title: Imatinib Treatment in PDGFRA-Negative Childhood Hypereosinophilic Syndrome.
abstract: We report a 4-year-old female who presented with severe hypereosinophilia (215.7 K/μl) and end-organ dysfunction. Extensive evaluation including whole exome sequencing was performed, revealing no causative mutation. Initial treatment with corticosteroids, leukapheresis, and hydroxyurea decreased her absolute eosinophil count (AEC), although it remained elevated. Despite the absence of a PDGFRA mutation, an imatinib trial resulted in normalization of her AEC. Imatinib was discontinued after sustained normal counts for 1 month. AECs have remained normal for more than 1 year off therapy. This provides support for consideration of imatinib in the treatment of hypereosinophilia even in the absence of a known tyrosine kinase mutation.
authors.affiliation: Division of Pediatric Hematology and Oncology, Department of Pediatrics and Communicable Diseases, University of Michigan Medical Center, Ann Arbor, Michigan.
authors.forename: Angela C
authors.initials: AC
authors.lastname: Weyand
authors.affiliation: Division of Pediatric Hematology and Oncology, Department of Pediatrics and Communicable Diseases, University of Michigan Medical Center, Ann Arbor, Michigan.
authors.forename: Gregory A
authors.initials: GA
authors.lastname: Yanik
authors.affiliation: Department of Pathology, University of Michigan Medical Center, Ann Arbor, Michigan.
authors.forename: Nathanael G
authors.initials: NG
authors.lastname: Bailey
authors.affiliation: Michigan Center of Translational Pathology (MCTP), University of Michigan Medical Center, Ann Arbor, Michigan.
authors.forename: Yi-Mi
authors.initials: YM
authors.lastname: Wu
authors.affiliation: Division of Pediatric Hematology and Oncology, Department of Pediatrics and Communicable Diseases, University of Michigan Medical Center, Ann Arbor, Michigan.
authors.forename: Rajen J
authors.initials: RJ
authors.lastname: Mody
authors.affiliation: Division of Pediatric Hematology and Oncology, Department of Pediatrics and Communicable Diseases, University of Michigan Medical Center, Ann Arbor, Michigan.
authors.forename: Valerie P
authors.initials: VP
authors.lastname: Castle
mesh_terms: D002675:Child, Preschool; D005260:Female; D006801:Humans; D017681:Hypereosinophilic Syndrome / Q000188:drug therapy* / Q000235:genetics; D000068877:Imatinib Mesylate / Q000627:therapeutic use*; D047428:Protein Kinase Inhibitors / Q000627:therapeutic use; D020796:Receptor, Platelet-Derived Growth Factor alpha / Q000032:analysis*; D017422:Sequence Analysis, DNA
chemical_list: D047428:Protein Kinase Inhibitors; D000068877:Imatinib Mesylate; D020796:Receptor, Platelet-Derived Growth Factor alpha
keywords: PDGFRA; hypereosinophilia; imatinib; pediatric