title: Characterization of peripheral natural killer cells in primary Sjögren's syndrome: impaired NK cell activity and low NK cell number.
abstract: The aim of this study was to compare the number of peripheral blood natural killer (NK) cells, NK cell activity, expression of NK cell activating receptors, and serum cytokine levels in patients with primary Sjögren's syndrome (SS) vs normal controls. The authors found that NK cell number, NK cell killing activity, and the expression of activating receptors CD2 and NKG2D were significantly decreased, and the expression of NKp46, as well as the percentage of apoptotic NK cells, were significantly increased in primary SS patients compared with healthy controls. NK cell killing activity on a per-cell basis was similar in primary SS patients and healthy controls. Moreover, the levels of IL-18 and TNF-alpha, cytokines that have been shown to promote NK cell death, were significantly increased in sera from patients with primary SS compared with controls. These data suggest that reduced NK cell numbers, probably a result of apoptotic death, may contribute to impaired NK cell activity in patients with primary SS.
authors.affiliation: First Department of Internal Medicine, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan.
authors.forename: Yasumori
authors.initials: Y
authors.lastname: Izumi
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Ida
authors.forename: Mingguo
authors.initials: M
authors.lastname: Huang
authors.forename: Nozomi
authors.initials: N
authors.lastname: Iwanaga
authors.forename: Fumiko
authors.initials: F
authors.lastname: Tanaka
authors.forename: Kouichiro
authors.initials: K
authors.lastname: Aratake
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: Tomoki
authors.initials: T
authors.lastname: Origuchi
authors.forename: Atsushi
authors.initials: A
authors.lastname: Kawakami
authors.forename: Paul
authors.initials: P
authors.lastname: Anderson
authors.forename: Katsumi
authors.initials: K
authors.lastname: Eguchi
mesh_terms: D017209:Apoptosis; D002452:Cell Count; D016207:Cytokines / Q000378:metabolism; D003602:Cytotoxicity, Immunologic; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D007694:Killer Cells, Natural / Q000276:immunology* / Q000378:metabolism / Q000473:pathology; D007958:Leukocyte Count; D008297:Male; D008875:Middle Aged; D011971:Receptors, Immunologic / Q000378:metabolism; D012859:Sjogren's Syndrome / Q000276:immunology* / Q000378:metabolism / Q000473:pathology
chemical_list: D016207:Cytokines; D011971:Receptors, Immunologic