Effect of complete or partial proteinuria recovery on long-term outcomes of lupus nephritis

Abstract

Background/purpose: We aimed to evaluate the effect of complete recovery (CR), partial recovery (PR), and no recovery (NR) of proteinuria at 2 years from the diagnosis of LN on long-term renal and extra-renal outcomes.

Methods: Patients with LN and proteinuria attending the Lupus Center from 1970 to 2015 were analyzed. At 2 years from diagnosis of LN, patients were divided into three groups (CR, PR, and NR), and long-term outcomes were studied up to 15 years or last visit available. CR was defined as resolution of proteinuria, PR as a reduction ≥50% in baseline proteinuria, and NR as a reduction <50% compared to baseline. Long-term outcomes examined included renal outcomes [low eGFR, ESRD, and composite renal (low eGFR, ESRD, and dialysis/transplant)], cardiovascular outcomes, damage, and death. Kaplan-Meier plots, time-independent and time-dependent Cox proportional hazards models were applied to examine the effect of CR, PR, or NR on long-term outcomes.

Results: Of 277 patients, 71.8% achieved CR, 18.4% PR, and 9.8% NR at 2 years. CR compared to NR and CR compared to PR were protective against low eGFR and composite renal outcome in time-independent and time-dependent analyses. CR compared to PR protected against damage in the time-independent analysis. Overall, the comparison of CR and PR favored CR for long-term renal outcomes.

Conclusion: CR at 2 years from diagnosis of LN protected against renal outcomes (low eGFR, ESRD/dialysis, and transplant). CR is more favorable compared to PR and clinicians should aim for CR to improve long-term outcomes in LN.

Keywords: Kidney; Lupus nephritis; Systemic lupus erythematosus.