title: Decreased CD161+CD8+ T cells in the peripheral blood of patients suffering from rheumatic diseases.
abstract: OBJECTIVE
  Although it has been reported that the numbers of both CD4(-)CD8(-) and CD4(+) natural killer T (NKT) cells are selectively decreased in the peripheral blood of patients with rheumatic diseases, there have been no reports concerning a novel subpopulation of CD8(+) NKT cells. To examine whether CD161(+)CD8(+) T cells, which are closely related to CD8(+) NKT cells, are also decreased in patients with rheumatic diseases, we have investigated the expression of CD161, together with that of CD28, CD25 and CD62L, on T cells in the peripheral blood of these patients.
  
  
  METHODS
  The rheumatic diseases evaluated in this study were systemic lupus erythematosus (SLE) (n= 54), mixed connective-tissue disease (MCTD) (n= 15), systemic sclerosis (SSc) (n= 14), polymyositis/dermatomyositis (PM/DM) (n= 13) and rheumatoid arthritis (RA) (n= 24). Healthy donors were examined as controls (n= 18). The expression of CD161, CD28, CD25 and CD62L on T cells was analysed by flow cytometry.
  
  
  RESULTS
  Both the frequency of CD161 expression on CD8(+) cells and the absolute number of CD161(+)CD8(+) cells were significantly decreased in patients with SLE, MCTD, SSc and PM/DM. Only the absolute number of CD161(+)CD8(+) T cells was significantly decreased in RA. CD161 expression on CD28(-)CD8(+) T cells was significantly decreased in SLE, MCTD and SSc. The absolute number of CD161(+)CD8(+)CD62L(-) T cells was significantly decreased in SLE, MCTD and SSc.
  
  
  CONCLUSIONS
  Both the frequency and the absolute number of CD161(+)CD8(+) T cells were decreased in the peripheral blood of patients suffering from SLE, MCTD, SSc and PM/DM. This result suggests that there is also an abnormality of NKT cells in the CD8(+) population.
authors.affiliation: Department of Rheumatology and Internal Medicine, Juntendo University School of Medicine, 2-1-1 Hongo, Tokyo, Japan. iwai-kkr@umin.ac.jp
authors.forename: A
authors.initials: A
authors.lastname: Mitsuo
authors.forename: S
authors.initials: S
authors.lastname: Morimoto
authors.forename: Y
authors.initials: Y
authors.lastname: Nakiri
authors.forename: J
authors.initials: J
authors.lastname: Suzuki
authors.forename: H
authors.initials: H
authors.lastname: Kaneko
authors.forename: Y
authors.initials: Y
authors.lastname: Tokano
authors.forename: H
authors.initials: H
authors.lastname: Tsuda
authors.forename: Y
authors.initials: Y
authors.lastname: Takasaki
authors.forename: H
authors.initials: H
authors.lastname: Hashimoto
mesh_terms: D000328:Adult; D000368:Aged; D000954:Antigens, Surface / Q000097:blood*; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D002478:Cells, Cultured; D018920:Coculture Techniques; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000096:biosynthesis; D019041:L-Selectin / Q000097:blood; D037181:Lectins, C-Type / Q000097:blood*; D008180:Lupus Erythematosus, Systemic / Q000276:immunology; D018655:Lymphocyte Count; D008297:Male; D008875:Middle Aged; D008947:Mixed Connective Tissue Disease / Q000276:immunology; D055651:NK Cell Lectin-Like Receptor Subfamily B; D017285:Polymyositis / Q000276:immunology; D012216:Rheumatic Diseases / Q000276:immunology*; D012595:Scleroderma, Systemic / Q000276:immunology; D016176:T-Lymphocyte Subsets / Q000276:immunology*
chemical_list: D000954:Antigens, Surface; D007074:Immunoglobulin G; C527203:KLRB1 protein, human; D037181:Lectins, C-Type; D055651:NK Cell Lectin-Like Receptor Subfamily B; D019041:L-Selectin