Melvin T, Kim Y, Michael A F
Am J Pathol. 1984 Jun;115(3):443-6.
Renal tissue from 9 patients with diabetes mellitus (4 with mild and 5 with end-stage disease) and 3 with antiglomerular basement membrane (GBM) nephritis, as well as 5 normal human kidneys, were examined by immunofluorescence microscopy for the presence of plasma proteins of varying isoelectric point (pI). In normal and diabetic kidneys, IgG deposition in basement membranes was restricted to IgG4 (pI 5.5-6.0), the subclass present in lowest concentration in human plasma. IgG1, IgG2, and IgG3 (pI 7.0-9.5) were not detected. In contrast, in anti-GBM nephritis, all four subclasses were present in a linear pattern in GBM. Other plasma proteins of low isoelectric point were detected in basement membranes: albumin (pI 4.9), alpha-1-acid glycoprotein (pI 2.7), amyloid P (pI 3.9-4.8), and alpha-1-antitrypsin (pI 4.5). These studies are consistent with the hypothesis that circulating anionic plasma proteins are electrostatically bound in vivo to positively charged moieties in normal and especially diabetic basement membranes.
对9例糖尿病患者（4例轻度和5例终末期疾病患者）、3例抗肾小球基底膜（GBM）肾炎患者的肾组织以及5个正常人类肾脏进行免疫荧光显微镜检查，以检测不同等电点（pI）的血浆蛋白的存在情况。在正常肾脏和糖尿病肾脏中，基底膜中的IgG沉积仅限于IgG4（pI 5.5 - 6.0），这是人类血浆中浓度最低的亚类。未检测到IgG1、IgG2和IgG3（pI 7.0 - 9.5）。相比之下，在抗GBM肾炎中，所有四个亚类均以线性模式存在于GBM中。在基底膜中还检测到其他低等电点的血浆蛋白：白蛋白（pI 4.9）、α-1-酸性糖蛋白（pI 2.7）、淀粉样蛋白P（pI 3.9 - 4.8）和α-1-抗胰蛋白酶（pI 4.5）。这些研究与以下假设一致，即循环中的阴离子血浆蛋白在体内通过静电作用与正常尤其是糖尿病基底膜中的带正电荷部分结合。
