title: Comparison of adenosine deaminase levels in serum and synovial fluid between patients with rheumatoid arthritis and osteoarthritis.
abstract: OBJECTIVE
  Adenosine deaminase (ADA) is an enzyme being involved in purine metabolism and plays a significant role in the immune system. The aim of this study was to investigate the use of adenosine deaminase levels in differentiating between rheumatoid arthritis and osteoarthritis.
  
  
  METHODS
  Thirty patients with rheumatoid arthritis and 30 osteoarthritis patients enrolled the study. They were matched in sex and age. Using the ROC curve, we determined the optimal serum and synovial cutoff for rheumatoid effusion.
  
  
  RESULTS
  The results showed a statistically significant difference between ADA levels in joint effusion and serum of patients with rheumatoid arthritis and osteoarthritis (p<0.001). Synovial fluid cutoff value for diagnosing rheumatoid arthritis was 20 with a sensitivity of 90% and specificity of 80% and the serum cutoff value was 15 with a sensitivity of 93% and specificity of 53.3%. Area under ROC curve for synovial ADA, ESR and CRP co-linearity was 99%.
  
  
  CONCLUSIONS
  We concluded that synovial total ADA assay can be a sensitive and specific test, being suitable for rapid diagnosis of rheumatoid effusions.
authors.forename: Zahra
authors.initials: Z
authors.lastname: Zakeri
authors.forename: Shahrokh
authors.initials: S
authors.lastname: Izadi
authors.forename: Abassali
authors.initials: A
authors.lastname: Niazi
authors.forename: Zohre
authors.initials: Z
authors.lastname: Bari
authors.forename: Soodabeh
authors.initials: S
authors.lastname: Zendeboodi
authors.forename: Mansoor
authors.initials: M
authors.lastname: Shakiba
authors.forename: Mohammadali
authors.initials: M
authors.lastname: Mashhadi
authors.forename: Behzad
authors.initials: B
authors.lastname: Narouie
authors.forename: Mohammad
authors.initials: M
authors.lastname: Ghasemi-Rad