Masked polycythemia vera (mPV): results of an international study

Diagnostic Approaches to Investigate JAK2-Unmutated Erythrocytosis Based on a Single Tertiary Center Experience

INTRODUCTION

Erythrocytosis is attributed to various clinical and molecular factors. Many cases of JAK2-unmutated erythrocytosis remain undiagnosed. We investigated the characteristics and causes of JAK2-unmutated erythrocytosis.

METHODS

We assessed the clinical and laboratory results of patients with erythrocytosis without JAK2 mutations and performed targeted next-generation sequencing (NGS) panels for somatic and germline mutations.

RESULTS

In total, 117 patients with JAK2-unmutated erythrocytosis were included. The median hemoglobin and hematocrit levels were 17.9 g/dL and 53.4%, respectively. Erythropoietin levels were not below the reference range. Thrombotic events were reported in 17 patients (14.5%). Among JAK2-unmutated patients, 44 had undergone targeted panel sequencing consisting of myeloid neoplasm-related genes, and 16 had one or more reportable variants in ASXL1 (5/44), TET2, CALR, FLT3, and SH2B3 (2/44). Additional testing for germline causes revealed eight variants in seven genes in eight patients, including NF1, BPGM, EPAS1, PIEZO1, RHAG, SH2B3, and VHL genes. One NF1 pathogenic, one BPGM likely pathogenic, and six variants of undetermined significance were detected.

CONCLUSION

Somatic and germline mutations were identified in 36.4% and 33.3 % of the JAK2-unmutated group; most variants had unknown clinical significance. Not all genetic causes have been identified; comprehensive diagnostic approaches are crucial for identifying the cause of erythrocytosis.

Erythrocytosis: Diagnosis and investigation

An absolute erythrocytosis is present when the red cell mass is greater than 125% of the predicted. This is suspected when the hemoglobin or hematocrit is above the normal range. An erythrocytosis can be classified as primary or secondary and congenital or acquired. The commonest primary acquired disorder is polycythemia vera. The diagnostic criteria for PV have evolved over time and this is the main diagnosis managed in hematology clinics. There are a variety of rare congenital causes both primary and secondary. In particular in young patients and/or those with a family history a congenital cause is suspected. There remains a larger cohort with acquired erythrocytosis mainly with non-hematological pathology. In order to explore for a cause of erythrocytosis, measurement of the erythropoietin level is a first step. A low erythropoietin level indicates a primary cause and a normal or elevated level indicates a secondary etiology. Further investigation is then dictated by initial findings and includes mutational testing with PCR and NGS for those in whom a congenital cause is suspected. Following this possibly bone marrow biopsy, scans, and further investigation as indicated by history and initial findings. Investigation is directed toward the identification of those with a hematological disorder which would be best managed following guidelines in hematology clinics and referral elsewhere in those for whom there are non-hematological reasons for the elevated hemoglobin.

Updated threshold, renewed problems: should the diagnostic criteria of polycythemia vera be reconsidered? A retrospective cross-sectional cohort study

OBJECTIVE

This aim of this study was to evaluate hemoglobin and hematocrit values of polycythemia vera and secondary polycythemia patients with updated World Health Organization thresholds. In addition, by determining our own threshold values, we aimed to demonstrate the necessity of bone marrow biopsy and genetic analysis to be used for further diagnosis in patients with high-normal hematocrit and hemoglobin values.

METHODS

A cross-sectional and retrospective study was performed with the medical records of patients from Eskisehir City Hospital hematology clinics and outpatient clinics between July 1, 2019 and July 1, 2020. The study included patients with polycythemia, divided into two groups according to polycythemia vera and secondary polycythemia. A bone marrow biopsy was performed on patients with either Janus kinase mutation positivity and/or subnormal erythropoietin levels. Receiver operating characteristics analysis was used to find threshold values, and the diagnostic efficiency of these values in differentiating World Health Organization thresholds in 2008 and 2016 was evaluated.

RESULTS

A total of 73 patients were included. The median age was 43.5 years (min: 18; max: 84). The hematocrit value of 54.1 was predicted to diagnose polycythemia vera with a sensitivity of 45% and a specificity of 80%. Subsequent analysis revealed that an hemoglobin value of 17.7 was indicative of diagnosing polycythemia vera with a sensitivity of 60% and a specificity of 63%. The mean follow-up length was 6.4 months (2-12).

CONCLUSION

Our study demonstrated that modified World Health Organization criteria might lead to unnecessary additional tests for polycythemia vera patients with high-normal hemoglobin and hematocrit values.

One thousand patients with essential thrombocythemia: the Mayo Clinic experience

We describe 1000 patients with essential thrombocythemia seen at the Mayo Clinic between 1967 and 2023: median age 58 years (18-90), females 63%, JAK2/CALR/MPL-mutated 62%/27%/3%, triple-negative (TN) 8%, extreme thrombocytosis (ExT; platelets ≥1000 × 109/L) 26%, leukocytosis (leukocyte count >11 × 109/L) 20%, and abnormal karyotype 6%. JAK2-mutated patients were older (median 71 years), and CALR mutated (52 years), and TN (50 years) younger (p < 0.01). Female gender clustered with TN (73%) and JAK2 (69%) vs. CALR/MPL (49%/47%) mutations (p < 0.01). ExT clustered with CALR (type-2 more than type-1) and TN and leukocytosis with JAK2 mutation (p < 0.01). In multivariable analysis, risk factors for overall survival were older age (p < 0.01), male gender (HR 1.8), absolute neutrophil count (ANC) ≥ 8 × 109/L (HR 1.6), absolute lymphocyte count (ALC) < 1.7 × 109/L (HR 1.5), hypertension (HR 1.7), and arterial thrombosis history (HR 1.7); for leukemia-free survival, ExT (HR 2.3) and abnormal karyotype (HR 3.1); for myelofibrosis-free survival, ANC ≥ 8 × 109/L (HR 2.3) and MPL mutation (HR 3.9); for arterial thrombosis-free survival, age ≥60 years (HR 1.9), male gender (HR 1.6), arterial thrombosis history (HR 1.7), hypertension (HR 1.7), and JAK2 mutation (HR 1.8); for venous thrombosis-free survival, male gender (HR 1.8) and venous thrombosis history (HR 3.0). Associations between ExT and leukemic transformation and between ANC and fibrotic progression were limited to JAK2-mutated cases. Aspirin therapy appeared to mitigate both arterial (HR 0.4) and venous (HR 0.4) thrombosis risk. HR-based risk models delineated patients with median survivals ranging from 10 years to not reached and 20-year leukemia/myelofibrosis incidences from 3%/21% to 12.8%/49%. The current study provides both novel and confirmatory observations of essential thrombocythemia.

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.

A Rational Approach to JAK2 Mutation Testing in Patients with Elevated Hemoglobin: Results from the JAK2 Prediction Cohort (JAKPOT) Study

BACKGROUND

Erythrocytosis, most often measured as an increase in hemoglobin and/or hematocrit, is a common reason for referral to internal medicine and hematology clinics and a rational approach is required to effectively identify patients with polycythemia vera while avoiding over-investigation.

