title: CD4+CD28-T cells are expanded in sarcoidosis.
abstract: OBJECTIVE
  A subset of CD4+ lymphocytes lacking CD28, an important costimulatory molecule, is increased in certain inflammatory conditions. However, studies have not directly studied CD4+CD28-lymphocytes in patients with chronic sarcoidosis. The aim of this study was to further characterize the CD4+CD28-T cell population in patients with sarcoidosis, particularly those with active disease.
  
  
  METHODS
  Seventeen patients with chronic sarcoidosis and 15 blood donors were studied. Bronchoalveolar lavage cells were available for paired analysis in seven sarcoid patients. In 4 sarcoid patients, adequate sample was available for intracellular cytokine analysis by flow cytometry. IFN-gamma production in plasma and BAL was determined by ELISA and cytometric bead array analysis and compared to previously studied controls.
  
  
  RESULTS
  Peripheral blood from patients with sarcoidosis had a significantly higher proportion of CD4+CD28- cells compared with healthy donors. A higher percentage of CD4+CD28- cells was evident in the BAL relative to peripheral blood in patients with active sarcoid. IFN-gamma levels were greater both in the plasma and concentrated BAL fluid of sarcoid subjects compared to controls. The majority of IFN-gamma and TNF-alpha producing lymphocytes were CD28+ in both healthy blood donors and sarcoid subjects.
  
  
  CONCLUSIONS
  CD4+CD28- cells are increased in the peripheral blood and lungs of patients with sarcoidosis requiring treatment. These cells may contribute to the inflammatory response; however, they are not major contributors of IFN-gamma or TNF-alpha.
authors.affiliation: Indiana University School of Medicine, Indianapolis, Indiana, USA.
authors.forename: Scott D
authors.initials: SD
authors.lastname: Roberts
authors.forename: Lisa L
authors.initials: LL
authors.lastname: Kohli
authors.forename: Karen L
authors.initials: KL
authors.lastname: Wood
authors.forename: David S
authors.initials: DS
authors.lastname: Wilkes
authors.forename: Kenneth S
authors.initials: KS
authors.lastname: Knox
mesh_terms: D000328:Adult; D001992:Bronchoalveolar Lavage Fluid / Q000166:cytology; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D016022:Case-Control Studies; D002908:Chronic Disease; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D007371:Interferon-gamma / Q000096:biosynthesis; D008297:Male; D008875:Middle Aged; D012507:Sarcoidosis / Q000276:immunology*; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis
chemical_list: D014409:Tumor Necrosis Factor-alpha; D007371:Interferon-gamma