Anti-dsDNA and anti-Sm antibodies do not predict damage in systemic lupus erythematosus

Abstract

We aimed to determine whether anti-dsDNA and anti-Sm antibodies predict damage in systemic lupus erythematosus (SLE). Five-hundred inception patients from the University of Toronto Lupus Clinic were studied. Predictors assessed for the entire study period were: 1) raised anti-dsDNA on two consecutive occasions; 2) anti-dsDNA levels (normal, mildly or highly elevated); 3) presence of anti-Sm on any occasion. To account for disease duration, the following were assessed at three years post-inception: raised anti-dsDNA on two consecutive occasions; anti-dsDNA levels. These predictors were correlated with the following outcomes: 1) overall SLICC/ACR Damage Index (SDI) at the end of the study period; 2) frequency of damage in the cardiovascular, neuropsychiatric, musculoskeletal and renal components of SDI; 3) SDI at five years for the predictors assessed at three years post-inception. In the multivariate analysis, presence of anti-DNA antibodies or of anti-SM were non-significant but sex, age at SLE diagnosis, disease duration, corticosteroid use and cumulative dose were strong predictors of damage. Raised anti-dsDNA on two occasions or anti-dsDNA levels in the three years post-inception patients did not predict damage at five years. The presence and levels of anti-dsDNA and anti-Sm antibodies do not predict damage in SLE.