title: Abnormal expression pattern of the IL-2 receptor β-chain on CD4+ T cells in ANCA-associated vasculitis.
abstract: OBJECTIVE
  ANCA-associated vasculitis (AAV) is a small-vessel vasculitis of autoimmune origin. In addition to autoantibodies, T cells have a pivotal pathophysiological role in this disease. T-cell homeostasis and immune tolerance critically depend on IL-2 and its receptor expressed by T cells. In this study, we investigated the IL-2 receptor (IL-2r) expression on CD4(+) T cells in AAV.
  
  
  METHODS
  Thirty patients with AAV and 15 age-matched healthy controls (HC) were enrolled. T cells from peripheral blood were analysed by flow cytometry for expression of the IL-2r α - and β-chain.
  
  
  RESULTS
  The IL-2r α-chain was overexpressed in AAV as compared to HC (36 ± 16% versus 20 ± 9%, P < 0.005). The IL-2r-β-chain expression was significantly reduced on CD25(+) CD4(+) T-cells and CD4(+)CD25(+)FoxP3(pos) regulatory T-cells (Tregs; AAV versus HC: 48 ± 14% versus 62 ± 9%, P = 0.002 and 38 ± 18% versus 68 ± 5%, P = 0.002). Low β -chain expression in AAV was associated with relapsing disease and systemic vasculitis with renal involvement.
  
  
  CONCLUSIONS
  The IL-2r expression pattern is abnormal in AAV. To our knowledge, we are the first to show that the β -chain expression is drastically diminished on T cells in AAV and related to a less favorable disease course. Given the indispensable function of the β -chain in IL-2 signaling of T cells, diminished expression may contribute to disturbed immune homeostasis in AAV.
authors.affiliation: Department of Nephrology, University Hospital Essen, University Duisburg-Essen, Hufelandstraße 55, 45122 Essen, Germany.
authors.forename: Benjamin
authors.identifier: 0000-0002-5115-6799
authors.initials: B
authors.lastname: Wilde
authors.affiliation: Department of Pediatrics II, Pediatric Nephrology, Gastroenterology, Endocrinology, and Transplant Medicine, Children's Hospital Essen, University Duisburg-Essen, 45122 Essen, Germany.
authors.forename: André
authors.initials: A
authors.lastname: Hoerning
authors.affiliation: Department of Nephrology, University Hospital Essen, University Duisburg-Essen, Hufelandstraße 55, 45122 Essen, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Kribben
authors.affiliation: Department of Nephrology, University Hospital Essen, University Duisburg-Essen, Hufelandstraße 55, 45122 Essen, Germany.
authors.forename: Oliver
authors.initials: O
authors.lastname: Witzke
authors.affiliation: Department of Nephrology, University Hospital Essen, University Duisburg-Essen, Hufelandstraße 55, 45122 Essen, Germany.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Dolff
mesh_terms: D000328:Adult; D000368:Aged; D056648:Anti-Neutrophil Cytoplasmic Antibody-Associated Vasculitis / Q000378:metabolism*; D015496:CD4-Positive T-Lymphocytes / Q000378:metabolism*; D016022:Case-Control Studies; D005260:Female; D015870:Gene Expression; D006801:Humans; D053645:Interleukin-2 Receptor alpha Subunit / Q000378:metabolism; D053646:Interleukin-2 Receptor beta Subunit / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies
chemical_list: D053645:Interleukin-2 Receptor alpha Subunit; D053646:Interleukin-2 Receptor beta Subunit