Comparison of different criteria for the diagnosis of primary myelofibrosis reveals limited clinical utility for measurement of serum lactate dehydrogenase

Primary myelofibrosis shows histological and pathogenetic overlap with essential thrombocythemia and polycythemia vera. Several diagnostic classifications have been proposed for primary myelofibrosis, although little is known about their clinical utility. In a comparison of three recent classifications, overall concordance was 79%. Inclusion of raised serum lactate dehydrogenase categorized 9% of patients as primary myelofibrosis when other criteria were not met. Although mean serum lactate dehydrogenase levels were higher in patients with primary myelofibrosis, levels were also increased in the majority of patients with essential thrombocythemia or polycythemia vera, and significant overlap was observed. A positive correlation with higher leukocyte and platelet count, and disease duration in primary myelofibrosis, suggests that serum lactate dehydrogenase is a biomarker for disease bulk and/or cellular proliferation. In conclusion, raised lactate dehydrogenase lacks specificity for primary myelofibrosis, consistent with the concept of a phenotypic continuum between essential thrombocythemia, polycythemia vera and primary myelofibrosis.     

Aspirin-responsive painful red,blue, black toe,or finger syndrome in polycythemia vera associated with thrombocythemia

Five patients with red, purple blue, or black toes or fingers due to thrombocythemia associated with polycythemia vera (polycythemia and thrombocythemia vera) in four and essential thrombocythemia (thrombocythemia vera) in one are described. The microvascular erythromelalgic syndrome of thrombocythemia was overlooked and progressed to cold blue swollen and painful fingers or black toes in three patients with polycythemia and thrombocythemia vera due to arteriographically documented occlusions of digital or large peripheral arteries with no evidence of preexistent atherosclerotic vascular disease. Concomitant erythromelalgia of the hand palm could be confirmed by the histopathological findings of arteriolar thrombotic lesions in the reticular dermis in two patients with polycythemia and thrombocythemia vera. The increased hematocrit in the presented patients with polycythemia and thrombocythemia vera contributed to the progression of the microvascular syndrome of thrombocythemia to major occlusive ischemic events of the extremities. Standard therapy with oral anticoagulants and reduction of the hematocrit to normal by bloodletting did not affect the platelet-mediated microvascular erythromelalgic, ischemic symptoms in the patients with polycythemia vera because thrombocythemia vera persisted. Complete relief of pain and restoration of the ischemic acral circulation disturbances in patients with thrombocythemia vera or thrombocythemia associated with polycythemia vera in maintained remission by bloodletting could be obtained by long-term treatment with low-dose aspirin.     

Monoclonal gammopathy in chronic myeloproliferative disorders

Summary The incidence of monoclonal gammopathy in 61 patients with chronic myeloproliferative disorders (CMPD) was studied. The distribution of patients among the CMPD subgroups was: chronic myelocytic leukemia, 24 patients; myelofibrosis, 11; polycythemia vera, 15; essential thrombocythemia, 7; unclassified MPD, 4 patients. Monoclonal gammopathy was found in 5 patients (8.2%). Two of these patients (1 IgA/k and 1 IgM/k) had myelofibrosis and 3 (2 IgG/k and 1 IgG/) polycythemia vera.The presence of monoclonal gammopathy indicates an involvement of the lymphoplasmatic system in CMPD.     

Allogeneic hematopoietic stem cell transplantation in patients with polycythemia vera or essential thrombocythemia transformed to myelofibrosis or acute myeloid leukemia: a report from the MPN Subcommittee of the Chronic Malignancies Working Party of the European Group for Blood and Marrow Transplantation

