title: Reduced Cd4+Cd25+ T cells in patients with idiopathic thrombocytopenic purpura.
abstract: Immunoregulatory CD4(+)CD25(+) T cells play an important role in the induction and maintenance of peripheral self-tolerance. These professional regulatory cells prevent the activation and proliferation of potentially autoreactive T cells that have escaped thymic deletion. Therefore, CD4(+)CD25(+) T cells are believed to possibly play an important role in pathogenic autoimmune diseases. We measured the count of CD4(+)CD25(+) T cells in 44 patients with idiopathic thrombocytopenic purpura (ITP), and the number of CD4(+)CD25(+) T cells and clinical features were then analyzed. By using a flow cytometric analysis, the number of CD4(+)CD25(+) T cells in the patients with ITP showed a very wide distribution in comparison to healthy volunteers. The number of CD4(+)CD25(+) T cells was significantly lower in the ITP patients in the severe phase, and in patients positive for anti-glycoprotein IIb-IIIa antibody. However, the number of those cells increased in the patients at the complete remission phase, especially after a splenectomy. The Foxp3 mRNA levels of peripheral blood mononuclear cells (PBMC) of ITP patients were higher with an improved platelet count than in those with a low platelet count. In addition, the Foxp3 mRNA levels closely correlated with the number of CD4(+)CD25(+) cells. These mechanisms remain to be fully elucidated, however, the count of CD4(+)CD25(+) T cells is considered to possibly be related to the severity of ITP.
authors.affiliation: Department of Hematology and Oncology, Mie University Graduate School of Medicine, Tsu, Japan.
authors.forename: Miho
authors.initials: M
authors.lastname: Sakakura
authors.forename: Hideo
authors.initials: H
authors.lastname: Wada
authors.forename: Isao
authors.initials: I
authors.lastname: Tawara
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Nobori
authors.forename: Takashi
authors.initials: T
authors.lastname: Sugiyama
authors.forename: Norimasa
authors.initials: N
authors.lastname: Sagawa
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Shiku
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001323:Autoantibodies / Q000097:blood; D001483:Base Sequence; D001792:Blood Platelets / Q000276:immunology; D016022:Case-Control Studies; D017931:DNA Primers / Q000235:genetics; D005260:Female; D005434:Flow Cytometry; D051858:Forkhead Transcription Factors / Q000235:genetics; D006801:Humans; D018655:Lymphocyte Count; D008297:Male; D008875:Middle Aged; D016553:Purpura, Thrombocytopenic, Idiopathic / Q000097:blood / Q000235:genetics / Q000276:immunology*; D012333:RNA, Messenger / Q000097:blood / Q000235:genetics; D050378:T-Lymphocytes, Regulatory / Q000276:immunology*
chemical_list: D001323:Autoantibodies; D017931:DNA Primers; C418974:FOXP3 protein, human; D051858:Forkhead Transcription Factors; D012333:RNA, Messenger