title: Prior anti-dsDNA antibody status does not predict later disease manifestations in systemic lupus erythematosus.
abstract: OBJECTIVE
  To determine if the past presence of anti-double-strand (ds)DNA antibody (Ab) will predict subsequent disease activity in patients with systemic lupus erythematosus (SLE).
  
  
  METHODS
  A longitudinal study of clinical and serological disease manifestations registered during 2,412 patient months of follow-up in a well-defined lupus cohort. Organ-specific disease manifestations, the modified SLE disease activity index (M-SLEDAI) score, disease flares (M-SLEDAI increase > or =3) and predictive value of anti-dsDNA Ab testing [by enzyme-linked immunoabsorbent assay (ELISA) and Crithidia luciliae immunofluorescence (CLIFT) assays] were related to past anti-dsDNA Ab status.
  
  
  RESULTS
  Anti-dsDNA Ab was previously demonstrated in 54 (57%) patients (group 1), while they were not earlier detected in 40 (43%) patients (group 2). The number of patients experiencing flares (46 vs 25%, p<0.01), the total number of flares (75 vs 17, p<0,001) as well as overall (60 vs 24 per 100 patient years, p<0,001) and organ-specific flare rate were higher in group 1. After adjustment for control frequency, group 1 remained at a higher risk for renal flares [odds ratio (OR) 2.4; confidence interval (CI) 1.5-4.1], and group 2 was at a higher risk for skin flares (OR 0.7; CI 0.5-0.8). While anti-dsDNA Ab testing overall was performed slightly more often in group 1 (OR 1.45; CI 1.0-4.6), anti-dsDNA Ab testing during flares was similar in both groups.
  
  
  CONCLUSIONS
  The past presence of anti-dsDNA Ab identified patients with an increased risk of subsequent renal flares. However, as a new onset of anti-dsDNA Abs occurred late in the disease course, prior anti-dsDNA status was not adequate to predict disease flares.
authors.affiliation: Institute of Clinical Medicine, Rheumatology, University of Tromso Breivika, 9037 Tromso, Norway.
authors.forename: Loes
authors.initials: L
authors.lastname: van den Berg
authors.forename: Hans
authors.initials: H
authors.lastname: Nossent
authors.forename: Ole
authors.initials: O
authors.lastname: Rekvig
mesh_terms: D000328:Adult; D000974:Antibodies, Antinuclear / Q000097:blood*; D004247:DNA / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005455:Fluorescent Antibody Technique; D006304:Health Status; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D008137:Longitudinal Studies; D008180:Lupus Erythematosus, Systemic / Q000276:immunology* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012008:Recurrence; D012720:Severity of Illness Index
chemical_list: D000974:Antibodies, Antinuclear; D004247:DNA