The clinical course of polycythemia vera and essential thrombocythemia is potentially associated with long-term severe complications, such as evolution to myelofibrosis or acute myeloid leukemia. Allogeneic stem cell transplantation is currently the only potentially curative treatment for advanced polycythemia vera or essential thrombocythemia. We analyzed 250 consecutive patients with an initial diagnosis of polycythemia vera (n=120) or essential thrombocythemia (n=130), who underwent transplantation due to progression to myelofibrosis (n=193) or acute myeloid leukemia (n=57) and who were reported to the European Group for Blood and Marrow Transplantation registry between 1994 and 2010. Their median age was 56 years (range, 22–75) and in 52% of cases the interval between diagnosis and transplantation was 10 years or more. With a median follow-up from transplantation of 13 months, the 3-year overall survival rate and relapse incidence were 55% and 32%, respectively. In univariate analysis, the main parameters that negatively affected post-transplantation outcomes were older age (>55 years), a diagnosis at transplant of acute myeloid leukemia and the use of an unrelated donor. The overall 3-year cumulative incidence of non-relapse mortality was 28%, but was significantly higher in older patients than in younger ones (>55 years, 35% versus 20%, P=0.032), in those transplanted from an unrelated donor rather than a related donor (34% versus 18%, P=0.034) and in patients with a diagnosis of acute myeloid leukemia compared to myelofibrosis (29% versus 27%, P=0.045). This large retrospective study confirms that transplantation is potentially curative for patients with end-stage polycythemia vera/essential thrombocythemia progressing to myelofibrosis or acute myeloid leukemia. Relapse and non-relapse mortality remain unsolved problems for which innovative treatment approaches need to be assessed.     

Characteristic changes in platelet-large cell ratio, lactate dehydrogenase and C-reactive protein in thrombocytosis-related diseases

We examined the clinical usefulness of 3 parameters of routine laboratory tests [platelet-large cell ratio (P-LCR), lactate dehydrogenase (LDH) and C-reactive protein (CRP)] in 84 patients with thrombocytosis-related diseases (reactive thrombocytosis, chronic myeloid leukemia, essential thrombocythemia and polycythemia vera). These thrombocytosis-related diseases were characterized using the 3 parameters P-LCR, LDH and CRP as follows: high P-LCR and high LDH in chronic myeloid leukemia; high CRP in reactive thrombocytosis; slightly high P-LCR and high LDH in essential thrombocythemia and polycythemia vera. For essential thrombocythemia and polycythemia vera, levels of P-LCR and CRP were nearly identical, but the LDH level in essential thrombocythemia was significantly higher than in polycythemia vera. These characteristics of P-LCR, LDH and CRP may be useful for simple and very rough differentiation of the thrombocytosis-related disease mentioned above.     

Splenectomy in chronic myeloid leukemia and myelofibrosis with myeloid metaplasia

Myelofibrosis with myeloid metaplasia (MMM) is a collective term that describes the related disorders AMM, PPMM, and PTMM. The chronic myeloid disorders include chronic myeloid leukemia, polycythemia vera, essential thrombocythemia, and agnogenic myeloid metaplasia (myelofibrosis). These disorders display varying propensities for pathologic enlargement of the spleen which can lead to mechanical discomfort, hypercatabolic symptoms, anemia, thrombocytopenia, and portal hypertension. Splenectomy has been found to be of little benefit in the early stages of chronic myeloid leukemia. Similarly, the benefit of splenectomy in advanced cases is limited to symptomatic palliation and treatment of delayed engraftment after allogeneic bone marrow transplantation. Although polycythemia vera and essential thrombocythemia are also characterized by splenomegaly, splenectomy is not considered a therapeutic option in the absence of transformation of the disease into myelofibrosis with myeloid metaplasia. Splenectomy has been studied most in myelofibrosis with myeloid metaplasia. Although there is no clear survival advantage to splenectomy in this disorder, the surgical procedure can result in substantial palliation of mechanical discomfort, hypercatabolic symptoms, portal hypertension, and anemia. However, the procedure is associated with an approximately 9% mortality rate, and the postsplenectomy occurrence of extreme thrombocytosis, hepatomegaly, and leukemic transformation is of major concern.     

Frequent reduction or absence of detection of the JAK2-mutated clone in JAK2V617F-positive patients within the first years of hydroxyurea therapy

We analyzed the effect of hydroxyurea on the JAK2V617F allelic ratio (%JAK2V617F), measured in purified blood granulocytes, of patients with polycythemia vera and essential thrombocythemia. Thirty-six patients were examined sequentially prior to and after start of hydroxy-urea therapy (8 polycythemia vera, 17 essential thrombocythemia), or while remaining untreated (2 polycythemia vera, 9 essential thrombocythemia). Hydroxyurea therapy (median duration: 15 months) reduced the %JAK2V617F by >30% in 13/25 patients (4 polycythemia vera, 9 essential thrombocythemia). For 3 patients, JAK2V617F remained undetectable for 3-27 months. In addition, a single time point study of two large cohorts of patients, examined either at the time of diagnosis (99 polycythemia vera, 178 essential thrombocythemia) or while receiving hydroxyurea (36 polycythemia vera, 98 essential thrombocythemia; median length of therapy: 32 months), confirmed reduction of %JAK2V617F in the hydroxyurea-treated group (24% vs. 33% JAK2V617F at diagnosis, p<0.01). Prospective studies are needed to determine the prognostic value of reduced JAK2V617F allele burden under cytoreductive therapy.     

