Waters P, Vincent Angela
Neurosciences Group, Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford, UK.
Int MS J. 2008 Sep;15(3):99-105.
Neuromyelitis optica (NMO) is a severe inflammatory demyelinating disease that predominantly affects the optic nerve and spinal cord. Since the discovery of a specific serum marker for NMO in 2004, and its subsequent identification as an antibody to aquaporin-4 (AQP-4), various methods have been developed to test for the antibodies in patients sera.
To assess the principal methods used to measure AQP-4 antibodies in patients sera, describe their contribution to neuromyelitis spectrum disease and examine their value in the early detection of disease.
We compared the published data on each assay and used the relapsing NMO cohort as a uniform patient group for direct assay comparison.
The indirect immunofluorescence assay, a cellbased assay (CBA) and a fluorescence-based immunoprecipitation assay have broadly similar high sensitivities (86%, 91% and 83%) in the relapsing cohort, but the indirect immunofluorescence has a lower specificity (91%) compared with the other two (both 100% specific).
The indirect immunofluorescence assay for NMO-IgG allows the detection of antibodies in routine screening, but the CBA for AQP-4 antibodies is the most sensitive. The fluoroimmunoprecipitation assay is a potentially high-throughput test for identifying positive sera and for serial estimations of antibody levels, but in its present form is slightly less sensitive. Overall, these assays are proving very useful in helping to diagnose those patients with longitudinally extensive transverse myelitis or recurrent optic neuritis who are likely to have relapsing NMO, including patients with myelopathy and Sjogrens syndrome, but it appears to be less often positive in patients with monophasic NMO.
视神经脊髓炎（NMO）是一种主要累及视神经和脊髓的严重炎性脱髓鞘疾病。自2004年发现NMO的一种特异性血清标志物，并随后将其鉴定为水通道蛋白4（AQP-4）抗体以来，已开发出多种方法来检测患者血清中的抗体。
评估用于检测患者血清中AQP-4抗体的主要方法，描述它们对视神经脊髓炎谱系疾病的贡献，并检验它们在疾病早期检测中的价值。
我们比较了每种检测方法的已发表数据，并将复发型NMO队列作为一个统一的患者组进行直接检测比较。
间接免疫荧光法、基于细胞的检测法（CBA）和基于荧光的免疫沉淀法在复发队列中的敏感性大致相似（分别为86%、91%和83%），但间接免疫荧光法的特异性（91%）低于其他两种方法（均为100%特异性）。
用于检测NMO-IgG的间接免疫荧光法可在常规筛查中检测抗体，但AQP-4抗体的CBA检测法最敏感。荧光免疫沉淀法是一种潜在的高通量检测方法，可用于鉴定阳性血清和连续估计抗体水平，但目前形式的敏感性略低。总体而言，这些检测方法在帮助诊断那些可能患有复发型NMO的纵向广泛横贯性脊髓炎或复发性视神经炎患者（包括患有脊髓病和干燥综合征的患者）方面非常有用，但在单相NMO患者中似乎阳性率较低。
