Risk of chronic kidney disease in newly diagnosed systemic lupus erythematosus with preserved renal function: a national study

OBJECTIVES: Systemic lupus erythematosus (SLE) is strongly associated with lupus nephritis (LN), a major cause of chronic kidney disease (CKD). However, long-term renal and cardiovascular outcomes in patients with SLE who have preserved kidney function and do not develop LN remain poorly characterized. We sought to investigate the development of CKD among newly diagnosed patients with SLE who had preserved kidney function and no evidence of concomitant LN at baseline, compared with matched control individuals. METHODS: A national database study of newly diagnosed patients with SLE between 2015 and 2023. Patients with estimated glomerular filtration rate (eGFR) >60 mL/min/1.73 m2 at diagnosis were matched to non-SLE controls by age, sex, and ethnicity. Patients with LN were excluded. The primary outcome was incident CKD, defined as eGFR ≤60 mL/min/1.73 m2 after diagnosis. Secondary outcomes included end-stage kidney disease (ESKD), major adverse cardiovascular events (MACE), and all-cause mortality. RESULTS: We identified 1,145 patients with SLE and 91,681 matched controls, with a median follow-up of 5.77 years and similar baseline eGFR (103 vs 104 mL/min/1.73 m2). SLE was associated with a higher risk of CKD (5.2% vs 2.7%; HR 1.96, 95% CI 1.50-2.54), ESKD (HR 3.13, 95% CI 1.38-7.08), MACE (HR 1.63, 95% CI 1.31-2.04), and all-cause mortality (HR 4.52, 95% CI 3.71-5.50). Mean eGFR trajectories were similar between groups. Diabetes (HR 1.51, 95% CI 1.39-1.64) and hypertension (HR 2.72, 95% CI 2.42-3.07) were the strongest risk factors for CKD and ESKD. CONCLUSION: Patients with SLE and preserved kidney function at diagnosis, without LN, are at increased risk of adverse renal outcomes, cardiovascular events, and mortality, highlighting the importance of long-term monitoring and optimization of modifiable CKD risk factors.