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Archived Comments for: Sequential occurrence of thrombotic thrombocytopenic purpura, essential thrombocythemia, and idiopathic thrombocytopenic purpura in a 42-year-old African-American woman: a case report and review of the literature

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  1. Comments on ¿ Sequential occurrence of thrombotic thrombocytopenic purpura, essential thrombocythemia, and idiopathic thrombocytopenic purpura in a 42-year-old African-American woman: a case report and review of the literature¿

    Thein H Oo, University of Texas MD Anderson Cancer Center

    30 July 2014

    To the Editor: I read this case report with interest and would like to give some comments.

    Firstly, the authors did not mention in the case report the degree of schistocytosis, other blood smear findings, results of reticulocyte count, direct antiglobulin test (DAT), lactate dehydrogenase, haptoglobin, prothrombin time and activated partial thromboplastin time in 1994. They also did not mention computed tomography findings of the brain. Presence of schistocytes per se is not diagnostic of thrombotic thrombocytopenic purpura (TTP) as schistocytes can even be seen in normal people and in other conditions. Burns et al reported that schistocytes can be seen in 58% of normal people with a mean of 0.05% (range 0-0.27%) of all red cells while TTP patients have more schistocytes with a mean of 5% (range 1.1-9.4%) [1]. In this case, if the DAT test had been reported positive with IgG together with small amount of schistocytes, the diagnosis might have been changed to warm autoimmune hemolytic anemia with immune thrombocytopenic purpura (ITP). There have been many case reports of warm autoimmune hemolytic anemia and ITP responding to plasmapheresis [2- 4]. Efficacy of plasmapheresis in those disorders is due to removal of the autoantibodies. It is also noted that JAK-2 positive latent myeloproliferative disorders (MPD) can present with stroke and other thromboses several years before developing into overt MPD [5- 7].

    Secondly, the authors did not mention the white cell count, red cell count, hemoglobin and hematocrit levels in March 2001. The presence of thrombocytosis, clustering megakaryocytes and cellularity of the marrow per se is not diagnostic of essential thrombocythemia [ET]. So also, the authors did not describe the morphology of the erythroid and granulocytic series as well as the status of the stainable iron in the bone marrow for March 2001. Later in October 2001, the patient was found to have absent stainable iron in the bone marrow. Had she had absent stainable iron in the bone marrow in March 2001, she might as well have masked polycythemia vera (PV) as coexisting iron deficiency anemia could bring down the hemoglobin level to a normal level. Rarely, PV patients can present with anemia [8]. Of note, positive JAK-2 mutation status is not unique to ET alone and can be seen in other MPD including PV [9]. So also, autoimmune hemolytic anemia and ITP can be seen in patients with MPD [10-12]. ET and PV can also eventually evolve into myelofibrosis.

    Finally, I would like to point out that there are many missing points in this case report due to the reasons mentioned above. Rather than reporting the extremely small possibility of the occurrence of three platelet disorders albeit sequentially in this patient, would not it be reasonable to try to unify those diagnoses. This patient certainly has MPD of some kind due to positive JAK-2 mutation although I am not sure about the certainty of the ET diagnosis. Due to response of low platelet count to intravenous immune globulin, I believe she also had ITP. However, whether she truly had TTP in 1994 was not clear due to paucity of clinical data in this report.


    1. Burns ER, Lou Y, Pathak A. Morphologic diagnosis of thrombotic thrombocytopenic purpura. Am J Hematol 2004;75:18-21
    2. McLeod BC. Evidence-based therapeutic apheresis in autoimmune and other hemolytic anemia. Curr Opin Hematol 2007;14:647-654
    3. Patten E, Reuter FP. Evan¿s syndrome: possible benefit from plasma exchange. Transfusion 1980;20:589-593
    4. Patel TC, Moore SB, Pineda AA, et al. Role of plasmapheresis in thrombocytopenic purpura associated with Waldenström's macroglobulinemia. Mayo Clin Proc 1996;71:597-600
    5. McCarthy N, McCarron SL, Langabeer SE. Prevalence of the JAK2 V617F and MPL mutations in stroke, abdominal and peripheral venous thrombosis. Acta Haematol 2010;124:160-161
    6. Zerjavik K, Zagradisnik B, Strangler Herodez S, et al. Is the JAK2 V617F mutation a hallmark of different forms of thrombosis? Acta Haematol 2010;124:49-56
    7. Allegra A, Alonci A, Penna G, et al. JAK2 V617F-positive latent essential thrombocythemia and splanchnic vein thrombosis: the role of bone marrow biopsy for the diagnosis of myeloproliferative disease. Acta Haematol 2009;121:218-220
    8. Hassoun H, Pavlovsky M, Mansoor S, et al. Diagnosis of polycythemia vera in an anemic patient. South Med J 2000;93;710-712
    9. Cross NC. Genetic and epigenetic complexity in myeloproliferative neoplasms. Hematology Am Soc Hematol Educ Program 2011;2011:208-214
    10. Khumbanonda M, Horowitz HI, Eyster ME. Coombs' positive hemolytic anemia in myelofibrosis with myeloid metaplasia. Am J Med Sci 1969;258:89-93
    11. Schreiber ZA. Immune thrombocytopenia in postpolythemic myelofibrosis. Am J Hematol 1997;54:146-148
    12. Ramachrishna R, Kyle PW, Day PJ, et al. Evans' syndrome, myelofibrosis and systemic lupus erythematosus: role of procollagens in myelofibrosis. Pathology 1995;27:255-259

    Competing interests