Division of Nephrology, Department of Internal Medicine and Medical Specialities, Columbus-Gemelli University Hospital, Catholic University, Rome, Italy 00176; Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN 37232.
Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN 37232.
Hum Pathol. 2018 Nov;81:229-234. doi: 10.1016/j.humpath.2018.02.024. Epub 2018 Mar 9.
Alport syndrome is due to mutations in one of the genes encoding (α3,4,5) type IV collagen resulting in defective type IV collagen, a key component of the glomerular basement membrane (GBM). The GBM is initially thin and, with ongoing remodeling, develops a thickened basket-woven appearance. We report a unique case of a 9-year-old boy who underwent biopsy for hematuria and proteinuria, diagnosed as IgA nephropathy, with normal GBM appearance and thickness. Because of a family history of hematuria and chronic kidney disease, he subsequently underwent genetic evaluation, and a mutation of α3 type IV collagen (COL4A3) was detected. Additional studies of the initial biopsy demonstrated abnormal type IV collagen immunostaining. A repeat biopsy 4 years later showed characteristic glomerular basement membrane morphology of Alport syndrome and scarring consistent with sequelae of IgA nephropathy. This is the first description of this unusual transition from an initial normal appearance of the glomerular basement membrane to the classic Alport phenotype.
Alport 综合征是由于编码 (α3,4,5)IV 型胶原的基因突变导致 IV 型胶原缺陷，IV 型胶原是肾小球基底膜 (GBM) 的关键组成部分。GBM 最初是薄的，随着进行性重塑，会发展成增厚的篮状外观。我们报告了一个独特的 9 岁男孩的病例，他因血尿和蛋白尿接受了活检，诊断为 IgA 肾病，GBM 外观和厚度正常。由于有血尿和慢性肾脏病的家族史，他随后接受了基因评估，发现 α3 型 IV 型胶原 (COL4A3) 突变。对初始活检的进一步研究显示异常的 IV 型胶原免疫染色。4 年后的重复活检显示出典型的 Alport 综合征肾小球基底膜形态和与 IgA 肾病后遗症一致的瘢痕。这是首例从肾小球基底膜初始正常外观到经典 Alport 表型的这种异常转变的描述。
