Department of Nephrology and Blood Purification, Kidney Disease Center, Tokyo Medical University Hachioji Medical Center, 1163 Tatemachi, Hachioji, Tokyo, 193-0998, Japan.
CEN Case Rep. 2021 Aug;10(3):442-447. doi: 10.1007/s13730-021-00585-y. Epub 2021 Mar 3.
A 74-year-old Japanese woman was referred to our department because of anasarca and massive proteinuria. She was clinically diagnosed with nephrotic syndrome, and renal biopsy showed membranoproliferative glomerulonephritis accompanied by marked glomerular infiltration with macrophages and full-house immunofluorescence glomerular deposition. Furthermore, randomly arranged nonbranching fibrils, approximately 12 nm in diameter, were found by electron microscopy, and immunostaining for DnaJ homolog subfamily B member 9 (DNAJB9), a recently identified diagnostic biomarker of fibrillary glomerulonephritis (FGN), showed positive result, thereby confirming the diagnosis of FGN. Steroid treatment was initiated, and she obtained complete remission of nephrotic syndrome and has maintained it. FGN is an uncommon form of glomerular disease, and reported cases of DNAJB9-positive FGN among Asians, particularly among Japanese population, are rare. There have been no established therapeutic regimens and its renal prognosis is generally unfavorable. The present case suggests that some patients with FGN can achieve favorable clinical outcomes through steroid monotherapy.
一位 74 岁的日本女性因水肿和大量蛋白尿被转至我科。临床诊断为肾病综合征，肾活检显示膜增殖性肾小球肾炎，伴有明显的巨噬细胞浸润和满堂免疫荧光肾小球沉积。此外，电镜下还发现了随机排列的无分支纤维，直径约 12nm，免疫组化染色显示 DnaJ 同源亚家族 B 成员 9（DNAJB9）阳性，该蛋白是新近发现的纤维状肾小球肾炎（FGN）的诊断性生物标志物，从而确诊为 FGN。开始给予激素治疗，患者肾病综合征完全缓解并持续缓解至今。FGN 是一种罕见的肾小球疾病，在亚洲人群，尤其是日本人中，报道的 DNAJB9 阳性 FGN 病例很少。目前尚无标准的治疗方案，其肾脏预后通常较差。本病例提示，部分 FGN 患者可通过激素单药治疗获得良好的临床结局。
