title: Significance of circulating T-cell clones in Sezary syndrome.
abstract: Identification of malignant Sézary cells by T-cell receptor (TCR) clonality studies is routinely used for the diagnosis of Sézary syndrome, but T-cell clones expressed in a single patient have never been accurately characterized. We previously reported that CD158k expression delineates Sézary syndrome malignant cells, and, more recently, we identified vimentin at the surface membranes of Sézary cells and normal activated lymphocytes. In the present study, T-cell clones from 13 patients with Sézary syndrome were identified by immunoscopy and further characterized in the blood according to their TCR Vbeta, CD158k, and vimentin cell-surface expression. We found in most patients a unique malignant T-cell clone that coexpressed CD158k and vimentin and that, when patients were tested, was also present in the skin. However, in some patients we detected the presence of a nonmalignant circulating clone expressing high amounts of vimentin and lacking CD158k. These results indicate that clonal expansion may originate from circulating malignant and nonmalignant CD4(+) T cell populations in patients with Sézary syndrome. Identification of the malignant cells in Sézary syndrome cannot be achieved by T-cell clonality studies or by TCR Vbeta monoclonal antibody (mAb) analysis alone; it also relies on CD158k phenotyping.
authors.affiliation: INSERM U659, Faculté de Médecine de Créteil, 8 rue du Général Sarrail, F-94010 Créteil Cedex, France.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Ortonne
authors.forename: Delphine
authors.initials: D
authors.lastname: Huet
authors.forename: Caroline
authors.initials: C
authors.lastname: Gaudez
authors.forename: Anne
authors.initials: A
authors.lastname: Marie-Cardine
authors.forename: Valérie
authors.initials: V
authors.lastname: Schiavon
authors.forename: Martine
authors.initials: M
authors.lastname: Bagot
authors.forename: Philippe
authors.initials: P
authors.lastname: Musette
authors.forename: Armand
authors.initials: A
authors.lastname: Bensussan
mesh_terms: D000293:Adolescent; D000368:Aged; D015703:Antigens, CD / Q000235:genetics; D002999:Clone Cells; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D016130:Immunophenotyping; D008297:Male; D008875:Middle Aged; D010641:Phenotype; D011948:Receptors, Antigen, T-Cell / Q000097:blood; D011971:Receptors, Immunologic / Q000235:genetics; D054340:Receptors, KIR; D054343:Receptors, KIR2DL2; D054347:Receptors, KIR3DL2; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012751:Sezary Syndrome / Q000097:blood / Q000235:genetics / Q000276:immunology* / Q000473:pathology; D013601:T-Lymphocytes / Q000276:immunology* / Q000473:pathology
chemical_list: D015703:Antigens, CD; C515077:KIR2DL2 protein, human; D011948:Receptors, Antigen, T-Cell; D011971:Receptors, Immunologic; D054340:Receptors, KIR; D054343:Receptors, KIR2DL2; D054347:Receptors, KIR3DL2