[Distribution of memory B cell subsets in peripheral blood of children with frequently relapsing nephrotic syndrome].

To investigate the change in the distribution of memory B cell subsets in children with frequently relapsing nephrotic syndrome (FRNS) during the course of the disease.A total of 35 children with primary nephrotic syndrome (PNS) who attended the Department of Pediatrics of the Affiliated Hospital of Xuzhou Medical University from October 2020 to October 2021 were enrolled as subjects in this prospective study. According to the response to glucocorticoid (GC) therapy and frequency of recurrence, the children were divided into two groups: FRNS (n=20) and non-FRNS (NFRNS; n=15). Fifteen children who underwent physical examination were enrolled as the control group. The change in memory B cells after GC therapy was compared between groups, and its correlation with clinical indicators was analyzed.Before treatment, the FRNS and NFRNS groups had significantly increased percentages of total B cells, total memory B cells, IgD+ memory B cells, and IgE+ memory B cells compared with the control group, and the FRNS group had significantly greater increases than the NFRNS group (P<0.05); the FRNS group had a significantly lower percentage of class-switched memory B cells than the NFRNS and control groups (P<0.05). After treatment, the FRNS and NFRNS groups had significant reductions in the percentages of total B cells, total memory B cells, IgM+IgD+ memory B cells, IgM+ memory B cells, IgE+ memory B cells, IgD+ memory B cells, and IgG+ memory B cells (P<0.05) and a significant increase in the percentage of class-switched memory B cells (P<0.05). The FRNS group had a significantly higher urinary protein quantification than the NFRNS and control groups (P<0.05) and a significantly lower level of albumin than the control group (P<0.05). In the FRNS group, urinary protein quantification was negatively correlated with the percentage of class-switched memory B cells and was positively correlated with the percentage of IgE+ memory B cells (P<0.05).Abnormal distribution of memory B cell subsets may be observed in children with FRNS, and the percentages of IgE+ memory B cells and class-switched memory B cells can be used as positive and negative correlation factors for predicting recurrence after GC therapy in these children.目的: 观察记忆B细胞在频复发肾病综合征（frequently relapsing nephrotic syndrome，FRNS）患儿病程中分布变化。方法: 前瞻性选择2020年10月—2021年10月就诊于徐州医科大学附属医院儿科的原发肾病综合征（primary nephrotic syndrome，PNS）患儿35例，根据其糖皮质激素（glucocorticoid，GC）治疗后的反应及复发频次，分为FRNS组、非频复发肾病综合征（non-frequently relapsing nephrotic syndrome，NFRNS）组；选择同期15例体检儿童为健康对照组。比较各组GC治疗前后记忆B细胞变化，并与临床指标作相关性分析。结果: 治疗前，FRNS组、NFRNS组总B细胞、总记忆B细胞、IgD+记忆B细胞、IgE+记忆B细胞比例均较健康对照组增高，且FRNS组较NFRNS组增高明显（P<0.05）；FRNS组类别转换记忆B细胞比例较NFRNS组及健康对照组降低（P<0.05）；治疗后，FRNS组、NFRNS组总B细胞、总记忆B细胞、IgM+IgD+记忆B细胞、IgM+记忆B细胞、IgE+记忆B细胞、IgD+记忆B细胞、IgG+记忆B细胞比例较治疗前降低（P<0.05）；类别转换记忆B细胞比例较治疗前增高（P<0.05）。FRNS组尿蛋白定量高于NFRNS组及健康对照组（P<0.05），FRNS组白蛋白水平低于健康对照组（P<0.05）；FRNS组尿蛋白定量与类别转换记忆B细胞比例呈负相关，与IgE+记忆B细胞比例呈正相关（P<0.05）。结论: FRNS患儿存在记忆B细胞亚群的分布异常；而IgE+记忆B细胞和类别转换记忆B细胞比例可作为FRNS患儿在GC治疗后复发的正相关和负相关因素。.