Semin Thromb Hemost 2006; 32(3): 174-207
DOI: 10.1055/s-2006-939431
Copyright © 2006 by Thieme Medical Publishers, Inc., 333 Seventh Avenue, New York, NY 10001, USA.

Clinical and Laboratory Features, Pathobiology of Platelet-Mediated Thrombosis and Bleeding Complications, and the Molecular Etiology of Essential Thrombocythemia and Polycythemia Vera: Therapeutic Implications

Jan J. Michiels1 , 5 , Zwi Berneman1 , Dirk Van Bockstaele2 , Marc van der Planken3 , Hendrik De Raeve4 , Wilfried Schroyens1
  • 1Department of Hematology, University Hospital Antwerp, Belgium
  • 2Laboratory of Molecular Diagnostics, University Hospital Antwerp, Belgium
  • 3Laboratory of Hematology and Hemostasis, University Hospital Antwerp, Belgium
  • 4Department of Pathology, University Hospital Antwerp, Belgium
  • 5Hematology, Hemostasis and Thrombosis Science Center, Goodheart Institute, Rotterdam, The Netherlands
Further Information

Publication History

Publication Date:
02 May 2006 (online)

ABSTRACT

Microvascular disturbances in essential thrombocythemia (ET) and polycythemia vera (PV), including erythromelalgia, and atypical and typical transient cerebral, ocular, and coronary ischemic attacks, are caused by platelet-mediated transient and occlusive thrombosis in the end-arterial circulation. ET patients with microvascular disturbances have shortened platelet survival, increased β-thromboglobulin (β-TG), platelet factor 4 (PF4), and thrombomodulin (TM) levels, and increased urinary thromboxane B2 (TXB2) excretion, indicating platelet-mediated thrombotic processes. Inhibition of platelet cyclooxygenase-1 by aspirin is followed by relief of microvascular disturbances; correction of shortened platelet survival; correction of increased plasma β-TG, PF4, and TM levels; and correction of increased TXB2 excretion to normal. In PV associated with thrombocythemia, increased hematocrit and whole blood viscosity aggravate the platelet-mediated microvascular syndrome of thrombocythemia to produce major arterial and venous thrombotic complications. Correction of hematocrit to normal by phlebotomy will reduce the major arterial and venous thrombotic complications, but fails to prevent the platelet-mediated microvascular circulation disturbances in PV patients because thrombocythemia persists. Complete relief and prevention of microvascular and major thrombosis in ET and PV patients, in addition to phlebotomy, are obtained by treatment with aspirin and not with coumarin. The discovery of JAK2 V617F gain of function mutation in patients with myeloproliferative disorders (MPDs) expands our insights into the molecular etiology and biological features of ET, PV, and chronic idiopathic myelofibrosis (CIMF). The current concept is that heterozygous JAK2 V617F mutation with increased kinase activity is enough for megakaryocyte proliferation and increased hypersensitive platelets with no or slightly increased erythropoiesis in ET and in early PV mimicking ET. Homozygous JAK2 mutation with pronounced kinase activity is associated with trilinear megakaryocyte, erythroid, and granulocytic myeloproliferation, myeloid metaplasia, and secondary myelofibrosis (MF), with the most frequent clinical picture of classical PV complicated by major thrombosis in addition to the platelet-mediated microvascular thrombotic syndrome of thrombocythemia. The positive predictive value of a JAK2 V617F polymerase chain reaction test for the diagnosis of MPDs is high (near to 100%), but only half of ET and MF (sensitivity 50%) and the majority of PV (sensitivity 85 to 97%) are JAK2 V617F positive. Bone marrow histopathology, when used in combination with specific markers such as serum erythropoietin, PRV-1, endogenous erythroid colony formation, peripheral blood parameters and red cell mass, has a high sensitivity and specificity (near 100%) to detect the early and overt stages of the MPDs and to differentiate between ET, PV, and CIMF in both JAK2 V617F-positive and -negative MPDs.

