Predictors of renal and patient survival in lupus nephritis: a 28-year single-center cohort study.

Introduction: Despite advances in the understanding and treatment of lupus nephritis (LN), long-term renal and patient outcomes remain suboptimal. Identifying reliable predictors of prognosis and early treatment response is essential for improving risk stratification and guiding management. Methods: We conducted a retrospective cohort study of patients with biopsy-proven LN. Long-term renal and patient survival, renal response at 6 and 12 months, and predictors of a composite outcome (doubling of serum creatinine, end-stage kidney disease [ESKD], or death) were evaluated. Results: A total of 147 patients were included, with a median follow-up of 39.5 months. 10.3% of patients had a doubling of serum creatinine, 11.0% progressed to ESKD, and 6.8% died. Proteinuria <0.7 g/day was achieved by 49.1% and 54.4% of patients at 6 and 12 months, respectively. In multivariate analysis, baseline predictors of the composite outcome included age >50 years, proteinuria ≥3 g/day, and hemoglobin <10 g/dL, while an activity index ≥9 and low baseline C4 levels showed a protective trend. Achieving proteinuria <0.7 g/day at 12 months emerged as the strongest protective factor. A prognostic score demonstrated good discrimination (area under the curve [AUC] 0.82), which improved further with the addition of proteinuria at 12 months (AUC 0.86). Conclusions: In this biopsy-proven LN cohort, early renal response, particularly proteinuria <0.7 g/day at 12 months, was the strongest predictor of long-term renal and patient survival. These findings support a dynamic, response-based approach to prognostication in LN and provide the basis for a clinically applicable prognostic score that requires external validation.