Division of Nephrology, Department of Pediatrics, West China Second University Hospital, Sichuan University, NO. 20, Section 3, Renmin Nan Lu, Chengdu, 610041, China.
Key Laboratory of Birth Defects and Related Diseases of Women and Children (Sichuan University), Ministry of Education, Chengdu, 610041, China.
J Nephrol. 2023 Nov;36(8):2213-2222. doi: 10.1007/s40620-023-01724-7. Epub 2023 Aug 5.
Mesangial IgM and C3 deposition is commonly observed in patients with primary immunoglobulin A nephropathy (IgAN), but its characteristics and prognosis have rarely been reported. The aim of this study was to investigate the relationship between combined mesangial IgM and C3 deposition and disease progression in children with IgAN.
One hundred sixteen children diagnosed with IgAN between 2016 and 2020 were selected. Renal biopsies were scored by Oxford classification including the presence of mesangial hypercellularity, endocapillary hypercellularity, segmental glomerulosclerosis, tubular atrophy/interstitial fibrosis and crescents. The primary renal outcome was an event of either ≥ 50% reduction of eGFR from the baseline value or the onset of end-stage renal disease within the follow-up period. Cox regression analysis was performed to examine the effect of the combined mesangial IgM and C3 deposition on renal outcomes.
Forty-seven (40.52%) patients presented combined mesangial IgM and C3 deposition. Compared with children without combined IgM and C3 deposition, children with combined IgM and C3 deposition presented higher mesangial hypercellularity, endocapillary hypercellularity and cresentic lesions in kidney biopsies, and higher prevalence of renal dysfunction (19.15% versus 2.90%; P = 0.007). Renal outcome was also significantly worse as revealed by Kaplan-Meier curves (P = 0.0034). Multivariable Cox analysis identified tubular atrophy/interstitial fibrosis lesions [hazard ratio (HR) 14.843, 95% CI, 3.497-62.997, P < 0.001] and intensity of IgM deposition (HR 2.838, 95% CI, 1.321-6.094, P = 0.007) as independent risk factors for poor renal function.
Combined mesangial IgM and C3 deposition was associated with unfavorable histopathological features. Mesangial IgM deposition was an independent risk factor for poor renal outcomes in children with primary IgAN.
免疫球蛋白 A 肾病（IgAN）患者常伴有系膜区 IgM 和 C3 沉积，但系膜区 IgM 和 C3 沉积的特征及其与疾病进展的关系鲜有报道。本研究旨在探讨 IgAN 患儿系膜区 IgM 和 C3 沉积与疾病进展的关系。
选择 2016 年至 2020 年期间诊断为 IgAN 的 116 例患儿。采用牛津分类法对肾脏活检进行评分，包括系膜细胞增生、内皮下细胞增生、节段性肾小球硬化、肾小管萎缩/间质纤维化和新月体。主要肾脏结局为 eGFR 较基线值下降≥50%或随访期间发生终末期肾病。采用 Cox 回归分析检测系膜区 IgM 和 C3 联合沉积对肾脏结局的影响。
47 例（40.52%）患儿存在系膜区 IgM 和 C3 联合沉积。与无系膜区 IgM 和 C3 联合沉积的患儿相比，有系膜区 IgM 和 C3 联合沉积的患儿肾脏活检中系膜细胞增生、内皮下细胞增生和新月体病变更明显，肾功能不全的发生率更高（19.15%比 2.90%；P=0.007）。Kaplan-Meier 曲线显示肾脏预后也明显更差（P=0.0034）。多变量 Cox 分析确定肾小管萎缩/间质纤维化病变[危险比（HR）14.843，95%可信区间，3.497-62.997，P<0.001]和 IgM 沉积强度（HR 2.838，95%可信区间，1.321-6.094，P=0.007）是肾功能不良的独立危险因素。
系膜区 IgM 和 C3 联合沉积与不良的组织病理学特征相关。系膜区 IgM 沉积是 IgAN 患儿肾脏不良结局的独立危险因素。
