title: Analysis of tear cytokines and clinical correlations in Sjögren syndrome dry eye patients and non-Sjögren syndrome dry eye patients.
abstract: OBJECTIVE
  To compare concentrations of tear cytokines in 3 groups composed of Sjögren syndrome (SS) dry eye, non-Sjögren syndrome (non-SS) dry eye, and normal subjects. Correlations between ocular surface parameters and tear cytokines were also investigated.
  
  
  METHODS
  Prospective cross-sectional study.
  
  
  METHODS
  SS dry eye patients (n = 24; 40 eyes) were diagnosed with primary SS according to the criteria set by the American-European Consensus Group. Non-SS dry eye patients (n = 25; 40 eyes) and normal subjects (n = 21; 35 eyes) were also enrolled. Tear concentrations of interleukin (IL)-17, IL-6, IL-10, IL-4, IL-2, interferon γ (IFN-γ), and tumor necrosis factor α (TNF-α) were measured by a multiplex immunobead assay. Ocular Surface Disease Index (OSDI), tear film breakup time (TBUT), Schirmer I test, and fluorescein staining scores were obtained from dry eye patients.
  
  
  RESULTS
  All cytokine levels except for IL-2 were highest in the SS group, followed by non-SS dry eye group and control subjects. Concentrations of IL-17, TNF-α, and IL-6 were significantly different among the 3 groups (IL-17: SS > control P < .001, non-SS > control P = .042, SS > non-SS P < .001; TNF-α: SS > control P = .006, non-SS > control P = .034, SS > non-SS P = .029; IL-6: SS > control P = .002, non-SS > control P = .032, SS > non-SS P = .002). IL-17 was significantly correlated with TBUT (R = -0.22, P = .012) and Schirmer I test (R = -0.36, P = .027) scores in the SS group. IL-6 was significantly correlated only with TBUT (R = -0.38, P = .02) in the non-SS group.
  
  
  CONCLUSIONS
  Differences in tear cytokine levels and correlation patterns between SS dry eye and non-SS dry eye patients suggest the involvement of different inflammatory processes as causes of dry eye syndrome.
authors.affiliation: Institute of Vision Research, Department of Ophthalmology, Severance Eye and ENT Hospital. Yonsei University College of Medicine, Seoul, South Korea.
authors.forename: Sang Yeop
authors.initials: SY
authors.lastname: Lee
authors.forename: Soo Jung
authors.initials: SJ
authors.lastname: Han
authors.forename: Sang Min
authors.initials: SM
authors.lastname: Nam
authors.forename: Sang Chul
authors.initials: SC
authors.lastname: Yoon
authors.forename: Ji Min
authors.initials: JM
authors.lastname: Ahn
authors.forename: Tae-Im
authors.initials: TI
authors.lastname: Kim
authors.forename: Eung Kweon
authors.initials: EK
authors.lastname: Kim
authors.forename: Kyoung Yul
authors.initials: KY
authors.lastname: Seo
mesh_terms: D000328:Adult; D000368:Aged; D003430:Cross-Sectional Studies; D016207:Cytokines / Q000378:metabolism*; D005136:Eye Proteins / Q000378:metabolism*; D005260:Female; D006801:Humans; D007118:Immunoassay; D008875:Middle Aged; D011446:Prospective Studies; D012859:Sjogren's Syndrome / Q000175:diagnosis / Q000378:metabolism*; D013666:Tears / Q000737:chemistry / Q000378:metabolism*
chemical_list: D016207:Cytokines; D005136:Eye Proteins; C042434:tear proteins