Serial measurements of anti–double-stranded DNA (anti-dsDNA) and complement are routine in the management of systemic lupus erythematosus (SLE), but their utility as biomarkers in preemptive treatment to prevent flares remains a subject of controversy. We hypothesized that concomitant elevation of anti-dsDNA and C3a can predict SLE activity in patients with stable or inactive disease and that short-term treatment with corticosteroids can avert flares.
In this prospective, randomized, double-blind, placebo-controlled trial, 154 patients were evaluated monthly for up to 18 months, with measurements of C3a, C3, C4, CH50, and anti-dsDNA levels. Patients who remained clinically stable but showed serologic evidence of an SLE flare (elevation of both the anti-dsDNA level by 25% and the C3a level by 50% over the previous 1–2 monthly visits) were randomized to receive either prednisone or placebo therapy at a dosage of 30 mg/day for 2 weeks, 20 mg/day for 1 week, and 10 mg/day for 1 week.
Forty-one patients (21 randomized to prednisone and 20 randomized to placebo) experienced a serologic flare. Analysis of severe flares occurring ≤90 days from randomization revealed that 6 occurred in patients taking placebo and none occurred in patients taking prednisone (P = 0.007). Severe flares resulted in an increase in the prednisone dosage to >40 mg/day and/or the addition of an immunosuppressive agent. Furthermore, improvement in scores on the Systemic Lupus Erythematosus Disease Activity Index, decreased levels of anti-dsDNA antibodies, and increased levels of C4 occurred 1 month after initiation of prednisone treatment.
These preliminary data support our hypothesis that in a subset of clinically stable SLE patients with a combination of elevated C3a and anti-dsDNA levels, short-term corticosteroid therapy may avert a severe flare.