Primary nephrotic syndrome (PNS) is one of the common glomerular diseases in children.Glomerular disease treatment by anti-CD 20 monoclonal antibodies is currently a hot topic.There are three generations of anti-CD 20 monoclonal antibodies.As a representative of the first generation of anti-CD 20 monoclonal antibodies, Rituximab (RTX) has been proven effective in treating children with steroid-dependent/frequent-relapsing nephrotic syndrome (SDNS/FRNS). Ofatumumab (OFA) and Obinutuzumab (OBI) represent the second-and the third-generation anti-CD 20 monoclonal antibodies, respectively.OFA and OBI have showed good efficacy and safety in pediatric PNS.In this paper, clinical studies and applications of anti-CD 20 monoclonal antibodies in the treatment of children with PNS were reviewed, so as to provide a reference for the treatment of PNS in children.

Objective:To investigate the efficacy and safety of Rituximab (RTX) in the treatment of children with frequently relapsing/steroid-dependent nephrotic syndrome (FRNS/SDNS) and to analyze the factors influencing the efficacy.Methods:Case series study.The clinical data of children with FRNS/SDNS who received B-cell-guided RTX (single dose: 375 mg/m 2, maximum dose: 500 mg, one additional dose when peripheral blood CD19 + B lymphocytes ≥0.01) in the First Affiliated Hospital of Zhengzhou University from September 2019 to March 2022 were retrospectively collected.The frequency of relapse and cumulative dose of glucocorticoids before and after RTX treatment were compared.The Kaplan-Meier method was used to analyze relapse-free survival rate and FRNS/SDNS-free survival rate after RTX treatment.The influencing factors of relapse were analyzed using the Cox proportional hazards regression model. Results:Totally 47 children were enrolled, including 35 males and 12 females; the age of first application of RTX was 10.2 (6.9, 13.0) years; 33 children had used one type of immunosuppressant before, and 14 children had used two or more types of immunosuppressant before; the dose of RTX treatment was 3.0 (2.0, 3.0). The frequency of relapse[0(0, 0.55) times/year vs.1.62 (1.09, 2.40) times/year] and cumulative dose of glucocorticoids[0.12 (0.05, 0.21) mg/(kg·d) vs.0.40 (0.20, 0.56) mg/(kg·d)] after RTX treatment significantly decreased compared with previous immunosuppressive treatment ( Z=-5.56, -5.54, all P<0.001). The relapse-free survival rates at 6, 12, 18 and 24 months after treatment were 80.9%, 72.3%, 68.1% and 68.1%, respectively, and the FRNS/SDNS-free survival rates were 93.6%, 89.4%, 89.4% and 89.4%, respectively.Univariate Cox regression analysis showed that the high frequency of relapse during previous immunosuppressive therapy was a risk factor for relapse after RTX treatment ( P<0.05). Of the 14 children who relapsed, 6 occurred in children whose CD19 + B lymphocytes<0.01, and the frequency of relapse after RTX treatment was significantly higher than those whose CD19 + B lymphocytes≥0.01 ( Z=-2.84, P=0.005). No severe adverse reactions occurred during RTX treatment and follow-up. Conclusions:The B-cell-guided RTX is effective and safe in the treatment of FRNS/SDNS in children.The high frequency of relapse during previous immunosuppressive therapy is a risk factor for relapse after RTX treatment, and relapse in the state of B lymphocyte depletion predicts poor outcomes of RTX treatment.