草酸钙肾结石患者肾乳头钙盐沉积特点及其形成机制

Renal papillary calcareous deposits in patients with calcium oxalate kidney stones:characteristics and formation mechanism

目的:分析草酸钙肾结石患者肾乳头钙盐沉积特点及其在肾结石形成中的作用,并探讨肾钙盐沉积的机制。方法:选择21例行经皮肾取石术(PCNL)的草酸钙肾结石(采用傅立叶转换红外光谱法检测结石成分)患者,术中观察肾乳头钙斑情况;获取肾组织标本,行茜素红染色,显微镜下观察钙盐沉积特点;免疫组化检测骨桥蛋白、骨形成蛋白-2(BMP-2)和Ⅱ型胶原在肾结石患者肾组织的表达情况。另选7例非结石肾切除标本作为正常对照。结果:21例草酸钙肾结石患者均可见肾乳头钙斑;活检标本可见钙盐沉积于肾小管基底膜附近肾间质,并可向肾乳头黏膜延伸;当钙盐突破尿路上皮进入集合系统后,其上可见小结石生长。肾结石患者肾组织和正常肾组织均可见骨桥蛋白表达,未见BMP-2和Ⅱ型胶原明显表达。结论:肾乳头钙盐沉积是草酸钙肾结石形成的起始病灶之一;钙盐的形成可能并不是一种类似于动脉钙化的成骨性反应。

Objective：To investigate the characteristics of renal papillary calcareous deposits and their role in the formation of calcium oxalate kidney stone,and to explore the formation mechanism of renal calcareous deposits.Methods：A total of 21 patients with calcium oxalate kidney stones were included in the present study.The components of the calculi were detected by Fourier-transform infrared spectroscopy.The calcific plaques were observed and the renal papilla biopsy specimens were obtained during PCNL.The specimens were then subjected to alizarin bordeaux staining and light microscopic examination.The expression of osteopontin,BMP-2,and type Ⅱcollagen in the kidneys was examined by immunohistochemistry.Seven resected renal specimens from patients with non-urolithiasis served as control.Results：Renal papillary calcific plaques were found in all the 21 patients with renal calculi.Local calcareous deposits were found in the renal interstitium around tubular basement membrane and extended toward the mucous membrane in the renal papillas.Microscopically,once the calcareous deposits pierced into the collection system,tiny stones could be seen growing on the deposits.Immunohistochemistristry showed the renal tissues of renal stone patients and normal renal tissues both expressed osteopontin,but not BMP-2 or typeⅡ collagen.Conclusion：Renal papillary calcareous deposits may be one of the initiating nidi for kidney stone formation and they may not be an osteoblastic reaction resembling arteriosteogenesis.