Systemic lupus erythematosus (SLE) is a chronic systemic autoimmune disease with the incidence of about 70/100,000 in China. Recurrent relapses of disease and development of long-term organ damage are two key unsolved clinical problems. Its pathogenesis is still unclear, but B cells have been confirmed to play a vital role in it. Belimumab, a B-lymphocyte stimulating factor (Blys) inhibitor, was the only FDA-approved biological agent for SLE. BLISS-52 showed that more active lupus patients had their SELENA-SLEDAI score reduced by at least 4 points during 52 weeks with belimumab 10 mg/kg (58% vs 46%, p=0·0024) than with placebo. But there was limited data about belimumab in SLE patients with low disease activity. Our previous study indicated that even these patients still have an annual flare rate of 30-40%. Therefore, we try to explore whether low-dose of belimumab could prevent the disease flares in SLE patients with low disease activity.
