title: Imatinib mesylate as a novel treatment option for hypereosinophilic syndrome: two case reports and a comprehensive review of the literature.
abstract: Hypereosinophilic syndromes (HES) are a heterogenous group of rare disorders characterized by sustained and otherwise unexplained overproduction of eosinophils with organ involvement and consecutive dysfunction. Recent reports document the efficacy of imatinib mesylate in a large proportion of HES patients (65%). Rearrangements involving the platelet-derived growth factor receptor genes (PDGFRA and PDGFRB), both tyrosine kinase receptors, have been demonstrated to be pathogenetically linked to the dysregulated clonal overproduction of eosinophils. This refined hypothesis has been confirmed by the discovery of the novel FIP1L1-PDGFRA fusion gene, which is a gain-of-function gene on chromosome 4q12. Its product is an imatinib-sensitive tyrosine kinase, which can be found in a subset of patients with HES, particularly in those responding to treatment with imatinib mesylate. Here, we sum up recent knowledge of clinical features, pathophysiology and novel treatment aspects of HES by performing a comprehensive search of the available literature and report on 94 patients. We particularly address the issue of organ involvement and specific characteristics of the variable clinical pictures. In addition, two cases will be presented, which illustrate typical clinical scenarios and treatment outcome.
authors.affiliation: Hematology and Oncology Department, University Medical Center Freiburg, Hugstetterstr. 55, 79106 Freiburg, Germany.
authors.forename: Antonia M S
authors.initials: AM
authors.lastname: Müller
authors.forename: Uwe M
authors.initials: UM
authors.lastname: Martens
authors.forename: Silke C
authors.initials: SC
authors.lastname: Hofmann
authors.forename: Leena
authors.initials: L
authors.lastname: Bruckner-Tuderman
authors.forename: Roland
authors.initials: R
authors.lastname: Mertelsmann
authors.forename: Michael
authors.initials: M
authors.lastname: Lübbert
mesh_terms: D000328:Adult; D000368:Aged; D001549:Benzamides; D002894:Chromosomes, Human, Pair 4 / Q000235:genetics; D005260:Female; D006801:Humans; D017681:Hypereosinophilic Syndrome / Q000188:drug therapy* / Q000235:genetics / Q000473:pathology; D000068877:Imatinib Mesylate; D008297:Male; D015514:Oncogene Proteins, Fusion / Q000235:genetics; D010879:Piperazines / Q000008:administration & dosage*; D047428:Protein Kinase Inhibitors / Q000008:administration & dosage*; D011743:Pyrimidines / Q000008:administration & dosage*; D020796:Receptor, Platelet-Derived Growth Factor alpha / Q000235:genetics; D020797:Receptor, Platelet-Derived Growth Factor beta / Q000235:genetics; D012074:Remission Induction; D039221:mRNA Cleavage and Polyadenylation Factors / Q000235:genetics
chemical_list: D001549:Benzamides; D015514:Oncogene Proteins, Fusion; D010879:Piperazines; D047428:Protein Kinase Inhibitors; D011743:Pyrimidines; D039221:mRNA Cleavage and Polyadenylation Factors; D000068877:Imatinib Mesylate; C479819:FIP1L1-PDGFRA fusion protein, human; D020796:Receptor, Platelet-Derived Growth Factor alpha; D020797:Receptor, Platelet-Derived Growth Factor beta