Background:The EULAR/ERA-EDTA recommendations for lupus nephritis (LN) state that renal response should be achieved within 12 months following induction therapy. However, there is an unmet need for early predictors of renal outcome in order to adjust the immunosuppression regimen and optimize the renal outcome.Objectives:To identify predictors of poor renal outcome at baseline, 3 months and 6 months after starting induction therapy.Methods:Retrospective cohort study over 36 months including patients with Systemic lupus erythematosus (SLE) fulfilling the ACR’97 and/or the SLICC’12 classification criteria and with biopsy-proven proliferative LN (class III/IV), enrolled in the CHUC Lupus Cohort from 1999 to 2018. Poor renal outcome was defined as longer time to complete renal response (CRR), characterized by proteinuria <0.5g/day and normal renal function, according to EULAR/ERA-EDTA criteria. Clinical-analytical characteristics at baseline, 3 months and 6 months after starting induction treatment were compared using survival analysis for time-to-CRR. Variables with p<0.25 on univariate analysis using Log-Rank tests were further evaluated as predictors applying multivariate Cox proportional hazards regression models (Backward Stepwise method, Wald-based) with estimation of hazard ratios (HR) and 95% confidence intervals (95%CI).Results:56 patients were included (76.8% female, age at LN diagnosis 30.0 ± 13.2 years). Over the follow-up, 51 patients (91.1%) achieved CRR, within a median time of 6.0 months. In multivariate analysis, predictors of poor renal outcome were proteinuria >2g/day at baseline (HR 1.98; 95%CI 1.04-3.77; p=0.037) and induction therapy with pulse cyclophosphamide (CYC), as compared to mycophenolate mofetil (MMF) (HR=2.05; 95%CI 1.07-3.94; p=0.030) (Figure 1). Diabetes mellitus (HR=6.0; 95%CI 1.24-29.07; p=0.026) and negative anti-RNP antibody (HR 3.17; 95%CI 1.27-7.93; p=0.013) at baseline predicted poor renal outcome at 3 months. At this timepoint, level of proteinuria and clearance rate were not predictive of renal response. At 6 months, no predictors of LN outcome were found for those patients that did not achieve CRR up to this timepoint. Use of glucocorticoid pulses and/or antihypertensive drugs did not predict LN outcome.Figure 1.Conclusion:In this SLE cohort, most patients with proliferative LN achieved CRR. Proteinuria above 2 g/day at baseline and diabetes mellitus were predictors of poor renal outcome, while positive anti-RNP was protective. Induction treatment with CYC was associated with poorer outcome as compared with MMF. Given the retrospective non-randomized nature of this study, caution is needed when drawing conclusions regarding both treatments efficacy.Disclosure of Interests:Mariana Luis: None declared, Ana Rita Prata: None declared, Helena Assunção: None declared, José Antonio P. da Silva Grant/research support from: Pfizer, Abbvie, Consultant of: Pfizer, AbbVie, Roche, Lilly, Novartis, Luís Inês: None declared
Initial Preserved Renal Function as a Predictor of Favorable Renal Response to Rituximab in Refractory or Relapsing Lupus Nephritis: A Single-center Cohort Study in Korea
