2.6 g/dL vs. 18.4±2.6 g/dL, respectively; P=0.010), and higher platelet counts (616.6±284.2×10⁹/L vs. 437.7±191.7×10⁹/L, respectively; P=0.020) than PV patients without PH. PMF patients with PH had higher monocyte counts (1.3±0.5×10⁹/L vs. 0.8±0.4×10⁹/L, respectively; P=0.031) than those without PH. PH was a risk factor for poor survival in PV (HR, 12.4; 95% CI, 1.8‒86.6).

Conclusion

PH is common in patients with Ph^- MPNs and hence, careful screening for PH is warranted.

Blockade of JAK2 protects mice against hypoxia-induced pulmonary arterial hypertension by repressing pulmonary arterial smooth muscle cell proliferation

Objectives

Hypoxia is an important risk factor for pulmonary arterial remodelling in pulmonary arterial hypertension (PAH), and the Janus kinase 2 (JAK2) is believed to be involved in this process. In the present report, we aimed to investigate the role of JAK2 in vascular smooth muscle cells during the course of PAH.

Methods

Smooth muscle cell (SMC)‐specific Jak2 deficient mice and their littermate controls were subjected to normobaric normoxic or hypoxic (10% O₂) challenges for 28 days to monitor the development of PAH, respectively. To further elucidate the potential mechanisms whereby JAK2 influences pulmonary vascular remodelling, a selective JAK2 inhibitor was applied to pre‐treat human pulmonary arterial smooth muscle cells (HPASMCs) for 1 hour followed by 24‐hour hypoxic exposure.

Results

Mice with hypoxia‐induced PAH were characterized by the altered JAK2/STAT3 activity in pulmonary artery smooth muscle cells. Therefore, induction of Jak2 deficiency in SMCs protected mice from hypoxia‐induced increase of right ventricular systolic pressure (RVSP), right ventricular hypertrophy and pulmonary vascular remodelling. Particularly, loss of Jak2 significantly attenuated chronic hypoxia‐induced PASMC proliferation in the lungs. Similarly, blockade of JAK2 by its inhibitor, TG‐101348, suppressed hypoxia‐induced human PASMC proliferation. Upon hypoxia‐induced activation, JAK2 phosphorylated signal transducer and activator of transcription 3 (STAT3), which then bound to the CCNA2 promoter to transcribe cyclin A2 expression, thereby promoting PASMC proliferation.

Conclusions

Our studies support that JAK2 could be a culprit contributing to the pulmonary vascular remodelling, and therefore, it could be a viable target for prevention and treatment of PAH in clinical settings.

Severe but reversible pulmonary hypertension in scleromyxedema and multiple myeloma: a case report

Background

Scleromyxedema is a progressive, systemic connective tissue disorder characterized by fibro-mucous skin lesions and increased serum monoclonal immunoglobulin levels. Pulmonary involvement occurs in a subset of patients, though the overall prevalence of pulmonary lesions in scleromyxedema is unknown. Since pulmonary hypertension presumably occurs in these patients due to disease progression and development of additional conditions, treatment of the underlying plasma cell dyscrasia and connective tissue disorder may improve pulmonary hypertension symptoms.

Case presentation

An elderly patient with scleromyxedema developed pulmonary hypertension refractory to vasodilator and diuretic therapy and subsequently multiple myeloma that responded to a combination therapy of bortezomib, cyclophosphamide, and dexamethasone treatment.

Conclusions

Treatment of the underlying disease(s) that contributed to pulmonary hypertension development with anti-neoplastic agents like bortezomib may improve cardiopulmonary symptoms secondary to reducing abnormal blood cell counts and paraprotein levels.

Association of Disease Subtype and Duration with Echocardiographic Evidence of Pulmonary Hypertension in Myeloproliferative Neoplasm

BACKGROUND

Pulmonary hypertension (PH) can complicate the course of myeloproliferative neoplasms (MPNs). Echocardiography is a useful noninvasive screening test for PH in populations at risk. We aimed to investigate the echocardiographic evidence of PH and clinical characteristics of patients with MPNs.

METHODS

This study included 197 patients with MPNs (mean age, 59 ± 14 years; females, 53%; mean disease duration, 3.4 ± 2.8 years). Clinical and laboratory characteristics, including JAK2V617F mutation status, were obtained. All participants underwent a comprehensive transthoracic echocardiographic examination. The echocardiographic evidence of PH was defined as systolic pulmonary artery pressure (SPAP) ≥40 mm Hg.

