AB1099 RENAL FUNCTION TRAJECTORIES IN LUPUS NEPHRITIS PATIENTS RECEIVING IMMUNOSUPPRESSIVE OR B CELL-DEPLETING THERAPY
Authors: T. J. Lee, T. Y. Lan, T. W. Chang, C. H. Lu, S. C. Hsieh
Journal: Annals of the Rheumatic Diseases (2024)

<h3>Background:</h3> Lupus nephritis (LN) remains the most challenging complication for patients with systemic lupus erythematosus (SLE). The current standard of care included initial immunosuppressive therapy with either mycophenolate mofetil (MMF) or intravenous cyclophosphamide (CYC) with or without B cell-targeting therapy or calcineurin inhibitors, followed by subsequent MMF or azathioprine. However, questions remained in patients with initial renal function impairment, the trajectory of estimated glomerular infiltration rate (eGFR) with different treatment strategies, and the long-term renal survival using B cell-depleting monotherapy. <h3>Objectives:</h3> To analyse the long-term renal outcomes and renal function trajectories in lupus nephritis patients with normal or impaired renal function receiving different immunosuppressive therapies. <h3>Methods:</h3> In this retrospective study, we collected the lupus nephritis patients. The dates of diagnosis and lupus nephritis, background immunomodulatory therapy and glucocorticoids at the time of induction, and renal biopsy reports (when available) were reviewed. The serial renal functions and proteinuria levels, as well as the medications, renal-related events, and major clinical events were recorded. The outcomes of interest included progression to end-stage renal disease (ESRD) (defined as a sustained eGFR less than 15 mL/min/1.73 m<sup>2</sup> or requiring long-term renal replacement therapy), and death. <h3>Results:</h3> From August 2009 to October 2022, 106 patients were included for the analysis. The median (IQR) follow-up time was 57 (27-87) months. The induction treatment regimens include MMF (n=52), CYC (n=38), and RTX (n=16). The median (IQR) eGFRs at baseline were 87 (62, 117) in MMF, 67 (42-104) in CYC, and 103 (67, 130) in RTX groups. The moderate renal function impairment (eGFR less than 60 mL/min/1.73 m<sup>2</sup>) was observed in 23% in MMF, 42% in CYC, and 19% in RTX groups. Throughout the observation period, the progression to end-stage renal disease was observed in 6 (5.7%) patients <b>(Figure 1</b>). Among these patients, 4 had CYC, and 2 had RTX as the induction treatment. The ESRD occurred more commonly with initial age greater than 35 (9.40 vs. 4.76%, HR 2.66, HR 0.66-10.8), decreased eGFR at baseline (HR 0.91, 95% CI 0.85-0.96), and stage 3 and 4 chronic kidney disease at treatment initiation (23.1% vs. 0) In patients with at least moderate renal function impairment at treatment initiation (eGFR&lt;60, n=30), increase in eGFR in the first 6 months were observed in MMF and CYC <b>(Figure 2</b>). However, in all groups of patients, the renal functions from the maintenance phase remained stationary through month 60. <h3>Conclusion:</h3> The long-term renal survivals of lupus nephritis patients are favorable across various treatment strategies in this longitudinal single-center study. In patients with moderately decreased eGFR at baseline, improvements in renal function occurs in the first 6 months of induction immunosuppressive therapy of mycophenolate mofetil or cyclophosphamide. Long-term stabilization of the renal function was observed in patients receiving either mycophenolate mofetil, cyclophosphamide, or rituximab therapy. <h3>REFERENCES:</h3> [1] Fanouriakis A, Kostopoulou M, Andersen J, et alEULAR recommendations for the management of systemic lupus erythematosus: 2023 updateAnnals of the Rheumatic Diseases 2024;83:15-29. <h3>Acknowledgements:</h3> <b>NIL.</b> <h3>Disclosure of Interests:</h3> <b>None declared.</b>