title: Clinical features of hypereosinophilic syndrome: FIP1L1-PDGFRA fusion gene-positive disease is a distinct clinical entity with myeloproliferative features and a poor response to corticosteroid.
abstract: We conducted a retrospective analysis of the clinical features of 20 patients with severe eosinophilia at our institution, including 10 cases of hypereosinophilic syndrome (HES) (5 definite and 5 probable cases) and 10 cases of other eosinophilic disorders. Of the 20 patients, 14 initially received prednisolone treatment, which resulted in rapid improvement and normalization of eosinophilia within 8 weeks; however, 2 patients with splenomegaly showed poor control of eosinophilia in response to corticosteroid treatment. In addition, the FIP1L1-PDGFRA fusion gene was detected only in these 2 cases. One of the FIP1L1-PDGFRA - positive HES cases featured bone marrow fibrosis. Treatment of this patient with imatinib mesylate resulted in a dramatic improvement of eosinophilia, organomegaly, and the bone marrow fibrosis. Taken together, our data and previous reports suggest that FIP1L1-PDGFRA - positive HES is a distinct clinical entity with myeloproliferative features and showing a poor response to corticosteroid treatment.
authors.affiliation: First Department of Internal Medicine (Hematology/Oncology), Tokyo Medical University, Tokyo, Japan. miyazawa@tokyo-med.ac.jp
authors.forename: Keisuke
authors.initials: K
authors.lastname: Miyazawa
authors.forename: Naoki
authors.initials: N
authors.lastname: Kakazu
authors.forename: Kazuma
authors.initials: K
authors.lastname: Ohyashiki
mesh_terms: D000305:Adrenal Cortex Hormones / Q000627:therapeutic use*; D000328:Adult; D000368:Aged; D001853:Bone Marrow / Q000473:pathology; D004802:Eosinophilia / Q000188:drug therapy / Q000235:genetics / Q000473:pathology; D005260:Female; D005355:Fibrosis / Q000209:etiology; D006801:Humans; D017681:Hypereosinophilic Syndrome / Q000188:drug therapy / Q000235:genetics* / Q000473:pathology*; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D008875:Middle Aged; D009196:Myeloproliferative Disorders / Q000235:genetics*; D015514:Oncogene Proteins, Fusion / Q000235:genetics*; D011239:Prednisolone / Q000627:therapeutic use; D011379:Prognosis; D020796:Receptor, Platelet-Derived Growth Factor alpha / Q000235:genetics*; D012189:Retrospective Studies; D013163:Splenomegaly; D039221:mRNA Cleavage and Polyadenylation Factors / Q000235:genetics*
chemical_list: D000305:Adrenal Cortex Hormones; C479818:FIP1L1 protein, human; D015514:Oncogene Proteins, Fusion; D039221:mRNA Cleavage and Polyadenylation Factors; D011239:Prednisolone; D020796:Receptor, Platelet-Derived Growth Factor alpha