title: Anti-cyclic citrullinated peptide antibodies and paraoxonase-1 polymorphism in rheumatoid arthritis.
abstract: BACKGROUND
  Rheumatoid arthritis (RA) is the most common chronic inflammatory joint disease, with a worldwide prevalence of 0.5% to 1%. Anti-cyclic citrullinated peptide antibody (anti-CCP-2 Ab) is a marker of choice for diagnosing early and late RA. Anti-oxidant enzymes activity decreases in RA patients. Till now, the relationship between the rheumatoid factor (RF) and anti-CCP-2 Ab, anti-oxidant activity and polymorphism of paraoxenase-1 (PON-1) 192 Q/R in patients with RA has not been investigated. In this study, we aimed to determine the serum level of RF and anti-CCP-2 Ab, PON-1 activity and 192 Q/R polymorphism and arylesterase (ARE) activity in patients with RA. Also, we studied RA markers in different genotypes of PON-1 of RA patients.
  
  
  METHODS
  A total of 120 RA patients and 90 healthy persons were subjected to full clinical examinations and routine laboratory tests. PON-1 and ARE activities were determined using an enzymatic spectrophotometric method. PON-1 192 gene polymorphism was determined using polymerase chain reaction based restriction fragment analysis. RF was measured by immunoturbidimetry method and anti-CCP-2 Ab was assayed by enzyme-linked immunosorbent assay (ELISA). Statistical analysis was performed using SPSS for windows 20.0.
  
  
  RESULTS
  The sensitivity and specificity of anti-CCP-2 Ab for the diagnosis of RA were 76.2% and 100% respectively. PON-1 and ARE activities were statistically lower (P <0.001) in the RA group compared to the control group. A negative correlation between RF and anti-CCP-2 Ab levels and PON-1 and ARE activities was found. No significant difference in the genotype distribution between RA patients and healthy persons was detected. RF and anti-CCP-2 Ab levels were higher in RA patients carried RR genotype than in those carried QQ genotype.
  
  
  CONCLUSIONS
  High RF and anti-CCP-2 antibody serum levels were found to be associated with decreased PON-1 and ARE activities with no correlation between PON-1 polymorphism and serum levels of RF and anti-CCP-2 Ab in patients with RA. These results may indicate an implication between antioxidant enzymes activity and serum levels of RF and anti-CCP-2 Ab.
authors.forename: Hassan
authors.initials: H
authors.lastname: El-Banna
authors.affiliation: Department of Medical Microbiology and Parasitology, Faculty of Medicine, King Abdulaziz University, Jeddah, Kingdom of Saudi Arabia. afatani@kau.edu.sa.
authors.forename: Asif
authors.initials: A
authors.lastname: Jiman-Fatani
mesh_terms: D000293:Adolescent; D000328:Adult; D001172:Arthritis, Rheumatoid / Q000097:blood* / Q000175:diagnosis / Q000235:genetics*; D043303:Aryldialkylphosphatase / Q000235:genetics*; D001323:Autoantibodies / Q000097:blood*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010456:Peptides, Cyclic / Q000097:blood*; D011110:Polymorphism, Genetic / Q000235:genetics*; D055815:Young Adult
chemical_list: D001323:Autoantibodies; D010456:Peptides, Cyclic; C487763:cyclic citrullinated peptide; D043303:Aryldialkylphosphatase; C468406:PON1 protein, human