Chronic Kidney Disease G3-5 in Lupus Nephritis - Prevalence, Progression, and Risk Factors

Abstract Background Despite treatment advances, there is limited data on the development of chronic kidney disease (CKD) in patients with lupus nephritis (LN) on long-term follow up. In this study, we aim to investigate the prevalence of chronic kidney disease (CKD), its progression over time and associated risk factors in patients with LN. Methods We conducted a retrospective study on Chinese patients with biopsy-proven LN diagnosed in 1981–2017. CKD G3-5 wasdefined according to an estimated glomerular filtration rate (eGFR)of 60 ml/min/m2, for more than 3 months. Risk factors for CKD progression and adverse outcomes were determined by multivariate logistic regression. Results 183 patients were included. Over a mean follow-up of 19.9 ± 9.7 years, 34.4% (63 patients) developed CKD G3-5, 9.8% developed kidney failure (KF) and 14.2% died. CKD G3-5 was associated with older age, renal impairment and hypertension at presentation, and the occurrence of nephritis flares. eGFR 60 ml/min/1.73m2 was present in 24.6% of patients at presentation, and the prevalence decreased to 13.6% and 12% after 6 and 12 months of treatment respectively, followed by a gradual increase to 15.3%, 16.4%, and 20.8% after 2, 5, and 10 years of follow-up respectively. In multivariate analysis, eGFR 80 ml/min/1.73m2 at 1 year OR 16.684 (95%CI 4.305–64.660), p 0.001 and ≥ 2 nephritis flares OR 7.237 (95% CI 2.041–25.919), p = 0.002 were significant predictors of CKD G3-5 development and adverse clinical outcomes during follow-up. Continuous induction-maintenance treatment with mycophenolate and glucocorticoid was associated with reduced risk of CKD G3-5 at 10-years OR 0.196 (95% CI 0.046–0.835), p = 0.028. Conclusion CKD G3-5 is common, affecting approximately one-fifth of LN patients after 10 years of follow-up. eGFR 80 ml/min/1.73m2 at 1-year after treatment for active LN and ≥ 2 nephritis flares are important risk factors, while mycophenolate and glucocorticoid induction-maintenance treatment regimen was associated with a reduced risk of CKD G3-5 during follow-up.