title: Lymphocyte subpopulations in patients with primary fibromyalgia.
abstract: OBJECTIVE
  Fibromyalgia (FM) is a clinical entity of unknown etiology frequently diagnosed in rheumatology. The potential involvement of the immune system in its pathogenesis has been suggested. Studies of abnormal T cell subpopulations often have been inconclusive. We attempted to clear this point by comparing lymphocyte subpopulations, including some of the newer activation markers, in patients with FM and healthy controls.
  
  
  METHODS
  Sixty-five patients with FM and 56 healthy controls were studied. Flow cytometry was used as a quantification technique to measure lymphocyte subpopulations, CD3 (T cells), CD19 (B cells), CD16 (natural killer cells), CD4 (T helper/inducer cells), CD8 (T cytotoxic/suppressor cell), CD25 (interleukin 2 receptor), CD69 (activation inducer molecule marker), CD71 (transferrin receptor) and CD54 (ICAM-1); CD4/CD8 ratios were also estimated.
  
  
  RESULTS
  The number of T cells expressing activation markers CD69 and CD25 was decreased in patients with FM; the other subpopulations were similar in patients and controls.
  
  
  CONCLUSIONS
  Our results suggest a defect in T cell activation in patients with FM.
authors.affiliation: Rheumatology Service, Hospital Universitario Virgen Del Rocio, Sevilla, Spain.
authors.forename: W
authors.initials: W
authors.lastname: Hernanz
authors.forename: A
authors.initials: A
authors.lastname: Valenzuela
authors.forename: J
authors.initials: J
authors.lastname: Quijada
authors.forename: A
authors.initials: A
authors.lastname: Garcia
authors.forename: J L
authors.initials: JL
authors.lastname: de la Iglesia
authors.forename: A
authors.initials: A
authors.lastname: Gutierrez
authors.forename: J
authors.initials: J
authors.lastname: Povedano
authors.forename: I
authors.initials: I
authors.lastname: Moreno
authors.forename: B
authors.initials: B
authors.lastname: Sanchez
mesh_terms: D000293:Adolescent; D000328:Adult; D015703:Antigens, CD / Q000032:analysis; D000944:Antigens, Differentiation, B-Lymphocyte / Q000032:analysis; D000945:Antigens, Differentiation, T-Lymphocyte / Q000032:analysis; D001402:B-Lymphocytes / Q000276:immunology*; D016516:CD4-CD8 Ratio; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D005260:Female; D005356:Fibromyalgia / Q000276:immunology*; D005434:Flow Cytometry; D006801:Humans; D018799:Intercellular Adhesion Molecule-1 / Q000032:analysis; D007694:Killer Cells, Natural / Q000276:immunology; D037181:Lectins, C-Type; D018655:Lymphocyte Count; D008297:Male; D008875:Middle Aged; D015375:Receptors, Interleukin-2 / Q000032:analysis; D011990:Receptors, Transferrin; D016176:T-Lymphocyte Subsets / Q000276:immunology*; D000099192:CD69 Antigens
chemical_list: D015703:Antigens, CD; D000944:Antigens, Differentiation, B-Lymphocyte; D000945:Antigens, Differentiation, T-Lymphocyte; D018799:Intercellular Adhesion Molecule-1; D037181:Lectins, C-Type; D015375:Receptors, Interleukin-2; D011990:Receptors, Transferrin; D000099192:CD69 Antigens; C068126:CD71 antigen