内容紹介
A Case of Merkel Cell Carcinoma Complicated with Severe Thrombocytopenia Treated with Carboplatin/Etoposide Regimen after Surgery
Summary
Thrombocytopenia is often caused by myelosuppression during chemotherapy. However, when platelet transfusions are required, pathological conditions such as idiopathic thrombocytopenic purpura(ITP)and thrombotic thrombocytopenic purpura(TTP)also occur. We report a case of Merkel cell carcinoma complicated with severe thrombocytopenia treated with carboplatin/etoposide regimen after surgery. The patient's platelet count did not increase in spite of platelet transfusions. However, the platelet count increased after steroid treatment was chosen under the diagnosis of ITP. Subsequent examinations revealed that the patient had HLA antibody, which caused the platelet transfusion refractoriness. When the platelet count does not increase in spite of platelet transfusions during chemotherapy, the possibility that the platelet transfusion refractoriness is due to the presence of HLA antibody should be considered.
要旨
化学療法中に起こる血小板減少は骨髄抑制によるものが多いが,その他に特発性血小板減少性紫斑病(ITP)や血栓性血小板減少性紫斑病(TTP)などの病態も原因となることがあり,必要に応じて血小板輸血を行わなければならない。本症例では,Merkel細胞癌に対するcarboplatin/etoposide併用療法中に著明な血小板減少を来し,血小板輸血を行うも血小板値が上昇せず,治療に難渋した。ITPなどを考慮し,ステロイド治療を開始した上で血小板輸血を行い改善が得られたが,その後の検査で免疫学的機序による血小板輸血不応であることがわかった。化学療法後の血小板減少に対して血小板輸血を投与しても血小板値が上昇しない場合は,抗HLA抗体による血小板輸血不応である可能性も考慮する必要があると考えられた。
目次
Summary
Thrombocytopenia is often caused by myelosuppression during chemotherapy. However, when platelet transfusions are required, pathological conditions such as idiopathic thrombocytopenic purpura(ITP)and thrombotic thrombocytopenic purpura(TTP)also occur. We report a case of Merkel cell carcinoma complicated with severe thrombocytopenia treated with carboplatin/etoposide regimen after surgery. The patient's platelet count did not increase in spite of platelet transfusions. However, the platelet count increased after steroid treatment was chosen under the diagnosis of ITP. Subsequent examinations revealed that the patient had HLA antibody, which caused the platelet transfusion refractoriness. When the platelet count does not increase in spite of platelet transfusions during chemotherapy, the possibility that the platelet transfusion refractoriness is due to the presence of HLA antibody should be considered.
要旨
化学療法中に起こる血小板減少は骨髄抑制によるものが多いが,その他に特発性血小板減少性紫斑病(ITP)や血栓性血小板減少性紫斑病(TTP)などの病態も原因となることがあり,必要に応じて血小板輸血を行わなければならない。本症例では,Merkel細胞癌に対するcarboplatin/etoposide併用療法中に著明な血小板減少を来し,血小板輸血を行うも血小板値が上昇せず,治療に難渋した。ITPなどを考慮し,ステロイド治療を開始した上で血小板輸血を行い改善が得られたが,その後の検査で免疫学的機序による血小板輸血不応であることがわかった。化学療法後の血小板減少に対して血小板輸血を投与しても血小板値が上昇しない場合は,抗HLA抗体による血小板輸血不応である可能性も考慮する必要があると考えられた。