title: Cytokine levels in serum and synovial fluid of patients with juvenile rheumatoid arthritis.
abstract: OBJECTIVE
  Cytokines play an important role in mediating inflammation and in regulating the immune response of many rheumatological diseases. In patients with juvenile rheumatoid arthritis (JRA), levels of 6 cytokines, interleukin 1 alpha (IL-1 alpha), IL-1 beta (IL-1 beta), IL-2, IL-2 receptor (IL-2R), IL-6, and tumor necrosis factor alpha (TNF-alpha) were measured in serum and synovial fluid (SF) in an effort to evaluate their significance.
  
  
  METHODS
  Serum concentrations of the 6 cytokines were measured in 62 patients with JRA including 22 pauciarticular onset, 26 polyarticular onset, and 14 systemic onset patients, and 29 disease and healthy controls using enzyme-linked immunoabsorbent assays (ELISA). Seventeen SF from patients with JRA were examined for cytokine levels.
  
  
  RESULTS
  Elevated serum levels of IL-2R were found in patients with systemic onset and elevated IL-2 levels in pauciarticular and polyarticular onset JRA as compared to controls. Pauciarticular and polyarticular onset patients also had elevated IL-1 alpha and IL-6 levels. There were no statistical differences found between the groups for TNF-alpha and IL-1 beta. SF revealed elevated levels of IL-1 beta, IL-2R, and IL-6; however, correlation was noted between serum and SF levels only for IL-1 alpha, not for the other cytokines. Mean serum levels of IL-2R in all onset types with active disease and IL-6 levels in active polyarticular and pauciarticular onset were elevated when compared with mean inactive levels.
  
  
  CONCLUSIONS
  Our studies indicate that (1) IL-1 alpha, IL-2, IL-2R, and IL-6 levels are increased in serum of patients with JRA with different onset types; (2) elevated levels of IL-1 beta, IL-2R, and IL-6 are found in their SF compared to serum levels; (3) a correlation exists between serum and SF levels only for IL-1 alpha; (4) mean IL-2R levels are elevated with active disease in all onset types and mean IL-6 levels with active polyarticular and pauciarticular onset disease are elevated compared to mean levels of inactive patients; and (5) cytokines may thus play a role as inflammatory mediators in JRA.
authors.affiliation: Department of Internal Medicine, Saint Louis University Health Sciences Center, MO 63104.
authors.forename: K L
authors.initials: KL
authors.lastname: Madson
authors.forename: T L
authors.initials: TL
authors.lastname: Moore
authors.forename: J M
authors.initials: JM
authors.lastname: Lawrence
authors.forename: T G
authors.initials: TG
authors.lastname: Osborn
mesh_terms: D000293:Adolescent; D001171:Arthritis, Juvenile / Q000097:blood / Q000378:metabolism*; D002648:Child; D002675:Child, Preschool; D016207:Cytokines / Q000097:blood / Q000378:metabolism*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007378:Interleukins / Q000097:blood / Q000378:metabolism; D008297:Male; D015375:Receptors, Interleukin-2 / Q000378:metabolism; D013582:Synovial Fluid / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: D016207:Cytokines; D007378:Interleukins; D015375:Receptors, Interleukin-2; D014409:Tumor Necrosis Factor-alpha