title: Anti-cyclic citrullinated peptide antibodies distinguish hepatitis B virus (HBV)-associated arthropathy from concomitant rheumatoid arthritis in patients with chronic HBV infection.
abstract: OBJECTIVE
  To determine whether anti-cyclic citrullinated peptide (anti-CCP) antibodies, which are a highly specific test for rheumatoid arthritis (RA), could differentiate between hepatitis B virus (HBV)-associated arthropathy and concomitant RA in Korean patients with chronic HBV infection.
  
  
  METHODS
  We investigated 240 patients with HBV infection. Anti-CCP antibodies were measured by ELISA and rheumatoid factor (RF) by the latex fixation test. Patient records were reviewed, and a standard form was used to record all demographic, clinical, and laboratory characteristics. Patients were divided into 4 groups according to joint symptoms: asymptomatic, arthralgia, oligoarthritis, and RA. We categorized liver disease into 3 groups: carrier, chronic hepatitis, and cirrhosis.
  
  
  RESULTS
  Anti-CCP antibodies and RF were detected in 11 and 28 of 240 patients, respectively. Anti-CCP antibodies were detected in 9 of 10 RA (90%) and 2 of 230 non-RA patients (0.86%). The positive rate for RF was 90% in RA and 8.3% in non-RA. Eight of 10 RA patients were positive for both RF and anti-CCP antibodies. RF was detected in 11 patients without joint symptoms, 4 with arthralgia, and 4 with oligoarthritis, whereas anti-CCP antibodies were found in 1 patient without joint symptoms and 1 with oligoarthritis. Specificity of anti-CCP antibody for RA was 99.1%, whereas RF showed 91.7% specificity (p<0.0002). We compared the titers and positive detection rates of anti-CCP antibodies and RF among liver disease subgroups. There was no significant between-subgroup difference.
  
  
  CONCLUSIONS
  Measurement of anti-CCP antibodies is better than RF detection to discriminate HBV-associated arthropathy from concomitant RA in patients with chronic HBV infection.
authors.affiliation: Department of Internal Medicine, Eulji University, and Department of Medicine, Eulji University Hospital, Seogu Dunsandong 1306, 302-799 Daejeon, South Korea.
authors.forename: Mi-Kyoung
authors.initials: MK
authors.lastname: Lim
authors.forename: Dong-Hyuk
authors.initials: DH
authors.lastname: Sheen
authors.forename: Yun Jung
authors.initials: YJ
authors.lastname: Lee
authors.forename: You Ri
authors.initials: YR
authors.lastname: Mun
authors.forename: Mira
authors.initials: M
authors.lastname: Park
authors.forename: Seung-Cheol
authors.initials: SC
authors.lastname: Shim
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001172:Arthritis, Rheumatoid / Q000150:complications / Q000175:diagnosis* / Q000276:immunology / Q000473:pathology; D001323:Autoantibodies / Q000097:blood* / Q000276:immunology; D015415:Biomarkers / Q000097:blood; D003430:Cross-Sectional Studies; D003937:Diagnosis, Differential; D005260:Female; D019694:Hepatitis B, Chronic / Q000150:complications* / Q000276:immunology / Q000473:pathology; D006801:Humans; D007592:Joint Diseases / Q000175:diagnosis* / Q000276:immunology / Q000473:pathology / Q000821:virology*; D007723:Korea; D008297:Male; D008875:Middle Aged; D010456:Peptides, Cyclic / Q000097:blood / Q000276:immunology*; D012189:Retrospective Studies; D012217:Rheumatoid Factor / Q000097:blood / Q000276:immunology; D012680:Sensitivity and Specificity; D055815:Young Adult
chemical_list: D001323:Autoantibodies; D015415:Biomarkers; D010456:Peptides, Cyclic; C487763:cyclic citrullinated peptide; D012217:Rheumatoid Factor