title: Increased levels of interleukin-33 associated with bone erosion and interstitial lung diseases in patients with rheumatoid arthritis.
abstract: OBJECTIVE
  To analyze the levels of interleukin-33 (IL-33) in the serum of patients with rheumatoid arthritis (RA) and investigated its possible pathophysiological importance.
  
  
  METHODS
  The concentrations of IL-33 and matrix metalloproteinase (MMP)-3 were measured by enzyme-linked immunosorbent assay (ELISA) in the serum of 121 patients with RA and 47 controls. Erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), rheumatoid factor (RF), and anticyclic citrullinated peptide (anti-CCP) were measured by standard laboratory techniques. Interstitial lung disease (ILD) was identified on high-resolution computed tomography. Disease activity in RA was scored with the Disease Activity Score 28 based on C-reactive protein levels (DAS28-CRP). The bone erosion of RA patients was evaluated by modified Sharp Score (MSS).
  
  
  RESULTS
  Serum levels of IL-33 and MMP-3 were significantly higher in RA patients than in healthy controls. Significant higher levels of IL-33 were found in CCP-positive group and in patients with ILD. There was positive correlation between the levels of IL-33 and RF. Moreover, there was also positive correlation between IL-33 and MMP-3, MSS.
  
  
  CONCLUSIONS
  These data support the hypothesis that IL-33 may be involved in RA pathogenesis and it may partly contribute to the bone erosion in RA patients.
authors.affiliation: Department of Rheumatology, 1st Affiliated Hospital of China Medical University, Shen Yang 110001, China.
authors.forename: Zhu
authors.initials: Z
authors.lastname: Xiangyang
authors.forename: Yao
authors.initials: Y
authors.lastname: Lutian
authors.forename: Zhao
authors.initials: Z
authors.lastname: Lin
authors.forename: Xia
authors.initials: X
authors.lastname: Liping
authors.forename: Shen
authors.initials: S
authors.lastname: Hui
authors.forename: Lu
authors.initials: L
authors.lastname: Jing
mesh_terms: D000328:Adult; D000368:Aged; D001172:Arthritis, Rheumatoid / Q000097:blood* / Q000150:complications / Q000473:pathology; D001323:Autoantibodies / Q000097:blood; D001862:Bone Resorption / Q000209:etiology / Q000473:pathology; D002097:C-Reactive Protein / Q000032:analysis; D005260:Female; D006801:Humans; D000067596:Interleukin-33; D007378:Interleukins / Q000097:blood*; D017563:Lung Diseases, Interstitial / Q000097:blood*; D008297:Male; D019278:Matrix Metalloproteinase 3 / Q000097:blood; D008875:Middle Aged; D010456:Peptides, Cyclic / Q000097:blood / Q000276:immunology; D012217:Rheumatoid Factor / Q000097:blood
chemical_list: D001323:Autoantibodies; C506536:IL33 protein, human; D000067596:Interleukin-33; D007378:Interleukins; D010456:Peptides, Cyclic; C487763:cyclic citrullinated peptide; D002097:C-Reactive Protein; D012217:Rheumatoid Factor; D019278:Matrix Metalloproteinase 3