title: 2-Chlorodeoxyadenosine therapy for idiopathic hypereosinophilic syndrome.
abstract: Idiopathic hypereosinophilic syndrome (HES) is a rare disease with no established effective therapy. It has been reported that interleukin-5 (IL-5) produced by helper T cells plays a major role in the proliferation of eosinophils. The nucleotide analogue 2-chlorodeoxyadenosine (2-CdA), which induces excellent clinical responses in hairy cell leukemia, is known to suppress helper T cells; therefore, we used 2-CdA, alone or in combination with cytarabine, to treat patients with idiopathic HES. 2-CdA alone and combined with cytarabine resulted in a rapid and sustained decrease in circulating eosinophils in two patients with idiopathic HES that was refractory to steroids, hydroxyurea and cytarabine. The efficacy of 2-CdA alone and combined with cytarabine exceeded by far that of cytarabine alone. However, reverse transcription-polymerase chain reaction (RT-PCR) did not show production of IL-5 or granulocyte-macrophage colony-stimulating factor mRNA in T cells as previously reported, and multiple cytokine receptors were found on eosinophils in idiopathic HES, suggesting that IL-5 may not be the sole cytokine involved in the regulation of idiopathic HES. The clinical efficacy of 2-CdA in idiopathic HES needs to be established on a large group of patients.
authors.forename: N T
authors.initials: NT
authors.lastname: Ueno
authors.forename: S
authors.initials: S
authors.lastname: Zhao
authors.forename: L E
authors.initials: LE
authors.lastname: Robertson
authors.forename: U
authors.initials: U
authors.lastname: Consoli
authors.forename: M
authors.initials: M
authors.lastname: Andreeff
mesh_terms: D000328:Adult; D017338:Cladribine / Q000627:therapeutic use*; D016207:Cytokines / Q000378:metabolism*; D006801:Humans; D017681:Hypereosinophilic Syndrome / Q000188:drug therapy*; D008297:Male; D018121:Receptors, Cytokine / Q000378:metabolism*
chemical_list: D016207:Cytokines; D018121:Receptors, Cytokine; D017338:Cladribine