title: Hypereosinophilia during 2-chlorodeoxyadenosine treatment for hairy cell leukaemia.
abstract: A 43-year-old male with newly diagnosed hairy cell leukaemia underwent a single course of 2-chlorodeoxyadenosine (2-CdA). Skin rash, facial swelling and marked eosinophilia developed 20 d after treatment and were resolved by 7 d of steroid therapy. Eosinophil peak in peripheral of the eosinophil population showed a high expression of the IL-2 receptor alpha-chain (CD25), representing up to 94% of gated cells. HLA-DR and CD4 antigens were constantly negative; eosinophils strongly reacted with the secretory form of the eosinophil cationic protein (ECP), recognized by EG2 monoclonal antibody. IL-5 serum levels were markedly elevated at the onset of eosinophilia, returned to normal levels after its disappearance and positively correlated with eosinophil count (r = 0.94, P = 0.016). Eosinophilia is an uncommon finding after treatment with 2-CdA. It is unclear whether these phenomena represented a true allergic reaction to the drug or the effect of massive tumour cell lysis and haemopoietic pancytopenia with immunosuppression, which induced the release of IL-5 and possibly other cytokines.
authors.affiliation: Department of Haematology, Catholic University, Rome, Italy.
authors.forename: S
authors.initials: S
authors.lastname: Rutella
authors.forename: S
authors.initials: S
authors.lastname: Sica
authors.forename: C
authors.initials: C
authors.lastname: Rumi
authors.forename: R
authors.initials: R
authors.lastname: Martucci
authors.forename: B
authors.initials: B
authors.lastname: Etuk
authors.forename: V
authors.initials: V
authors.lastname: De Stefano
authors.forename: U
authors.initials: U
authors.lastname: Testa
authors.forename: G
authors.initials: G
authors.lastname: Leone
authors.forename: C
authors.initials: C
authors.lastname: Peschle
mesh_terms: D000328:Adult; D017338:Cladribine / Q000009:adverse effects*; D004804:Eosinophils; D005434:Flow Cytometry; D006801:Humans; D017681:Hypereosinophilic Syndrome / Q000139:chemically induced* / Q000276:immunology; D015848:Interleukin-5 / Q000097:blood; D007943:Leukemia, Hairy Cell / Q000188:drug therapy* / Q000276:immunology; D008297:Male; D015375:Receptors, Interleukin-2 / Q000378:metabolism
chemical_list: D015848:Interleukin-5; D015375:Receptors, Interleukin-2; D017338:Cladribine