#1602 Lupus nephritis multidisciplinary consultation: a new strategy for increasingly complex patients

Abstract Background and Aims Lupus nephritis (LN) is a major course of morbidity and mortality in patients with systemic lupus erythematosus (SLE), best managed by a multidisciplinary group. Recent management advances require greater collaboration between specialists and individualized treatments in severe cases. Method We conducted a retrospective, single-center study of a cohort of incident patients which were diagnosed with LN between 2015 and 2022 and began follow-up in the multidisciplinary rheumatology and nephrology consultation of our institution. Clinical and analytical characteristics at diagnosis and during follow-up were studied. The primary endpoint was complete remission rate at follow-up end, according to GLOSEN (Grupo de Estudio de Enfermedades Glomerulares de la SEN) [1] criteria. Changes in immunosuppression schemes over time were studied. Results 26 patients (92.3% women) were included. Median age at SLE diagnosis was 30.5 years [Interquartile range (IQR) 23.7 – 44.2]. Most patients were Hispanic (14 patients, 53.8%). Median time between SLE and LN diagnosis was 21 months (IQR 0-129 months). In 9 patients (34.6%), SLE and LN onset happened simultaneously. Most common renal manifestation was hematuria, which appeared in 19 patients (73.1%). Median proteinuria was 1.83 g/d (IQR 0.88-2.92) and serum creatinine level, 0.69 (IQR 0.51-1.18). Hypocomplementemia (88.5%) and positivity to anti-DNA (69.2%) were common. Most frequent classes found in renal biopsies were IV (30.8%) and V (23.1%). At LN debut, SLEDAI score, which assesses SLE manifestations, had a median value of 16 (IQR 12-20). Mycophenolate mofetil (96.2%) was the main induction agent. Intravenous steroids were administered in 14 patients (53.8%) and the rest received steroids at a dose of 0.5 mg/kg/day. Addition of another therapy, mainly tacrolimus (6 patients, 23.1%) and belimumab (4 patients, 15.4%), was needed to achieve remission in 12 patients (46.2%). In 8 of them (66.6%), treatments were added within the first 6 months. These 12 patients had less chronicity in the biopsy (median chronicity index: 0 vs. 2; p 0.004) and had higher proteinuria (median 1.41 g/day vs. 0.4 g/day; p 0.001). Likewise, SLEDAI score at 3 months was significantly higher in these 12 patients than in the standard of care group (median SLEDAI score 13 vs. 8; p 0.016). No differences were found in 3 month serum creatinine (p 0.181) or 3 month hematuria (p 0.496) After a median follow-up of 47 months, 15 (57.7%) and 9 patients (34.6%) achieved complete and partial remission, respectively. No differences in percentages of remission were observed between the 2 groups. Steroids were withdrawn in 12 patients (46.2%). Median steroid dose at the end of follow-up was 5 mg (IQR 3-5). Conclusion In our LN cohort, higher SLEDAI and proteinuria indicated the need for an individualized approach. Collaboration between Rheumatology and Nephrology specialists is essential to identify patients with these needs.