title: Burden of autoantibodies and association with disease activity and damage in systemic lupus erythematosus.
abstract: OBJECTIVE
  To determine whether immunological burden of autoantibodies as reflected by the number of cumulative antibodies present at inception and after 3 and 5 years is associated with or predicts subsequent disease activity and damage in lupus.
  
  
  METHODS
  Patients with SLE followed from inception at a single centre between 1992 and 2007 were included. Twelve autoantibodies were assayed in each patient at years 1, 3 and 5 of disease. The relationship between the burden of autoantibodies and outcomes, SDI (Systemic Lupus International Collaborative Clinics Damage Index), AMS (Adjusted Mean SLEDAI-2K) and AMS excluding anti-ds DNA (AMS-DNA) was evaluated as an association and as prediction. We determined the association between autoantibody burden and outcomes at years 1, 3 and 5 and the prediction using autoantibody burden at year 1 and year 3 to predict outcomes at years 3 and 5 respectively.
  
  
  RESULTS
  Between 1992 and 2007, 235 inception patients were identified. Of these, 223, 163 and 129 patients had 10 or more autoantibodies tested at years 1, 3 and year 5 following diagnosis respectively. There was no association between the burden at years 1, 3 and 5 and outcome measures at years 1, 3 and 5 respectively. Furthermore, burden of autoantibodies at years 1 and 3 did not predict the outcome measures at years 3 and 5 respectively.
  
  
  CONCLUSIONS
  Immunological burden in SLE at years 1, 3 or 5 as reflected by the number of autoantibodies found, was not associated with or predictive of subsequent disease activity or damage over time.
authors.affiliation: University of Toronto Lupus Clinic and the Centre for Prognosis Studies in the Rheumatic Diseases, Toronto Western Hospital, Toronto, Canada. ztouma@uhnresearch.ca
authors.forename: Z
authors.initials: Z
authors.lastname: Touma
authors.forename: D D
authors.initials: DD
authors.lastname: Gladman
authors.forename: D
authors.initials: D
authors.lastname: Tulloch-Reid
authors.forename: S M
authors.initials: SM
authors.lastname: Toloza
authors.forename: D
authors.initials: D
authors.lastname: Ibañez
authors.forename: P R
authors.initials: PR
authors.lastname: Fortin
authors.forename: M B
authors.initials: MB
authors.lastname: Urowitz
mesh_terms: D000328:Adult; D001323:Autoantibodies / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D018450:Disease Progression; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008180:Lupus Erythematosus, Systemic / Q000097:blood / Q000276:immunology* / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D017063:Outcome Assessment, Health Care; D012189:Retrospective Studies; D012720:Severity of Illness Index; D013997:Time Factors
chemical_list: D001323:Autoantibodies; D015415:Biomarkers