AIM

We aimed to develop and validate a simple rule to predict JAK2 mutation positivity based on complete blood count parameters to aid in the diagnostic approach to patients referred for elevated hemoglobin.

SETTING

Internal medicine and hematology clinics at an academic tertiary referral center.

PARTICIPANTS

The JAK2 Prediction Cohort (JAKPOT), a large retrospective cohort (n = 901) of patients evaluated by internal medicine and hematology specialists for elevated hemoglobin.

DESIGN

JAK2 mutation analysis was performed in all patients and clinical and laboratory variables were collected. Patients were randomly divided into derivation and validation cohorts. A prediction rule was developed using data from the derivation cohort and tested in the validation cohort.

KEY RESULTS

The JAKPOT prediction rule included three variables: (i) red blood cell count >6.45×1012/L, (ii) platelets >350×109/L, and (iii) neutrophils >6.2×109/L; absence of all criteria was effective at ruling out JAK2-positivity with sensitivities 94.7% and 100%, and negative predictive values of 98.8% and 100% in the derivation and validation cohorts, respectively, with an overall low false negative rate of 0.4%. The rule was validated for three different methods of JAK2 testing. Applying this rule to our entire cohort would have resulted in over 50% fewer tests.

CONCLUSION

In patients with elevated hemoglobin, the use of a simple prediction rule helps to accurately identify patients with a low likelihood of having a JAK2 mutation, potentially limiting costly over-investigation in this common referral population.

Distinctive Attributes of Indian Patients With Classical BCR::ABL1 Negative Myeloproliferative Neoplasms: Unified Clinical and Laboratory Data

INTRODUCTION

We report one of the largest single center data from a mixed referral setting in India describing baseline characteristics and outcomes of patients with classical BCR::ABL1 negative myeloproliferative neoplasms (MPNs).

MATERIALS AND METHODS

Patients diagnosed from June 2019 to 2022 were included. Workup and treatment was as per current guidelines.

RESULTS

Diagnosis comprised polycythemia vera (PV) in 51(49%), ET in 33(31.7%) and prefibrotic primary myelofibrosis (MF) pre fibrotic myelofibrosis (prePMF) and myelofibrosis in 10(9.6%) patients each. Median age at diagnosis was 52 years for PV and ET, 65.5 for MF and 79 years for prePMF. Diagnosis was incidental in 63(56.7%) and after thrombosis in 8(7.2%) patients. Baseline next generation sequencing (NGS) was available for 63(60.5%) patients. Driver mutations in PV: JAK2 in 80.3%; in ET: JAK2 in 41%, CALR in 26%, MPL in 2.9%; in prePMF JAK2 in 70%, CALR in 20%, MPL in 10%, and in MF: JAK2 in 10%, MPL in 30% and CALR in 40%. Seven novel mutations were detected of which 5 were potentially pathogenic on computational analysis. After median follow up of 30 months, 2 patients had disease transformation and none had new episodes of thrombosis. Ten patients died, most commonly with cardiovascular events(n = 5,50%). Median overall survival was not reached. Mean OS time was 10.19 years(95%CI, 8.6 to 11.74) and mean time to transformation was 12.2 years(95% CI,11.8 to 12.6).

CONCLUSION

Our data indicates comparatively indolent presentation of MPNs in India with younger age and lower risk of thrombosis. Further follow up will enable correlation with molecular data and guide modification of age based risk stratification models.

Masked Polycythemia Vera and Iron Deficiency in a Fertile-Age Woman

Polycythemia vera (PV) is a myeloproliferative disorder that leads to increased red blood cell (RBC) mass. The V617F activating mutation for Janus kinase 2 (JAK2) is a classic finding in PV, but it is not exclusive to this condition. The radionuclide assay is an accurate method for accessing RBC, but hemoglobin (Hb) and hematocrit (Htc) values are frequently the first abnormal markers reported in a routine blood count and the basis for further investigation. Diagnostic criteria for PV were recently updated to include lower thresholds for Hb and Htc, increasing diagnostic sensitivity. However, it has been reported that a subset of patients does not meet these thresholds, besides having an active masked disease. We are presenting a case of a fertile-age woman with menometrorrhagia, whose blood loss and consequent iron depletion worked as a limiting factor for Hb and Htc increase, delaying the proper diagnosis. Splenomegaly, iron deficiency markers, and low erythropoietin supported PV investigation. The correction of iron depletion led to the unveiling of covert erythrocytosis. Concomitant hemoglobinopathies and secondary causes for erythrocytosis were excluded. The diagnosis was confirmed with polymerase chain reaction (PCR) for V617F-JAK2 mutation and bone marrow biopsy. As this case highlights, despite not meeting diagnostic criteria at presentation, masked PV exhibited clinical, laboratory, and imaging features of active symptomatic disease. For that, a higher level of suspicion must be held for fertile-age women who present with normal Hb and Htc levels and significant iron depletion, in the presence of low serum erythropoietin or splenomegaly.

The international consensus classification of myeloid neoplasms and acute Leukemias: myeloproliferative neoplasms

A group of international experts, including hematopathologists, oncologists, and geneticists were recently summoned (September 2021, Chicago, IL, USA) to update the 2016/17 World Health Organization classification system for hematopoietic tumors. After careful deliberation, the group introduced the new International Consensus Classification (ICC) for Myeloid Neoplasms and Acute Leukemias. This current in-depth review focuses on the ICC-2022 category of JAK2 mutation-prevalent myeloproliferative neoplasms (MPNs): essential thrombocythemia, polycythemia vera, primary myelofibrosis, and MPN, unclassifiable. The ICC MPN subcommittee chose to preserve the primary role of bone marrow morphology in disease classification and diagnostics, while also acknowledging the complementary role of genetic markers for establishing clonality, facilitating MPN subtype designation, and disease prognostication.

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.

Anagrelide in essential thrombocythemia: Efficacy and long-term consequences in young patient population

According to the current treatment recommendations, anagrelide, an oral antiplatelet agent, is recommended as a second-line therapy for patients with high-risk essential thrombocythemia experiencing intolerance or refractoriness to first-line approach, such as hydroxyurea or pegylated interferon alpha-2a. If there is a need for introduction of cytoreductive treatment in young patients with a perspective of lifelong exposure, both the efficacy and long-term outcomes should be known. We present the analysis of 48 young patients, diagnosed with essential thrombocythemia below the age of 60, who were exposed to anagrelide treatment for over 10 years. Our observations show that the highest proportion of complete remissions without adverse events and disease progression is seen in the JAK2-mutated patients. By evaluating the changes in hemoglobin concentration and serum erythropoietin throughout the study, we were able to reveal the development of progressive anemia, resulting from diminished susceptibility to erythropoietin and unrelated to bone marrow fibrosis, in patients harboring CALR mutation. Additionally, occurrence of new bone marrow fibrosis was confirmed in seven JAK2-unmutated patients at the end of the study. In summary, in young patient population, we recommend limiting the use of anagrelide to JAK2-mutated subgroup, reducing exposure time and underline the importance of periodic monitoring for the presence of bone marrow fibrosis.

