title: Association of plasma and synovial fluid interferon-γ inducible protein-10 with radiographic severity in knee osteoarthritis.
abstract: OBJECTIVE
  The objective of this study was to investigate interferon-γ inducible protein-10 (IP-10) concentrations in plasma and synovial fluid of patients with knee osteoarthritis (OA) and to analyze their relationship with disease severity.
  
  
  METHODS
  Forty OA patients and 15 healthy controls were enrolled in this study. OA grading was performed according to the Kellgren-Lawrence criteria. IP-10 levels in plasma and synovial fluid were assessed using enzyme-linked immunosorbent assay.
  
  
  RESULTS
  Plasma IP-10 levels in the knee OA patients were significantly lower than those of controls (P=0.006). IP-10 levels in plasma were markedly higher with regard to paired synovial fluid (P<0.001). Furthermore, IP-10 concentrations in plasma and synovial fluid displayed significant inverse correlation with radiographic severity (r=-0.713, P<0.001 and r=-0.561, P<0.001, respectively). Subsequent analysis revealed that plasma IP-10 levels were positively correlated with synovial fluid IP-10 levels (r=0.424, P=0.006).
  
  
  CONCLUSIONS
  IP-10 levels in both plasma and synovial fluid were inversely associated with the severity of knee OA. Accordingly, IP-10 could serve as a biomarker for determining disease severity and might play a possible role in the pathophysiology of osteoarthritis.
authors.affiliation: Department of Biochemistry, Inter-Department Program of BioMedical Sciences, Faculty of Medicine, Chulalongkorn University, King Chulalongkorn Memorial Hospital, Thai Red Cross Society, Bangkok 10330, Thailand.
authors.forename: Natthaphon
authors.initials: N
authors.lastname: Saetan
authors.forename: Sittisak
authors.initials: S
authors.lastname: Honsawek
authors.forename: Aree
authors.initials: A
authors.lastname: Tanavalee
authors.forename: Saran
authors.initials: S
authors.lastname: Tantavisut
authors.forename: Pongsak
authors.initials: P
authors.lastname: Yuktanandana
authors.forename: Vinai
authors.initials: V
authors.lastname: Parkpian
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D016022:Case-Control Studies; D054357:Chemokine CXCL10 / Q000097:blood / Q000378:metabolism*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000097:blood* / Q000000981:diagnostic imaging* / Q000503:physiopathology; D011859:Radiography; D012720:Severity of Illness Index; D013582:Synovial Fluid / Q000378:metabolism*
chemical_list: D015415:Biomarkers; C114753:CXCL10 protein, human; D054357:Chemokine CXCL10