Relation between onset of lupus nephritis and renal outcome

Background Lupus nephritis (LN) is a critical complication of systemic lupus erythematosus (SLE) that significantly impacts renal outcome. The aim of this study is to investigate the relationship between the timing of LN onset in SLE patients and long-term renal outcome. Patients and methods This retrospective cohort study included 300 patients with biopsy-proven LN divided into two groups: early-onset LN ( n =225), in which LN occurred within 5 years of SLE diagnosis, and late-onset LN ( n =75), in which LN occurred beyond 5 years of SLE diagnosis. Results Early-onset LN patients more frequently received pulse steroids and cyclophosphamide induction therapy ( P =0.003; P =0.024). After 1 year of diagnosis of LN, early-onset LN had a greater risk of Acute kidney injury episodes ( P =0.017). After 5 years of follow-up, more late-onset LN patients developed chronic kidney disease or required haemodialysis ( P =0.04). Multivariate analysis identified late-onset LN (OR=3.5, 95% CI 1.2–10.6, P =0.02), baseline serum creatinine (Ser Cr) (OR=1.6, 95% CI 1.12–2.3, P =0.009), and higher chronicity index (OR=1.34, 95% CI 1.13–1.6, P <0.001) as independent predictors of poor renal outcome. Conclusions While Acute kidney injury occurs more frequently in early-onset LN patients, late-onset LN is associated with greater chronic renal damage and poorer long-term renal outcomes. Baseline renal function and chronicity index are key prognostic indicators in LN patients.