SAT0184 MAINTENANCE THERAPY WITH AZATHIOPRINE ASSOCIATED WITH HIGHER RISK OF FLARE IN PROLIFERATIVE LUPUS NEPHRITIS. (2nd June 2020) - Luis, M.
Abstract : Background: Goals of lupus nephritis (LN) maintenance treatment include prevention of LN flares and long-term preservation of renal function, while minimizing drug iatrogenicity. There is an unmet need for identifying predictors of LN flare in order to guide optimization of maintenance immunosuppression. Objectives: To identify predictors of LN flare after attainment of complete renal response (CRR) in patients with proliferative LN. Methods: Retrospective cohort study over 36 months including patients with SLE fulfilling the ACR'97 and/or the SLICC'12 classification criteria, enrolled in the CHUC Lupus Cohort between 1999 and 2018, with a biopsy-proven proliferative LN (class III/IV) and who attained CRR (proteinuria <0.5g/day and normal renal function, according to EULAR/ERA-EDTA definition) following induction treatment. Only proteinuric flares were considered and defined as doubling of proteinuria to >1g/day. Clinical-analytic characteristics at baseline (time of first CRR attainment after induction) were compared using survival analysis for time-to-flare. Variables with p<0.10 on univariate analysis with Log-Rank tests were further evaluated as predictors with multivariate Cox proportional hazards regression models (Backward Stepwise method, Wald-based), with estimation of hazard ratios (HR) with 95% confidence intervals (95%CI). Results: A total of 50 patients in CRR were included in the analysis (78.4% female, age at baseline 30.0 ± 12.5 years-old). Over the follow-up period, 10 patients (20.0%) experienced a proteinuric flare, within a mean time of 29.1 months (95%CI 26.89-31.37). In univariate analysis, age <30years (p=0.020), arterial hypertension (p=0.020) and presence of anti-RNP antibody (p=0.002) at baseline were associated with higher risk of LN proteinuric flares. In multivariate analysis, age <30 years (HR 26.56; 95%CI 1.93-365.08; p=0.014), arterial hypertension (HR 8.30; 95%CI 1.21-56.92; p=0.031), use of antihypertensive antiproteinuric drugs (angiotensin-converting-enzyme inhibitors or angiotensin receptor blockers) (HR 11.18; 95%CI 1.24-100.66; p=0.031) and maintenance therapy with azathioprine (HR 6.23; 95%CI 1.51-25.66; p=0.011) (Figure 1 ) were predictors of LN proteinuric flares. Conclusion: In patients with proliferative LN, proteinuric flares are a frequent event after induction treatment leads to CRR. Younger age, arterial hypertension, use of antihypertensive drugs and use of azathioprine as maintenance therapy were risk factors for LN proteinuric flare in this cohort. 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