title: Association of rheumatoid arthritis treatment response and disease duration with declines in serum levels of IgM rheumatoid factor and anti-cyclic citrullinated peptide antibody.
abstract: OBJECTIVE
  To examine the association of treatment response and disease duration with changes in rheumatoid factor (RF) and anti-cyclic citrullinated peptide (anti-CCP) antibody levels among patients with rheumatoid arthritis (RA).
  
  
  METHODS
  The study sample included 66 RA patients who completed double-blind, randomized clinical protocols and for whom baseline and followup serum samples were available. Anti-CCP and RF levels were measured using commercially available assay kits. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were used to describe the association of response and disease duration with declines in antibody levels.
  
  
  RESULTS
  Patients had a mean +/- SD age of 49.9 +/- 12.0 years and were predominantly female (n = 51; 77%). The mean +/- SD duration between the times at which the baseline and followup serum samples were obtained was 13.7 +/- 8.6 months. Among the 64 subjects with positive antibody at baseline, 33 (52%) experienced a > or =25% reduction in the anti-CCP antibody level during the course of treatment, and 35 patients (55%) had a > or =25% reduction in RF. After adjustment for the baseline anti-CCP antibody level, only a shorter disease duration (< or =12 months) was significantly associated with a decline in the level of anti-CCP antibody (OR 3.0, 95% CI 1.0-8.8), and no association with treatment response was observed. Conversely, treatment response was the only significant determinant of a decrease in RF levels (OR 3.6, 95% CI 1.2-10.4).
  
  
  CONCLUSIONS
  Shorter disease duration predicts greater declines in anti-CCP antibody levels with treatment in RA. Although treatment response is a robust determinant of a decrease in RF, it does not appear to be associated with declines in the anti-CCP antibody level.
authors.affiliation: Department of Medicine, University of Nebraska Medical Center, Omaha, Nebraska 68198, USA. tmikuls@unmc.edu
authors.forename: T R
authors.initials: TR
authors.lastname: Mikuls
authors.forename: J R
authors.initials: JR
authors.lastname: O'Dell
authors.forename: J A
authors.initials: JA
authors.lastname: Stoner
authors.forename: L A
authors.initials: LA
authors.lastname: Parrish
authors.forename: W P
authors.initials: WP
authors.lastname: Arend
authors.forename: J M
authors.initials: JM
authors.lastname: Norris
authors.forename: V M
authors.initials: VM
authors.lastname: Holers
mesh_terms: D018501:Antirheumatic Agents / Q000627:therapeutic use*; D001172:Arthritis, Rheumatoid / Q000188:drug therapy / Q000276:immunology / Q000473:pathology; D002956:Citrulline / Q000276:immunology*; D004311:Double-Blind Method; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007075:Immunoglobulin M / Q000097:blood; D008297:Male; D008875:Middle Aged; D010456:Peptides, Cyclic / Q000276:immunology*; D016032:Randomized Controlled Trials as Topic; D012217:Rheumatoid Factor / Q000276:immunology*; D012720:Severity of Illness Index; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D018501:Antirheumatic Agents; D007075:Immunoglobulin M; D010456:Peptides, Cyclic; D002956:Citrulline; D012217:Rheumatoid Factor