Familial polycythemia vera with Budd-Chiari syndrome in childhood

Polycythemia vera is a myeloproliferative disorder that, in most cases, occurs sporadically with a median age at presentation of 60 years. Familial cases are very rare and usually manifest in elderly family members. The Budd-Chiari syndrome, characterized by the obstruction and occlusion of the suprahepatic veins, is a rare typical complication in polycythemia vera patients. To date, only two children or adolescents with polycythemia vera and Budd-Chiari syndrome have been described. Here, we report an 11-year-old girl with Budd-Chiari syndrome as the initial symptom of familial polycythemia vera, which was also found in the girl's grandmother. Details of the diagnostic procedures used and the clinical course are reported. The patient underwent orthotopic liver transplantation and is being treated with hydroxyurea. The available literature on familial polycythemia vera and polycythemia vera in childhood with and without Budd-Chiari syndrome is reviewed.     

Polycythemia vera and other primary polycythemias

PURPOSE OF REVIEW: Diagnosis and therapy of polycythemia vera are controversial since the molecular basis of polycythemia vera remains unknown. Distinguishing between polycythemia vera and other polycythemic disorders can be very challenging. The purpose of this review is to discuss the recent progress in this area and critically review the published data in context of our knowledge of other polycythemic disorders. RECENT FINDINGS: Erythropoietin is the principal regulator of regulator of erythropoiesis; its production is regulated by the degree of hypoxia. Our knowledge of cellular responses to hypoxia has recently exploded and led to the elucidation of the molecular basis of a polycythemia caused by augmentation of hypoxic sensing, Chuvash polycythemia. Similar progress in understanding the molecular basis of polycythemia vera has been elusive. A simple, readily available laboratory test to establish a diagnosis of polycythemia vera would be highly desirable; however, none exists. The value of quantization of neutrophil PRV-1 mRNA, platelet c-mpl expression, in vitro assays of erythroid progenitor cells, serum erythropoietin levels, establishing clonality in female subjects using assays employing X-chromosome-based polymorphism assays, and the progress in the chromosomal location of the gene is discussed. Integration of this information underlies the complexity of the molecular biology of polycythemia vera and indicates likely interaction of multiple genetic events in the genesis of polycythemia vera. SUMMARY: The existence of family clustering of PV may facilitate the search for PV molecular basis. Only collaborative interaction of clinical researchers and laboratory scientists will lead to meaningful progress in determining the molecular basis of PV.     

A case of Budd-Chiari syndrome secondary to multiple thrombogenic conditions: a case report and review of literature.

This report describes a case of Budd-Chiari syndrome caused by latent polycythemia vera and factor V Leiden mutation. This syndrome usually occurs due to thrombosis of hepatic veins or membranous obstruction of inferior vena cava. The most common reasons for thrombosis are manifest polycythemia vera and the other prothrombotic conditions. Recently, latent polycythemia vera and factor V Leiden mutation have been reported in increasing frequency. In this report, we aimed to emphasize that all prothrombotic conditions must be evaluated while investigating the etiology of Budd-Chiari syndrome, including latent polycythemia vera and factor V Leiden mutation, and appropriate antithrombotic and surgical therapies must be performed without delay.     

Anticoagulant-resistant thrombophilia in a patient with polycythemia vera: a case report

Mechanical valve thrombosis is a rare condition in an adequately anticoagulated patient in the absence of underlying thrombophilia. We report a case of a 76-year-old male with mechanical prosthetic mitral valve thrombosis as the presenting feature of polycythemia vera. The patient was treated with thrombolysis at the time of acute presentation and subsequently maintained on low molecular weight heparin, low-dose aspirin, phlebotomy and hydroxyurea. Hemoglobin, leucocytosis and platelet count were controlled for almost 4 years after which the patient suffered a second, fatal episode in the setting of therapeutic anti-Xa level. This case report highlights the thrombotic risks associated with polycythemia vera. The proposed mechanisms of hypercoagulability in polycythemia vera are reviewed. To the best of our knowledge, mechanical valve thromboses as the presenting feature of polycythemia vera has not been reported previously.     

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.     