Myeloproliferative Neoplasms, Version 3.2022, NCCN Clinical Practice Guidelines in Oncology

The classic Philadelphia chromosome-negative myeloproliferative neoplasms (MPN) consist of myelofibrosis, polycythemia vera, and essential thrombocythemia and are a heterogeneous group of clonal blood disorders characterized by an overproduction of blood cells. The NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) for MPN were developed as a result of meetings convened by a multidisciplinary panel with expertise in MPN, with the goal of providing recommendations for the management of MPN in adults. The Guidelines include recommendations for the diagnostic workup, risk stratification, treatment, and supportive care strategies for the management of myelofibrosis, polycythemia vera, and essential thrombocythemia. Assessment of symptoms at baseline and monitoring of symptom status during the course of treatment is recommended for all patients. This article focuses on the recommendations as outlined in the NCCN Guidelines for the diagnosis of MPN and the risk stratification, management, and supportive care relevant to MF.

Cytogenetic abnormalities in essential thrombocythemia: Clinical and molecular correlates and prognostic relevance in 809 informative cases

Cytogenetic studies among 809 consecutive patients with essential thrombocythemia (ET; median age 59 years; 65% females) revealed normal karyotype in 754 (93%), loss of chromosome Y only (-Y) in 16 (2%), and abnormalities other than -Y in 39 (4.8%), the most frequent being sole 20q- (n = 8). At presentation, abnormal karyotype, excluding -Y, was associated with older age (p = 0.04), higher leukocyte count (p = 0.03) and arterial thrombosis history (p = 0.02); no associations were apparent for JAK2/CALR/MPL mutations whereas ASXL1 mutations clustered with normal karyotype/-Y and TP53 with abnormal karyotype. Survival was significantly shorter in patients with abnormal karyotype or -Y, compared to those with normal karyotype (median 12, 10, and 21 years, respectively; p < 0.0001). During multivariable analysis that included IPSET (international prognostic score for ET) variables, abnormal karyotype (p < 0.01, HR 2.0), age >60 years (p < 0.01, HR 4.5), leukocytosis >11 × 10⁹/L (p < 0.01, HR 1.5), and male gender (p < 0.01, HR 1.4) were independently associated with inferior survival; abnormal karyotype and age >60 years remained significant, along with SF3B1/SRSF2/U2AF1/TP53 mutations (p = 0.04; HR 2.9), when the latter was included in the multivariable model. The current study suggests prognostic relevance for karyotype in ET.

Therapeutic Plateletpheresis in Patients With Thrombocytosis: Gender, Hemoglobin Before Apheresis Significantly Affect Collection Efficiency

Background: Thrombocytosis is a common symptom in myeloproliferative neoplasms (MPN), and excessive proliferation may deteriorate into thrombosis, bleeding, myelofibrosis, and may ultimately convert to acute leukemia. This study aimed to investigate the collection efficiency of plateletpheresis (CEPP) and factors influencing its efficacy in patients with thrombocytosis.

Materials and Methods: From September 2010 to December 2016, 81 patients from two institutions in China with myeloproliferative neoplasms and thrombocytosis accompanied by severe symptoms were treated with plateletpheresis by Fresenius COM. TEC machine.

Results: After apheresis, the median CEPP was 20.71% (IQR: 9.99–36.69%) and median PLT reduction rate was 25.87% (IQR: 21.78–36.23%). Further analysis showed that no significant difference was observed between PLT count with 800–1,000 × 10⁹/L and > 1,000 × 10⁹/L. The PLT counts significantly decreased (P < 0.001) after plateletpheresis, the red blood cell (RBC), white blood cell (WBC), hemoglobin (HGB), and hematocrit (HCT) levels showed no significant differences before- or after- plateletpheresis. Multivariate analysis showed that female sex (P = 0.009) and HGB (P = 0.010) before apheresis were associated with CEPP. Female (P = 0.022), HCT (P = 0.001) and blood volume (P = 0.015) were associated with the PLT reduction rate. Furthermore, symptoms were relieved after apheresis in patients whose PLT count was 800–1,000 × 10⁹/L accompanied with symptoms.

Conclusions: It is reasonable to perform plateletpheresis when the PLT count is over 800 × 10⁹/L and patients are complicated by clinical symptoms such as dizziness, headache, somnolence, and stupor. Plateletpheresis is effective in removing PLTs especially in females with high HGB.

Hematocrit to hemoglobin ratio as a prognostic marker in polycythemia vera

BACKGROUND

The hematocrit to hemoglobin ratio (HHR) is frequently used in everyday practice to measure hemoconcentration; however, clinical associations of HHR in the context of polycythemia vera (PV) have not been investigated so far.

PATIENTS AND METHODS

We retrospectively assessed HHR at the time of diagnosis in 107 PV and 40 secondary polycythemia (SP) patients from three community hospitals.

RESULTS

Median HHR was higher in PV than in SP patients (3.131 vs. 2.975, p = 0.041). Among PV patients, higher HHR correlated with splenomegaly, higher total leukocyte and absolute granulocyte counts, higher red blood cell counts, lower hemoglobin, higher red blood cell distribution width, lower mean corpuscular hemoglobin and lower ferritin levels, whereas in SP patients higher HHR correlated with older age, female sex and lower hemoglobin (p < 0.050 for all analyses). Using the receiver operating curve analysis-defined cut-off points, higher HHR in PV was associated with a shorter time to thrombosis (hazard ratio-HR 5.20, p = 0.022) independently of high-risk disease status (HR 4.48, p = 0.034) and shorter overall survival (HR 6.69, p = 0.009) independently of leukocytosis (HR 4.48, P = 0.034) and the absence of aspirin use (HR 15.53, p < 0.001).

CONCLUSION

Higher HHR may represent iron deficiency and a stronger clonal myeloproliferation in PV and could provide additional prognostic information to the classical risk assessment.

Pediatric Myeloproliferative Neoplasms

Myeloproliferative neoplasms can present early in life and may present a diagnostic challenge. Very few studies have focused on the diagnosis, prognosis, and therapy for pediatric myeloproliferative neoplasms. This article focuses on chronic myeloid leukemia, essential thrombocythemia, polycythemia vera, and primary myelofibrosis in children.

