Higher mortality without increased ESKD risk in late-onset SLE with lupus nephritis versus early-onset SLE: a Latin American cohort
Natalia A Uribe-Ruíz, Andrés Felipe Vargas-Camacho, Lina Aguirre-Hernández, Alejandra Taborda, Lina Serrato-Adrada, Mauricio Restrepo-Escobar, Luis Alonso González, Joaquín Rodelo-CeballosSummary
Objective
To compare kidney survival, mortality, and composite outcomes in lupus nephritis (LN) according to age at systemic lupus erythematosus (SLE) onset (late-onset ≥50 years vs early-onset 18–49 years) in a Latin American cohort.
Methods
We conducted a single-center retrospective cohort study of patients with biopsy-proven LN diagnosed between 2011 and 2024 at a tertiary referral center. Outcomes included end-stage kidney disease (ESKD), all-cause mortality, doubling of serum creatinine, and a composite outcome (ESKD, creatinine doubling, or death). Associations between age at SLE onset and outcomes were evaluated using Cox proportional hazards models and competing-risk analysis for ESKD, with death as a competing event.
Results
Among 428 patients, 370 (86.4%) had early-onset SLE and 58 (13.6%) had late-onset SLE. Patients with late-onset SLE had more comorbidities, lower baseline eGFR, and slightly higher chronicity scores at biopsy. Kidney survival did not differ significantly between groups. However, late-onset SLE with LN was associated with higher all-cause mortality (48.3% vs 24.3%, p < 0.001), more frequent creatinine doubling (18.5% vs 14.9%, p = 0.046), and an increased risk of the composite outcome (adjusted HR 1.58; 95% CI 1.05–2.36). In multivariable analyses, lower baseline eGFR, higher chronicity index, and greater non-renal damage were independently associated with ESKD and mortality.
Conclusions
Despite no significant difference in kidney survival, late-onset SLE with LN is characterized by higher comorbidity burden, slightly higher chronicity scores, worse intermediate renal decline, and higher mortality. These findings support integrating baseline kidney function, histological chronicity, comorbidity burden, and competing mortality risk into risk stratification.