Division of Molecular Neuroimmunology, Department of Neurology, University of Heidelberg, Heidelberg, Germany.
Mult Scler. 2011 Sep;17(9):1067-73. doi: 10.1177/1352458511403958. Epub 2011 May 4.
A new autoantibody (termed NMO-IgG, or AQP4-Ab) has recently been described in patients with neuromyelitis optica (NMO) and its formes frustes, longitudinally extensive transverse myelitis (LETM) and recurrent optic neuritis (rON). However, AQP4-Ab has been found also in patients with co-existing rheumatic diseases such as systemic lupus erythematosus (SLE) or Sjögren's syndrome (SS), conditions which are characterized by broad, polyspecific B cell activation.
In this study, we aimed at evaluating the syndrome specificity and frequency of AQP4-Ab in patients with rheumatic diseases and neurological symptoms.
For this purpose, serum samples from 109 neurological patients with established connective tissue disorders (CTD) (n = 54), possible CTD (n = 42), or vasculitis (n = 13) were analysed for the presence of AQP4-Ab by a cell-based assay employing recombinant human AQP4.
AQP4-Ab was detectable in 31/40 (78%) patients with CTD and NMO spectrum disorders (median titre, 1:1000) but in none of the samples obtained from patients with CTD or vasculitis and neurological disorders other than NMO, LETM, or rON (n = 69).
The high syndrome specificity of the antibody for neuromyelitis optica spectrum disorders (NMOSDs) in patients with CTD supports the concept of AQP4-Ab being involved in the pathogenesis of these neurological conditions, and argues against AQP4-Ab simply being part of the polyclonal B cell activation generally associated with rheumatic diseases. Moreover, the finding that AQP4-Ab is present in patients with CTD and co-existing NMOSD with approximately the same frequency as in patients without CTD strengthens the case of CTD and AQP4-Ab positive NMOSD representing two co-existing yet distinct entities in the majority of patients.
最近在视神经脊髓炎（NMO）及其顿挫型、长节段横贯性脊髓炎（LETM）和复发性视神经炎（rON）患者中描述了一种新的自身抗体（称为 NMO-IgG 或 AQP4-Ab）。然而，AQP4-Ab 也存在于合并风湿性疾病的患者中，如系统性红斑狼疮（SLE）或干燥综合征（SS），这些疾病的特点是广泛的多特异性 B 细胞激活。
本研究旨在评估风湿性疾病伴神经系统症状患者中 AQP4-Ab 的综合征特异性和频率。
为此，通过基于细胞的测定法，使用重组人 AQP4 分析了 109 例神经科患者的血清样本，这些患者患有已确诊的结缔组织疾病（CTD）（n=54）、可能的 CTD（n=42）或血管炎（n=13）。
在 40 例 CTD 和 NMO 谱障碍患者中（中位滴度为 1:1000）可检测到 AQP4-Ab，而在 CTD 或血管炎患者以及除 NMO、LETM 或 rON 以外的神经疾病患者的样本中均未检测到（n=69）。
该抗体对 CTD 患者 NMOSD 的高综合征特异性支持 AQP4-Ab 参与这些神经疾病发病机制的概念，并反对 AQP4-Ab 仅仅是与风湿性疾病相关的多克隆 B 细胞激活的一部分。此外，AQP4-Ab 存在于 CTD 患者和合并 NMOSD 的患者中，其频率与无 CTD 的患者大致相同，这一发现进一步支持了 CTD 和 AQP4-Ab 阳性 NMOSD 在大多数患者中代表两个同时存在但又不同的实体的观点。
