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

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.