REFERENCES

  • 1 Michiels J J. The myeloproliferative disorders. An historical appraisal and personal experiences.  Leuk Lymphoma. 1996;  22(suppl 1) 1-14
  • 2 Michiels J J. Diagnostic criteria of the myeloproliferative disorders (MPD): essential thrombocythemia, polycythemia vera and chronic megakaryocytic granulocytic metaplasia.  Neth J Med. 1997;  51 57-64
  • 3 Michiels J J, Juvonen E. Proposal for revised diagnostic criteria of essential thrombocythemia and polycythemia vera by the Thrombocythemia Vera Study Group.  Semin Thromb Hemost. 1997;  23 339-347
  • 4 Thiele J, Kvasnicka H M, Diehl V, Fischer R, Michiels J J. Clinicopathological diagnosis and differential criteria of thrombocythemias in various myeloproliferative disorders by histopathology, histochemistry and imunostaining from bone marrow biopsies.  Leuk Lymphoma. 1999;  33 207-218
  • 5 WHO classification of the chronic myeloproliferative diseases (CMPD) polycythemia vera, chronic idiopathic myelofibrosis, essential thrombocythemia and CMPD unclassifiable. WHO Classification of Tumours. Tumours of Haematopoiesis and Lymphoid Tissues. Lyon, France; IARC 2001: 31-42
  • 6 Michiels J J, Thiele J. Clinical and pathological criteria for the diagnosis of essential thrombocythemia, polycythemia vera and idiopathic myelofibrosis (agnogenic myeloid metaplasia).  Int J Hematol. 2002;  76 133-145
  • 7 Michiels J J, Kvasnicka H M, Thiele J. Myeloproliferative Disorders, Essential Thrombocythemia, Polycythemia Vera and Chronic Idiopathic Myelofibrosis. Munich, Germany; Verlag ME Grunwald 2005
  • 8 Osler W. A clinical lecture on erthremia (polycythemia) with cyanosis. Maladie du Vaquez.  Lancet. 1908;  1 143-147
  • 9 Oppenheimer B S. Vascular occlusion in polycythemia vera.  Trans Assoc Am Physiol. 1929;  44 338-344
  • 10 Brown G E, Giffin H Z. Peripheral arterial disease in polycythemia vera.  Arch Intern Med. 1930;  46 705-717
  • 11 Norman I L, Allen E V. The vascular complications of polycythemia.  Am Heart J. 1937;  13 257-274
  • 12 Barabas A P, Offen D N, Meinhard E A. The arterial complications of polycythemia vera.  Br J Surg. 1973;  60 183-187
  • 13 Edwards E A, Cooley M H. Peripheral vascular symptoms as the initial manifestation of polycythemia vera.  JAMA. 1970;  214 1463-1467
  • 14 Gillespie G. Peripheral gangrene as the presentation of myeloproliferative disorders.  Br J Surg. 1973;  60 377-380
  • 15 Smith L A, Allen E V. Erythermalgia (erythromelalgia) of the extremities: a syndrome characterized by redness, heat and pain.  Am Heart J. 1938;  16 175-188
  • 16 Michiels J J. Erythromelalgia and thrombocythemia: a disease of platelet prostaglandin metabolism. Thesis 1981, Rotterdam.  Semin Thromb Hemost. 1997;  23 335-338
  • 17 Michiels J J, Abels J, Steketee J, vanVliet HHDM, Vuzevski V D. Erythromelalgia caused by platelet-mediated arteriolar inflammation and thrombosis in thrombocythemia.  Ann Intern Med. 1985;  102 466-471
  • 18 Michiels J J, Van Joost T H. Erythromelalgia and thrombocythemia. A causal relation.  J Am Acad Dermatol. 1990;  22 107-111
  • 19 Annetts D L, Tracy G D. Idiopathic thrombocythemia presenting with ischemia of the toes.  Med J Aust. 1966;  2 180-182
  • 20 Vreeken J, Van Aken W S. Spontaneous aggregation of blood platelets as a cause of idiopathic and recurrent painful toes and fingers.  Lancet. 1971;  II 1394-1397
  • 21 Preston F E, Emmanuel I G, Winfield D A, Malia R G. Essential thrombocythemia and peripheral gangrene.  BMJ. 1974;  3 548-552
  • 22 Singh A K, Weitherley-Mein G. Microvascular occlusive lesions in primary thrombocythemia.  Br J Haematol. 1977;  36 553-564
  • 23 Redding K G. Thrombocythemia as a cause of erythromelalgia.  Arch Dermatol. 1977;  113 468-471
  • 24 Vera J C. Antiplatelet agents in the treatment of thrombotic complications of primary thrombocythemia.  CMAJ. 1979;  120 60-61
  • 25 Roth G J. Majerus PhW. The mechanism of the effect of aspirin on human platelets.  J Clin Invest. 1975;  56 624-632
  • 26 Smith J B, Ingerman C M, Silver M J. Malodialdehyde formation as an indicator of prostaglandin production by human platelets.  J Lab Clin Med. 1976;  88 167-173
  • 27 Crook D, Collins A J. Comparison of effects of aspirin and indomethacin on human platelet prostaglandin synthethase.  Ann Rheum Dis. 1977;  36 459-463
  • 28 Moncada S, Vane J R. Unstable metabolites of arachidonic acid and their role in haemostasis and thrombosis.  Br Med Bull. 1978;  34 129-135
  • 29 Huijgens P C, Van Den Berg C AM, Van Der Meer C, Imandt LMFM, Langenhuizen MMAC. Dosage of acetylsalicylic acid for inhibition of platelet function.  Scand J Haematol. 1980;  25 76-80
  • 30 Patrono C. Aspirin as an antiplatelet drug.  N Engl J Med. 1994;  330 1287-1294
  • 31 Schör K. Aspirin and platelets: the antiplatelet action of aspirin and its role in thrombosis treatment and prophylaxis.  Semin Thromb Hemost. 1997;  23 349-356
