title: Serum and knee synovial fluid matrix metalloproteinase-13 and tumor necrosis factor-alpha levels in patients with late-stage osteoarthritis.
abstract: OBJECTIVE
  The aim of this study was to compare serum and synovial fluid levels of matrix metalloproteinase-13 (MMP-13) and tumor necrosis factor-alpha (TNF-α) in 2 stages of osteoarthritis, and investigate their correlation with Western Ontario and McMaster Universities Arthritis Index (WOMAC) scores.
  
  
  METHODS
  Forty-two patients (mean age: 64±8.8 years) with grade 3 and grade 4 knee osteoarthritis according to Kellgren-Lawrence criteria were enrolled in the study and underwent total knee arthroplasty. TNF-α and MMP-13 levels were measured preoperatively from venous blood samples and intraoperatively from knee synovial fluid via enzyme-linked immunosorbent assay. Preoperative and 1-month postoperative knee functions were assessed by WOMAC.
  
  
  RESULTS
  Grade 4 synovial fluid MMP-13 (4.76±5.82 pg/ml) was elevated compared to grade 3 (3.95±4.45), whereas grade 3 serum MMP-13 (1.128±0.308 pg/ml) was found elevated compared to grade 4 (1.038±0.204) (p=0.438, p=0.430, respectively). Grade 4 serum TNF-α (0.253±0.277) was elevated compared to grade 3 (0.206±0.219), whereas grade 3 synovial fluid TNF-α (0.129±0.052) was elevated compared to grade 4 (0.118±0.014). Positive correlation was observed between synovial fluid MMP-13 levels and postoperative WOMAC scores. Mean serum TNF-α (0.226±0.246 pg/ml) was elevated compared to synovial levels (0.124±1.59), and synovial MMP-13 (4.31±1.24) was elevated compared to serum levels (1.089±1.519).
  
  
  CONCLUSIONS
  Despite the systemic increase in TNF-α levels concordant with osteoarthritis grade, MMP-13 levels are elevated via local manner, with a significant correlation with WOMAC scores.
authors.affiliation: Dr. Abdurrahman Yurtaslan Oncology Training and Research Hospital, Department of Orthopaedics and Traumatology, Ankara, Turkey.
authors.forename: Kenan
authors.initials: K
authors.lastname: Özler
authors.affiliation: Dr. Abdurrahman Yurtaslan Oncology Training and Research Hospital, Department of Orthopaedics and Traumatology, Ankara, Turkey.
authors.forename: Erdem
authors.initials: E
authors.lastname: Aktaş
authors.affiliation: Dr. Abdurrahman Yurtaslan Oncology Trainig and Research Hospital, Department of Biochemistry, Ankara, Turkey.
authors.forename: Çiğdem
authors.initials: Ç
authors.lastname: Atay
authors.affiliation: Fatih Sultan Mehmet Trainig and Research Hospital, Department of Orthopaedics and Traumatology, İstanbul, Turkey.
authors.forename: Barış
authors.initials: B
authors.lastname: Yılmaz
authors.affiliation: Dr. Abdurrahman Yurtaslan Oncology Training and Research Hospital, Department of Orthopaedics and Traumatology, Ankara, Turkey.
authors.forename: Murat
authors.initials: M
authors.lastname: Arıkan
authors.affiliation: Dr. Abdurrahman Yurtaslan Oncology Training and Research Hospital, Department of Orthopaedics and Traumatology, Ankara, Turkey.
authors.forename: Şafak
authors.initials: Ş
authors.lastname: Güngör
mesh_terms: D000368:Aged; D019645:Arthroplasty, Replacement, Knee; D005260:Female; D006801:Humans; D008297:Male; D053509:Matrix Metalloproteinase 13 / Q000097:blood / Q000737:chemistry*; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000378:metabolism*; D012699:Serology; D013582:Synovial Fluid / Q000737:chemistry*; D014409:Tumor Necrosis Factor-alpha / Q000097:blood / Q000737:chemistry*
chemical_list: D014409:Tumor Necrosis Factor-alpha; C507079:MMP13 protein, human; D053509:Matrix Metalloproteinase 13