Correlation Between Baseline CD19+ B-Cell Levels And The Efficacy Of Rituximab In The Treatment Of Refractory Nephrotic Syndrome In Children

Objective:To investigate the correlation between baseline CD19+B-cell levels and the efficacy of rituximab(RTX)in the treatment of refractory nephrotic syndrome in children.Methods:A total of 32 children with refractory nephrotic syndrome who were diagnosed and treated with RTX at the Department of Pediatrics,Renal and Rheumatic Immune Diseases Specialized Group,Second Hospital of Hebei Medical University(our hospital)from January 2019 to December 2021and were reviewed at our outpatient clinic were collected,and based on the initial CD19+B-cell level before RTX treatment,those below normal level were divided into group A,those at normal level were group B,and those above normal level were group C.All children were given RTX(375mg/m~2/dose,max 500 mg/dose,once a week for 2 weeks)and when B cells recover(CD19+B cell count>5/μl or>1%),administer a second course of RTX at the same dose as the first course.The frequency of relapse within 1year after treatment,the amount of hormone used in month 6 and 12,the time of B-cell depletion and recovery were compared between the three groups,and the occurrence of adverse events after RTX treatment was recorded.Results:1.At one year follow-up,the annual recurrence rates were 25%,15.4%,and 20%in groups A,B,and C,respectively,with no statistical difference(P=0.898),and there was no significant difference in recurrence-free survival time compared among the three groups(P=0.856).2.The application of RTX for RNS was effective in reducing hormone dosage(P=0.000),and there was no significant difference in the trend of hormone reduction and discontinuation between the three groups compared(P=0.142).3.CD19+B cells could all reach B-cell depletion within 1 month after the first dose of RTX treatment and started to recover in 3-6 months,and no significant difference was observed in the period of B-cell depletion in the three groups(P=0.972).4.2(6%)of the 32 children treated with RTX had infusion reactio ns(including rash,chest discomfort,etc.)and 6(18%)had respiratory i nfections that resolved with symptomatic management.19(59%)had hy pogammaglobulinemia detected at least once during the follow-up period,and no other serious adverse reactions were observed.Conclusions:1.No significant difference in baseline CD19+B-cell levels on the efficacy of RTX for RNS,including its post-application relapse rate,relapse-free survival time,and B-cell depletion period.2.The application of RTX for RNS is effective in reducing hormone dosage and has a good safety profile.