Long-term Outcomes of Lupus Nephritis in Comparison to Other CKD Etiologies

Introduction: Little is known regarding the comparison of cardiovascular and kidney outcomes between lupus nephritis (LN) and other etiologies of chronic kidney disease (CKD). Methods: Using data from the Swedish Renal Registry (2006-2021), we compared long-term outcomes between patients with LN-CKD and patients with CKD due to primary glomerular diseases (PGD) and other CKD causes (Other-CKD, mainly diabetes and nephroangiosclerosis). Adjusted hazard ratios (HRs) of mortality, major adverse cardiovascular events (MACE) and kidney replacement therapy (KRT) were estimated using Cox proportional hazard models. Results: At baseline, LN (n = 317, 61 years, 76% women) and PGD (n = 2296, 57 years, 30% women) had better kidney function and lower prevalence of cardiovascular disease than the Other-CKD (n = 34,778, 75 years, 36% women). The median follow-up was 6.2 (3.3-9.8) years. The absolute risks of death and MACE in LN-CKD were intermediate between those of Other-CKD and PGD. The 5-year absolute KRT risk of LNCKD was similar to Other-CKD's risk (22%) and lower than in PGD (37%). In multivariable analysis, as compared to PGD, the rates of death and MACE in LN-CKD were higher (HR: 1.63 [95% confidence interval: 1.32-2.02] and 1.65 [1.31-2.08]), whereas the rate of KRT tended to be lower (0.81 [0.64-1.02]). In contrast, the rate of adverse events was not different between LN-CKD and Other-CKD. Conclusion: Although patients with LN-CKD had a lower risk of KRT than PGD-CKD, they exhibited higher risk of death and MACE, reaching the risk magnitude of patients with high cardiovascular burden (OtherCKD). Our findings may inform decisions about prevention of cardiovascular events in patients with moderate and advanced LN-CKD.