Increased frequency of cells secreting interleukin-6 and interleukin-10 in peripheral blood of patients with primary Sjögren's syndrome.
Sjögren's syndrome (SS) is a chronic autoimmune disease of exocrine glands. There is increasing evidence that interferon-gamma (IFN-gamma) plays a role in the pathogenesis of SS. It has also been suggested that other type 1 cytokines, as well as interleukin-6 (IL-6), IL-10 and transforming growth factor-beta, are important in the induction and/or maintenance of SS. The aim of this study was to investigate the type 1/type 2 cytokine pattern in peripheral blood of primary SS patients. The enzyme-linked immunospot (ELISPOT) assay was performed to quantify the number of mononuclear cells (MNC) secreting IFN-gamma, IL-6 and IL-10 in peripheral blood samples from 33 patients with primary SS and 12 healthy controls. The mean number of cells secreting IFN-gamma was 9/105 MNC in the SS patient group, and 4/105 MNC in the control group (P = 0.73). Fifteen of the SS patients had anti-Ro 52 kDa antibodies in serum. In this patient group the mean number of cells secreting IFN-gamma was 4/105 MNC, while in the patient group without such antibodies the mean number of cells secreting IFN-gamma was 14/105 MNC (P = 0.04). The mean number of cells secreting IL-6 was 12 000/105 MNC in the SS patient group, and 5000/105 MNC in the control group (P = 0.01). The mean number of cells secreting IL-10 was 270/105 MNC in the SS patient group, and 180/105 MNC in the control group (P = 0.04). The SS patients had a significantly higher number of cells secreting IL-6 and IL-10 in peripheral blood than the healthy controls, which may facilitate B-cell activation and production of autoantibodies.
D000328:Adult; D000368:Aged; D000974:Antibodies, Antinuclear / Q000276:immunology; D001324:Autoantigens / Q000276:immunology; D005260:Female; D006801:Humans; D016753:Interleukin-10 / Q000097:blood / Q000378:metabolism*; D015850:Interleukin-6 / Q000097:blood / Q000378:metabolism*; D007958:Leukocyte Count; D007963:Leukocytes, Mononuclear / Q000378:metabolism; D008875:Middle Aged; D020733:RNA, Small Cytoplasmic; D012261:Ribonucleoproteins / Q000276:immunology; D012859:Sjogren's Syndrome / Q000276:immunology*; D000097585:SS-B Antigen; D000099207:SS-A Antigen