Development of SLE among "potential SLE" patients seen in consultation: long-term follow-up

To identify factors associated with development of systemic lupus erythematosus (SLE) among patients evaluated at a tertiary care Lupus Center for potential SLE.

We identified patients first seen at the Brigham and Women's Hospital Lupus Center between 1 January 1992 and 31 December 2012 and thought to have potential SLE by a board-certified rheumatologist. All had 1-3 SLE ACR criteria at initial visit and > 2 follow-up visits ≥ 3 months apart. We reviewed medical records through 15 May 2013 for: SLE signs and symptoms, autoimmune serologies, prescriptions and diagnoses by board-certified rheumatologists. Bivariable analyses and multivariable logistic regression models were used to identify independent predictors of developing SLE.

Two hundred and sixty four patients met inclusion criteria. At initial visit, mean age was 39.2 (SD 12.4) years, 94% were female and 67% white. Mean number of SLE ACR criteria was 2.7 (SD 1.0) and 88% were antinuclear antibody (ANA) positive at initial consultation. Mean follow-up time was 6.3 (SD 4.3) years and 67% were prescribed hydroxychloroquine in follow-up. At most recent visit, 56 (21%) had been diagnosed with SLE; 47 (18%) were thought not to have SLE and 161 (61%) were still considered to have potential SLE. In multivariable regression models, oral ulcers (OR 2.40, 95% CI 1.03-5.58), anti-dsDNA (OR 2.59, 95% CI 1.25-5.35) and baseline proteinuria or cellular casts (OR 16.20, 95% CI 1.63-161.02) were independent predictors of developing SLE. The most common other final diagnoses included fibromyalgia, Sjögren's syndrome, mixed connective tissue disease and cutaneous lupus.

Among patients with potential SLE at initial consultation, 21% were diagnosed with definite SLE within 6.3 years. Oral ulcers, anti-dsDNA and proteinuria or cellular casts were independent predictors of developing definite SLE. A better means of accurately identifying those who will develop SLE among those presenting with potential disease is necessary.