title: Levels of chemerin and interleukin 8 in the synovial fluid of patients with inflammatory arthritides and osteoarthritis.
abstract: OBJECTIVE
  Chemerin and interleukin (IL)-8 are pro-inflammatory mediators whose role in joint inflammation and cartilage degradation has been demonstrated in in-vitro findings. Studies on their presence in synovial fluid (SF) samples may offer further information on their pathogenic role. The aim of this study was to investigate SF chemerin and IL-8 levels in patients with different joint diseases.
  
  
  METHODS
  37 patients were enrolled: 18 with rheumatoid arthritis (RA), 8 with psoriatic arthritis (PsA) and 11 with osteoarthritis (OA). 41 SF samples were obtained by arthrocentesis in case of knee synovitis. Serum samples were obtained from 13 patients (4 with RA, 6 with PsA and 3 with OA) at the time of arthrocentesis. Chemerin, IL-8, TNF-α and IL-6 levels were measured using commercially available ELISA kits. Immunohistochemical analysis of synovial RA specimens was also performed.
  
  
  RESULTS
  No difference in chemerin SF levels emerged between patients with immune-mediated inflammatory arthritides and those with OA (p=0.0656), while subjects with inflammatory arthritis displayed significantly higher levels of SF IL-8 compared to OA (p=0.0020). No significant difference emerged across the three conditions in the serum levels of both chemerin and IL-8. IL-8 strongly correlated with inflammatory markers as ESR, CRP, IL-6 and TNF-α.
  
  
  CONCLUSIONS
  We observed similar chemerin SF and serum levels in the three conditions. Although flawed by some limitations, our findings support the emerging concept of OA as an inflammatory disorder. However the increased IL-8 levels we described in patients with inflammatory arthritis suggest a selective involvement of this pro-inflammatory and angiogenic cytokine in these conditions.
authors: Division of Rheumatology, Istituto G. Pini, Milan, Italy and Doctorate Course in Genetics, Oncology and Clinical Medicine, University of Siena, Siena, Italy. eli.valcamonica@libero.it.
authors: E
authors: E
authors: Valcamonica
authors: C B
authors: CB
authors: Chighizola
authors: D
authors: D
authors: Comi
authors: O
authors: O
authors: De Lucia
authors: L
authors: L
authors: Pisoni
authors: A
authors: A
authors: Murgo
authors: V
authors: V
authors: Salvi
authors: S
authors: S
authors: Sozzani
authors: P L
authors: PL
authors: Meroni
mesh_terms: D000368:Aged; D015535:Arthritis, Psoriatic / Q000175:diagnosis / Q000378:metabolism* / Q000503:physiopathology; D001172:Arthritis, Rheumatoid / Q000175:diagnosis / Q000378:metabolism* / Q000503:physiopathology; D015415:Biomarkers / Q000378:metabolism; D001799:Blood Sedimentation; D002097:C-Reactive Protein / Q000032:analysis; D002358:Cartilage, Articular / Q000378:metabolism / Q000503:physiopathology; D018925:Chemokines / Q000032:analysis*; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins; D016209:Interleukin-8 / Q000032:analysis*; D007596:Joints / Q000378:metabolism / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D010003:Osteoarthritis / Q000175:diagnosis / Q000378:metabolism* / Q000503:physiopathology; D013223:Statistics as Topic; D013582:Synovial Fluid / Q000737:chemistry / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha / Q000032:analysis
chemical_list: D015415:Biomarkers; D018925:Chemokines; D036341:Intercellular Signaling Peptides and Proteins; D016209:Interleukin-8; C478630:RARRES2 protein, human; D014409:Tumor Necrosis Factor-alpha; D002097:C-Reactive Protein