title: Elevated circulating interleukin-7 levels in patients with systemic juvenile rheumatoid arthritis.
abstract: OBJECTIVE
  Since interleukin-7 (IL-7) has been shown to induce monocyte production of IL-1, IL-6, IL-8, and tumor necrosis factor-alpha, we investigated plasma and synovial fluid levels of IL-7 in patients with juvenile rheumatoid arthritis (JRA).
  
  
  METHODS
  IL-7 levels were measured using an ELISA in 60 patients with JRA and in 25 patients with other rheumatic disorders (ORD).
  
  
  RESULTS
  In patients with systemic JRA, but not in patients with polyarticular or pauciarticular JRA or with ORD, plasma IL-7 levels were significantly higher (p < 0.0001) than those of healthy controls. IL-7 was undetected in all synovial fluid tested. Among patients with systemic JRA, those with persistent systemic symptoms had IL-7 levels significantly higher (p < 0.01) than those of patients in which systemic symptoms subsided.
  
  
  CONCLUSIONS
  Plasma IL-7 levels are elevated in patients with systemic JRA and are associated with the presence and severity of systemic symptoms.
mesh_terms: D000293:Adolescent; D001171:Arthritis, Juvenile / Q000097:blood* / Q000378:metabolism; D002648:Child; D002675:Child, Preschool; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D015850:Interleukin-6 / Q000097:blood; D015851:Interleukin-7 / Q000032:analysis / Q000097:blood*; D012216:Rheumatic Diseases / Q000097:blood / Q000378:metabolism; D013582:Synovial Fluid / Q000737:chemistry
chemical_list: D015850:Interleukin-6; D015851:Interleukin-7