Purpose: The aim of this study was to evaluate the efficacy of rituximab therapy in the management of idiopathic membranous nephropathy (IMN).
Methods: After literature search, data from eligible studies were used to perform random-effects meta-analyses to estimate remission rates and changes in proteinuria at the latest follow-up after rituximab therapy. The outcomes were used for metaregression to identify the factors affecting the efficacy of rituximab.
Results: Twenty-one studies were included in the analysis (602 patients; age 50 years [95% CI 46.8, 53.3]; 30% females [95% CI 23, 31]). Follow-up duration was 20.3 months [95% CI 17.1, 23.5]. Remission rate (67% [95% CI 61, 73]) was higher in studies with below average baseline proteinuria (76% [95% CI 61, 88]) than in studies with above average baseline proteinuria (61% [95% CI 54, 68]). The complete and partial remission rates were 26% [95% CI 20, 33] and 37% [95% CI 31, 43], respectively. Rituximab therapy significantly reduced proteinuria (mean difference between final and baseline values: - 4.90 g/day [95% CI - 6.18, - 3.63]; p < 0.00001; % reduction: 62% [95% CI 57, 68]). The reduction in proteinuria was inversely associated with baseline serum albumin levels (p = 0.021) and the estimated glomerular filtration rate (p < 0.00001) and was positively associated with baseline proteinuria (p < 0.00001). The remission rate or decrease in proteinuria was not significantly related to the anti-PLA2R antibody status or previous immunosuppressant therapy.
Conclusion: Rituximab therapy in IMN patients can provide approximately 67% remission rate. The reduction in proteinuria was greater in patients who had higher baseline proteinuria.
Keywords: CD20 antibody; Immunosuppression; Membranous nephropathy; Remission; Rituximab.