Department of Nephrology, Teine Keijinkai Hospital, 1-40, 1 jo 12 chome Maeda Teine-ku, Sapporo, 006-8555, Japan.
Department of Cardiovascular, Renal, and Metabolic Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan.
CEN Case Rep. 2022 Aug;11(3):309-313. doi: 10.1007/s13730-021-00672-0. Epub 2022 Jan 6.
Although cases of secondary membranous nephropathy associated with autoimmune thyroid disease (AITD) have been reported, most of them, if not all, present with symptomatic thyroid disease. Here we report an asymptomatic case of AITD complicated with secondary membranous nephropathy. A 16-year-old girl was referred to our institute because of proteinuria found by an annual medical checkup. Urinalysis showed a urinary protein creatinine ratio (UPCR) of 3.0 g/gCre. Blood examination revealed that she had Graves' disease, although she did not have any symptoms of hyperthyroidism such as weight loss, anxiety, tremor, tachycardia, or eye symptoms. In a kidney biopsy, periodic acid silver-methenamine staining showed spike formation in the basement membrane. Electron microscopy showed electron-dense deposits on the epithelial side of the glomerular basement membrane. Immunofluorescent staining showed co-localization of thyroid peroxidase and IgG deposition along the glomerular capillary walls. A diagnosis of membranous nephropathy secondary to asymptomatic Graves' disease was made on the basis of results of the examinations. Treatment with thiamazole added to enalapril improved proteinuria (reduction of UPCR to 0.83 g/gCr) and hypoalbuminemia. Consideration should be given to the possibility of AITD in differential diagnosis of etiologies of membranous nephropathy even when typical symptoms of AITD are lacking.
虽然已有与自身免疫性甲状腺疾病（AITD）相关的继发性膜性肾病病例报告，但大多数（如果不是全部）病例均存在有症状的甲状腺疾病。在此，我们报告一例无症状的 AITD 合并继发性膜性肾病。一名 16 岁女孩因年度体检发现蛋白尿而被转至我院。尿分析显示尿蛋白与肌酐比值（UPCR）为 3.0 g/gCre。血液检查显示她患有格雷夫斯病（Graves' disease），尽管她没有任何甲亢症状，如体重减轻、焦虑、震颤、心动过速或眼部症状。肾脏活检中，过碘酸雪夫染色显示基底膜呈钉突状形成。电子显微镜显示肾小球基底膜上皮侧有电子致密沉积物。免疫荧光染色显示甲状腺过氧化物酶和 IgG 沿肾小球毛细血管壁沉积。根据检查结果，诊断为无症状性格雷夫斯病继发膜性肾病。加用噻唑烷二酮类药物治疗甲状腺功能亢进症可改善蛋白尿（UPCR 降低至 0.83 g/gCr）和低白蛋白血症。在鉴别膜性肾病的病因时，即使缺乏典型的 AITD 症状，也应考虑到 AITD 的可能性。
