Idiopathic membranous nephropathy (MN) is an autoimmune disease characterized by specific antibodies. However, the underlying mechanisms by which lymphocytes promote the development of MN remain poorly understood. This study aims to determine the changes of B-cell subsets and their clinical significance in MN patients. We included a cohort of 21 idiopathic MN patients with new onset or a relapse, 19 healthy controls (HCs) and 10 patients with minimal change disease (MCD). Immunohistochemistry and flow cytometry were performed to assess the B-cell infiltration in renal biopsy tissues and peripheral blood, respectively. Idiopathic MN patients (including new-onset and relapse groups) had lower percentages of marginal-zone B (MZB) and non-switched memory B cells, and higher percentages of plasmablasts than HCs ( < 0.01). Particularly, the new-onset group had lower percentages of switched memory B cells and MZB cells, and higher percentages of Naïve B cells than HCs (<0.05). Interestingly, the percentage of plasmablasts was significantly correlated with urine protein to creatinine ratio, serum albumin, IgG, anti-M-type phospholipase A2 receptor antibody level and age in MN patients ( < 0.05). MN with Ehrenreich-Churg stage Ⅱ-Ⅳ had a lower median percentage of MZB and non-switched memory B cells, while a higher median percentage of plasmablasts than those in MN patients with stage Ehrenreich-Churg I ( < 0.05). Idiopathic MN patients had specific changes in B-cell subsets proportions in peripheral blood. Further studies are needed to precisely determine the roles of B-cell subsets in MN.

中文翻译：

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成人特发性膜性肾病患者外周血中 B 细胞亚群的变化

特发性膜性肾病（MN）是一种以特异性抗体为特征的自身免疫性疾病。然而，淋巴细胞促进 MN 发展的潜在机制仍知之甚少。本研究旨在确定 MN 患者 B 细胞亚群的变化及其临床意义。我们纳入了 21 名新发或复发的特发性 MN 患者、19 名健康对照 (HC) 和 10 名微小病变 (MCD) 患者的队列。免疫组织化学和流式细胞术分别评估肾活检组织和外周血中的 B 细胞浸润。特发性 MN 患者（包括新发和复发组）的边缘区 B (MZB) 和非转换记忆 B 细胞百分比较低，浆母细胞百分比高于 HC (< 0.01)。特别是，与 HC 相比，新发组的转换记忆 B 细胞和 MZB 细胞百分比较低，而幼稚 B 细胞百分比较高（<0.05）。有趣的是，MN患者浆母细胞的百分比与尿蛋白肌酐比、血清白蛋白、IgG、抗M型磷脂酶A2受体抗体水平和年龄显着相关（<0.05）。与 Ehrenreich-Churg I 期 MN 患者相比，Ehrenreich-Churg Ⅱ-IV 期 MN 的 MZB 和非转换记忆 B 细胞中位百分比较低，而浆母细胞中位百分比较高（ < 0.05）。特发性 MN 患者外周血中 B 细胞亚群比例有特定的变化。需要进一步的研究来精确确定 B 细胞亚群在 MN 中的作用。