Polycythemia vera (PV) is a chronic myeloproliferative neoplasm. Virtually all PV patients are iron deficient at presentation and/or during the course of their disease. The co-existence of iron ...deficiency and polycythemia presents a physiological disconnect. Hepcidin, the master regulator of iron metabolism, is regulated by circulating iron levels, erythroblast secretion of erythroferrone, and inflammation. Both decreased circulating iron and increased erythroferrone levels, which occur as a consequence of erythroid hyperplasia in PV, are anticipated to suppress hepcidin and enable recovery from iron deficiency. Inflammation which accompanies PV is likely to counteract hepcidin suppression, but the relatively low serum ferritin levels observed suggest that inflammation is not a major contributor to the dysregulated iron metabolism. Furthermore, potential defects in iron absorption, aberrant hypoxia sensing and signaling, and frequency of bleeding to account for iron deficiency in PV patients have not been fully elucidated. Insufficiently suppressed hepcidin given the degree of iron deficiency in PV patients strongly suggests that disordered iron metabolism is an important component of the pathobiology of PV. Normalization of hematocrit levels using therapeutic phlebotomy is the most common approach for reducing the incidence of thrombotic complications, a therapy which exacerbates iron deficiency, contributing to a variety of non-hematological symptoms. The use of cytoreductive therapy in high-risk PV patients frequently works more effectively to reverse PV-associated symptoms in iron-deficient relative to iron-replete patients. Lastly, differences in iron-related parameters between PV patients and mice with JAK2 V617F and JAK2 exon 12 mutations suggest that specific regions in JAK2 may influence iron metabolism by nuanced changes of erythropoietin receptor signaling. In this review, we comprehensively discuss the clinical consequences of iron deficiency in PV, provide a framework for understanding the potential dysregulation of iron metabolism, and present a rationale for additional therapeutic options for iron-deficient PV patients.
Thrombosis is a major cause of morbimortality in patients with polycythemia vera (PV). Furthermore, neutrophils play a significant role in thrombosis, but their role in the pathogenetic mechanisms of ...PV is not well characterized. Therefore, we investigated the role and mechanisms by which neutrophils regulate thrombosis in PV patients. Univariate and multivariate logistic regression analysis of clinicopathological factors was performed to determine the independent risk factors of thrombosis in PV. Pearson's correlation analysis was performed to determine the relationship between absolute neutrophil count (ANC) and the hypercoagulable state in PV patients. Bioinformatics analysis of the GSE54644 dataset was used to identify hemostasis-related pathways in neutrophils of PV patients. Weighted gene co-expression network analysis (WGCNA) of the integrated dataset (GSE57793, GSE26049 and GSE61629) was used to identify neutrophils-related genes and pathways associated with thrombosis in PV. Ingenuity pathway analysis (IPA) was performed to identify the differentially activated pathways in PV patients with or without thrombosis using GSE47018 dataset. Our data showed increased ANC in PV patients. Multivariate logistic regression analysis showed that ANC was an independent risk factor for the thrombotic events in PV patients before or at diagnosis. ANC correlated with the hypercoagulable state in PV patients. Neutrophil extracellular traps (NETs) pathway was significantly enriched in the neutrophils of PV patients. IPA results demonstrated that PRKCD-mediated NETs pathway was hyperactivated in PV patients with thrombosis. In summary, ANC was an independent risk factor for the thrombotic events in PV patients before or at diagnosis, and PRKCD-mediated NETs pathway was aberrantly activated in the neutrophils of PV patients and was associated with the thrombotic events.
Polycythemia vera (PV), a Philadelphia chromosome-negative myeloproliferative neoplasm, is characterized by panmyelosis, pancytosis, and a
mutation. Patients are at increased risk of ...thrombohemorrhagic events, and progression to myelofibrosis or acute leukemia. Current treatments include aspirin, phlebotomy, and cytoreductive drugs (most commonly hydroxyurea). Givinostat is a potent, class I/II histone deacetylase (HDAC) inhibitor that is in phase I/II clinical trials in PV. Givinostat was well tolerated and yielded promising clinico-hematological responses. A phase III study of givinostat versus hydroxyurea in high-risk PV patients is planned.