Evaluation of beta-2 microglobulin, erythropoietin and tobacco use in polycythemic cases

In the 2016 WHO classification, hemoglobin and hematocrit thresholds for diagnosing polycythemia vera (PV) have been lowered, increasing the number of consultations for polycythemia investigations. In PV, beta-2 microglobulin (B2m) levels are reportedly increased, whereas erythropoietin (EPO) levels are usually low. Most secondary polycythemia cases (SP) are caused by tobacco use. We decided to analyze the relevance of these three parameters in all patients seen for polycythemia investigations to help differentiate PV from SP cases. A cohort of 257 patients (123 PV; 134 SP) was identified. The median B2m level was higher for PV patients (3.16 vs 1.98 mg/l, p < 0.0001). Increased B2m levels were observed in 83.7% of PV patients (11.9% in SP). The median EPO level was lower in PV patients (4.4 vs 12.3 UI/l, p < 0.0001). Tobacco was used by 42.8% of SP patients (8% in PV, p < 0.0001). Increased B2m, low EPO and no tobacco exposure was predictive of PV (specificity and positive predictive value = 100%). Normal B2m, normal EPO and tobacco exposure was predictive of SP (positive predictive value = 100%). These simple and inexpensive parameters could be used to rapidly differentiate PV from SP cases, before prescribing time-consuming JAK2 V617F mutation analysis by specialists.

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.

Recent Advances in the Use of Molecular Analyses to Inform the Diagnosis and Prognosis of Patients with Polycythaemia Vera

Genetic studies in the past decade have improved our understanding of the molecular basis of the BCR-ABL1-negative myeloproliferative neoplasm (MPN) polycythaemia vera (PV). Such breakthroughs include the discovery of the JAK2V617F driver mutation in approximately 95% of patients with PV, as well as some very rare cases of familial hereditary MPN caused by inherited germline mutations. Patients with PV often progress to fibrosis or acute myeloid leukaemia, both associated with very poor clinical outcome. Moreover, thrombosis and major bleeding are the principal causes of morbidity and mortality. As a result of increasingly available and economical next-generation sequencing technologies, mutational studies have revealed the prognostic relevance of a few somatic mutations in terms of thrombotic risk and risk of transformation, helping to improve the risk stratification of patients with PV. Finally, knowledge of the molecular basis of PV has helped identify targets for directed therapy. The constitutive activation of the tyrosine kinase JAK2 is targeted by ruxolitinib, a JAK1/JAK2 tyrosine kinase inhibitor for PV patients who are resistant or intolerant to cytoreductive treatment with hydroxyurea. Other molecular mechanisms have also been revealed, and numerous agents are in various stages of development. Here, we will provide an update of the recent published literature on how molecular testing can improve the diagnosis and prognosis of patients with PV and present recent advances that may have prognostic value in the near future.

Diagnostic Performance of Erythropoietin Levels in Polycythemia Vera: Experience at a Comprehensive Cancer Center

INTRODUCTION

Considering the evolving diagnostic criteria of polycythemia vera (PV), we analyzed the utility of serum erythropoietin (EPO) as a predictive marker for differentiating polycythemia vera (PV) from other etiologies of erythrocytosis.

PATIENTS AND METHODS

We conducted a retrospective study after a review of electronical medical records from January 2005 to December 2016 with diagnosis of erythrocytosis using International Classification of Disease-specific codes. To evaluate the diagnostic performance of EPO levels and JAK2-V617F mutation, we constructed a receiver-operated characteristic curve of sensitivity versus 1-specificity for serum EPO levels and JAK2-V617F mutation as predictive markers for differentiating PV from other causes of erythrocytosis.

RESULTS

We surveyed 577 patients with erythrocytosis. Median patient age was 59.2 years, 57.72% (n = 329) were male, 86.3% (n = 491) were white, and only 3.3% (n = 19) were African American. A total of 80.88% (n = 351) of those diagnosed with PV had a JAK2-V617F mutation compared to only 1.47% (n = 2) whose primary diagnosis was secondary polycythemia. When comparing JAK2-V617 mutation to the EPO level, the area under the curve of JAK2-V617 (0.8970) was statistically larger than that of EPO test (0.6765). Therefore, the PV diagnostic methodology using JAK2-V617 is better than the EPO test. An EPO level of < 2 mIU/mL was > 99% specific to predict PV but was only 12% sensitive.

CONCLUSION

In the appropriate clinical setting, cytogenetic and molecular studies such as JAK2 mutation status prevail as the most useful tools for PV case identification. The use of isolated EPO to screen patients with erythrocytosis is not a good diagnostic approach.

Polycythemia Vera (PV): Update on Emerging Treatment Options

Polycythemia Vera (PV) is a chronic myeloproliferative neoplasm characterized by exuberant red cell production leading to a broad range of symptoms that compromise quality of life and productivity of patients. PV reduces survival expectation, primarily due to thrombotic events, transformation to blast phase and post-PV myelofibrosis or to development of second cancers, which are associates with poor prognosis. Current therapeutic first line recommendations based on risk adapted classification divided patients into two groups, according to age (< or >60 years) and presence of prior thrombotic events. Low-risk patients (age <60 years and no prior history of thrombosis) should be treated with aspirin (81-100 mg/d) and phlebotomy, to maintain hematocrit <45%. High-risk patients (age >60 years and/or prior history of thrombosis), in addition to aspirin and phlebotomies, should receive cytoreductive therapy in order to reduce thrombotic risk. Nowadays hydroxyurea still remains the cytoreductive agent of first choice, reserving Interferon to young patients or childbearing women. During the last years, ruxolitinib emerged as a new treatment in PV patients, as second line therapy: it appeared especially effective in patients with severe pruritus, symptomatic splenomegaly, or post-PV myelofibrosis symptoms. Currently, in PV treatment, several molecules have been tested or are under investigation. At present, the drug that has shown the most encouraging results is givinostat.

Polycythaemia vera: molecular genetics, diagnostics and therapeutics

Polycythaemia vera is one of several classical myeloproliferative neoplasms that may occur in a juvenile onset or late-onset adult forms. It is linked to specific genetic mutations that cause a deleterious elevation in the patient's red cell mass. The discourse on genetics includes an exposé on the molecular biology of the disease and how a shared JAK2 V617F mutation can co-exist among three distinct neoplasms. Concepts of genetics and immunology help define the origin and behaviour of the disease: the tracking of allele burdens of mutations (genetic dosage), the timing or order of acquired mutations, the import of bystander mutations and the onco-inflammatory response; all theories are invoked to explain the progression of disease severity and potential transformational leukaemia. The World Health Organization's diagnostic criteria are accessed to focus on the subtleties of the Hb laboratories and sifting through the challenging listing of differential diagnoses that mimic PV, and our report includes an overview of manual and automated phlebotomy (erythrocytapheresis) procedures, enumerating their clinical indications, significance of temporary phlebotomy resistance and optimizing safety/ efficacy, quality and cost. Stratification of low and high-risk disease distinguishes when to commence chemo-cytoreductive therapy in the high-risk patient to prevent thrombotic complications. Drug resistance is circumvented by artfully switching drugs or using novel drug designs.

Clinical and Molecular Attributes of Patients With BCR/ABL1-negative Myeloproliferative Neoplasms in India: Real-world Data and Challenges

INTRODUCTION

Classic BCR/ABL1-negative myeloproliferative neoplasms (MPNs) are characterized by clinical and genetic heterogeneity and include 4 distinct constituents. Very little data on clinical presentation and epidemiology of the same is available from the Indian setting.

