クームス陰性自己免疫性溶血性貧血を併発しリツキシマブが奏効した後天性無巨核球性血小板減少性紫斑病  [in Japanese] Successful rituximab treatment for acquired amegakaryocytic thrombocytopenic purpura complicated with Coombs-negative autoimmune hemolytic anemia  [in Japanese]

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Abstract

後天性無巨核球性血小板減少性紫斑病(AATP)は,骨髄巨核球が選択的に消失または高度に減少する希少疾患である。症例は67歳,男性。2ヶ月前からの出血傾向を自覚し近医を受診。高度の血小板減少を認め,当科紹介となった。骨髄は巨核球のみが欠如し,顆粒球系,赤芽球系に異形成を認めないことからAATPと診断した。また,軽度の正球性正色素性貧血,ハプトグロビン測定感度以下,直接・間接coombs試験陰性および赤血球結合IgG高値より,coombs陰性自己免疫性溶血性貧血(AIHA)の併発と診断した。Cyclosporin 200 mg/日を開始し,prednisoloneを併用するも血小板輸血依存性であった。Rituximab 375 mg/m<sup>2</sup>/週の8回の投与にて著明な貧血と血小板減少の改善が得られた。AATPは血小板減少症の鑑別疾患の一つであり,免疫抑制療法が第一選択と考えられる。AATPにAIHAが併発しrituximabが奏効した症例は本報告が初である。

Acquired amegakaryocytic thrombocytopenic purpura (AATP) is a rare disorder characterized by severe thrombocytopenia associated with total absence or a selective decrease in bone marrow megakaryocytes. A 67-year-old male presented with a 2-month bleeding tendency. He was referred to our hospital because of severe thrombocytopenia. Bone marrow biopsy showed complete absence of megakaryocytes without dysplasia in cells of the myeloid and erythroid lineages. AATP was diagnosed. In addition, mild normocytic normochromic anemia and reticulocytosis were also observed and haptoglobin was below the detectable level. Coombs-negative autoimmune hemolytic anemia (AIHA) was diagnosed based on the high titer of RBC-bound IgG and negative direct and indirect coombs test results. He was first treated with cyclosporine 200 mg per day and subsequently with prednisolone but only slight temporary improvement was achieved. Administration of eight doses of rituximab 375 mg/m<sup>2</sup> per week ameliorated both thrombocytopenia and anemia. AATP should be considered in the differential diagnosis of thrombocytopenia, and immunosuppressive therapy is a potential first-line treatment. This is the first case report of AATP accompanied by AIHA successfully treated with rituximab.

Journal

  • Rinsho Ketsueki

    Rinsho Ketsueki 54(6), 568-573, 2013-06-30

    The Japanese Society of Hematology

References:  15

Codes

  • NII Article ID (NAID)
    10031185458
  • NII NACSIS-CAT ID (NCID)
    AN00252940
  • Text Lang
    JPN
  • Article Type
    NOT
  • ISSN
    04851439
  • NDL Article ID
    024741072
  • NDL Call No.
    Z19-295
  • Data Source
    CJP  NDL  J-STAGE 
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