C3 and systemic lupus erythematosus: Tapering PDN below 5 mg/day was achieved and maintained in about half of newly diagnosed SLE patients. Spending every month on PDN <5 mg/day was associated with lower damage accrual (IRR: 0.96; p=0.007). Predictors of Failed Tapering: Active renal involvement (HR: 0.41; p=0.009) and lower C3 serum levels (HR: 1.04; p=0.025) were associated with a lack of PDN tapering below 5 mg/day. Disease Activity and Dose Increase: High ECLAM scores were associated with a greater probability of increasing PDN dose (OR: 1.6; p=0.004).