title: Elevated serum level of IL-33 and sST2 in patients with ankylosing spondylitis: associated with disease activity and vascular endothelial growth factor.
abstract: OBJECTIVE
  Interleukin (IL)-33 is a cytokine belonging to the IL-1 family and was recently identified as a ligand for ST2, which belongs to the IL-1 receptor (IL-1R) family. In this study, we aimed to investigate the possible pathophysiological role of IL-33/sST2 in ankylosing spondylitis (AS).
  
  
  METHODS
  The levels of IL-33/sST2 and vascular endothelial growth factor in serum samples of 140 patients with AS and 90 controls were measured by enzyme-linked immunosorbent assay. Erythrocyte sedimentation rate, C-reactive protein level, and human leukocyte antigen B27 were measured by standard laboratory techniques. Disease activity in AS was measured by the Bath Ankylosing Spondylitis Disease Activity Index. Hip involvement, peripheral arthritis, and eye involvement were also recorded.
  
  
  RESULTS
  The serum levels of IL-33/sST2 were remarkably higher in the patients with AS than the healthy groups and significantly correlated with vascular endothelial growth factor and the Bath Ankylosing Spondylitis Disease Activity Index. The sST2 levels correlated with erythrocyte sedimentation rate, C-reactive protein, platelet, and human leukocyte antigen B27. Elevated levels of IL-33/sST2 were detected in the patients with peripheral arthritis, and sST2 were detected to be increased in the patients with hip involvement. By contrast, levels of IL-33 but not sST2 increased in the patients with eye involvement.
  
  
  CONCLUSIONS
  IL-33/sST2 may regulate the immunological or inflammatory process of AS.
authors.affiliation: Department of Rheumatology, The First Affiliated Hospital of China Medical University, Shenyang, China.
authors.forename: Xiao-lin
authors.initials: XL
authors.lastname: Li
authors.forename: Tian-tian
authors.initials: TT
authors.lastname: Lin
authors.forename: Chen-yue
authors.initials: CY
authors.lastname: Qi
authors.forename: Lin
authors.initials: L
authors.lastname: Yuan
authors.forename: Li-ping
authors.initials: LP
authors.lastname: Xia
authors.forename: Hui
authors.initials: H
authors.lastname: Shen
authors.forename: Jing
authors.initials: J
authors.lastname: Lu
mesh_terms: D000328:Adult; D001168:Arthritis / Q000097:blood / Q000150:complications; D015415:Biomarkers / Q000097:blood; D016022:Case-Control Studies; D005123:Eye / Q000473:pathology; D005260:Female; D015796:HLA-B27 Antigen / Q000276:immunology; D006615:Hip / Q000473:pathology; D006801:Humans; D007249:Inflammation / Q000097:blood / Q000473:pathology; D000072179:Interleukin-1 Receptor-Like 1 Protein; D000067596:Interleukin-33; D007378:Interleukins / Q000097:blood*; D008297:Male; D011956:Receptors, Cell Surface / Q000097:blood*; D012995:Solubility; D013167:Spondylitis, Ankylosing / Q000097:blood* / Q000150:complications; D014409:Tumor Necrosis Factor-alpha / Q000037:antagonists & inhibitors / Q000378:metabolism; D042461:Vascular Endothelial Growth Factor A / Q000097:blood*
chemical_list: D015415:Biomarkers; D015796:HLA-B27 Antigen; C079241:IL1RL1 protein, human; C506536:IL33 protein, human; D000072179:Interleukin-1 Receptor-Like 1 Protein; D000067596:Interleukin-33; D007378:Interleukins; D011956:Receptors, Cell Surface; D014409:Tumor Necrosis Factor-alpha; C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A