ETIOLOGIC FACTORS IN FOCAL GLOMERULAR SCLEROSIS

肾小球增大的循环因子的存在 局灶性硬化症患者大分子通透性的研究 肾小球肾炎(FSGS)由反复出现的蛋白尿支持 移植后的紧接时期和观察到的 血浆置换在逆转这种蛋白尿方面通常是有效的。 试图确定FSGS中肾小球损伤的相关因素 在很大程度上都不成功。我们已经在体外开发出一种灵敏的 肾小球蛋白通透性的测定，并已采用该测定 证明患者的血清或血浆中存在某种因子 FSGS可增加肾小球大分子通透性。 在含有活性血清的培养液中孵育肾小球可增加白蛋白 渗透率从正常值0到高达0.9。他的存在 移植前的这种活动与 蛋白尿早期复发和进行性肾功能不全 在肾移植后。初步研究表明， 活性成分是一种相对分子质量为110-120kD的蛋白质。它的 活性起效快，且呈浓度依赖性。活动是 中和了正常血清的存在；这一发现可能解释了 其他人在通过输液证明其存在时遇到的困难 变成完好无损的动物。拟议研究的目标是：1)净化 并鉴定了猪血清白蛋白通透性增强因子 FSGS患者采用硫酸铵沉淀、凝胶过滤、离子 交换柱层析、高效液相色谱、凝胶电泳法和 必要的等电聚焦和毛细管电泳法；2)至 测定其氨基酸组成和氨基酸序列 因子，以便将其与已知蛋白质进行比较。可提供的 活性的生物测定提供了一个独特的机会来识别和 描述导致蛋白尿的因素，并在以后的研究中 研究，建立该因子的免疫学测定，以鉴定其 来源，以确定其目标和行动机制，最后， 为FSGS患者开发合理有效的治疗方法。

The presence of a circulating factor that increases glomerular macromolecular permeability in patients with focal sclerosing glomerulonephritis (FSGS) is supported by recurrence of proteinuria in the immediate post-transplant period and by the observation that plasmapheresis is often effective in reversing this proteinuria. Attempts to identify the factor responsible for glomerular injury in FSGS have been largely unsuccessful. We have developed a sensitive in vitro assay for glomerular protein permeability and have employed this assay to demonstrate the presence of a factor in serum or plasma of patients with FSGS which increases glomerular macromolecular permeability. Incubation of glomeruli in media containing active sera increases albumin permeability from a normal value of 0 to as high as 0.9. The presence of this activity prior to transplantation is strongly associated with early recurrence of proteinuria and progressive renal insufficiency following renal transplantation. Preliminary studies suggest that the active component is a protein of molecular weight 110-120 kD. Its activity is rapid in onset and is concentration dependent. Activity is neutralized by the presence of normal serum; this finding may explain the difficulty that others have had in demonstrating its presence by infusion into intact animals. The goals of the proposed studies are: 1) to purify and characterize the albumin permeability enhancing factor from sera of FSGS patients using ammonium sulphate precipitation, gel filtration, ion exchange column chromatography, HPLC, gel electrophoresis and, if necessary, isoelectric focusing and capillary electrophoresis; 2) to determine the amino acid composition and amino acid sequence of the factor in order to compare it to known proteins. The availability of a bioassay for activity provides a unique opportunity to identify and characterize the factor responsible for proteinuria and, in later studies, to develop an immunologic assay for the factor, to identify its source, to define its targets and mechanism of action, and, finally, to develop rational and effective treatment for patients with FSGS.