Serum erythropoietin (ESF) titers in polycythemia

Serum ESF titers were measured in 42 polycythemic patients using the fetal mouse liver cell bioassay. ESF titers in patients with secondary polycythemia differed significantly from those in patients with polycythemia vera (p less than 0.0001). Among the 21 patients with secondary polycythemia, 1 patient had an ESF titer less than 10 mU/ml (the lower limit of sensitivity) and 20 had ESF titers that ranged between 11 and 112 mU/ml, with a mean titer of 56 mU/ml. Among the 21 patients with polycythemia vera, 13 patients had ESF titers less than 10 mU/ml and 8 had ESF titers ranging between 12 and 55 mU/ml, with a mean titer of 26 mU/ml. The mean hemoglobin concentration in the 8 patients with ESF titers greater than 10 mU/ml was significantly below that in the 13 polycythemia vera patients with ESF titers less than 10 mU/ml (p less than 0.03). If ESF titers less than 10 mU/ml had been indicative of polycythemia vera and ESF titers greater than 10 mU/ml had been indicative of secondary polycythemia in patients with hemoglobin concentrations greater than 17.7 g/dl, but not indicative of either condition in patients with hemoglobin concentrations less than 17.7 g/dl, 71.5% of the polycythemic patients in this study would have been diagnosed correctly, 9.5% incorrectly, and in the 19% the diagnosis would have remained uncertain. It was concluded that measurement of serum ESF titers using this in vitro bioassay can be of clinical importance in differentiating between polycythemia vera and secondary polycythemia.     

Treatment of the myeloproliferative disorders with 32P

Abstract: The use of radioactive phosphorus (³²P) to treat the myeloproliferative disorders (chronic leukemia, polycythemia vera and essential thrombocythemia) began in 1939 when John H. Lawrence treated the first patient on the basis of work done in the laboratory anima that found localization of the radioisotope in the spleen, liver, bone and in leukemic cells sufficient to indicate a therapeutic potential. After World War II when ³²P became widely available, it was used extensively to treat the chronic leukemias and polycythemia vera. Its use in the treatment of essential thrombocythemia began later in 1950. Today it is not widely used in the treatment of the chronic leukemia, if at all, its use in polycythemia vera appears to have decreased substantially and replaced by hydroxyurea, and its use in the management of essential thrombocythemia is not widespread. In each instance it has been replaced by a drug developed for use in cancer chemotherapy, and in some instances by interferon. It probably has wider use in polycythemia vera in the rest of Western Europe than in the UK, and there are cogent reasons to suggest that it may be the best tool for the treatment of polycythemia vera. Thus have we discarded a treatment modality that in polycythemia vera may be the best?     

Systemic mastocytosis in a patient with polycythemia vera treated with radioactive phosphorus.

Systemic mastocytosis occurred as a fatal event in a patient with long-standing polycythemia vera. The patient had been treated over the course of 21 yr with radioactive phosphorus. Possible relationships between mastocytosis and polycythemia vera, and also between mastocytosis and treatment with ionizing radiation, are discussed. Histopathologic and electron microscopic findings are illustrated. Difficulties in establishing the diagnosis of mast cell disease in this setting are also described.     

Isolated cerebellar infarction as a presenting symptom of polycythemia vera.

Although polycythemia vera is one of the reported causes for cerebral infarction, isolated cerebellar infarction, a rare disorder, was never reported in combination with polycythemia vera. This is a report of a 72-year-old woman in whom isolated cerebellar infarction was the presenting manifestation of polycythemia vera. The patient was treated with recurrent phlebotomies until the hematocrit decreased to < 45%. This treatment was followed by marked neurological improvement. A better awareness of the possibility of cerebellar infarction in polycythemia vera may disclose additional cases.     

Tissue plasminogen activator levels in different types of polycythemia

The plasma level of tissue plasminogen activator antigen (t-PA-Ag) was examined in 86 patients with polycythemia (29 polycythemia vera, 11 secondary polycythemia and 46 with spurious polycythemia) and 24 healthy volunteers. Tissue plasminogen activator antigen was significantly decreased in patients with polycythemia vera in comparison with healthy controls. On the other hand, in patients with spurious polycythemia and secondary polycythemia t-PA-Ag concentration was significantly increased. There was no significant difference in t-PA-Ag levels in polycythemic patients with or without thromboembolic disease. A significant correlation was detected between t-PA-Ag level and hemoglobin or hematocrit concentration in patients with polycythemia vera (p = 0.02, r = 0.43). However, in patients with secondary polycythemia and spurious polycythemia, no significant correlation between t-PA-Ag and hemoglobin level was found. Plasminogen activator inhibitor (PAI) levels in patients with polycythemia vera and healthy volunteers did not differ significantly.     