  • 32 Michiels J J, Ten Kate F WJ, Vuzevski V D, Abels J. Histopathology of erythromelalgia in thrombocythemia.  Histopathology. 1984;  8 669-678
  • 33 Van Genderen P JJ, Michiels J J. Erythromelalgia: a pathognomonic microvascular thrombotic complication in essential thrombocythemia and polycythemia vera.  Semin Thromb Hemost. 1997;  23 357-363
  • 34 Van Genderen P JJ, Lucas I S, van Strik R et al.. Erythromelalgia in essential thrombocythemia is characterized by platelet activation and endothelial cell damage but not by thrombin generation.  Thromb Haemost. 1996;  76 333-338
  • 35 Van Genderen P JJ, Michiels J J, van Strik R, Lindemans J, van Vliet HHDM. Platelet consumption in thrombocythemia complicated by erythromelalgia: reversal by aspirin.  Thromb Haemost. 1995;  73 210-214
  • 36 Bellucci S, Ignatova E, Jaillet N, Boffa M C. Platelet activation in patients with essential thrombocythemia is not associated with vascular endothelial cell damage as judged by the level of plasma thrombomodulin, protein S, PAI-1, t-PA and vWF.  Thromb Haemost. 1993;  70 736-742
  • 37 Patrignani P, Filabozzi P, Patrono C. Selective cumulative inhibition of platelet thromboxane production by low-dose aspirin in healthy subjects.  J Clin Invest. 1982;  69 1366-1372
  • 38 Davi G, Catalano I, Averna M et al.. Thromboxane biosynthesis and platelet function in type II diabetes mellitus.  N Engl J Med. 1990;  322 1769-1774
  • 39 Davi G, Averni M, Catalano I et al.. Increased thromboxane biosynthesis in hypercholesterolemia type IIa.  Circulation. 1992;  85 1792-1798
  • 40 Patrono C, Davi G, Ciabattoni G. Thromboxane biosynthesis and metabolism in relation to cardiovascular risk factors.  Agents Actions Suppl. 1992;  37 10-17
  • 41 Landolfi R, Ciabattoni G, Patrinani P et al.. Increased thromboxane biosynthesis in patients with polycythemia vera: evidence for aspirin-suppressible platelet activation in vivo.  Blood. 1992;  80 1965-1971
  • 42 Rocca B, Ciabattoni G, Tartaglione R et al.. Increased thromboxane biosynthesis in essential thrombocythemia.  Thromb Haemost. 1995;  74 1225-1230
  • 43 Michiels J J, Zijlstra F J. Prostaglandin cyclooxygenase products but not thromboxane A2 are involved in the pathogenesis of erythromelalgia in thrombocythemia.  Mediators Inflamm. 1993;  2 385-389
  • 44 Van Genderen P JJ, Prins F, Michiels J J, Schrör K. Thromboxane-dependent platelet activation in vivo precedes arterial thrombosis in thrombocythaemia: a rationale for the use of low-dose aspirin as an antithrombotic agent.  Br J Haematol. 1999;  104 438-441
  • 45 Koudstaal P, Koudstaal A. Neurlogic and visual symptoms in essential thrombocythemia: efficacy of low-dose aspirin.  Semin Thromb Hemost. 1997;  23 365-370
  • 46 Jabaily J, Iland H J, Laszlo J et al.. Neurologic manifestations of essential thrombocythemia.  Ann Intern Med. 1983;  99 513-518
  • 47 Michiels J J, Koudstaal P, Mulder A H, van Vliet HHDM. Transient neurologic and ocular manifestations in primary thombocythemia.  Neurology. 1993;  43 1107-1110
  • 48 Michiels J J, Van Genderen P JJ, Janssen P HP, Koudstaal P. Atypical transient ischemic attacks in thrombocythemia of various myeloproliferative disorders.  Leuk Lymphoma. 1996;  22(suppl 1) 65-70
  • 49 Scheffer M G, Michiels J J, Simoons M L, Roelandt JRTC. Thrombocythemia and coronary artery disease.  Am Heart J. 1991;  22 573-577
  • 50 Fröhli P, Graf C, Rhyner K. Die Prophylaxe vasculärer Komplikationen bei Polycythaemia Vera und primärer Thrombozythämie mit niedrigdosierter Acetylsalicylsäure.  Schweiz Med Wochenschr. 1983;  113 1622-1627
  • 51 Cortelazzo S, Viero P, Finazzi G et al.. Incidence and risk factors for thrombotic complications in a historical cohort of 100 patients with essential thrombocythemia.  J Clin Oncol. 1990;  8 556-562
  • 52 Besses C, Cervantes F, Pereira A et al.. Major vascular complications in essential thrombocythemia: a study of the predictive factors in a series of 148 patients.  Leukemia. 1999;  13 150-154
  • 53 Michiels J J. Normal life expectancy and thrombosis-free survival in aspirin treated essential thrombocythemia.  Clin Appl Thromb Hemost. 1999;  5 30-36
  • 54 Bazzan M, Tamponi G, Schinco P et al.. Thrombosis-free survival and life expectancy in 187 consecutive patients with essential thrombocythemia.  Ann Hematol. 1999;  78 539-543
  • 55 Ruggeri M, Finazzi G, Tosetto A, Riva S, Rodeghiero F, Barbui T. No treatment for low-risk thrombocythemia: results from a prospective study.  Br J Haematol. 1998;  103 772-777
  • 56 Van Genderen P JJ, Michiels J J. Erythromelalgic, thrombotic and hemorrhagic manifestations of thrombocythaemia.  Presse Med. 1994;  23 73-77
  • 57 Michiels J J. Acquired von Willebrand Disease due to increasing platelet count can readily explain the paradox of thrombosis and bleeding in thrombocythemia.  Clin Appl Thromb Hemost. 1999;  5 147-151