PATIENTS AND METHODS

Patients referred to Hematology-Oncology from January 2018 to August 2020 with suspected MPNs were included in the analysis and prospectively followed-up. All patients were initially screened, and only those meeting the updated World Health Organization 2016 criteria were included in the analysis. Epidemiologic, clinical, and molecular characteristics were documented, and patients were followed-up prospectively.

RESULTS

A total of 233 patients were referred for evaluation of MPN, of which 63 were included in the analysis, including 39 males and 24 females. The median age at diagnosis was 57 years (range, 28-82 years), and 38% patients were younger than 50 years of age. The most common presentations were incidental detection in 35 (55.5%), abdominal symptoms in 13 (20%), fatiguability in 7 (11%), and recent vascular events in 6 (9.5%) patients. Final diagnosis was polycythemia vera in 27, essential thrombocytosis (ET) in 21, prefibrotic myelofibrosis in 9, and myelofibrosis in 6 patients. The frequency of driver mutations in polycythemia vera included JAK2 in 75%; in ET, JAK2 in 33%, CALR in 33%, and MPL in 4%; and in prefibrotic myelofibrosis, JAK2 in 66% and CALR in 33%. Aspirin was used for all patients along with risk-adapted cytoreduction with hydroxyurea. Ruxolitinib was reserved for symptoms refractory to hydroxyurea. After a median follow-up of 15 months (interquartile range, 10-28 months) from diagnosis, disease progression was noted in 4 patients. Two patients died at the end of the follow-up period, including 1 with secondary acute myeloid leukemia post myelofibrosis and one with ET and coexistent oral malignancy. The remaining 61 patients are alive and on regular treatment.

RESULTS

This is one of the first systematic descriptions and prospective follow-up of patients with BCR/ABL-negative MPNs from India. Our study indicates a younger median age of presentation and higher proportion of JAK2-unmutated disease across all subtypes. The primary role of bone marrow morphology and supportive role of somatic mutations in differentiating MPN subtypes is indicated.

CONCLUSIONS

This study sets the stage for a collaborative registry for defining epidemiologic data and long-term outcomes with MPN in India.

[Pathological characteristics of megakaryocytes in myeloproliferative neoplasms and their correlation with driver gene mutations]

Objective: To investigate the pathological characteristics of megakaryocytes in myeloproliferative neoplasms(MPN)and their correlations with driver gene mutations. Methods: Trephine specimens administered for 160 patients with MPN from February 2012 to October 2017 were reevaluated according to the World Health Organization(WHO)'s(2016)diagnostic criteria. Results: This cohort of patients included 72(45.0%)men, with the median age of 59(range, 13-87)years, comprising 39 with polycythemia vera(PV), 33 with essential thrombocythemia(ET), 37 with prefibrotic/early-primary myelofibrosis(pre-PMF), 37 with overt PMF, 1 with post-ET MF, 2 with post-PV MF, and 11 with MPN-unclassifiable(MPN-U)after the re-diagnosis. With PV, ET, pre-PMF, and overt PMF changes, proportions of dense clusters, hypolobulated nuclei, and naked nuclei of megakaryocytes gradually increased, whereas erythropoiesis gradually decreased. Proportions of reticulin, collagen, and osteosclerosis grades of ≥1 also increased. Dense clusters, hypolobulated nuclei, and naked nuclei of megakaryocytes were negatively correlated with erythropoiesis and positively correlated with granulopoiesis and fibrosis. In patients with pre- and overt PMF, dense clusters and naked nuclei of megakaryocytes were positively correlated with fibrosis. Patients with JAK2V617F MPN had significantly increased erythropoiesis(P=0.022). Patients with CALR-mutated MPN were characterized by increased loose and dense clusters; paratrabecular distribution and naked nuclei of megakaryocytes(P=0.055, P=0.002, P=0.018, P=0.008); and increased reticulin, collagen, and osteosclerosis(P=0.003, P<0.001, P=0.001). In patients with pre- and overt PMF, patients with JAK2V617F had increased cellularity(P=0.037). CALR-mutated patients had increased dense clusters and giant sizes of megakaryocytes, collagen, and osteosclerosis(P=0.055, P=0.059, P=0.011, P=0.046). Conclusion: Megakaryocytes showed abnormal MPN morphology and distribution, which were related to fibrosis. CALR mutation was probably associated with abnormal morphology and distribution of megakaryocytes and fibrosis.

The 2020 revision of the guidelines for the management of myeloproliferative neoplasms

In 2016, the World Health Organization revised the diagnostic criteria for myeloproliferative neoplasms (MPNs) based on the discovery of disease-driving genetic aberrations and extensive analysis of the clinical characteristics of patients with MPNs. Recent studies have suggested that additional somatic mutations have a clinical impact on the prognosis of patients harboring these genetic abnormalities. Treatment strategies have also advanced with the introduction of JAK inhibitors, one of which has been approved for the treatment of patients with myelofibrosis and those with hydroxyurea-resistant or intolerant polycythemia vera. Recently developed drugs aim to elicit hematologic responses, as well as symptomatic and molecular responses, and the response criteria were refined accordingly. Based on these changes, we have revised the guidelines and present the diagnosis, treatment, and risk stratification of MPNs encountered in Korea.

How Does 2016 WHO Criteria for Polycythemia Vera Contribute to Our Daily Practice? A Single-Center Study from Turkey

Background: We evaluated the frequency of subnormal erythropoietin levels, Janus kinase 2 (JAK2) V617F positivity and polycythemia vera (PV) in patients who did not meet World Health Organization (WHO) 2008 criterion for hemoglobin levels but were suggested to be investigated for PV in 2016 revision. Materials and Methods: We assessed the data of 92 patients who were further evaluated with JAK2V617F mutation and serum erythropoietin (EPO) levels and bone marrow biopsy, if necessary. We also compared this patient group with 20 patients whose Hgb>18.5 g/dL for men and >16.5 g/dL for women. Results: Nine patients (45%) in the higher hemoglobin group were JAK2V617F positive, while 4 patients (4.3%) in the lower hemoglobin group were JAK2V617F positive (p<0.001). The number of patients with serum EPO levels <4.3 mIU/mL was significantly higher in the higher hemoglobin group (n=13, 65%) than the lower hemoglobin group (n=7, 7.6%) (p<0.001). Finally, the number of patients who received a diagnosis of PV was significantly higher in the higher hemoglobin group (n=13, 65%) than the lower hemoglobin group (n=9, 9.8%) (p<0.001). Conclusion: We found a substantial increase in patients who were candidates for testing for PV with the introduction of WHO 2016 criteria; these patients were diagnosed with PV with a rate (9.8%) that cannot be underestimated.