Extent of hematopoietic involvement by TET2 mutations in JAK2V⁶¹⁷F polycythemia vera

TET2 mutations are found in polycythemia vera and it was initially reported that there is a greater TET2 mutational burden than JAK2(V617F) in polycythemia vera stem cells and that TET2 mutations precede JAK2(V617F). We quantified the proportion of TET2, JAK2(V617F) mutations and X-chromosome allelic usage in polycythemia vera cells, BFU-Es and in vitro expanded erythroid progenitors and found clonal reticulocytes, granulocytes, platelets and CD34(+) cells. We found that TET2 mutations may also follow rather than precede JAK2(V617F) as recently reported by others. Only a fraction of clonal early hematopoietic precursors and largely polyclonal T cells carry the TET2 mutation. We showed that in vitro the concomitant presence of JAK2(V617F) and TET2 mutations favors clonal polycythemia vera erythroid progenitors in contrast with non-TET2 mutated progenitors. We conclude that loss-of-function TET2 mutations are not the polycythemia vera initiating events and that the acquisition of TET2 somatic mutations may increase the aggressivity of the polycythemia vera clone.     

Cytogenetic studies in polycythemia vera

A group of 54 patients with the original diagnosis of polycythemia vera were subjected to cytogenetic examination. Six (17.6%) of the 34 cases examined in the period of the advanced phase of the polycythemia vera had a chromosomal change. Thirteen (65%) of the 20 patients undergoing the cytogenetic examination in the period when the polycythemia vera turned into another myeloproliferative disease showed chromosomal aberration. This suggests a relationship between the number of chromosomal changes and the transformation of the disease. No connection between the cytogenetic changes and myelosuppressive cures could be confirmed in our material. The chromosomal change 20q- considered to be the most frequent kind in the polycythemia vera was not discovered until in patients with the polycythemia vera transformed into a different myeloproliferative disease.     

Polycythemia vera--a case report and discussion on pathogenic mechanisms of increased thrombosis

Polycythemia vera is a myeloproliferative disorder characterized by increased red cell mass and frequently complicated by venous and arterial thrombosis. The mechanism underlying the increased incidence of thrombotic events remains illusive. Presented in this report are a case of a 77-year-old man diagnosed with polycythemia vera and a review of the current literature on the mechanisms underlying the increased incidence of thrombotic events in polycythemia vera.     

Apoptosis and polycythemia vera

Polycythemia vera is an acquired clonal myeloproliferative disorder characterized by increased numbers of erythroid cells, often with a concomitant rise in neutrophils and/or megakaryocytes. Normally, erythropoietin is essential for the survival and proliferation of erythroid progenitors; however in polycythemia vera the erythroid progenitor cells can survive and develop in the absence of erythropoietin. Members of the Bcl-2 family of apoptosis regulators have been shown to mediate the erythropoietin-dependent survival of erythroid cells. In this article, recent advances in understanding the mechanisms used by erythroid progenitors from patients with polycythemia vera to control apoptosis, are discussed.     

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.     

Megakaryoblastic transformation of polycythemia vera associated with hypercalcemia

Leukemic transformation is not uncommon in polycythemia vera, particularly after treatment with chemotherapeutic agents. The leukemias that supervene are mostly of myeloid type but megakaryoblastic transformation is distinctly uncommon. We report a case of polycythemia vera terminating in megakaryoblastic leukemia with associated hypercalcemia.     

Intraventricular thrombosis in polycythemia vera: A cause of intractable cardiac failure

The occurrence of thrombotic events is central to the course of polycythemia vera.^1–5 Myocardial, cerebral, peripheral, and pulmonary infarctions are frequent and are consequences of thromboses in small and medium caliber arteries. Thrombosis in large caliber arteries is a rare event. Thrombosis within the chambers of the heart has not been hitherto reported.This report documents the occurrence of massive left ventricular thrombosis in a patient with polycythemia vera. The thrombus reduced the left ventricular capacity by about 75% and caused intractable congestive heart failure.     

Leukemic transformation of polycythemia vera after treatment with hydroxyurea and chromosome 17 abnormalities

The authors present two patients with polycythemia vera where they recorded after several years' treatment with hydroxyurea development of acute myeloblastic leukaemia. In both instances they found, associated with leukaemia, abnormalities of chromosome no.17, in one case meeting criteria of the so-called 17p-syndrome. Progression of polycythemia vera into acute leukaemia is explained by the possible association with the long-term use of the drug and loss of chromosomal material (short arm of chromosome 17), the part where genes important in the process of leukaemogenesis are located. The authors draw attention to contemplated long-term administration of hydroxyurea to young patients with polycythemia vera. As cytogenetic analysis is a suitable method for evidence of progressing polycythemia vera into acute leukaemia, dynamic follow up of chromosomal changes is necessary, in particular in patients where long-term treatment with hydroxyurea is assumed.