Life expectancy and prognostic factors for survival in patients with polycythemia vera and essential thrombocythemia

PURPOSE: To assess life expectancy and prognostic factors for survival in patients with polycythemia vera and essential thrombocythemia. METHODS: The study sample consisted of 831 consecutive patients with polycythemia vera (n = 396; 4184 person-years of follow-up) or essential thrombocythemia (n = 435; 4304 person-years of follow-up). Mortality in each group was compared with the Italian population using the standardized mortality ratio (SMR) based on life expectancy data obtained from the Italian Institute of Statistics. RESULTS: The 15-year survival was 65% in patients with polycythemia and 73% in those with thrombocythemia. By Cox regression analysis, the independent predictors of death were a history of thrombosis for polycythemia (hazard ratio [HR] = 2.2; P = 0.0002) and thrombocythemia (HR = 2; P = 0.01), and male sex (HR = 1.8; P = 0.03) for thrombocythemia. Mortality compared with the general population was 1.6-fold higher (P <0.001) in patients with polycythemia but was not increased in those with thrombocythemia (SMR = 1; P = 0.8). CONCLUSION: Life expectancy of patients with polycythemia vera (especially if younger than 50 years) was reduced compared with the general population, whereas life expectancy of patients with essential thrombocythemia was not affected significantly by the disease, reflecting the more indolent nature of the proliferation. History of thrombosis was the main predictor of death in both diseases.     

Differentiation between essential thrombocythemia and polycythemia vera with marked thrombocytosis

Accurate distinction between essential thrombocythemia and thrombocytotic polycythemia vera requires determination of the red cell mass in the presence of adequate iron stores, but this is not always possible. We therefore compared the clinical and laboratory features at the time of presentation of 50 patients with unequivocal essential thrombocythemia and 27 patients with thrombocytotic polycythemia vera. Univariate analysis failed to identify any single parameter capable of reliably separating the groups. A logistic regression algorithm incorporating hematocrit, white cell count, and spleen size markedly increased the diagnostic accuracy (92%) compared with predictions based on the hematocrit alone (52%). The algorithm's usefulness for patients with intermediate hematocrits was confirmed by analysis of independent samples of essential thrombocythemia and thrombocytotic polycythemia vera patients, and also by analysis of patients with probable essential thrombocythemia in whom the diagnosis could not be confirmed because of inadequate exclusion of polycythemia vera. Furthermore, comparison of survival data suggests that differentiating these disorders is prognostically important. The algorithm is recommended as an alternate method for differentiating essential thrombocythemia from thrombocytotic polycythemia vera whenever the red cell mass is unavailable or iron deficiency cannot be excluded.     

Hemostatic gene polymorphisms and the prevalence of thrombotic complications in polycythemia vera and essential thrombocythemia.

Patients with polycythemia vera and essential thrombocythemia are at risk for thrombotic and bleeding complications. Currently, no diagnostic test can predict thrombohemorrhagic complications. In a prospective study of 86 patients with polycythemia vera (43 patients) or essential thrombocythemia (43 patients), we examined the possible role of polymorphisms of platelet adhesion receptors [glycoprotein (GP) Ibalpha, GPIa, GPIIIa) and clotting factor II (prothrombin's G20210A mutation) and clotting factor V (Leiden mutation) in determining the risk of thrombotic or bleeding complications. Except for an association between vasomotor symptoms and prothrombin mutation (P < 0.001), no significant correlation between polymorphism of clotting factors and thrombohemorrhagic complications was identified. When the entire patient cohort was considered, the polymorphisms of platelet adhesion receptors were not associated with the risk for thrombotic or bleeding complications. However, among patients with polycythemia vera, the presence of the PlA2 allele of GPIIIa was associated with an increased risk of arterial thrombosis. In view of previous studies linking the presence of the PlA2 allele of GPIIIa to a higher risk for coronary artery thrombosis, our data have physiologic relevance. However, they need to be confirmed in a larger study.     

