Gastaldi Matteo, Zardini Elisabetta, Scaranzin Silvia, Uccelli Antonio, Andreetta Francesca, Baggi Fulvio, Franciotta Diego
Neuroimmunology Laboratory, IRCCS Mondino Foundation, Pavia, Italy.
Department of Brain and Behavioral Science, University of Pavia, Pavia, Italy.
Front Neurol. 2020 Jan 14;10:1385. doi: 10.3389/fneur.2019.01385. eCollection 2019.
Neuroimmunology has impressively expanded in the past decade. Novel assays, especially cell-based assays (CBAs) can detect conformational antibodies (Abs) recognizing antigens in their native conformation. Generally, the availability of in-house and of commercial tests has improved the diagnostics, but introduced demanding laboratory tasks. Hence, standardization and quality controls represent a key step to promote accuracy. We report on the results of the 2018 external quality assessment program (EQAP) organized by the Italian Neuroimmunology Association. EQAP regarded 10 schemes, including oligoclonal bands (OCBs), intracellular-neuronal (ICN)-Abs, neuronal-surface (NS)-Abs, aquaporin-4 (AQP4)-Abs, myelin oligodendrocyte glycoprotein (MOG)-Abs, myelin-associated glycoprotein (MAG)-Abs, ganglioside-Abs, acetylcholine-receptor (AChR)-Abs, and muscle-specific-kinase (MuSK)-Abs, and 34 laboratories. Assays were classified as tissue-based assays (TBAs), solid-phase assays (SPAs), liquid-phase assays (LPAs), and CBAs. Thirty-three samples were provided. Three-quarter of the tests were commercial. Median accuracy for the laboratories was 75% (range 50-100). In 8/10 schemes, at least one sample provided discrepant results. Inter-laboratory "substantial agreement" was found in 6/10 schemes (AChR, MuSK, MAG, AQP4, MOG, and NS-Abs), whereas the worst agreements regarded OCBs and ganglioside-Abs. Both commercial and in-house assays performed better in experienced laboratories. Assays could be divided in (a) robust commercial tests with substantial inter-laboratory agreement (MAG-Abs; AChR- and MuSK-Abs); commercial/"in-house" tests with (b) partial inter-laboratory agreement (AQP4-Abs, MOG-Abs, NS-Abs, ICN-Abs), and (c) with large inter-laboratory disagreement (OCBs, ganglioside-Abs). This real-life snapshot of the neuroimmunology test performances highlights shortcomings attributable to technician-dependent performances, assay structural limitations, and errors in test interpretations.
在过去十年中，神经免疫学取得了令人瞩目的发展。新型检测方法，尤其是基于细胞的检测方法（CBAs），能够检测识别天然构象抗原的构象抗体（Abs）。一般来说，内部检测和商业检测的可用性提高了诊断水平，但也带来了艰巨的实验室任务。因此，标准化和质量控制是提高准确性的关键步骤。我们报告了意大利神经免疫学协会组织的2018年外部质量评估计划（EQAP）的结果。EQAP涉及10种检测项目，包括寡克隆带（OCBs）、细胞内神经元（ICN）抗体、神经元表面（NS）抗体、水通道蛋白4（AQP4）抗体、髓鞘少突胶质细胞糖蛋白（MOG）抗体、髓鞘相关糖蛋白（MAG）抗体、神经节苷脂抗体、乙酰胆碱受体（AChR）抗体和肌肉特异性激酶（MuSK）抗体，以及34个实验室。检测方法分为基于组织的检测方法（TBAs）、固相检测方法（SPAs）、液相检测方法（LPAs）和基于细胞的检测方法（CBAs）。提供了33个样本。四分之三的检测是商业检测。各实验室的中位准确率为75%（范围为50%-100%）。在10种检测项目中的8种中，至少有一个样本给出了不一致的结果。在10种检测项目中的6种（AChR、MuSK、MAG、AQP4、MOG和NS抗体）中发现了实验室间的“实质性一致”，而一致性最差的是OCBs和神经节苷脂抗体。商业检测和内部检测在经验丰富的实验室中表现更好。检测方法可分为：（a）具有实验室间实质性一致的可靠商业检测（MAG抗体；AChR和MuSK抗体）；（b）具有部分实验室间一致的商业/“内部”检测（AQP4抗体、MOG抗体、NS抗体、ICN抗体），以及（c）具有较大实验室间差异的检测（OCBs、神经节苷脂抗体）。神经免疫学检测性能的这一真实写照凸显了由于技术人员依赖的性能、检测结构限制和检测解释错误所导致的不足。
