Abstract:

Primary Nephrotic Syndrome（PNS）in children is a common glomerular disease whose pathogen⁃ esis is closely related to the abnormal expression of B lymphocyte function. With the application of biological agents，antibody drugs targeting CD20 are divided into three generations.（1）First generation：Rituximab（RTX） as a human⁃mouse chimeric anti⁃CD20 monoclonal antibody，mainly depletes B lymphocytes and reduces cytokine secretion by effectively blocking B cell proliferation and differentiation. Clinically RTX enables children with PNS on long⁃term hormone and immunosuppressant use to reduce the dose or even stop using it，reducing PNS relapse with fewer side effects.（2）Second generation：Ofatumumab，as a monoclonal antibody to the humanised target CD20，is the most promising biologic agent for renal applications other than RTX，recognising a different epitope to RTX and reducing its immunogenicity. It appears to be superior to RTX due to fewer adverse effects when ap⁃ plied at high doses. It is used clinically in PNS with RTX⁃resistant or allergic.（3）Third generation：Obinutuzum⁃ ab，the first glycosylated type II anti⁃CD20 monoclonal antibody，has a glycosylated Fc fragment that improves the specificity of the antibody and its affinity for antigen binding. Biological agentsare expected to be the first⁃line drugs for the treatment of nephrotic syndrome in children.

Key words: biological agents,  , nephrotic syndrome,  , treatment,  , clinical, children