title: Interleukin-2-inducible T-cell kinase expression and relation to disease severity in systemic lupus erythematosus.
abstract: BACKGROUND
  Interleukin-2 inducible T-cell kinase (ITK) is expressed in T cells, and plays an important role in autoimmune inflammatory diseases through regulating the balance of Th17/Treg. However, its role in human systemic lupus erythematosus (SLE) remains unclear. The present study aims to measure the activation status of ITK in T cells from SLE patients and healthy controls, and identify its possible correlation to disease severity. We also discuss the serum levels of Th17, Treg related cytokines including IL-17, IL-21, IL-22, IL-10, analyzing correlation between ITK and Th17/Treg related cytokines.
  
  
  METHODS
  Peripheral blood samples were drawn from 42 patients with SLE and 43 healthy blood donors, and the phosphorylation of ITK protein was studied in T cells using flow cytometry. In addition, serum levels of Th17/Treg related cytokines were studied with enzyme-linked immunosorbent assay (ELISA).
  
  
  RESULTS
  Percentages of CD4+pITK+T cells, CD8+pITK+T cells were higher in SLE patients compared with controls, and were positively related to disease activity, some clinical and laboratory parameters. Percentages of CD4+pITK+T cells, CD8+pITK+T cells were more prominent in active SLE patients compared with less active patients. Serum levels of Th17 and Treg related cytokines were higher in patients compared with controls. CD4+pITK+T cells were related to levels of IL-17, IL-21.
  
  
  CONCLUSIONS
  These data indicate that increased ITK expression could act as a disease activity marker and as a risk factor for involvement in SLE, but it still needs further study to confirm.
authors.affiliation: Department of Rheumatology and Immunology, West China Hospital, Sichuan University, 37 Guoxue Xiang, Chengdu, Sichuan 610041, PR China.
authors.forename: Wang-Dong
authors.initials: WD
authors.lastname: Xu
authors.affiliation: Department of Rheumatology and Immunology, West China Hospital, Sichuan University, 37 Guoxue Xiang, Chengdu, Sichuan 610041, PR China.
authors.forename: Lin-Chong
authors.initials: LC
authors.lastname: Su
authors.affiliation: Department of Rheumatology and Immunology, West China Hospital, Sichuan University, 37 Guoxue Xiang, Chengdu, Sichuan 610041, PR China.
authors.forename: Qi-Bing
authors.initials: QB
authors.lastname: Xie
authors.affiliation: Department of Rheumatology and Immunology, West China Hospital, Sichuan University, 37 Guoxue Xiang, Chengdu, Sichuan 610041, PR China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: Department of Rheumatology and Immunology, West China Hospital, Sichuan University, 37 Guoxue Xiang, Chengdu, Sichuan 610041, PR China. Electronic address: yi2006liu@163.com.
authors.forename: Yi
authors.initials: Y
authors.lastname: Liu
mesh_terms: D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D008180:Lupus Erythematosus, Systemic / Q000378:metabolism* / Q000473:pathology*; D011505:Protein-Tyrosine Kinases / Q000096:biosynthesis*; D013601:T-Lymphocytes / Q000378:metabolism*
chemical_list: D011505:Protein-Tyrosine Kinases; C080813:emt protein-tyrosine kinase
keywords: ITK; Lupus; Th17; Treg