好酸球増多症候群、多臓器障害とイマチニブへの反応

Hypereosinophilic Syndrome, Multiorgan Involvement and Response to Imatinib.

• Caroline K Hana
• Humberto Caldera

抄録

好酸球増多症候群（HES）は、末梢血好酸球数が 1,500/mm を超えることを特徴とするまれな症候群であり、それに伴う組織障害を伴う。寄生虫感染や炎症などによる一次的なものと二次的なものがある。胆嚢炎、胃炎、尿路膀胱炎、膵炎で再入院した49歳のアジア人女性の症例を紹介する。末梢血の好酸球数は15,600～19,000/mmと過多であった．胆嚢と胃の病理検査では好酸球浸潤を認めた．骨髄生検では、正常細胞性の骨髄に活発な三尖造血、好酸球増多、軽度の巨核球性過形成（少数の非定型型を含む）、軽度のT細胞リンパ球症が認められた。フローサイトメトリーでは、急性白血病、T細胞またはB細胞のリンパ増殖性障害は認められなかった。蛍光in-situハイブリダイゼーション（FISH）では、骨髄増殖性新生物（MPN）検査では、血小板由来成長因子受容体α（PDGFRA）、血小板由来成長因子受容体β（PDGFRB）、線維芽細胞成長因子受容体-1（FGFR1）再配列は陰性であった。FIP1L1-PDGFRA(factor interacting with PAPOLA and CPSF1-platelet-derived growth factor receptor, alpha polypeptide)遺伝子融合体を有するDespitenotを投与したところ、好酸球数の絶対値が大幅に減少し、症状が改善した。

Hypereosinophilic syndrome (HES) is an uncommon syndrome characterized by peripheral blood eosinophils count of more than 1,500/mm with associated tissue damage. It can be either primary or secondary, for example, due to parasitic infections or inflammation. We present a case of a 49-year-old Asian female with recurrent hospital admissions for cholecystitis, gastritis, urinary cystitis, and pancreatitis. Her peripheral blood count showed excessive eosinophils 15,600-19,000/mm on different occasions. Pathology of her gallbladder and her gastric biopsies showed eosinophilic infiltration. Her bone marrow biopsy showed a normocellular marrow with active trilineage hematopoiesis, eosinophilia, mild megakaryocytic hyperplasia with a few atypical forms, and mild T-cell lymphocytosis. Flow cytometry showed no evidence of acute leukemia, or T-cell or B-cell lymphoproliferative disorder. On fluorescent in-situ hybridization (FISH), myeloproliferative neoplasms (MPN) testing was negative for platelet-derived growth factor receptor-alpha (PDGFRA), platelet-derived growth factor receptor-beta (PDGFRB), and fibroblast growth factor receptor-1 (FGFR1) rearrangement. Despite not having the FIP1L1-PDGFRA (factor interacting with PAPOLA and CPSF1-platelet-derived growth factor receptor, alpha polypeptide) gene fusion, our patient responded to the treatment with a significant decrease in her absolute eosinophils count and resolution of her symptoms.

Copyright © 2020, Hana et al.