ABSTRACT

Introduction: Myasthenia gravis (MG) is a prototypical autoimmune disease, characterized by pathogenic autoantibodies targeting structures of the neuromuscular junction. Radioimmunoprecipitation assays (RIPAs) represent the gold standard for their detection. However, new methods are emerging to complement, or overcome RIPAs, also with the perspective of eliminating the use of radioactive reagents.

Areas covered: We discuss advances in laboratory methods, prompted especially by cell-based assays (CBAs), for the detection of the autoantibodies of MG diagnostics, above all those to the nicotinic acetylcholine receptor (AChR), muscle-specific kinase (MuSK), and low molecular-weight receptor-related low-density lipoprotein-4 (LRP4).

Expert opinion: CBA technology makes AChRs aggregate on cell membranes, thus allowing to detect autoantibodies to clustered AChRs, with reduction of seronegative MG cases. The diagnostic relevance of RIPA/CBA-measurable LRP4 antibodies is still unclear, in Caucasian patients at least. Live CBAs for the detection of AChR, MuSK, and LRP4 antibodies might represent an alternative to RIPAs, but first require full validation. CBAs could be used as screening tests, limiting RIPAs for antibody quantification. To this end, ELISAs might be an alternative.

Fixation procedures preserving enough degree of antigen conformationality could yield AChR and MuSK CBAs suitable for a wide use in clinical-chemistry laboratories

摘要

简介: 重症肌无力 (MG) 是一种典型的自身免疫性疾病，其特征是针对神经肌肉接头结构的致病性自身抗体。放射免疫沉淀测定 (RIPAs) 代表了其检测的金标准。然而，正在出现新的方法来补充或克服 RIPA，同时也考虑到消除放射性试剂的使用。

涵盖的领域：我们讨论了实验室方法的进步，尤其是基于细胞的检测 (CBA)，用于检测 MG 诊断的自身抗体，尤其是烟碱乙酰胆碱受体 (AChR)、肌肉特异性激酶 (MuSK)和低分子量受体相关的低密度脂蛋白 4 (LRP4)。

专家意见：CBA 技术使 AChRs 聚集在细胞膜上，从而可以检测聚集 AChRs 的自身抗体，减少血清阴性 MG 病例。至少在白种人患者中，RIPA/CBA 可测量的 LRP4 抗体的诊断相关性仍不清楚。用于检测 AChR、MuSK 和 LRP4 抗体的活 CB​​A 可能代表 RIPA 的替代方案，但首先需要全面验证。CBA 可用作筛选测试，限制 RIPA 用于抗体定量。为此，ELISA 可能是一种替代方法。

保留足够程度的抗原构象的固定程序可以产生适用于临床化学实验室广泛使用的 AChR 和 MuSK CBA