title: A significantly impaired natural killer cell activity due to a low activity on a per-cell basis in rheumatoid arthritis.
abstract: To elucidate the characterization of peripheral natural killer (NK) cells in patients with rheumatoid arthritis (RA), we investigated the NK cell activity, the expression of NK cell activating receptors and intracellular molecules. The NK activity was analyzed in 27 RA patients, 22 primary Sjögren's syndrome (SS) patients, and 15 healthy individuals using the (51)Chrominium release assay. The expression of NK cell activating receptors (NKG2D, CD244, CD2, and CD16) and intracellular molecules (granzyme B, perforin, and TCR zeta chain) in CD3-CD56+ cells were characterized by flow cytometry. The serum cytokine levels (IL-6, TNFalpha, and IL-18) were measured using ELISA. Both the NK cell activity and the activity on a per-cell basis were observed to significantly decrease in the RA patients in comparison to the controls. The expression of NKG2D and CD244 also significantly decreased in both the RA and primary SS patients, whereas the significant decrease in the CD16 expression was only observed in the RA patients. The titer of the serum IL-6, TNFalpha, and IL-18 was significantly higher in the RA patients than in the controls. These data suggest that a low NK activity on a per-cell basis might therefore contribute to an impaired NK activity in the patients with RA.
authors.affiliation: First Department of Internal Medicine, Nagasaki University Hospital of Medicine and Dentistry, Graduate School of Biomedical Sciences, Nagasaki University, Sakamoto, Nagasaki, Japan.
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Aramaki
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Ida
authors.forename: Yasumori
authors.initials: Y
authors.lastname: Izumi
authors.forename: Keita
authors.initials: K
authors.lastname: Fujikawa
authors.forename: Mingguo
authors.initials: M
authors.lastname: Huang
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Arima
authors.forename: Mami
authors.initials: M
authors.lastname: Tamai
authors.forename: Makoto
authors.initials: M
authors.lastname: Kamachi
authors.forename: Hideki
authors.initials: H
authors.lastname: Nakamura
authors.forename: Atsushi
authors.initials: A
authors.lastname: Kawakami
authors.forename: Tomoki
authors.initials: T
authors.lastname: Origuchi
authors.forename: Naoki
authors.initials: N
authors.lastname: Matsuoka
authors.forename: Katsumi
authors.initials: K
authors.lastname: Eguchi
mesh_terms: D000328:Adult; D000368:Aged; D015703:Antigens, CD / Q000378:metabolism*; D001172:Arthritis, Rheumatoid / Q000276:immunology*; D016022:Case-Control Studies; D005260:Female; D058851:GPI-Linked Proteins; D006801:Humans; D020382:Interleukin-18 / Q000097:blood; D015850:Interleukin-6 / Q000097:blood; D007694:Killer Cells, Natural / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D055655:NK Cell Lectin-Like Receptor Subfamily K / Q000378:metabolism*; D017452:Receptors, IgG / Q000378:metabolism*; D011971:Receptors, Immunologic / Q000378:metabolism*; D000071176:Signaling Lymphocytic Activation Molecule Family; D012859:Sjogren's Syndrome / Q000276:immunology; D014409:Tumor Necrosis Factor-alpha / Q000097:blood
chemical_list: D015703:Antigens, CD; C084093:CD244 protein, human; C428200:FCGR3B protein, human; D058851:GPI-Linked Proteins; C508600:IL6 protein, human; D020382:Interleukin-18; D015850:Interleukin-6; C527085:KLRK1 protein, human; D055655:NK Cell Lectin-Like Receptor Subfamily K; D017452:Receptors, IgG; D011971:Receptors, Immunologic; D000071176:Signaling Lymphocytic Activation Molecule Family; D014409:Tumor Necrosis Factor-alpha