New Perspectives on Polycythemia Vera: From Diagnosis to Therapy

Polycythemia vera (PV) is mainly characterized by elevated blood cell counts, thrombotic as well as hemorrhagic predisposition, a variety of symptoms, and cumulative risks of fibrotic progression and/or leukemic evolution over time. Major changes to its diagnostic criteria were made in the 2016 revision of the World Health Organization (WHO) classification, with both hemoglobin and hematocrit diagnostic thresholds lowered to 16.5 g/dL and 49% for men, and 16 g/dL and 48% for women, respectively. The main reason leading to these changes was represented by the recognition of a new entity, namely the so-called “masked PV”, as individuals suffering from this condition have a worse outcome, possibly owing to missed or delayed diagnoses and lower intensity of treatment. Thrombotic risk stratification is of crucial importance to evaluate patients’ prognosis at diagnosis. Currently, patients are stratified into a low-risk group, in the case of younger age (<60 years) and no previous thromboses, and a high-risk group, in the case of patients older than 60 years and/or with a previous thrombotic complication. Furthermore, even though they have not yet been formally included in a scoring system, generic cardiovascular risk factors, particularly hypertension, smoking, and leukocytosis, contribute to the thrombotic overall risk. In the absence of agents proven to modify its natural history and prevent progression, PV management has primarily been focused on minimizing the thrombotic risk, representing the main cause of morbidity and mortality. When cytoreduction is necessary, conventional therapies include hydroxyurea as a first-line treatment and ruxolitinib and interferon in resistant/intolerant cases. Each therapy, however, is burdened by specific drawbacks, underlying the need for improved strategies. Currently, the therapeutic landscape for PV is still expanding, and includes several molecules that are under investigation, like long-acting pegylated interferon alpha-2b, histone deacetylase inhibitors, and murine double minute 2 (MDM2) inhibitors.

Leukocytosis and thrombosis in essential thrombocythemia and polycythemia vera: a systematic review and meta-analysis

In the last years, a growing amount of evidence has been produced regarding the role of leukocytosis as a risk factor for thrombosis in patients with myeloproliferative neoplasms, predominantly in polycythemia vera (PV) and essential thrombocythemia (ET). Results from epidemiologic studies on this issue, however, are inconclusive. We conducted a systematic review and meta-analysis of articles published in the last 12 years addressing the issue, according to a predefined protocol. Forty-one articles analyzing >30 000 patients met our inclusion criteria and were deemed of acceptable methodologic quality. In addition to data on thrombosis, data were collected on bleeding, hematologic evolution, secondary cancer, and death. The relative risk (RR) of thrombosis in the presence of leukocytosis was 1.59 (95% CI, 1.40-1.80), mainly accounted for by ET (RR, 1.65; 95% CI, 1.43-1.91) and arterial thrombosis (RR, 1.45; 95% CI, 1.13-1.86) subgroups; the effect was not significant in venous thrombosis alone. Sensitivity analyses considering recurrent events as well as white blood cell estimates adjusted or unadjusted for confounding factors confirmed the primary results. In addition, the pooled RR of studies that tested white blood cell counts in time-dependent models suggested a causative effect of leukocytes in the mechanism that triggers thrombosis. The effect of leukocytosis on bleeding (RR, 1.87; 95% CI, 1.26-2.77) and death (RR, 1.89; 95% CI, 1.59-2.23) was confirmed, whereas conclusions on hematologic evolutions and solid tumors were uncertain. To confirm the accuracy of these results, an investigation on individual patient data in a large collective archive of homogeneous patients is warranted.

Polycythemia Vera Presenting With Normal Hemoglobin and Hematocrit: A Rare Variant

Polycythemia vera (PV) is a myeloproliferative neoplasm, and its diagnosis requires elevated hemoglobin level (>16.5 mg/dL in men and >16 mg/dL in women), bone marrow characteristics of PV (hypercellularity for age with trilineage growth), and presence of JAK2 (Janus kinase 2) mutations or subnormal erythropoietin level if JAK2 mutation is not present. There exists a subset of patients with normal hemoglobin and hematocrit due to either from dilution of the blood or from coincidental blood loss anemia but these patients still might have underlying PV. These patients have masked PV, which is a variant of overt PV. We present a case of masked PV presenting with venous thrombosis as a first presentation and with normal blood counts. A 42-year-old male with past medical history of portal vein thrombosis and portal hypertension presented with nausea and vomiting presumably secondary to viral gastroenteritis. He was not an alcoholic nor a smoker. He was diagnosed with portal vein thrombosis six years ago which was treated with warfarin but was never investigated for a cause. His physical exam was within normal limits except he had splenomegaly. His laboratory values on admission showed hemoglobin of 14.1 g/dL, white blood count of 7.4 x10⁹/L, and platelet count of 164 x10⁹/L. His liver function test and renal function tests were within normal limits. His viral gastroenteritis improved within 48 hours. Extensive workup to rule out myeloproliferative neoplasm, thrombophilia, antiphospholipid syndrome, and paroxysmal nocturnal hemoglobinuria was arranged. Final results revealed JAK2V617F genetic mutation with a subsequent bone marrow analysis revealing a hypercellular marrow with increased trilineage hematopoiesis, consistent with primary PV. It is rare for myeloproliferative neoplasms to present with normal blood counts. There is a subgroup of patients with JAK2-positive PV presenting with normal hemoglobin and hematocrit. The prognosis of these subgroups seems to be poor especially when present in the older age group and with associated leukocytosis. Our case emphasizes two important points: first, need for extensive workup in a patient with unusual site thrombosis including JAK2 analysis and second, investigating for myeloproliferative neoplasm if presented with thrombosis even with normal blood counts.

Anagrelide in Essential Thrombocythemia (ET): Results from 150 patients over 25 years by the "Ph1-negative Myeloproliferative Neoplasms Latium Group"

BACKGROUND AND AIMS

Anagrelide is a drug effective in reducing platelet counts in essential thrombocythemia (ET) and Ph1-negative myeloproliferative neoplasms. The aim of this study was to evaluate the real-life use of anagrelide in patients with ET followed over 25 years at the Haematological Institutes belonging to "Ph1-negative Myeloproliferative Neoplasms Latium Group."

PATIENTS AND METHODS

Eligibility criteria were diagnosis of ET and treatment with anagrelide. Data were collected through an ad hoc case report form.

RESULTS

One hundred and fifty patients received anagrelide for a median time of 7.4 years (0.1-23.2). Anagrelide was administered as first-line therapy in 34.7% of patients, as second-line in 52% and as third-line in 13.3%: 85.4% responded to therapy. Sixty-eight/136 evaluable patients reported side effects: palpitations, peripheral vasodilation, anaemia, diarrhoea and gastric distress. Fourteen thrombotic (arterial 10, venous 4) and 51 bleeding events (minor 48, major 3) occurred. Sixteen/150 (10.6%) patients developed secondary myelofibrosis and 3/150 (2%) an acute myeloid leukaemia.

CONCLUSIONS

In our experience, anagrelide is an effective drug in reducing platelet levels in a high percentage of patients with ET. It is especially addressed to younger people. A careful assessment of the thrombotic risk and monitoring of cardiac function, at diagnosis and during follow-up, is mandatory.