  • 58 Chim C-S, Kwong Y-L, Lie K-W et al.. Long-term outcome of 231 patients with essential thrombocythemia.  Arch Intern Med. 2005;  165 2651-2658
  • 59 Griesshammer M, Bangerter M, van Vliet HHDM, Michiels J J. Aspirin in essential thrombocythemia: status quo and quo vadis.  Semin Thromb Hemost. 1997;  23 371-377
  • 60 Murphy S, Iland H, Rosenthal D, Laszlo J. Essential thrombocythemia: an interim report from the Polycythemia Vera Study Group.  Semin Hematol. 1986;  23 177-182
  • 61 Thiele J, Kvasnicka H M. Chronic myeloproliferative disorders with thrombocythemia: a comparative study of two classification systems (PVSG, WHO) on 839 patients.  Ann Hematol. 2003;  82 148-152
  • 62 Florena A M, Tripodi C, Iannitto E, Porcasi R, Ingrao S, Franco V. Value of bone marrow biopsy in the diagnosis of essential thrombocythemia.  Haematologica. 2004;  89 911-919
  • 63 Campbell P J, Green A R. Management of polycythemia vera and essential thrombocythemia.  Hematology (Am Soc Hematol Educ Program). 2005;  201-208
  • 64 Cortelazzo S, Finazzi G, Ruggeri M et al.. Hydroxyurea for patients with essential thrombocythemia and a high risk of thrombosis.  N Engl J Med. 1995;  332 1132-1136
  • 65 Van Genderen P JJ, Michiels J J. Hydroxyurea in essential thrombocythemia.  N Engl J Med. 1995;  333 802-803
  • 66 Michiels J J. Aspirin and platelet-lowering agents for the prevention of vascular complications in essential thrombocythemia.  Clin Appl Thromb Hemost. 1999;  5 247-251
  • 67 Van Genderen P JJ, Mulder P GH, Waleboer M, van de Moesdijk D, Michiels J J. Prevention and treatment of thrombotic complications in essential thrombocythemia: efficacy and safety of aspirin.  Br J Haematol. 1997;  97 179-184
  • 68 Budde U, Schaefer G, Mueller N, Egli H, Ruggeri Z M, Zimmerman T S. Acquired von Willebrand disease in the myeloproliferative syndrome.  Blood. 1984;  64 981-985
  • 69 Budde U, Dent J A, Berkovitz S D, Ruggeri Z M, Zimmerman T S. Subunit composition of plasma von Willebrand factor in patients with the myeloproliferative syndrome.  Blood. 1986;  68 1213-1217
  • 70 Van Genderen P JJ, Michiels J J, van der Poel-Luitgaarden SCAPM, van Vliet HHDM. Acquired von Willebrand disease as a cause of recurrent mucocutaneous bleeding in primary thrombocythemia: relationship with platelet count.  Ann Hematol. 1994;  69 81-84
  • 71 Van Genderen P JJ, Budde U, Michiels J J, van Strik R, van Vliet HHDM. The reduction of large von Willebrand factor multimers in plasma in essential thrombocythemia is related to the platelet count.  Br J Haematol. 1996;  93 962-965
  • 72 Van Genderen P JJ, Leenknegt H, Michiels J J. The paradox of bleeding and thrombosis in thrombocythemia: is von Willebrand factor the link?.  Semin Thromb Hemost. 1997;  23 385-389
  • 73 Barbui T, Barosi G, Grssi A et al.. Practice for the therapy of essential thrombocythemia. A statement from the Italian Society of Hematology.  Haematologica. 2004;  89 215-232
  • 74 Marchioli R, Finazzi G, Marfasi R M, Tognoni G, Barbui T. Clinical trials in myeloproliferative disorders: looking forward.  Semin Hematol. 2005;  42 259-265
  • 75 Harrison C, Campbell P J, Buck G et al.. Hydroxyurea compared with anagrelide in high-risk essential thrombocythaemia.  N Engl J Med. 2005;  353 33-45
  • 76 Michiels J J, Van Genderen P JJ, Lindemans J, Van Vliet HHDM. Erythromelalgic, thrombotic and hemorrhagic manifestations in 50 cases of thrombocythemia.  Leuk Lymphoma. 1996;  22(Suppl 1) 27-56
  • 77 Michiels J J, Berneman Z, Schroyens W, Krestin G P. Bilateral adrenal swelling as a cause of chest, back and upper abdominal pain in essential thrombocythemia and polycythemia vera is due to microvascular ischemic thrombosis rather than to hemorrhage.  Ann Hematol. 2002;  81 691-694
  • 78 Finazzi G, Budde U, Michiels J J. Bleeding time and platelet function in essential thrombocythemia and other myeloproliferative disorders.  Leuk Lymphoma. 1996;  22(suppl 1) 71-78
  • 79 Rao A K. Molecular and biochemical basis for the platelet dysfunction in myeloprolifretive disorders.  Semin Hematol. 2004;  41 6-9
  • 80 Li N, Goodall A H, Hjemdahl P. A sensitive flow cytometric assay for circulating platelet-leukocyte aggregates.  Br J Haematol. 1997;  99 808-816
  • 81 Falanga A, Marchetti M, Evangelista V et al.. Polymorphphonuclear leukocyte activation and hemostasis in patients with essential thrombocythemia and polycythemia vera.  Blood. 2000;  96 4216-4226
  • 82 Jensen M K, de Nully Brown P, Lund B V, Nielsen O J, Hasselbalch H C. Increased circulating platelet-leukocyte aggregates in myeloproliferative disorders is correlated to previous thrombosis, platelet activation and platelet count.  Eur J Haematol. 2001;  66 143-151
  • 83 Alvarez-Larran A, Garcia-Pagan J C, Abraldes J G et al.. Increased CD11b neutrophil expression in Budd-Chiari syndrome or portal vein thrombosis secondary to polycythaemia vera.  Br J Haematol. 2004;  124 329-335
