Immunological monitoring investigation of cyclophosphamide combined with Belimumab in the treatment of pediatric lupus nephritis

LI Nana; GUAN Fengjun

doi:10.3969/j.issn.1002-7386.2025.09.015

Abstract：Objective To explore the immune status of children with lupus nephritis(LN)treated with cyclophosphamide(CTX)combined with belimumab,and its relationship with clinical efficacy and concurrent infections.Methods A total of 20 children with LN admitted to the Pediatric Department between August 2021 and August 2023 were collected.After the combination treatment of CTX and Belimumab,the absolute count of lymphocyte subsets,immunoglobulins,complements,anti-ds DNA antibody titers,white blood cell count(WBC),neutrophil count(NEU),serum albumin(ALB),creatinine(Cr),blood urea nitrogen(BUN),24-hour urine protein,the Systemic Lupus Erythematosus Disease Activity Index 2000(SLEDAI-2K),monthly infection rate and infection type were analyzed,and correlation analysis was performed.Results After the application of CTX combined with Belimumab,the absolute count of B-lymphocyte subsets showed a decreasing trend.A significant difference was detected in the absolute count of B-lymphocyte subsets at 12 weeks was found in comparison to baseline before medication(P＜0.05).Cell counts of CD4+T lymphocyte subpopulation and NK cells showed an upward trend(P＞0.05).The count of CD8+T lymphocyte subsets showed a decreasing trend(P＞0.05).The levels of complement C3 and C4 showed a significant increasing trend(P＜0.05).SLEDAI-2K,anti-ds DNA titer,and 24-hour urine protein level showed a significant decreasing trend(P＜0.05).In addition,the infection rate gradually decreased from 25.0％before medication,10.0％at 4 weeks and 5.0％at 12 weeks.Conclusion CTX combined with Belimumab significantly reduces the absolute count of B lymphocytes at 12 weeks,leading to an immunosuppressive state.Within 24 weeks of medication,the incidence of infection decreases with a prolonged medication.