title: Eosinophilia associated with clonal T-cell proliferation.
abstract: Eosinophilia associated with the expansion of cloned T-cells is reviewed in relation to cytokine production. It has been proved that eosinophilopoiesis is caused by eosinophil-stimulating cytokines, including interleukin-5 (IL-5), granulocyte-macrophage colony-stimulating factor and interleukin-3, which are secreted from T-cells. Recently, we and other groups have reported several cases of eosinophilia including hypereosinophilic syndrome (HES) accompanied with proliferation of abnormal T-cells with an unusual phenotype CD3- CD4+ or CD3+ CD4- CD8- in the peripheral blood. The T-cells clonally proliferate, as confirmed by clonal rearrangements of the T-cell receptor (TCR) gene, and produce eosinophil-stimulating cytokines, especially IL-5, with or without stimulation in vitro. Although HES is defined by the combination of unexplained prolonged eosinophilia and evidence of organ involvement, these observations suggest that increased production of eosinophil-stimulating cytokines from the abnormal T-cells with phenotype CD3- CD4+ or CD3+ CD4- CD8- may cause eosinophilia, some of which have been diagnosed as HES.
authors.affiliation: The Second Department of Internal Medicine, Shinshu University School of Medicine, Matsumoto, Nagano-ken, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Kitano
authors.forename: N
authors.initials: N
authors.lastname: Ichikawa
authors.forename: S
authors.initials: S
authors.lastname: Shimodaira
authors.forename: T
authors.initials: T
authors.lastname: Ito
authors.forename: F
authors.initials: F
authors.lastname: Ishida
authors.forename: K
authors.initials: K
authors.lastname: Kiyosawa
mesh_terms: D017252:CD3 Complex / Q000097:blood; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D002455:Cell Division / Q000276:immunology; D002999:Clone Cells / Q000166:cytology / Q000276:immunology*; D004802:Eosinophilia / Q000276:immunology*; D006801:Humans; D016399:Lymphoma, T-Cell / Q000276:immunology; D013601:T-Lymphocytes / Q000166:cytology*
chemical_list: D017252:CD3 Complex