  • 84 Villmow T, Kemkes-Matthes B, Matzdorff A C. Markers of platelet activation and platelet-leukocyte interaction in patients with myeloproliferative syndromes.  Thromb Res. 2002;  108 139-145
  • 85 Falanga A, Marchetti M, Vignoli A, Balducci D, Barbui T. Leukocyte-platelet interaction in patients with essential thrombocythemia and polycythemia vera.  Exp Hematol. 2005;  33 523-530
  • 86 Falanga A, Marchetti M, Barbui T, Smith C W. Pathogenesis of thrombosis in essential thrombocythemia and polycythemia vera: the role of neutrophils.  Semin Hematol. 2005;  42 239-247
  • 87 Passamonti F, Pietra D, Malabarba L et al.. Clinical significance of neutrophil CD177 mRNA expression in Ph-negative chronic myeloproliferative disorders.  Br J Haematol. 2004;  126 650-656
  • 88 Bench A J, Pahl H L. Chromosomal abnormalities and molecular markers in myeloproliferative disorders.  Semin Hematol. 2005;  42 196-205
  • 89 Karakantza M, Giannakouloas N C, Zikos P et al.. Markers of endothelial and in vivo platelet activation in patients with essential thrombocythemia and polycythemia vera.  Int J Hematol. 2004;  79 253-259
  • 90 Berlin N. Diagnosis and classification of the polycythemias.  Semin Hematol. 1975;  12 339-351
  • 91 Thiele J, Zankovich R, Schneider G, Kremer B, Fischer R, Deihl V. Primary (essential) thrombocythemia versus polycythemia vera rubra.  Anal Quant Cytol Histol. 1988;  10 375-382
  • 92 Thiele J, Schneider G, Hoeppner B, Wienbold S, Zankovich R, Fischer R. Histomorphometry of bone marrow biopsies in chronic myeloproliferative disorders with associated thrombocytosis-features of significance for the diagnosis of primary (essential) thrombocythaemia.  Virchows Arch A Pathol Anat. 1988;  413 407-417
  • 93 Thiele J, Wagner S, Degel C et al.. Megakaryocyte precursors (pro- and megakaryoblasts) in bone marrow tissue from patients with reactive thrombocytosis, polycythemia vera and primary (essential) thrombocythemia.  Virchows Arch B Cell Pathol Incl Mol Pathol. 1990;  58 295-302
  • 94 Thiele J, Kvasnicka H M, Fischer R. Histochemistry and morphometry on bone marrow biopsies in chronic myeloproliferative disorders: aids to diagnosis and classification.  Ann Hematol. 1999;  78 495-506
  • 95 Thiele J, Kvasnicka H M, Zankovich R, Diehl V. The value of bone marrow histology in differentiating between early stage polycythemia vera and secondary (reactive) polycythemias.  Haematologica. 2001;  86 368-374
  • 96 Michiels J J. Bone marrow histopathology and biological markers as specific clues to the differential diagnosis of essential thrombocythemia, polycythemia vera and prefibrotic or fibrotic agnogenic myeloid metaplasia.  Hematol J. 2004;  5 93-102
  • 97 Thiele J, Kvasnicka H M. Diagnostic impact of bone marrow histopathology in polycythemia vera (PV).  Histol Histopathol. 2005;  20 317-328
  • 98 Thiele J, Kvasnicka H M, Diehl V. Initial (latent) polycythemia vera with thrombocytosis mimicking essential thrombocythemia.  Acta Haematol. 2005;  113 213-219
  • 99 Thiele J, Kvasnicka H M, Orazi A. Bone marrow histopathology in myeloproliferative disorders-Current diagnostic approach.  Semin Hematol. 2005;  42 184-195
  • 100 Westwood N B, Pearson T C. Diagnostic applications of haetopoietic progenitor culture techniques in polycythaemias and thrombocythaemias.  Leuk Lymphoma. 1996;  22 95-103
  • 101 Johanson P, Andreason B, Safai-Kutti S et al.. The presence of a significant association between elevated PRV-1 mRNA expression and low plasma erythropoietin concentration in essential thrombocythemia.  Eur J Haematol. 2003;  70 358-362
  • 102 Messinezy M, Westwood N B, El-Hemaida I, Marsden J T, Sherwood R S, Pearson T C. Serum erythropoietin values in erythrocytoses and in primary thrombocythaemia.  Br J Haematol. 2002;  117 47-53
  • 103 Liu E, Jelinek J, Pastore Y D, Guan Y L, Prchal J F, Prchal J T. Discrimination of polycythemias and thrombocytosis by novel, simple, accurate clonality assays and comparison with PRV-1 expression and BFU-E response to erythropoietin.  Blood. 2003;  101 3294-3301
  • 104 Shih L-Y, Lee C-T. Identification of masked polycythemia vera from patients with idiopathic marked thrombocytosis by endogenous erythroid colony assay.  Blood. 1994;  83 744-748
  • 105 Griesshammer M, Klippel S, Strunk E et al.. PRV-1 mRNA expression discriminates two types of essential thrombocythemia.  Ann Hematol. 2004;  83 364-370
  • 106 Cotes P M, Dore C J, Tin J A et al.. Determination of serum immunoreactive erythropoietin in the investigation of erythrocytosis.  N Engl J Med. 1986;  315 283-287
  • 107 Birgegard G, Wide L. Serum erythropoietin in the diagnosis of polycythemia and after phlebotomy treatment.  Br J Haematol. 1992;  81 603-606
  • 108 Messinezy M, Westwood N B, Woodstock S P, Strong R M, Pearson T C. Low serum erythropoietin: a strong diagnostic criterion of primary polycythaemia even at normal haemoglobin levels.  Clin Lab Haematol. 1995;  17 217-220