A clinical update in polycythemia vera and essential thrombocythemia

Polycythemia vera and essential thrombocythemia pose specific management issues that distinguish them from other chronic myeloproliferative disorders. They are associated with a better prognosis, as well as a variable risk of thrombohemorrhagic complications. In addition, essential thrombocythemia occurs comparatively more often in young people and women. Treatment strategies for patients with polycythemia vera and essential thrombocythemia must consider the possibility of long-term survival, morbidity from thrombotic complications, transformation into myelofibrosis with myeloid metaplasia or acute myeloid leukemia, and the effect of specific therapies on the incidence of leukemic transformation and on pregnancy. There is increasing concern about the possible leukemogenic effect of hydroxyurea. Newer therapeutic agents, including interferon alpha and anagrelide, are being used more often. Ongoing studies are reexamining the effects of low-dose aspirin in preventing thrombotic complications.     

Inflammation and thrombosis in essential thrombocythemia and polycythemia vera: different role of C-reactive protein and pentraxin 3

We tested the hypothesis that levels of pentraxin high sensitivity C-reactive protein and pentraxin 3 might be correlated with cardiovascular complications in patients with essential thrombocythemia and polycythemia vera. High sensitivity C-reactive protein and pentraxin 3 were measured in 244 consecutive essential thrombocythemia and polycythemia vera patients in whom, after a median follow up of 5.3 years (range 0-24), 68 cardiovascular events were diagnosed. The highest C-reactive protein tertile was compared with the lowest (>3 vs. <1 mg/L) and correlated with age (P=0.001), phenotype (polycythemia vera vs. essential thrombocythemia, P=0.006), cardiovascular risk factors (P=0.012) and JAK2V617F allele burden greater than 50% (P=0.003). Major thrombosis rate was higher in the highest C-reactive protein tertile (P=0.01) and lower at the highest pentraxin 3 levels (P=0.045). These associations remained significant in multivariate analyses and indicate that blood levels of high sensitivity C-reactive protein and petraxin 3 independently and in opposite ways modulate the intrinsic risk of cardiovascular events in patients with myeloproliferative disorders.     

Significant increase in the apparent incidence of essential thrombocythemia related to new WHO diagnostic criteria: a population-based study

To observe the effect of the new World Health Organization (WHO) criteria on the incidence of myeloproliferative neoplasms, we performed a retrospective study of a population-based registry in the Côte d’Or area, France, from 1980 to 2007. A total of 524 myeloproliferative neoplasms were registered for the 1980–2007 period, including 135 polycythemia vera, 308 essential thrombocythemia and 81 idiopathic myelofibroses. No change in the incidence of either polycythemia vera or idiopathic myelofibrosis was observed for the 2005–2007 period, compared to 1980–2004. On the contrary, a pronounced increase in the incidence of essential thrombocythemia was noted after 2005, mainly due to the use of JAK2 mutation screening and a lower threshold of platelet count. Our study confirms the relevance of the new WHO diagnostic criteria in allowing earlier diagnosis of essential thrombocythemia.     

The Jak2V617F mutation, PRV-1 overexpression, and EEC formation define a similar cohort of MPD patients

Recently, a Jak2V617F mutation has been described in the vast majority of patients with polycythemia vera (PV) as well as in subsets of patients with essential thrombocythemia (ET) and idiopathic myelofibrosis (IMF). The question arises whether this mutation is observed in those patients with ET and IMF who have also displayed previously described molecular markers, notably the ability to form endogenous erythroid colonies (EECs), overexpression of polycythemia rubra vera 1 (PRV-1), and decreased c-Mpl expression. We therefore analyzed the Janus kinase 2 (Jak2) DNA sequence, EEC growth, PRV-1 expression, and c-Mpl (myeloproliferative) levels in a cohort of 78 myeloproliferative disorder (MPD) patients (42 ET, 22 PV, and 14 IMF). Presence of the Jak2V617F mutation was very highly correlated with PRV-1 overexpression and the ability to form EECs in all 3 subtypes of MPDs (P < .001). (     

JAK2 inhibitors: What's the true therapeutic potential?