RESULTS

Overall, 11 patients (5.5%) with SPAP ≥40 mm Hg had echocardiographic evidence of PH. Patients with myelofibrosis had echocardiographic evidence of PH more often than patients with other MPNs (p < 0.001). Disease duration since the diagnosis of MPNs was 6.7 ± 4.6 years in the PH group and 3.1 ± 2.5 years in the non-PH group (p < 0.001). There was a weak positive correlation between SPAP values and time since diagnosis (r = 0.236, p =0.001). JAK2V617F mutation was not associated with PH. In multivariate logistic regression analysis, the presence of myelofibrosis (odds ratio [OR]: 22.177, 95% CI: 4.480-109.790, p < 0.001), long disease duration (OR: 1.217, 95% CI: 1.024-1.447, p = 0.026), and high uric acid levels (OR: 1.868, 95% CI: 1.049-3.328, p = 0.034) were found to be related with the echocardiographic evidence of PH. Survival was worse in the PH group (p = 0.0001).

CONCLUSION

Our results suggest that patients with myelofibrosis are more likely to develop PH than other MPNs patients. Disease duration may predict the development of PH in MPN patients.

Incidence of Silent Thrombosis in Patients Younger Than 60 Years With Myeloproliferative Neoplasms: Single-Center Egyptian Study

BACKGROUND

Identification of janus kinase 2 (JAK2) mutation even in absence of myeloproliferative disorders (MPNs) was found to be related to venous thromboembolism occurrence. Venous thrombosis screening is not routinely requested in patients with myeloproliferative neoplasms unless the patient is symptomatic. It has been reported that the incidence of thrombosis in elderly patients is much higher than in young patients. The aim of this work was to screen MPN patients for venous thrombosis and study its correlation with JAK2 allele burden and with MPN 10 score.

PATIENTS AND METHODS

We enrolled 73 patients with JAK2-positive MPN from our Hematology Clinic in the period August 2015 to Feb 2017. All patients had been screened for thrombosis in the venous system in lower limbs (LLs), upper limbs, portal, and mesenteric systems using color Doppler ultrasound imaging.

RESULTS

Fifty-three (72.6%) patients were younger than 60 years. Twenty-two (30%) had essential thrombocytosis, 35 (47.9%) had polycythemia rubra vera, and 16 (22%) had idiopathic myelofibrosis. Twenty-seven venous thrombotic attacks were reported in 22 (30.1%) patients. Five (6.8%) had thrombosis in 2 sites. Seventeen (23%) had superior mesenteric and portal vein thrombosis. Six (8%) had iliofemoral (8%) and 4 (5%) had combined LL and portal thrombosis. Eight (10.8%) had active thrombosis at screening. Only 3 patients (4%) were symptomatic with abdominal pain during screening. Pruritis (P = .02) and abdominal pain (P = .039) were significantly different between cases with and without thrombosis. There was no significant difference in MPN 10 score between cases with active or previous thrombosis.

CONCLUSION

We recommend routine screening for venous thrombosis in any case of MPN when diagnosed and screening for MPNs in any patient with venous thrombosis especially of the portal vein or atypical sites. If MPN patients present with increasing pruritus or abdominal pain, they also should be screened for venous thrombosis. Further research on a large scale in MPN age groups younger than 60 years regarding pathogenesis of thrombosis is highly recommended.

Combination treatment of captopril and prazosin to treat patients with gestational hypertension

Gestational hypertensive disorder is a complication of pregnancy, which adversely affects mother-child health. Captopril and prazosin are two agents that are frequently applied for the treatment of patients with gestational hypertension. However, the cooperative efficacy of captopril and prazosin has been not investigated in a previous study. In the present study, the comprehensive treatment of captopril and prazosin for the treatment of patients with gestational hypertension was investigated. A total of 324 patients with gestational hypertension were recruited to analyze the therapeutic effects of captopril and prazosin in patients with gestational hypertension. The duration of the treatment, dose-limiting toxicities and maximum tolerated dose of captopril and prazosin were examined in this cohort. Furthermore, the levels of blood pressure and proteinuria were also examined in patients with gestational hypertension who received treatment with captopril and/or prazosin with placebo as a control. Serum levels of vasodilation-converting enzyme and α-adrenergic receptor were also examined prior to and during the 4-week post-treatment period. It was observed that the most common treatment-emergence adverse events were hypertension and proteinuria following 4-week treatments. The data revealed that captopril or prazosin treatments significantly ameliorated gestational hypertension and symptoms compared with placebo (P<0.01). Notably, the combination of captopril and prazosin treatments significantly ameliorated hypertension and proteinuria and reduced the expression levels of vasodilation-converting enzyme and α-adrenergic receptor (all P<0.01), which contributed to beneficial effects on complications and blood coagulation mechanism compared with either captopril or prazosin treatment. In conclusion, the present clinical study indicated that combination treatment of captopril and prazosin exhibited more efficient outcomes than the single agent by improving gestational hypertension, indicating that a comprehensive therapeutic regimen of captopril and prazosin may be a potential clinical opinion for patients with gestational hypertension.