  • 109 Dobo I, Donnard M, Giridon F et al.. Standardization and comparison of endogenous erythroid colony assays performed with bone marrow or blood progenitors for the diagnosis of polycythemia vera.  Hematol J. 2004;  5 161-167
  • 110 Mossuz P, Giridon F, Latger-Cannoard V et al.. Diagnostic value of serum erythropoietin level in patients with absolute erythrocytosis.  Haematologica. 2004;  89 1194-1198
  • 111 Berk P D, Goldberg J D, Silverstein M N et al.. Increased incidence of acute leukaemia in polycythemia vera associated with chlorambucil therapy.  N Engl J Med. 1981;  304 441-447
  • 112 Berk P D, Goldberg J D, Donovan P B, Fruchtman S M, Berlin N I, Wasserman L R. Therapeutic recommendations in polycythemia vera based on Polycythemia Vera Study Group protocols.  Semin Hematol. 1986;  23 132-143
  • 113 Berk P, Wasserman L R, Fruchtman S M, Goldberg J D. Treatment of polycythemia vera: a summary of clinical trials conducted by the Polycythemia Vera study Group. In: Wasserman LR, Berk PD, Berlin NI Polycythemia Vera and the Myeloproliferative Disorders. Philadelphia, PA; WB Saunders 1995
  • 114 Fruchtman S M, Mack K, Kaplan M E, Peterson P, Berk P D, Wasserman L R. From efficacy to safety: a Polycythemia Vera Study Group report on hydroxyurea in patients with polycythemia vera.  Semin Hematol. 1997;  34 17-23
  • 115 Barbui T, Finazzi G, de Gaetano G et al.. Polycythemia vera: the natural history of 1213 patients followed for 20 years.  Ann Intern Med. 1995;  123 656-664
  • 116 Pearson T C, Wetherley-Mein G. Vascular occlusive episodes and venous hematocrit in primary proliferative polycythaemia.  Lancet. 1978;  2 1219-1222
  • 117 Thomas D J, Marshall J, Russell R WR et al.. Cerebral blood-flow in polycythemia.  Lancet. 1977;  2 161-163
  • 118 Thomas D J, du Boullat G H, Marshall J et al.. Effect of haematocrit on cerebral blood flow in man.  Lancet. 1977;  2 941-943
  • 119 Egli F, Wieczorek A, Niemöller M et al.. Polycythemia vera: Klinik und Verlauf bei 86 Patienten.  Schweiz Med Wschr. 1988;  1969-1975
  • 120 Messinezy M, Pearson T C, Pochazka A, Wetherley-Mein G. Treatment of primary proliferative polycythemia by venasection and low dose busulphan. Retrospective study from one centre.  Br J Haematol. 1985;  61 657-666
  • 121 Landolfi R, Marchioli R. on behalf of the ECLAP investigators. European Collaboratio on Low-dose Aspirin in Polycythemia Vera (ECLAP): a randomized trial.  Semin Thromb Hemost. 1997;  23 463-478
  • 122 Michiels J J. Erythromelalgia and vascular complication in polycythemia vera.  Semin Thromb Hemost. 1997;  23 441-454
  • 123 Landolfi R. Bleeding and thrombosis in myeloproliferative disorders.  Curr Opin Hematol. 1998;  11 721-749
  • 124 Landolfi R, Marchioli R, Kutti J et al.. Efficacy and safety of low-dose aspirin in polycythemia vera: results of the ECLAP trial.  N Engl J Med. 2004;  350 114-124
  • 125 Finazzi G. A prospective analysis of thrombotic events in the European collaboration study on low-dose aspirin in polycythemia (ECLAP).  Pathol Biol. 2004;  52 285-288
  • 126 Michiels J J, Berneman Z, Schroyens W, Urk H. Aspirin-responsive painful red blue, black toe or finger syndrome in plocythemia vera associated with thrombocythemia.  Ann Hematol. 2003;  82 153-159
  • 127 Michiels J J, Berneman Z, Schroyens W, Van Vliet HHDM. Pathophysiology and treatment of platelet-mediated microvascular disturbances, major thrombosis and bleeding complications in essential thrombocythemia.  Platelets. 2004;  15 67-84
  • 128 Najean Y, Rain J D. Treatment of polycythemia vera: use of 32P alone or in combination with maintenance therapy using hydroxyurea in 461 patients greater than 65 years of age. The French Polycythemia Vera Study Group.  Blood. 1997;  89 2319-2327
  • 129 Najean Y, Rain J D. Treatment of polycythemia vera: the use of hydroxyurea and pipobroman in 292 patients under the age of 65 years.  Blood. 1997;  90 3370-3377
  • 130 Michiels J J, Barbui T, Finazzi G et al.. Diagnosis and treatment of polycythemia vera and possible future study designs of the PVSG.  Leuk Lymphoma. 2000;  36 239-253
  • 131 Streiff M B, Smith B, Spivak J L. The diagnosis of polycythemia vera in the era since the Polycythemia Vera Study Group: a survey of American Society Hematology members' practice patterns.  Blood. 2002;  99 1144-1149
  • 132 Spivak J L. The optimal management of polycythemia vera.  Br J Haematol. 2002;  116 243-254
  • 133 Spivak J L. Polycythemia vera: myths, mechanisms, and management.  Blood. 2002;  100 4272-4290
  • 134 Tefferi A. Polycythemia vera: a comprehensive review and clinical recommendations.  Mayo Clin Proc. 2003;  78 174-194
  • 135 Elliott M A, Tefferi A. Thrombosis and hemorrhage in polycythemia vera and essential thrombocythemia.  Br J Haematol. 2005;  128 275-290
