Qin Ai-Bo, Lin Zi-Shan, Wang Su-Xia, Wang Hui, Cui Zhao, Zhou Fu-de, Zhao Ming-Hui
Renal Division, Department of Medicine, Peking University First Hospital, Renal Pathology Center, Institute of Nephrology, Peking University, Key Laboratory of Renal Disease, Ministry of Health of China, Key Laboratory of CKD Prevention and Treatment, Ministry of Education of China, Research Units of Diagnosis and Treatment of Immune-mediated Kidney Diseases, Chinese Academy of Medical Sciences, Beijing, China.
Renal Division, Department of Medicine, Peking University First Hospital, Renal Pathology Center, Institute of Nephrology, Peking University, Key Laboratory of Renal Disease, Ministry of Health of China, Key Laboratory of CKD Prevention and Treatment, Ministry of Education of China, Research Units of Diagnosis and Treatment of Immune-mediated Kidney Diseases, Chinese Academy of Medical Sciences, Beijing, China; Electron Microscopy Laboratory, Peking University First Hospital Beijing, China.
Am J Med Sci. 2021 Mar;361(3):327-335. doi: 10.1016/j.amjms.2020.11.019. Epub 2020 Nov 26.
Prolonged exposure to mercury can cause membranous nephropathy. Mercury-associated membranous nephropathy (M-MN) and idiopathic membranous nephropathy (I-MN) have similar clinical manifestations, making misdiagnoses likely. We compared the clinicopathological and ultrastructural features of M-MN and I-MN.
We retrospectively analyzed the clinicopathological data of 13 M-MN patients and 13 I-MN patients. Electron micrographs of glomerular capillaries were taken, and foot process width (FPW) and the number of foot processes per 10 μm glomerular basement membrane (GBM) were calculated. The presence and location of electron-dense deposits were recorded.
Compared with I-MN patients, M-MN patients were younger (38.7 ± 8.5 versus 45.8 ± 5.7 years, P = 0.020), achieved complete remission more quickly (9.0 ± 6.1 versus 20.3 ± 9.8 months, P = 0.004), and had a lower relapse rate (0 versus 45.5%, P = 0.014). Patients with M-MN also had lower FPW (974.3 [interquartile range or IQR, 791.2-1504.4] nm versus 2370.6 [IQR, 2219.4-2559.1] nm, P = 0.001), more foot processes per 10 μm GBM (8.1 [IQR, 5.2-10.0] versus 3.3 [IQR, 3.1-3.5], P = 0.001), and a higher rate of mesangial electron-dense deposits (41.7% versus 0, P = 0.015). A cut-off FPW of <1654 nm differentiated M-MN from I-MN with high sensitivity (92.3%) and specificity (83.3%).
Foot process effacement was less severe in M-MN than in I-MN. In patients with mercury toxic exposure, MN with less severe foot processes effacement suggested mercury could be the cause. Better prognosis in patients with M-MN may be associated with minor podocyte damage.
长期接触汞可导致膜性肾病。汞相关膜性肾病（M-MN）和特发性膜性肾病（I-MN）具有相似的临床表现，容易造成误诊。我们比较了M-MN和I-MN的临床病理及超微结构特征。
我们回顾性分析了13例M-MN患者和13例I-MN患者的临床病理数据。拍摄肾小球毛细血管的电子显微镜照片，计算足突宽度（FPW）以及每10μm肾小球基底膜（GBM）的足突数量。记录电子致密沉积物的存在情况及位置。
与I-MN患者相比，M-MN患者更年轻（38.7±8.5岁对45.8±5.7岁，P = 0.020），更快达到完全缓解（9.0±6.1个月对20.3±9.8个月，P = 0.004），且复发率更低（0对45.5%，P = 0.014）。M-MN患者的FPW也更低（974.3[四分位数间距或IQR，791.2 - 1504.4]nm对2370.6[IQR，2219.4 - 2559.1]nm，P = 0.001），每10μm GBM的足突更多（8.1[IQR，5.2 - 10.0]对3.3[IQR，3.1 - 3.5]，P = 0.001），且系膜电子致密沉积物的发生率更高（41.7%对0，P = 0.015）。FPW < 1654nm的截断值区分M-MN和I-MN具有高敏感性（92.3%）和特异性（83.3%）。
M-MN中足突消失比I-MN中轻。在汞中毒暴露患者中，足突消失较轻的MN提示汞可能是病因。M-MN患者较好的预后可能与轻微的足细胞损伤有关。
