Department of Neurology, Mayo Clinic, Rochester, Minnesota, USA.
Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota, USA.
Ann Clin Transl Neurol. 2024 Nov;11(11):2855-2865. doi: 10.1002/acn3.52178. Epub 2024 Oct 15.
This study aimed to evaluate the diagnostic accuracy of dried blood spot (DBS) compared with conventional serum Aquaporin-4-IgG (AQP4-IgG) testing.
Prospective multicenter diagnostic study was conducted between April 2018 and October 2023 across medical centers in the United States, Uganda, and the Republic of Guinea. Neuromyelitis optica spectrum disorder (NMOSD) patients and controls collected blood on filter paper cards along with concurrent serum samples. These samples underwent analysis using flow cytometric live-cell-based assays (CBA) and enzyme-linked immunosorbent assay (ELISA) to determine AQP4 serostatus. The accuracy of AQP4-IgG detection between DBS and serum (gold standard) was compared.
Among 150 participants (47 cases, 103 controls), there was a strong correlation between DBS and serum samples (Spearman's correlation coefficient of 0.82). The AUC was 0.97 (95% CI: 0.92-0.99). AQP4-IgG detection through DBS showed 87.0% sensitivity (95% CI: 0.74-0.95) and 100% specificity (95% CI: 0.96-1.00) using CBA, and 65.2% sensitivity (95% CI: 0.43-0.84) and 95.2% specificity (95% CI: 0.76-0.99) using ELISA. Serum ELISA demonstrated 69.6% sensitivity (95% CI: 0.47-0.87) and 98.4% specificity (95% CI: 0.91-0.99). The stability of DBS in detecting AQP4-IgG persisted over 24 months for most cases.
The DBS represents a viable alternative for detecting AQP4-IgG in resource-limited settings to diagnose NMOSD, offering high sensitivity and specificity comparable to serum testing. Moreover, DBS has low shipping costs, is easy to administer, and is suitable for point-of-care testing.
本研究旨在评估与传统血清水通道蛋白 4 免疫球蛋白 G（AQP4-IgG）检测相比，干血斑（DBS）的诊断准确性。
本前瞻性多中心诊断研究于 2018 年 4 月至 2023 年 10 月在美国、乌干达和几内亚共和国的医疗中心进行。视神经脊髓炎谱系疾病（NMOSD）患者和对照者在滤纸片上采集血液，同时采集血清样本。这些样本使用流式细胞术活细胞测定（CBA）和酶联免疫吸附测定（ELISA）进行分析，以确定 AQP4 血清状态。比较了 DBS 和血清（金标准）之间 AQP4-IgG 检测的准确性。
在 150 名参与者（47 例病例，103 例对照）中，DBS 和血清样本之间存在很强的相关性（Spearman 相关系数为 0.82）。AUC 为 0.97（95%CI：0.92-0.99）。通过 DBS 进行的 AQP4-IgG 检测，CBA 显示 87.0%的敏感性（95%CI：0.74-0.95）和 100%的特异性（95%CI：0.96-1.00），ELISA 显示 65.2%的敏感性（95%CI：0.43-0.84）和 95.2%的特异性（95%CI：0.76-0.99）。血清 ELISA 显示 69.6%的敏感性（95%CI：0.47-0.87）和 98.4%的特异性（95%CI：0.91-0.99）。在大多数情况下，DBS 检测 AQP4-IgG 的稳定性可维持 24 个月以上。
DBS 是一种在资源有限的环境中检测 AQP4-IgG 以诊断 NMOSD 的可行替代方法，具有高灵敏度和特异性，与血清检测相当。此外，DBS 具有较低的运输成本、易于管理，并且适合于即时检测。
