Serologically Active, Clinically Quiet SLE
In a UCL cohort of prolonged SACQ lupus patients — elevated anti-dsDNA and/or low C3 for 6+ months with no clinical activity — 63% flared over a mean 3.3 years. Rising IgG anti-dsDNA and falling C3 at one visit independently predicted flare and sustained activity at the next, including moderate-to-severe disease, in a visit-by-visit longitudinal model. The risk from low C3 rose sharply below 0.9 g/L and flattened above it.