#514 Efficacy of continues low dose rituximab in PLA2R-associated primary membranous nephropathy

Abstract

Abstract Background and Aims We reported that rituximab 100 mg monthly showed an effective regimen for low anti-phospholipase A2 receptor (anti-PLA2R) primary membranous nephropathy (PMN), especially for those elderly and susceptible PMN. Here we attempted to compare effect of the rituximab (RTX) 100 mg monthly vs traditional corticosteroid-cyclophosphamide (GC-Cy) for the treatment of PLA2R-associated PMN in our hospital. Method All the included PMN patients were treated in our hospital between June 2017 and June 2022 and were retrospectively analyzed. The inclusion criteria:(1) age >18 years old, (2) biopsy-proven PMN, (3) anti-PLA2R titers >20 RU/ml, (4) nephrotic syndrome (NS, both proteinuria >3.5 g/24 and serum albumin <30 g/L), (5) eGFR >30 ml/ min. 1.73 m2, (6) followed up at least 12 months. Patients were stratified into the RTX and GC-Cy groups according to their received treatment. In the RTX group, patients received RTX 100 mg monthly until the NS was remission or at least serum anti-PLA2R less than 2 RU/ml. In the GC-Cy group, patients received prednisolone (0.5-1.0 mg/kg/day) or methylprednisolone (similar dose) orally for 1-2 months, then dosage was reduced gradually, and the total duration about one year; meanwhile received intravenous cyclophosphamide (0.6-1.0 g every month), total doses 6-12 g. Results The baseline parameters (included age, gender, anti-PLA2R antibody, urinary protein, serum albumin, and eGFR) did not differ significantly between the two groups (see Table 1). Total RTX dosed were 819 ± 240 (400-1200 mg) in the RTX group. After different treatment, anti-PLA2R antibody was significantly higher in rituximab group than in the GC-Cy group at 3 months (P < 0.05), but were not significantly different between the two groups at 6, 9, and 12 months (P > 0.05, see Fig. 1A); urinary proteins were significantly higher in RTX group than in the GC-Cy group at 3, 6, and 9 months (P < 0.001), but were not significantly different between the two groups at 12 months (P > 0.05, see Fig. 1B); serum albumin were significantly lower in RTX group than in the GC-Cy group at 3, 6, 9 and 12 months (P < 0.01, see Fig. 1C). The total remission rate was not significantly different between the two groups at 12 months (P > 0.05, see Fig. 1D). Conclusion Compared to traditional GC-Cy treatment, RTX 100 mg monthly appeared as a weak but lasting effective regimen for anti-PLA2R-associated PMN.