  • 136 Finazzi G, Barbui T. Risk-adapted therapy in essential thrombocythemia and polycythemia vera.  Blood Rev. 2005;  19 243-252
  • 137 Harrison C. Essential thrombocythemia: challenges and evidence-based management.  Br J Haematol. 2005;  130 153-165
  • 138 Finazzi G, Harrison C. Essential thrombocythemia.  Semin Hematol. 2005;  42 230-238
  • 139 Tefferi A, Spivak J L. Polycythemia vera: scientific advances and current practice.  Semin Hematol. 2005;  42 206-220
  • 140 Prchal J F, Axelrad A E. Bone marrow responses in polycythemia vera.  N Engl J Med. 1974;  290 1382 , (letter)
  • 141 Dobo I, Mossuz P, Campos I et al.. Comparison of four serum-free, cytokine-free media for analysis of endogenous erythroid colony growth in polycythemia vera and essential thrombocythemia.  Hematol J. 2001;  2 396-403
  • 142 Correa P N, Eskinazi D, Axelrad A A. Circulating erythroid progenitors in polycythemia vera are hypersensitive to insulin-like growth factor-1: studies in an improved serum-free medium.  Blood. 1994;  83 99-112
  • 143 Juvonen E, Ikkala E, Oksanen K, Ruutu T. Megakaryocyte and erythroid colony formation in essential thrombocythemia and reactive thrombocytosis: diagnostic value and correlation to complications.  Br J Haematol. 1993;  83 192-197
  • 144 Florensa L, Bessis C, Woessner S et al.. Endogenous megakaryocyte and erythroid colony formation from blood in essential thrombocythemia.  Leukemia. 1995;  9 271-273
  • 145 Jantunen R, Juvonen E, Ikkala E et al.. Essential thrombocythemia at diagnosis: causes of diagnostic evaluation and presence of positive diagnostic findings.  Ann Hematol. 1998;  77 101-106
  • 146 Axelrad A A, Eskinazi D, Correa P N, Amata D. Hypersensitivity of circulating progenitor cells to megakaryocyte growth and development factor (PEG-rHU MGDF) in essential thrombocythemia.  Blood. 2000;  96 3310-3321
  • 147 Le Bousse-Kerdiles M C. Martyré. Dual implication of fibronigenic cytokines in the pathogenesis of fibrosis and myeloproliferation in myeloid metaplasia with myelofibrosis.  Ann Hematol. 1999;  78 437-444
  • 148 Axelrad A A, Eskinazi D, Amato D. Does hypersensitivity of progenitor cells to normal cytokine(s) play a role in the pathogenesis of idiopathic myelofibrosis with myeloid metaplasia?.  Blood. 1999;  94(suppl 1) 2866
  • 149 Mirza A M, Correa P N, Axelrad A A. Increased basal and induced tyrosine phosphorylation of the insulin-like growth factor 1 receptor beta subunit in circulating mononuclear cells of patients with polycythemia vera.  Blood. 1995;  86 877-882
  • 150 Mirza A M, Ezzat S, Axelrad A A. Insulin-like growth factor binding protein-1 is elevated in patients with polycythemia vera and stimulates erythroid burst formation in vitro.  Blood. 1997;  89 1862-1869
  • 151 Temerinac S, Klippel S, Strunck E et al.. Cloning of PRV-1, a novel member of the uPAR receptor superfamily, which is over expressed in polycythemia rubra vera.  Blood. 2000;  95 2569-2576
  • 152 Klippel S, Strunck E, Termerinac S et al.. Quantification of PRV-1 expression, a molecular marker for the diagnosis of polycythemia vera.  Blood. 2001;  98 470a
  • 153 Pahl H L. Polycythaemia vera: will new markers help us answer old questions?.  Acta Haematol. 2002;  108 120-131
  • 154 Dameshek W. Physiopathology and course of polycythemia vera as related to therapy.  JAMA. 1950;  18 790-797
  • 155 James C, Ugo V, Le Couedic P F et al.. A unique clonal JAK2 mutation leading to constitutive signalling causes polycythemia vera.  Nature. 2005;  434 1144-1148
  • 156 James C, Ugo V, Casadevall N, Constantinescu S N, Vainchenker W A. JAK2 mutation in myeloproliferative disorders: pathogenesis and therapeutic and scientific prospects.  Trends Mol Med. 2005;  11 546-554
  • 157 Vainchenker W, Constantinescu S N. A unique activating mutation in JAK2 (V617F) is at the origin of polycythemia vera and allows a new classification of myeloproliferative diseases.  Hematology (Am Soc Hematol Educ Program). 2005;  195-200
  • 158 Staerk J, Kallin A, Demoulin J B, Vainchenker W, Constantinescu S N. JAK1 and TYK2 activation by homologous polycythemia vera JAK2 V617F mutation: cross talk with IGF1 receptor.  J Biol Chem. 2005;  280 41893-41899
  • 159 Kaushansky K. On the origin of the chronic myeloproliferative disorders: it makes all sense.  Blood. 2005;  105 4187-4190
  • 160 Goldman J M. A unifying mutation in chronic myeloproliferative disorders.  N Engl J Med. 2005;  352 1744-1745
  • 161 Cazzola M, Skoda R. Gain of function, loss of control. A molecular basis for chronic myeloproliferative disorders.  Haematologica Hematol J. 2005;  90 871-874
  • 162 Geddis A E, Linden H M, Kaushansky K. Thrombopoietin: a pan-hematopoietic cytokine.  Cytokine Growth Factor Rev. 2002;  13 61-73
  • 163 Tong W, Zhang J, Lodish H F. Lnk inhibits erythropoiesis and EPO-dependent JAK2 activation and downstream signalling pathways.  Blood. 2005;  105 4604-4612
