Pathological characteristics of BK polyomavirus-associated nephropathy with glomerular involvement
Pathological characteristics of BK polyomavirus-associated nephropathy with glomerular involvement
复制标题
累及肾小球的BK多瘤病毒相关肾病的病理特征
DOI：
10.21037/atm-20-1879
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发表时间：
2020-08-01
影响因子：
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通讯作者：
Huang, Gang
中科院分区：
文献类型：
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作者：
Chen, Xu-Tao;Deng, Rong-Hai;Huang, Gang
本研究旨在探讨肾移植受者BK多瘤病毒（BKPyV）相关性肾病（BKPyVAN）伴肾小球受累的病理特征。方法回顾性分析44例肾小球BKPyV感染患者的临床资料。使用单克隆小鼠抗SV 40大T抗原抗体对石蜡切片进行免疫组织化学（IHC）染色。结果BKPyV感染的肾小球壁上皮细胞（GPEC）肿胀、深染、增大，核质比（N/C）增加，核内病毒包涵体呈浑浊、嗜碱性。IHC染色显示BKPyV参与Bowman间隙内的GPEC、足细胞和脱落细胞的分布。值得注意的是，BKPyV影响GPEC增殖并引起新月体形成（7次活检，15.9%）。三个活检表现出纤维新月体和病毒夹杂物的情况下。其他4例活检显示细胞和纤维细胞新月体，病毒细胞病变和增殖的GPEC中的阳性IHC染色。电子显微镜显示病毒颗粒在GPEC和足细胞。BKPyV感染的GPEC变性，线粒体肿胀，内质网扩张，和多层膜结构的形成。12例（27.3%）患者在1.6至39.5个月（中位数：13.5个月）内接受了重复活检，但均未发现持续性肾小球BKPyV感染。结论BKPyVAN活检中明显的肾小球改变应提高肾小球受累的可能性。
Background This study aimed to investigate the pathological characteristics of BK polyomavirus (BKPyV)-associated nephropathy (BKPyVAN) with glomerular involvement in kidney transplant recipients. Methods Forty-four patients with glomerular BKPyV infection were retrospectively included for analysis. Immunohistochemical (IHC) staining was performed on paraffin sections using monoclonal mouse anti-SV40 large T antigen antibody. Results In BKPyV-infected glomeruli, the glomerular parietal epithelial cells (GPECs) were swollen, hyperchromatic, and enlarged, with an increased nuclear to cytoplasm (N/C) ratio and smudgy basophilic intra-nuclear viral inclusions. IHC staining revealed the distribution of BKPyV involvement in GPECs, podocytes, and shedding cells within Bowman’s space. Notably, BKPyV affected GPEC proliferation and caused crescent formation (7 biopsies, 15.9%). Three biopsies exhibited fibrous crescents and the absence of viral inclusions. The other 4 biopsies exhibited cellular and fibro-cellular crescents, with viral cytopathic changes and positive IHC staining in the proliferative GPECs. Electron microscopy showed viral particles in both GPECs and podocytes. BKPyV-infected GPECs were degenerative, with mitochondrial swelling, endoplasmic reticulum expansion, and multi-layered membranous structure formation. Twelve (27.3%) patients received repeat biopsies within 1.6 to 39.5 months (median: 13.5 months), but none revealed persistent glomerular BKPyV infection. Conclusions Distinct glomerular changes in BKPyVAN biopsies should raise the possibility of glomerular involvement.