Chronic kidney disease G3–5 in lupus nephritis—prevalence, progression, and risk factors

ABSTRACT Background Despite treatment advances, there are 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 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 was defined according to an estimated glomerular filtration rate (eGFR) of <60 ml/min/m2, for >3 months. Risk factors for CKD progression and adverse outcomes were determined by multivariate logistic regression. Results In total, 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/1.73 m2 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/1.73 m2 at 1 year [OR 16.684 (95% CI 4.305–64.660), P < .001] and ≥2 nephritis flares [OR 7.237 (95% CI 2.041–25.919), P = .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 = .028]. Conclusion CKD G3–5 is common, affecting approximately one-fifth of LN patients after 10 years of follow up. eGFR <80 ml/min/1.73 m2 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.