Kittelberger R, Kerjaschki D, Neale T J
Department of Medicine, Wellington School of Medicine, New Zealand.
Clin Nephrol. 1994 Feb;41(2):72-82.
In this communication 7-5Q/A, a recently described human kidney-specific acidic membrane glycoprotein, was immunolocalized by immunofluorescence in kidney and placenta, and by immunogold electron microscopy in the kidney. The antigen is located above and below the slit diaphragm on epithelial cell foot processes in the glomerulus, and also on proximal tubular brush border membranes. In the placenta it was present on epithelial membranes. 7-5Q/A and dipeptidylpeptidase IV were compared by a variety of techniques because of their similar size and possible location, and found to be distinct. A sensitive sandwich ELISA was developed using polyclonal and monoclonal antibodies to 7-5Q/A, and applied to the quantitation of this antigen in the urines and sera of patients with a variety of kidney diseases, and in the urines and sera of normal subjects. The concentration of 7-5Q/A in normal urines ranged from 0 to 2 ng/ml but levels of up to 150 ng/ml were found in urines of patients with renal disease. 7-5Q/A was not detectable in either normal or nephritic sera. Urinary quantitation of this unique antigen may be of value in the early diagnosis of renal disease.
在本交流中，一种最近描述的人肾特异性酸性膜糖蛋白7-5Q/A，通过免疫荧光法在肾脏和胎盘中进行了免疫定位，并通过免疫金电子显微镜法在肾脏中进行了定位。该抗原位于肾小球上皮细胞足突上裂孔隔膜的上方和下方，也存在于近端肾小管刷状缘膜上。在胎盘中，它存在于上皮膜上。由于7-5Q/A和二肽基肽酶IV大小相似且可能位置相同，因此通过多种技术对它们进行了比较，结果发现它们是不同的。利用针对7-5Q/A的多克隆和单克隆抗体开发了一种灵敏的夹心ELISA，并将其应用于多种肾脏疾病患者尿液和血清以及正常受试者尿液和血清中该抗原的定量分析。正常尿液中7-5Q/A的浓度范围为0至2 ng/ml，但在肾病患者的尿液中发现其水平高达150 ng/ml。在正常血清或肾炎血清中均未检测到7-5Q/A。对这种独特抗原进行尿液定量分析可能对肾病的早期诊断有价值。
