Response to imatinib mesylate in a patient with idiopathic hypereosinophilic syndrome associated with cyclic eosinophil oscillations.

Posted by rob on May 27, 2005 under Uncategorized | Be the First to Comment

Imashuku S, Kakazu N, Ueda I, Morimoto A, Harada H, Teramura T, Tamura S, Fukushima-Nakase Y, Kuroda H

Int J Hematol. 2005 May ; 81(4): 310-4

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 >1500/3L) 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.

Response to imatinib mesylate in a patient with idiopathic hypereosinophilic syndrome associated with cyclic eosinophil oscillations.