  • 164 Lu X, Levine R, Wernig G, Pikman Y, Zarnegar S, Gilliland D G. Expression of a homodimeric type I cytokine receptor is required for JAK2 V617F-mediated transformation.  Proc Natl Acad Sci USA. 2005;  102 18962-18967
  • 165 Levine R L, Wadleigh M, Cools J et al.. Activating mutation in the tyrosine kinase JAK2 in polycythemia vera, essential thrombocythemia and myeloid metaplasia with myelofibrosis.  Cancer Cell. 2005;  7 387-397
  • 166 Kralovics R, Paasamonti F, Buser A S et al.. A gain-of-function mutation of JAK2 in myeloproliferative disorders.  N Engl J Med. 2005;  352 1779-1790
  • 167 Baxter E J, Scott L M, Campbell P J et al.. Acquired mutation of the tyrosine kinase in human myeloproliferative disorders.  Lancet. 2005;  365 1054-1061
  • 168 Zhao R, Xing S, Li Z et al.. Identification of an acquired JAK2 mutation in polycythemia vera.  J Biol Chem. 2005;  280 22788-22792
  • 169 Jones A V, Kreil S, Xoi K et al.. Widespread occurrence of the JAK2 V617F mutation in chronic myeloproliferative disorders.  Blood. 2005;  106 2162-2168
  • 170 Goerttler P S, Steimle C, Maerz E et al.. The JAK2 V617F mutation, PRV-1 over expression and EEC formation define a similar cohort of MPD patients.  Blood. 2005;  106 2862-2864
  • 171 Kralovics R, Teo S S, Buser A S et al.. Altered gene expression in myeloproliferative disorders correlates with activation of signalling by the V617F mutation of JAK2.  Blood. 2005;  106 3374-3376
  • 172 Steensma D P, Dewald M, Lasho T L et al.. The JAK2 V617F activating tyrosine kinase mutation is an infrequent event in both atypical myeloproliferative disorders and the myelodysplastic syndrome.  Blood. 2005;  106 1207-1209
  • 173 Jelinek J, Oki Y, Gharibyan V et al.. JAK2 mutation 1849G >T is rare in acute leukemias but can be found in CMML, Philadelphia-chromosome negative CML and megakaryocytic leukemia.  Blood. 2005;  106 3370-3373
  • 174 Levine R L, Loriaux M, Huntly B JP et al.. The JAK2 V617F activating mutation occurs in chronic myelomonocytic leukemia and acute myeloid leukemia, but not in acute lymphoblastic leukemia or chronic lymphocytic leukemia.  Blood. 2005;  106 3377-3379
  • 175 Wolanskyj A P, Lasho T L, Schwager S M et al.. JAK2 V617 mutation in essential thrombocythaemia: clinical associations and long-term relevance.  Br J Haematol. 2005;  131 208-213
  • 176 Antonioli E, Guglielmelli P, Pancrazzi A et al.. Clinical implications of the JAK2 V617F mutation in essential thrombocythemia.  Leukemia. 2005;  19 1847-1849
  • 177 Tefferi A, Sirhan S, Terra L et al.. Concomittant neutrophil JAK2 V617F mutation screening and PRV-1 expression analysis in myeloproliferative disorders and secondary polycythemia.  Br J Haematol. 2005;  131 166-171
  • 178 Kiladjian J J, Elkassar N, Hetet G et al.. Analysis of JAK2 mutation in essential thrombocythemia (ET) patients with monoclonal and polyclonal X-chromosome inactivation patterns (XCIPs).  Blood. 2005;  (suppl) , 807-II (abst)
  • 179 Campbell P, Scott L M, Buck G et al.. Definition of essential thrombocythemia and relation of essential thrombocythemia to polycythaemia vera based on JAK2 V617F mutation status: a prospective study.  Lancet. 2005;  366 1945-1953
  • 180 Skoda R, Prchal J T. Lessons from familial myeloproliferative disorders.  Semin Hematol. 2005;  42 266-273
  • 181 Campbell P J, Griesshammer M, Dehmer K et al.. The V616F mutation in JAK2 is associated with poorer survival in idiopathic myelofibrosis.  Blood. 2005;  November 17 , [Epub ahead of print]
  • 182 Tefferi A, Terra L, Susan M et al.. The JAK2 V617F tyrosine kinase mutation in myelofibrosis with myeloid metaplasia: lineage specificity and clinical correlates.  Br J Haematol. 2005;  131 320-328
  • 183 Tefferi A, Lasho T L, Schwager S M et al.. The clinical phenotype of wild-type, heterozygous and homozygous JAK2 V617F in polycythemia vera.  Cancer. 2005;  December 20; , [Epub ahead of print]
  • 184 Tefferi A, Gilliland D G. The JAK2 V617F Tyrosine kinase mutation in myeloproliferative disorders: status report and immediate implications for disease classification and diagnosis.  Mayo Clin Proc. 2005;  80 947-958
  • 185 Tefferi A, Barbui T. BCR/ABL-Negative, classic myeloproliferative disorders: diagnosis and treatment.  Mayo Clin Proc. 2005;  80 1220-1232
  • 186 Michiels J J. Clinical, pathological and molecular features of myeloproliferative disorders: MPD 2005 and beyond.  Hematology. 2005;  10(suppl 1) 215-223
  • 187 Michiels J J, Berneman Z, Van Bockstaele D, De Raeve H, Schroyens W. Current diagnostic criteria of the chronic myeloproliferative disorders (MPD) essential thrombocythemia (ET), polycythemia vera (PV) and chronic idiopathic myelofibrosis (CIMF).  Pathol Biol. 2006;  In press

Jan Jacques MichielsM.D. Ph.D. 

Goodheart Institute, MPD Center Europe, Erasmus Tower, Veenmos 13

3069 AT Rotterdam, The Netherlands

Email: postbus@goodheartcenter.demon.nl

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