Sano M, Lennon V A
Department of Neurology, Mayo Clinic, Rochester, MN 55905.
Neurology. 1993 Mar;43(3 Pt 1):573-8. doi: 10.1212/wnl.43.3_part_1.573.
Anti-acetylcholine receptor (AChR) autoantibodies are a marker of acquired myasthenia gravis (MG). Some of these antibodies cause muscle weakness. Striational autoantibodies (StrAb) also are a marker of MG. They are most prevalent in older patients and patients with thymoma. Here we describe a reproducible enzyme immunoassay (AChR-EIA) for detecting antibodies reactive with human muscle AChR, using antigens concentrated on plastic by prior sequential application of a biotinylated carrier, avidin, and biotinylated monoclonal IgG against AChR. There was significant correlation between values for antibodies assayed by AChR-EIA and by immunoprecipitation of AChR complexed with 125I-alpha-bungarotoxin. Unexpectedly, AChR-EIA and StrAb values also were significantly correlated. Further studies revealed a significant and unprecedented correlation for StrAb and AChR precipitating antibodies. A plausible explanation for these findings is that some StrAb may react with cytoskeletal proteins that associate and copurify with AChR. The AChR-EIA offers a nonradioactive method for detecting two autoantibodies that are relatively restricted to patients with acquired MG.
抗乙酰胆碱受体（AChR）自身抗体是获得性重症肌无力（MG）的一个标志物。其中一些抗体可导致肌无力。横纹肌自身抗体（StrAb）也是MG的一个标志物。它们在老年患者和胸腺瘤患者中最为常见。在此，我们描述了一种可重复的酶免疫测定法（AChR-EIA），用于检测与人肌肉AChR反应的抗体，该方法使用通过依次预先应用生物素化载体、抗生物素蛋白和抗AChR生物素化单克隆IgG而浓缩在塑料上的抗原。通过AChR-EIA测定的抗体值与通过与125I-α-银环蛇毒素复合的AChR免疫沉淀法测定的抗体值之间存在显著相关性。出乎意料的是，AChR-EIA值和StrAb值也显著相关。进一步研究揭示了StrAb与AChR沉淀抗体之间存在显著且前所未有的相关性。对这些发现的一个合理的解释是，一些StrAb可能与与AChR相关并共同纯化的细胞骨架蛋白发生反应。AChR-EIA提供了一种非放射性方法来检测两种相对局限于获得性MG患者的自身抗体。