Myeloid-Derived Suppressor Cells and Pulmonary Hypertension

Myeloid–derived suppressor cells (MDSCs) comprised a heterogeneous subset of bone marrow–derived myeloid cells, best studied in cancer research, that are increasingly implicated in the pathogenesis of pulmonary vascular remodeling and the development of pulmonary hypertension. Stem cell transplantation represents one extreme interventional strategy for ablating the myeloid compartment but poses a number of translational challenges. There remains an outstanding need for additional therapeutic targets to impact MDSC function, including the potential to alter interactions with innate and adaptive immune subsets, or alternatively, alter trafficking receptors, metabolic pathways, and transcription factor signaling with readily available and safe drugs. In this review, we summarize the current literature on the role of myeloid cells in the development of pulmonary hypertension, first in pulmonary circulation changes associated with myelodysplastic syndromes, and then by examining intrinsic myeloid cell changes that contribute to disease progression in pulmonary hypertension. We then outline several tractable targets and pathways relevant to pulmonary hypertension via MDSC regulation. Identifying these MDSC-regulated effectors is part of an ongoing effort to impact the field of pulmonary hypertension research through identification of myeloid compartment-specific therapeutic applications in the treatment of pulmonary vasculopathies.

Clinico-hematological profile and thrombotic/hemorrhagic events in 150 chinese patients with essential thrombocythemia

Essential thrombocythemia (ET) is an uncommon chronic myeloproliferative disorder with no cure. Patients with ET are at risk of different complications, and currently there are no optimal prognostic standards to predict severe post-diagnosis complications such as thrombosis and hemorrhage. In this study, we retrospectively analyzed the full set of clinical data from 150 Chinese patients with ET enrolled from 2013 to 2016. We discovered that neutrophil-to-lymphocyte ratio (NLR), along with other known clinical parameters such as age, leukocyte count, incidence of thrombotic events is higher in patients with JAK2 V617F mutation. NLR is also higher in patients at high-risk stratification of thrombosis. Multivariate analysis showed that age (P = 0.001, 95% CI 1.023-1.089) and JAK2 V617F mutation (P = 0.003, 95% CI 1.837-21.035) were independent factors for thrombotic events, while age (P = 0.005, 95% CI 1.019-1.111) was the only predictive factor for hemorrhagic events at diagnosis. For future thrombotic events, multivariate analysis revealed NLR as the best predictive parameter (P < 0.001, 95% CI 1.173-1.486) when compared with other clinical parameters such as age (P = 0.037, 95% CI 1.004-1.126), thrombosis at diagnosis (P = 0.036, 95% CI 1.077-9.099) and WBC count (P = 0.047, 95% CI 1.001-1.109). Further ROC curve and Kaplan Meier analysis validated NLR as better prognostic marker for future thrombotic events and thrombosis-free survival. In summary, our data suggest that NLR parameter may possess great prognostic significance for future thrombosis in ET patients.

Medical Management of Pulmonary Hypertension with Unclear and/or Multifactorial Mechanisms (Group 5): Is There a Role for Pulmonary Arterial Hypertension Medications?

PURPOSE OF REVIEW

The purpose of this review was to outline the mechanisms and to review recent literature on pulmonary arterial hypertension (PAH) medications in group 5 pulmonary hypertension (PH).

RECENT FINDINGS

The first steps in management are to understand the mechanisms and hemodynamic profile and to exclude chronic thromboembolic disease. Recent studies in the past 5 years have found that PAH medications may improve hemodynamics in patients with pre-capillary pulmonary hypertension due to sarcoidosis, pulmonary Langerhans cell histiocytosis, lymphangioleiomyomatosis, and myeloproliferative disorders with dasatinib-induced PH. Improvements in exercise capacity are uncommon, and no survival benefit has been demonstrated. There is a risk of pulmonary edema in patients with pulmonary venous involvement or fibrosing mediastinitis when treated with PAH therapies. There is limited evidence supporting the use of PAH medications in group 5 patients, and they may be harmful in certain cases. In most patients with group 5 PH, treatment should be directed to the underlying disease with PAH therapies reserved for patients with severe pre-capillary PH.