We present an overview of PV, current treatment guidelines, and the putative mechanism(s) of action of givinostat. We discuss the preclinical and clinical studies of givinostat in PV and briefly review approved and investigational competitor compounds.
HDAC inhibitors have long been known to be active in PV, but chronic toxicities can be challenging. Givinostat, however, is active and well tolerated, and is entering a pivotal Phase III randomized trial. Givinostat offers the possibility of replacing hydroxyurea as the standard first-line cytoreductive choice for PV patients. This would completely change the current therapeutic paradigm and guidelines for PV management. Although surrogate clinical study endpoints may suffice for regulatory purposes, thrombosis reduction and prevention of disease progression remain most important to patients and clinicians.
Abstract
This study was conducted in the Department of Food Sciences - College of Agriculture - University of Tikrit to estimate the chemical and physical properties of yogurt prepared by adding aloe ...vera extract. The yogurt was made in a laboratory by following the standard method, where the manufactured yogurt was fortified with different concentrations of aloe vera extract (5, 4, 3, 2, 1%). Chemical tests were carried out, which included (estimation of protein, moisture, fat, ash and total solids), as well as physical tests, which included (estimation of viscosity, pH, turbidity, whey translucency, water binding strength and acidity). The results showed an increase in total solids through an increase in the percentage of protein, moisture, ash, turbidity, water binding strength and viscosity, while the percentage of whey permeation and pH decreased. These results are consistent with the results of the samples obtained after storage, as the study helped to improve the physicochemical properties by increasing the concentrations of the main chemical compounds of the laboratory-made yogurt.
The use of hydroxyurea (HU) as first line therapy in polycythemia vera (PV) has been criticized because no solid demonstration that this drug prevents thrombosis or prolongs survival has been so far ...produced. Here we present the outcomes of a large cohort of patients with PV included in the European Collaborative Low‐dose Aspirin (ECLAP) study. We selected 1,042 patients who, during the follow‐up, had received only phlebotomy (PHL) or HU to maintain the hematocrit level < 45%. To assure comparability, we conducted a propensity score matching analysis. The two groups (PHL n = 342 and HU n = 681) were well balanced for the parameters included in the propensity score (overall balance: χ2 = 2.44, P = 0.964). Over a comparable period of follow‐up (PHL = 29.9 vs. HU = 34.7 months), we documented an advantage of HU over PHL consistently significant with respect to the incidence of fatal/non‐fatal cardiovascular (CV) events (5.8 vs. 3.0 per 100 person‐years in PHL vs. HU group, P = 0.002) and myelofibrosis transformation that was only experienced by patients of PHL group. Evolution to acute leukemia was registered in three patients (two in PHL and one in HU group). The excess of mortality and total CV events in the PHL patients was restricted to the high‐risk group, and, compared with HU cases, was significant higher in the PHL patients who failed to reach the hematocrit target < 0.45% (P = 0.000). In conclusion, this analysis provides reliable and qualified estimates of the therapeutic profile of HU and PHL treatments for future experimental studies and for the management of PV in clinical practice.
Masked polycythaemia vera (PV) has been proposed as a new entity with poorer outcome than overt PV. In this study, the initial clinical and laboratory characteristics, response to treatment and ...outcome of masked and overt PV were compared using red cell mass and haemoglobin or haematocrit levels for the distinction between both entities. Sixty‐eight of 151 PV patients (45%) were classified as masked PV according to World Health Organisation diagnostic criteria, whereas 16 (11%) were classified as masked PV using the British Committee for Standards in Haematology (BCSH). In comparison with overt PV, a higher platelet count and a lower JAK2V617F allele burden at diagnosis were observed in masked PV. Patients with masked PV needed lower phlebotomies and responded faster to hydroxcarbamide than those with overt PV. Complete haematological response was more frequently achieved in masked than in overt PV (79% vs. 58%, P = 0.001). There were no significant differences in the duration of haematological response, the rate of resistance or intolerance to hydroxycarbamide and the probability of molecular response according to type of PV (masked vs. overt). Overall survival, rate of thrombosis and major bleeding, and probability of transformation was superimposable among patients with masked and overt PV.