Late polycythemic transformation in JAK2-mutated essential thrombocythemia patients-characteristics along with a validation of 2016 WHO criteria

INTRODUCTION AND OBJECTIVES

The most common mutation within the spectrum of myeloproliferative neoplasms (MPNs) is a mutation in Janus kinase 2 gene (JAK2V617F). It has been observed that, during a course of disease, transformation from JAK2-mutated essential thrombocythemia (ET) to overt polycythemia vera (PV) can occur. Primary objective of this study was to show the incidence of mentioned phenomenon.

METHODS

In this study, we analyzed data of 136 patients diagnosed with JAK2-positive ET observed for a median time of 9 years. We examined blood count of each patient at the time of diagnosis and confronted it with 2008 and 2016 WHO criteria for PV and mPV. Additionally, we analyzed JAK2V617F allele burden in two separate time points among selected cases.

RESULTS

Confrontation with new criteria resulted in change of diagnosis to PV and mPV in 10% and 9% cases, respectively. Within remaining patients, 14 showed increasing hemoglobin concentration over several months during late course of disease, resulting in change of diagnosis to overt PV. We did not find suggested increase in JAK2 allele burden among transforming patients.

CONCLUSIONS

Phenotype transformation to polycythemia was proven to be possible within the group of JAK2-mutated ET; however, cause of this effect remains uncertain.

Aquagenic pruritus in essential thrombocythemia is associated with a higher risk of thrombosis

BACKGROUND

Thromboses and phenotypic evolutions (leukemia, myelofibrosis) are the most frequent complications in polycythemia vera (PV) and essential thrombocythemia (ET). Aquagenic pruritus (AP) is not only PV symptom, but is also present in ET. The presence of pruritus in PV is associated with a lower risk of arterial thrombosis.

AIMS

To date, no equivalent study has been done to analyse the impact of AP for ET patients.

MATERIALS & METHODS

We used the data from our cohort of patients with myeloproliferative neoplasms seen in our institution (OBENE database, NCT02897297). We collect information at diagnosis, presence or not of AP and all types of complications during their follow-up. To avoid masked PV, all JAK2 positive cases were tested isotopic red mass cell if appropriate.

RESULTS

Among 396 ET patients, presence of AP was found in 42 (10.6%). ET patients with AP were more proliferative, more symptomatic at diagnosis and more difficult to treat. Furthermore, they presented increased risk of thromboses (30.9 versus 17%, P = .03; OR = 2.2 [1.01;4.66]) and phenotypic evolutions (33.3 versus 13.3%, P = .0007; OR = 3.2 [1.44;6.77]), during follow-up.

DISCUSSION

Aquagenic pruritus is classically associated to PV. But we confirmed here that AP is also present in ET and characterizes patients with higher risk of morbidity (thrombotic events and phenotypic evolutions).

CONCLUSIONS

The systematic determination of the presence of AP in ET patients should permit us to better identify these high-risk patients for better management and follow-up.

Impact of World Health Organization (WHO) Revised Criteria-2016 on the Diagnosis of Polycythemia Vera

The diagnosis of polycythemia vera (PV) requires the integration of clinical and laboratory findings, bone marrow morphologic features, and JAK2 analysis. JAK2V617F (exon 14) mutation is found in 95% of PV cases. In PV, addition of characteristic bone marrow morphology as one of three major diagnostic criteria allowed reduced hemoglobin/hematocrit threshold for diagnosis to 16.5 g/dL/49% in men and 16 g/dL/48% in women. JAK2 mutation is still the third major diagnostic criterion in PV. Low serum erythropoietin level is now considered as minor criterion in PV and is used to detect cases, which are negative for JAK2 mutation. In this retrospective study, cases diagnosed as PV from January 2013 to December 2015 were reclassified using WHO 2016 criteria. Their clinical and laboratory parameters along with treatment and outcome were studied. Out of 26 patients of previously diagnosed PV, either definitively or provisionally, twenty-one were found to comply with the new 2016 revision of the WHO Criteria. Median age was 55.5 years, with a male preponderance. The median values of hemoglobin, hematocrit and platelets were 17.5 gm/dL, 56.7% and 493 × 10⁹/L, respectively. JAK2V617F was mutated in 17 cases. Bone marrow showed hypercellularity, panmyelosis and marked megakaryocyte dyspoiesis in all patients. All patients had normal oxygen saturation, confirming the primary nature of the disease. Our study, first of its kind in India, underscores the importance of the 2016 revision of the WHO document in detecting cases of masked PV.

The red blood cell count and the erythrocyte sedimentation rate in the diagnosis of polycythaemia vera

BACKGROUND

Iron deficiency in polycythaemia vera (PV) may impact the validity of the haematocrit (HCT), since HCT is red blood cell count (RBC) × mean corpuscular volume (MCV).

OBJECTIVES

To investigate (a) the effect of microcytosis on HCT, (b) the erythrocyte sedimentation rate (ESR) as a possible additional diagnostic marker for PV.

MATERIAL AND METHODS

This study included 182 subjects: 39 with PV, 27 with essential thrombocythemia (ET) and 116 suspected of myeloproliferative neoplasm (MPN) with a secondary cause for either thrombocytosis or erythrocytosis.

RESULTS

Patients with PV had significantly lower ratio of MCV and serum ferritin compared to MPN suspects. A good correlation of RBC versus HCT was found for PV and MPN subjects when individuals with microcytosis were excluded (R²  = .87 in PV and R²  = .82 in MPN suspects). We found a specificity of 98% and a sensitivity of 37% for ESR <2 mm in the diagnosis of PV.

CONCLUSION

The RBC may more precisely reflect the total red cell mass and accordingly the hypercoagulable state of the PV patient, which is integrated in the ESR. A combination of RBC and ESR is proposed as a novel tool to substitute the Hb concentration and the HCT in the diagnosis of PV.

Updates in the management of polycythemia vera and essential thrombocythemia

Polycythemia vera (PV) and essential thrombocythemia (ET) are both classic, relatively indolent, chronic Philadelphia-chromosome-negative (Ph-) myeloproliferative neoplasms (MPNs) characterized by elevated blood counts, thrombotic as well as hemorrhagic tendencies, a variety of symptoms, cumulative risks of progression to myelofibrosis and transformation to acute myeloid leukemia over time, and long survival. Molecularly, PV is more homogenous, being driven by JAK2 mutations in virtually all cases, while ET can be JAK2-, CALR-, or MPL-mutated, as well as 'triple negative'. Recent targeted next-generation sequencing efforts have identified other, nondriver gene mutations, some with prognostic relevance. Prevention of thrombotic and hemorrhagic complications continues to be the major focus of management, although symptoms are increasingly being recognized as a relatively unmet need, particularly in ET. Thrombotic risk stratification in PV is still based on age and history of thrombosis, while in ET, the additional contribution of JAK2 V617F to thrombotic risk is now well established. The associations of leukocytosis with clotting risk (in both conditions) and mortality (in PV) have drawn increased attention with the availability of ruxolitinib as a second-line treatment in PV. Similarly, there is a renewed interest in interferons with the emergence of ropeginterferon alfa-2b as a potential new frontline treatment option in PV. Drug development is more difficult in ET, the most indolent of the classic Ph- MPNs, but ruxolitinib is being studied. Triggering apoptosis via the p53 pathway through pharmacologic inhibition of human double minute 2 (and synergism with interferon) is a new, promising therapeutic strategy.

