title: Immunohistochemistry of normal human knee synovium: a quantitative study.
abstract: OBJECTIVE
  To describe the immunohistochemical characteristics of knee synovium from normal healthy subjects.
  
  
  METHODS
  12 healthy subjects underwent needle biopsy of knee synovium. Using antibodies directed against CD3, CD4, CD8, L26, Kp-1,and HLA-DR, detailed quantitative immunohistochemical analysis of various cell subpopulations was undertaken.
  
  
  RESULTS
  The mean (SD) age of the subjects was 37 (9) years (five male, seven female). All had a negative history for arthritis, no knee pain, and a totally normal joint examination except for the presence of retropatellar crepitus in five. For technical reasons staining for all immunohistochemical markers could not be achieved in all subjects. CD3+ T lymphocytes were seen in nine of 10 subjects, either diffusely or, more commonly, in perivascular areas. CD4+ cells were seen in synovium in three of seven subjects and CD8+ cells in six of eight subjects, in almost equal numbers (CD4:CD8, 1.1:1). L26+ B lymphocytes were not seen in any biopsy. Kp1+ macrophages were found in 10 of 10 subjects, predominantly in surface lining cells, and in small numbers in diffuse and perivascular locations. HLA-DR+ cells were seen in 10 of 10 subjects, predominantly in surface lining cells and diffusely, but a few were seen perivascularly.
  
  
  CONCLUSIONS
  Synovium from apparently normal subjects contained a wide range of different cell subpopulations but no B cells. The significance of these immune cells in normal synovium is unclear. A better understanding of their role in normal synovium may be important in analysing the transition to synovitis.
authors.affiliation: Minneapolis VA Medical Center 111R, One Veteran's drive, Minneapolis, MN 55417, USA. singh046@umn.edu
authors.forename: J A
authors.initials: JA
authors.lastname: Singh
authors.forename: T
authors.initials: T
authors.lastname: Arayssi
authors.forename: P
authors.initials: P
authors.lastname: Duray
authors.forename: H R
authors.initials: HR
authors.lastname: Schumacher
mesh_terms: D000328:Adult; D015703:Antigens, CD / Q000032:analysis*; D015214:Antigens, Differentiation, Myelomonocytic / Q000032:analysis; D017252:CD3 Complex / Q000032:analysis; D015704:CD4 Antigens / Q000032:analysis; D016827:CD8 Antigens / Q000032:analysis; D002452:Cell Count; D005260:Female; D006684:HLA-DR Antigens / Q000032:analysis; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D007719:Knee Joint; D008264:Macrophages / Q000276:immunology; D008297:Male; D008875:Middle Aged; D013583:Synovial Membrane / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology*; D000097382:CD68 Molecule
chemical_list: D015703:Antigens, CD; D015214:Antigens, Differentiation, Myelomonocytic; D017252:CD3 Complex; D015704:CD4 Antigens; D016827:CD8 Antigens; D006684:HLA-DR Antigens; C067980:CD68 antigen, human; D000097382:CD68 Molecule