In this prospective, open-label, multicenter phase 1/2 dose escalation study, we used a next-generation, mono-pegylated interferon (IFN) α-2b isoform, ropeginterferon alfa-2b. The unique feature of ...ropeginterferon alfa-2b is a longer elimination half-life, which allows administration every 2 weeks. We present data from 51 polycythemia vera patients. The main goal was to define the maximum tolerated dose and to assess safety and efficacy. A dose range of 50 to 540 µg was tested without the appearance of dose-limiting toxicities. All drug-related adverse events were known toxicities associated with IFN-α. The cumulative overall response rate was 90%, comprising complete response in 47% and partial response in 43% of patients; the best individual molecular response level was a complete response in 21% of patients and partial response in 47%. Notably, we did not observe any correlation between the dose level and the response rate or response duration, suggesting that already low levels of ropeginterferon alfa-2b are sufficient to induce significant hematologic and molecular responses. These data suggest promising efficacy and safety of ropeginterferon alfa-2b and support the development of the drug in a randomized phase 3 clinical trial. The study was disclosed at www.clinicaltrials.gov as #NCT01193699 before including the first patient.
•The novel IFNα-2b, ropeginterferon alfa-2b, administered once every 2 weeks has low toxicity and induces high and sustained response rates in polycythemia vera patients.•Ropeginterferon alfa-2b induces significant partial and complete molecular response rates, as reflected by reduction of JAK2 allelic burden.
We studied the relationship between JAK2 (V617F) mutant allele burden and clinical phenotype, disease progression and survival in patients with polycythemia vera (PV). The percentage of granulocyte ...mutant alleles was evaluated using a quantitative real-time polymerase chain reaction-based allelic discrimination assay. Of the 338 patients enrolled in this prospective study, 320 (94.7%) carried the JAK2 (V617F) mutation. Direct relationships were found between mutant allele burden and hemoglobin concentration (P=0.001), white blood cell count (P=0.001), spleen size (P=0.001) and age-adjusted bone marrow cellularity (P=0.002), while an inverse relationship was found with platelet count (P<0.001). During the study period, eight patients progressed to post-PV myelofibrosis (MF) (all carrying >50% mutant alleles), while 10 patients developed acute myeloid leukemia (AML). The mutant allele burden was significantly related to the risk of developing myelofibrosis (P=0.029) and retained its significant effect also in multivariable analysis (P=0.03). By contrast, the risk of developing AML as well as that of thrombosis was not significantly related to mutant allele burden. Leukocytosis did not affect thrombosis, MF, leukemia or survival. In conclusion, a JAK2 (V617F) allele burden >50% represents a risk factor for progression to MF in PV.
Summary
Polycythaemia vera (PV) is a chronic blood cancer; its clinical features are dominated by myeloproliferation (erythrocytosis, often leucocytosis and/or thrombocytosis) and a tendency for ...thrombosis and transformation to myelofibrosis or acute myeloid leukaemia. In the past 10 years the pathophysiology of this condition has been defined as JAK/STAT pathway activation, almost always due to mutations in JAK2 exons 12 or 14 (JAK2 V617F). In the same time period our understanding of the optimal management of PV has expanded, most recently culminating in the approval of JAK inhibitors for the treatment of PV patients who are resistant or intolerant to therapy with hydroxycarbamide. It has also been demonstrated that life expectancy for many patients with PV is not normal, nor is their quality of life. We critically explore these findings and discuss their impact. In addition, we highlight persisting gaps in our current management strategy; for example, what is the optimal first line cytoreductive therapy and, indeed, which patients need cytoreductive drugs.
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