title: Increased interleukin-23 is associated with increased disease activity in patients with rheumatoid arthritis.
abstract: BACKGROUND
  Interleukin-23 (IL-23) is a pro-inflammatory cytokine that is thought to be central to the development of autoimmune diseases. This study was conducted to determine whether or not the serum concentration of IL-23 is elevated in patients with rheumatoid arthritis (RA), and to determine the relationship between the IL-23 level and disease activity in RA patients.
  
  
  METHODS
  Serum samples were obtained from 59 patients with RA and 30 healthy controls. The clinical parameters of disease activity were determined, including the 28-joint disease activity score (DAS28), C-reactive protein (CRP), rheumatoid factor (RF) levels, and the degree of bony erosions based on X-rays. The levels of IL-23 and IL-17 were determined by enzyme-linked immunosorbent assay (ELISA). The correlations between the serum levels of IL-23 and disease activity parameters of patients with RA were determined.
  
  
  RESULTS
  The serum IL-23 level was significantly elevated in patients with RA compared to healthy controls. The serum IL-23 levels in the RA patients correlated with IL-17 and CRP levels, and the DAS28. The levels of IL-23 based on X-ray classification phase I, II, III, and IV were gradually elevated in RA patients.
  
  
  CONCLUSIONS
  The levels of serum IL-23 in RA patients were higher than in healthy controls. Thus, elevated serum IL-23 levels may be useful markers to detect active RA. In addition, IL-23 is involved in disease progression and bony erosions in patients with RA.
authors.affiliation: Department of Rheumatism, Shengjing Hospital, China Medical University, Shenyang, Liaoning 110004, China.
authors.forename: Ying-ying
authors.initials: YY
authors.lastname: Guo
authors.forename: Nai-zhi
authors.initials: NZ
authors.lastname: Wang
authors.forename: Shuai
authors.initials: S
authors.lastname: Zhao
authors.forename: Lin-xin
authors.initials: LX
authors.lastname: Hou
authors.forename: Yan-bing
authors.initials: YB
authors.lastname: Xu
authors.forename: Ning
authors.initials: N
authors.lastname: Zhang
mesh_terms: D000328:Adult; D000368:Aged; D001172:Arthritis, Rheumatoid / Q000097:blood* / Q000473:pathology*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D053759:Interleukin-23 / Q000097:blood*; D008297:Male; D008875:Middle Aged
chemical_list: D053759:Interleukin-23