title: Multiparameter phenotyping of T-cell subsets in distinct subgroups of patients with pulmonary sarcoidosis.
abstract: OBJECTIVE
  Sarcoidosis is an inflammatory disorder in which elevated numbers of activated T cells are found in the lung. HLA-DRB1*0301(pos) (DR3(pos) ) patients are characterized by good prognosis and an accumulation of lung CD4(pos) T cells expressing the T-cell receptor (TCR) gene segment AV2S3. Our aim was to phenotype lung and blood T-cell subsets in distinct patient groups to better understand the function of these subsets.
  
  
  METHODS
  Bronchoalveolar lavage (BAL) fluid and whole blood were obtained from a total of 22 patients with sarcoidosis, of whom 11 were DR3(pos) . Using eight-colour flow cytometry, phenotyping of T cells was performed with regard to CD3, CD4, CD8, CD25, CD27, CD45RO, CD57, CD69, CD103, FOXP3 and TCR AV2S3.
  
  
  RESULTS
  DR3(pos) patients had fewer FOXP3(pos) (regulatory) CD45RO(pos) (memory) BAL T cells than DR3(neg) patients. Fewer AV2S3(pos) T cells were FOXP3(pos) , compared with AV2S3(neg) cells, thus indicating an effector function and not a regulatory role for this subset. Fewer lung and blood AV2S3(pos) T cells were CD25(pos)  CD27(pos) , and more were CD25(neg)  CD27(neg) and CD69(pos) , compared with AV2S3(neg) T cells, indicating a higher degree of differentiation and activation in both compartments.
  
  
  CONCLUSIONS
  Our main findings were a lower proportion of regulatory T cells in DR3(pos) patients, together with the accumulation of AV2S3(pos) T cells with a highly activated effector phenotype in the lungs of these patients. This may provide for efficient elimination of a harmful antigen in DR3(pos) patients and could thus help to explain the spontaneous recovery typically seen in these patients.
authors.affiliation: Respiratory Medicine Unit, Department of Medicine Solna, Karolinska Institutet, Stockholm, Sweden. Maria.Wiken@ki.se
authors.forename: M
authors.initials: M
authors.lastname: Wikén
authors.forename: J
authors.initials: J
authors.lastname: Grunewald
authors.forename: A
authors.initials: A
authors.lastname: Eklund
authors.forename: J
authors.initials: J
authors.lastname: Wahlström
mesh_terms: D000328:Adult; D000368:Aged; D015496:CD4-Positive T-Lymphocytes; D018414:CD8-Positive T-Lymphocytes; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010641:Phenotype; D017565:Sarcoidosis, Pulmonary / Q000276:immunology*; D016176:T-Lymphocyte Subsets / Q000145:classification*; D055815:Young Adult