抗谷氨酸脱羧酶（GAD）65自身抗体在自身免疫性神经疾病中的作用正在发展，但在澳大利亚的检测建议仍然保持不变，只有GAD酶联免疫吸附试验（ELISA）和免疫印迹作为唯一两种治疗商品管理局批准的检测方法。通常我们诊断1型糖尿病（T1DM）使用ELISA，而诊断GAD65相关神经疾病则使用免疫印迹。我们观察到一组在GAD相关神经疾病情况下，在免疫印迹结果为阴性而ELISA结果为阳性的病人样本。在缺乏关于首选检测模式的强有力共识指导的情况下，我们试图确定ELISA在GAD相关神经疾病诊断中是否比免疫印迹更具优势。我们使用两种测试平台对55个患者样本进行了抗GAD65自身抗体检测，其中40个样本是为神经疾病而请求的，15个1型糖尿病样本具有检测到的抗GAD65。我们使用欧洲免疫抗GAD酶联免疫吸附试验（ELISA）和Euroimmun EuroLine免疫印迹对神经类肿瘤综合征进行检测。这些结果与临床情况进行了相关性分析。阳性的ELISA结果对于GAD65相关神经疾病的敏感性为100％，特异性为91％。免疫印迹显示GAD65相关神经疾病的敏感性为43％，特异性为76％。与免疫印迹相比，ELISA对于GAD65相关神经疾病更为敏感和特异，这引发了关于该检测方法在神经疾病中的作用的问题。我们建议在所有GAD65抗体相关的神经疾病中，ELISA应作为唯一的诊断方法，而免疫印迹中的抗GAD65抗体的存在具有可疑的临床意义。版权所有 ©2023年澳大利亚病理学家皇家学院。保留所有权利。

The role of anti-glutamic acid decarboxylase (GAD) 65 autoantibodies in autoimmune neurological conditions is evolving, but testing recommendations remain unchanged in Australia with GAD enzyme-linked immunosorbent assay (ELISA) and immunoblot as the only two Therapeutic Goods Administration approved testing methods available in Australia. Common practice is for use of ELISA in diagnosis of type 1 diabetes mellitus (T1DM) and use of immunoblot for diagnosis of GAD65-associated neurological disease. We observed a cohort of patients with negative immunoblot results and positive ELISA in the context of GAD-associated neurological disease without T1DM. In the absence of robust consensus guidelines on preferred testing modalities, we sought to determine if ELISA could have a superior role in the diagnosis of GAD-associated neurological disease when compared to immunoblot in this paper. We tested for anti-GAD65 autoantibodies on 55 patient samples, 40 samples requested for neurological disease and 15 type 1 diabetes samples with detectable anti-GAD65, using two testing platforms: Euroimmun anti-GAD enzyme-linked immunosorbent assay (ELISA) and. Euroimmun EuroLine immunoblot for paraneoplastic neurologic syndromes. These results were correlated against the clinical scenario. Positive ELISA results had a sensitivity of 100% and specificity of 91% for GAD65-related neurological disease. Immunoblot showed sensitivity of 43% and specificity of 76% for GAD65-related neurological disease. ELISA proved more sensitive and specific for GAD65-related neurological disease compared to immunoblot, raising questions about the role of this testing modality in neurological disease. We propose that ELISA should be used as a sole diagnostic method for all GAD65 antibody-related neurological disease over immunoblot. The presence of anti-GAD65 antibody on immunoblot is of doubtful clinical significance.Copyright © 2023 Royal College of Pathologists of Australasia. All rights reserved.