Prevalence, Risk Factors, and Outcomes of Chronic Kidney Disease in Patients With Systemic Lupus Erythematosus With and Without Lupus Nephritis

Objective. Chronic kidney disease (CKD) has significant clinical and therapeutic implications. This study assessed CKD prevalence, risk factors, and long-term outcomes in patients with systemic lupus erythematosus (SLE), both with and without lupus nephritis (LN). Methods. This single-center, retrospective, medical records review study, conducted between 2014 and 2023, included adult patients with SLE. CKD was defined as estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73 m² or albuminuria ≥ 30 mg/24 h in ≥ 2 consecutive tests, spaced ≥ 3 months apart. Statistical analyses included chi-square tests, t tests, multivariable regression, and Cox proportional hazards models. Results. A total of 175 patients with SLE were included, with a mean follow-up of 18.3 (SD 14.7) years. Of these patients, 12 required kidney replacement therapy. CKD was diagnosed in 54.6% (89/163) of patients, including 15.7% with reduced eGFR only, 52.8% with albuminuria only, and 31.5% with both. LN was associated with a higher hazard ratio (HR) of 5.4 for CKD, and 46.1% of patients with CKD had no history of LN. CKD was associated with increased cardiovascular morbidity and hospitalization rates for SLE exacerbations and infections. Cox analyses identified LN as the strongest predictor of CKD, with age and lower eGFR at diagnosis identified as other predictors. CKD was an important predictor of mortality among patients with SLE, in both univariate and multivariable analyses (19.1% vs 1.4%, P < 0.001). Conclusion. CKD is highly prevalent in SLE, including in patients without prior LN. CKD is associated with increased morbidity and mortality. This study emphasizes the clinical relevance of CKD diagnosis and management in patients with SLE.