Response to imatinib mesylate in a patient with idiopathic hypereosinophilic syndrome associated with cyclic eosinophil oscillations.
A 26-year-old man with idiopathic hypereosinophilic syndrome (HES) was treated with imatinib mesylate following a 5-year history of prednisolone therapy. The patient had hypereosinophilia (absolute eosinophil counts >1500/microL) occurring in cyclic oscillations as well as histologically diagnosed eosinophilic vasculitis, bursitis, and periodic soft-tissue swellings. Laboratory data revealed high levels of serum tryptase and increased numbers of mast cells in the bone marrow, but serum interleukin 5 levels were within the normal range. The disease initially responded well to 100 mg/day of imatinib mesylate but recurred 8 weeks later. Thereafter, a daily 200-mg dose was temporarily effective. Despite the response to imatinib, the FIP1L1-PDGFRA fusion gene was not detected by fluorescence in situ hybridization analysis. Additional molecular and cytogenetic studies showed neither translocations of platelet-derived growth factor receptor (PDGFR) genes nor mutations in the c-KIT or the PDGFR genes. Although imatinib mesylate is a choice of treatment for patients with HES, its precise molecular mechanism in individual cases remains to be clarified.
Imashuku
Shinsaku
S
Division of Pediatrics, Takasago-seibu Hospital, Takasago 676-0812, Japan. shinim95@mbox.kyoto-inet.or.jp
Kakazu
Naoki
N
Ueda
Ikuyo
I
Morimoto
Akira
A
Harada
Hironori
H
Teramura
Tomoko
T
Tamura
Shinichi
S
Fukushima-Nakase
Yoko
Y
Kuroda
Hiroshi
H
D000328:Adult; D000970:Antineoplastic Agents / Q000494:pharmacology*; D001549:Benzamides; D004252:DNA Mutational Analysis; D006801:Humans; D017681:Hypereosinophilic Syndrome / Q000188:drug therapy*; D000068877:Imatinib Mesylate; D008297:Male; D010879:Piperazines / Q000494:pharmacology*; D011743:Pyrimidines / Q000494:pharmacology*; D017479:Receptors, Platelet-Derived Growth Factor / Q000235:genetics; D012008:Recurrence; D016896:Treatment Outcome
D000970:Antineoplastic Agents; D001549:Benzamides; D010879:Piperazines; D011743:Pyrimidines; D000068877:Imatinib Mesylate; D017479:Receptors, Platelet-Derived Growth Factor