Mahieu P, Lambert P H, Miescher P A
J Clin Invest. 1974 Jul;54(1):128-37. doi: 10.1172/JCI107734.
A radioimmunoassay for detection of anti-glomerular basement membrane (GBM) antibody was set up with a 70,000 mol wt GBM antigen, labeled with Iodine-(125)I and containing both types of oligosaccharidic chains present in the whole membrane. Separation of free radioactive antigens from antigens bound to immunoglobulins was obtained by precipitation with polyethylene glycol (mol wt, 6,000), at a final concentration of 20%. In the presence of normal human or rabbit sera, less than 20% of labeled antigens were precipitated. In the presence of rabbit anti-human GBM antibodies, up to 82% of GBM antigens were precipitated, while in the presence of sera or of kidney eluate from a patient with Goodpasture's syndrome, the precipitation of GBM antigens reached 43%. The avidity of rabbit anti-GBM antibodies for human GBM antigens is higher than that of human anti-GBM antibodies. In the case of Goodpasture's syndrome, the binding of anti-GBM antibodies to labeled antigens was inhibited more efficiently by the disaccharide-containing glycopeptide than by the heteropolysaccharide-containing glycopeptide purified from whole GBM.Anti-GBM antibodies were searched for in the serum of 300 normal blood donors, of 120 patients with glomerulonephritis (GN) and granular deposits, and of 14 patients with GN and linear deposits of immunoglobulins. After correction for the "nonspecific" precipitation, the average percentage (+/-1 SD) of labeled antigens precipitated in the serum of normal blood donors was 0.3+/-3.2%; 12 patients with GN and linear deposits exhibited high circulating anti-GBM antibody titers, while 8% of the patients with GN and granular deposits presented significant, albeit lower, anti-GBM activity in their sera.
建立了一种用于检测抗肾小球基底膜（GBM）抗体的放射免疫分析方法，使用的GBM抗原分子量为70,000，用碘 -（125）I标记，且包含全膜中存在的两种寡糖链类型。通过用聚乙二醇（分子量6,000）沉淀，最终浓度为20%，实现游离放射性抗原与结合到免疫球蛋白上的抗原的分离。在正常人或兔血清存在下，少于20%的标记抗原被沉淀。在兔抗人GBM抗体存在下，高达82%的GBM抗原被沉淀，而在患有Goodpasture综合征患者的血清或肾洗脱液存在下，GBM抗原的沉淀率达到43%。兔抗GBM抗体对人GBM抗原的亲和力高于人抗GBM抗体。在Goodpasture综合征的情况下，含二糖的糖肽比从全GBM中纯化的含杂多糖的糖肽更有效地抑制抗GBM抗体与标记抗原的结合。在300名正常献血者、120名患有肾小球肾炎（GN）和颗粒状沉积物的患者以及14名患有GN和免疫球蛋白线性沉积物的患者的血清中搜索抗GBM抗体。在校正“非特异性”沉淀后，正常献血者血清中沉淀的标记抗原的平均百分比（±1 SD）为0.3±3.2%；12名患有GN和线性沉积物的患者表现出高循环抗GBM抗体滴度，而8%患有GN和颗粒状沉积物的患者血清中呈现出显著的、尽管较低的抗GBM活性。