Clinical outcomes under hydroxyurea treatment in polycythemia vera: a systematic review and meta-analysis

Hydroxyurea is the standard treatment in high-risk patients with polycythemia vera. However, estimates of its effect in terms of clinical outcomes (thrombosis, bleeding, hematologic transformations and mortality) are lacking. We performed a meta-analysis to determine the absolute risk of events in recent cases of patients under hydroxyurea treatment. We searched for relevant articles or abstracts in the following databases: Medline, EMBASE, clinicaltrials.gov, WHO International Clinical Trials Registry, LILACS. Sixteen studies published from 2008 to 2018 reporting number of events using World Health Organization diagnosis for polycythemia vera were selected. Through a random effect logistic model, incidences, study heterogeneity and confounder effects were estimated for each outcome at different follow ups. Overall, 3,236 patients were analyzed. While incidences of thrombosis and acute myeloid leukemia were stable over time, mortality and myelofibrosis varied depending on follow-up duration. Thrombosis rates were 1.9%, 3.6% and 6.8% persons/year at median ages 60, 70 and 80 years, respectively. Higher incidence of arterial events was predicted by previous cardiovascular complication. Leukemic transformation incidence was 0.4% persons/year. Incidence of transformation to myelofibrosis and mortality were significantly dependent on age and follow-up duration. For myelofibrosis, rates were 5.0 at five years and 33.7% at ten years; overall mortality was 12.6% and 56.2% at five and ten years, respectively. In conclusion, we provide reliable risk estimates for the main outcomes in polycythemia vera patients under hydroxyurea treatment. These findings can help design comparative clinical trials with new cytoreductive drugs and prove the feasibility of using critical end points for efficacy, such as major thrombosis.

Distinguishing essential thrombocythemia JAK2V617F from polycythemia vera: limitations of erythrocyte values

Distinguishing essential thrombocythemia JAK2V617F from polycythemia vera is difficult because of shared mutation and phenotypic characteristics. The World Health Organization suggested hemoglobin and hematocrit values to diagnose polycythemia vera (PV), but their sensitivity and specificity were not tested. Moreover, red cell values do not accurately predict red cell mass, which we use to discriminate essential thrombocythemia JAK2V617F from PV. Eighty-three PV and 39 essential thrombocythemia JAK2V617F patients were diagnosed based on JAK2V617F positivity, chromium-51 red cell mass, and marrow biopsy findings. Red cell values used to construct a receiver operating characteristic analysis determined optimal thresholds for distinguishing essential thrombocythemia JAK2V617F from PV. Red cell value frequencies were plotted determining if overlap existed. Chromium-51 red cell mass separated PV from essential thrombocythemia JAK2V617F, but red cell values overlapped in 25.0-54.7%. Our data indicate that a significant proportion of PV patients may be underdiagnosed by using only red cell values. A bone marrow biopsy was performed in 199 of 410 (48.5%) and a serum erythropoietin value was measured in 225 of 410 (54.9%) of potential PV patients at our institution. Without isotope studies, marrow biopsies and serum erythropoietin values should improve diagnostic accuracy and become mandatory, but clinical data suggest these tests have not been routinely performed. Therefore, the clinical hematologist must be aware of imperfect accuracy when using only red cell values for distinguishing essential thrombocythemia JAK2V617F from PV.

When hemolysis masks polycythemia vera

Although uncommon, clinicians should be aware that polycythemia vera may be masked due to hemolysis. The report of such associations could help them in clinical practice to establish an early and accurate diagnosis that may be challenging in atypical presentations of myeloproliferative neoplasms.

[WHO classification of myeloid neoplasms]

In 2014, two advisory committees (one each for myeloid and lymphoid neoplasms) of about 100 pathologists, hematologists, oncologists, and geneticists met in Chicago to revise the WHO diagnostic criteria. The goal was to define disease entities that should be modified, removed, or added based on new insights. In particular, to improve a biologically meaningful classification, a number of new molecular genetic markers were included, which had proved to be of diagnostic and/or prognostic relevance. The resulting differentiated diagnostic procedure is a challenge for the hematopathologist. Not only is it necessary to pool the information from a multimodal diagnostic process and to compare the results of morphology, immunophenotyping, and clinical information. It is also essential to integrate the techniques of fluorescence in situ hybridization and next generation sequencing into the diagnostic process. Hematopathological diagnostics have become more labor-intensive and cost-intensive as a result of this further differentiation.

Recommendations for the diagnosis and treatment of patients with polycythaemia vera

OBJECTIVES

To present the Central European Myeloproliferative Neoplasm Organisation (CEMPO) treatment recommendations for polycythaemia vera (PV).

METHODS

During meetings held from 2015 through 2017, CEMPO discussed PV and its treatment and recent data.

RESULTS

PV is associated with increased risks of thrombosis/thrombo-haemorrhagic complications, fibrotic progression and leukaemic transformation. Presence of Janus kinase (JAK)-2 gene mutations is a diagnostic marker and standard diagnostic criterion. World Health Organization 2016 diagnostic criteria for PV, focusing on haemoglobin levels and bone marrow morphology, are mandatory. PV therapy aims at managing long-term risks of vascular complications and progression towards transformation to acute myeloid leukaemia and myelodysplastic syndrome. Risk stratification for thrombotic complications guides therapeutic decisions. Low-risk patients are treated first line with low-dose aspirin and phlebotomy. Cytoreduction is considered for low-risk (phlebotomy intolerance, severe/progressive symptoms, cardiovascular risk factors) and high-risk patients. Hydroxyurea is suspected of leukaemogenic potential. IFN-α has demonstrated efficacy in many clinical trials; its pegylated form is best tolerated, enabling less frequent administration than standard interferon. Ropeginterferon alfa-2b has been shown to be more efficacious than hydroxyurea. JAK1/JAK2 inhibitor ruxolitinib is approved for hydroxyurea resistant/intolerant patients.

CONCLUSIONS

Greater understanding of PV is serving as a platform for new therapy development and treatment response predictors.

Austrian recommendations for the management of polycythemia vera

Polycythemia vera (PV) is a clonal disease arising from hematopoietic stem cells. Erythrocytosis is the hallmark of the disease but leukocytosis, thrombocytosis and splenomegaly may also be present. Thromboembolic complications occur in about 20% of patients. Circulatory disturbances as well as pruritus represent frequent symptoms of the disease. Mutations in the JAK2 gene are present in 95% of patients in exon 14 (V617F) and in 3% in exon 12. The main goal of the treatment for patients with PV is the prevention of thromboembolic events, transformation to myelofibrosis and acute myeloid leukemia. Interferon alpha and hydroxyurea are used as first-line treatment for high risk patients. For patients unresponsive to first-line therapy ruxolitinib is available.