Burden of autoantibodies and association with disease activity and damage in systemic lupus erythematosus

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.