Morano S, Cancelli A, Mancuso M, Sensi M, Negri M, Gambardella S, Di Mario U
Clinica Medica 2 (Endocrinologia), Università La Sapienza, Policlinico Umberto I, Rome, Italy.
Diabetes Res. 1987 Dec;6(4):181-5.
In search of a marker for monitoring the progression of diabetic nephropathy from the stage of charge- to that of size-selectivity loss, attention has been focused on the evaluation of immunoglobulin G (IgG) subclasses in the urine. We have developed a new sensitive enzyme immunoassay for the quantitation of urinary IgG1 and IgG4. Mouse monoclonal antibodies specific for each subclass were bound to microtitre wells precoated with rabbit anti-mouse immunoglobulin antibody. IgG1 and IgG4 of standard preparations (or of samples to be tested) were revealed using peroxidase-conjugated rabbit anti-human IgG. The procedure was carried out at 4 degrees C. This method can detect about 2 ng/ml of IgG4 and 20 ng/ml of IgG1. The monoclonal antibodies used were shown to be highly subclass-specific. IgG1 and IgG4 have a similar molecular weight but a different pH (about 9 and 4.6 respectively); a change in their ratio in the urine of diabetic patients may indicate a progressive deterioration of kidney function at the stage of incipient diabetic nephropathy.
为了寻找一种能够监测糖尿病肾病从电荷选择性改变阶段发展到大小选择性丧失阶段的标志物，人们将注意力集中在尿液中免疫球蛋白G（IgG）亚类的评估上。我们开发了一种新的灵敏酶免疫测定法来定量检测尿IgG1和IgG4。针对每个亚类的小鼠单克隆抗体与预先包被有兔抗小鼠免疫球蛋白抗体的微量滴定孔结合。使用过氧化物酶偶联的兔抗人IgG来检测标准制剂（或待测样品）中的IgG1和IgG4。该操作在4℃下进行。此方法能够检测出约2 ng/ml的IgG4和20 ng/ml的IgG1。所使用的单克隆抗体显示出高度的亚类特异性。IgG1和IgG4分子量相似，但pH值不同（分别约为9和4.6）；糖尿病患者尿液中它们比例的变化可能表明在早期糖尿病肾病阶段肾功能逐渐恶化。