Physicians treating patients with the classic Philadelphia-negative myeloproliferative neoplasms (Ph-negative MPNs) (polycythemia vera [PV], essential thrombocythemia [ET] and primary myelofibrosis [PMF]) traditionally had few therapeutic drugs available. Spurred by the discovery of activating mutation of the JAK2 tyrosine kinase (JAK2 V617F mutation) in patients with Ph-negative MPNs several years ago, several JAK2 inhibitors were synthesized and are currently undergoing clinical trials in patients with PMF, PV and ET. Initial results from these studies have shown that these drugs can markedly reduce spleen size and alleviate constitutional symptoms, increase weight and improve exercise capacity in MF patients, thus improve quality of their life, which is significant clinical benefit. In ET and PV JAK2 inhibitor therapy may efficiently control blood cell count, as well as improve splenomegaly and control disease related symptoms. JAK2 inhibitors are a novel class of agents with promising results for treating patients with MF, PV and ET. In this article we will review the current evidence regarding the role of JAK2 mutations in the pathogenesis of Ph-negative MPNs and summarize results from the most recent clinical trials with JAK2 inhibitors in these disorders. JAK2 inhibitors are a novel class of agents with promising results for treating patients with MF, PV and ET.     

Advances in myelofibrosis: a clinical case approach

Primary myelofibrosis is a member of the myeloproliferative neoplasms, a diverse group of bone marrow malignancies. Symptoms of myelofibrosis, particularly those associated with splenomegaly (abdominal distention and pain, early satiety, dyspnea, and diarrhea) and constitutional symptoms, represent a substantial burden to patients. Most patients eventually die from the disease, with a median survival ranging from approximately 5–7 years. Mutations in Janus kinase 2 (JAK2), a kinase that is essential for the normal development of erythrocytes, granulocytes, and platelets, notably the V617F mutation, have been identified in approximately 50% of patients with myelofibrosis. The approval of a JAK2 inhibitor in 2011 has improved the outlook of many patients with myelofibrosis and has changed the treatment landscape. This article focuses on some of the important issues in current myelofibrosis treatment management, including differentiation of myelofibrosis from essential thrombocythemia and polycythemia vera, up-dated data on the results of JAK2 inhibitor therapy, the role of epigenetic mechanisms in myelofibrosis pathogenesis, investigational therapies for myelofibrosis, and advances in hematopoietic stem cell transplant. Three myelofibrosis cases are included to underscore the issues in diagnosing and treating this complex disease.     

Genetic and epigenetic alterations of myeloproliferative disorders

The classical BCR–ABL negative myeloproliferative neoplasms (MPN) polycythemia vera, essential thrombocythemia, and primary myelofibrosis are clonal hematopoietic disorders characterized by excessive production of terminally differentiated myeloid cells. In MPN patients, the disease can progress to secondary myelofibrosis or acute myeloid leukemia. Clonal hematopoiesis, disease phenotype, and progression are caused by somatically acquired genetic lesions of genes involved in cytokine signaling, RNA splicing, as well as epigenetic regulation. This review provides an overview of point mutations and cytogenetic lesions associated with MPN and addresses the role of these somatic lesions in MPN disease progression.     

Essential thrombocythemia and leukemic transformation

Alkylating agents and 32P have been widely employed in the treatment of patients with essential thrombocythemia (ET). During a four-month period, we observed 3 cases of ET that had transformed into leukemia. Two patients had been treated with uracil mustard: One developed acute myelogenous leukemia 79 months after institution of therapy, and the other patient developed chronic myelomonocytic leukemia 24 months after the start of therapy. The third patient had been treated with busulfan, and ET evolved into myelofibrosis and eventually into acute undifferentiated leukemia with myelofibrosis. The patient who developed acute myelogenous leukemia was asymptomatic at the time of diagnosis of ET but was treated because his platelet count was greater than 1,000,000/mm3. He died 1 month after leukemic transformation, during induction chemotherapy. The other 2 patients presented with symptoms referable to their thrombocythemia. Review of the English literature revealed 12 other definite or probable cases of ET with leukemic transformation, all but 1 having been treated with alkylating agents and/or 32P. We propose that the natural history of ET may be similar to that of polycythemia vera, with evolution into leukemia being an unusual occurrence except in the setting of previous chemotherapy. Therefore, the current practice of treating asymptomatic patients with ET may not be justified, since administration of alkylating agents or 32P may increase the risk of subsequent development of leukemia.