水通道蛋白4抗体检测的方法学比较及其临床意义

目的 比较经典分析法和水通道蛋白4(AQP4)抗体分析法对AQP4抗体检测率的异同,并探讨该抗体对区分中国视神经脊髓炎(NMO)和多发性硬化(MS)患者的诊断准确度.方法 选择44例NMO和46例MS患者的血清,采用经典分析法检测血清中的NMO-IgG(AQP4),AQP4抗体分析法检测血清中AQP4抗体.结果 90份血清中,两种方法检测结果均为阳性的36份,两种方法检测结果均为阴性的45份,经典分析法阳性但AQP4抗体分析法阴性血清4份,AQP4抗体分析法阳性但经典分析法阴性血清5份,2种方法的阳性率、阴性率差异无统计学意义(P=1.000).2种方法一致性检验Kappa=0.798,P=0.000.经典分析法检测NMO患者NMO-IgG的灵敏度为77.3%,阳性预测值85.0%,特异度87.0%,阴性预测值87.0%,诊断正确率为82.2%,Youden指数74.3%.AQP4抗体分析法检测NMO患者AQP4抗体的灵敏度为88.6%,阳性预测值95.1%,特异度95.7%,阴性预测值89.8%,诊断正确率为92.2%,Youden指数84.3%.结论 两种AQP4抗体检测方法对区分MS与NMO都具有高灵敏度与特异度,但是抗AQP4抗体分析法对NMO诊断具有更高的诊断准确性,值得推广.     

水通道蛋白4抗体检测的方法学比较及其临床意义

目的 比较经典分析法和水通道蛋白4(AQP4)抗体分析法对AQP4抗体检测率的异同,并探讨该抗体对区分中国视神经脊髓炎(NMO)和多发性硬化(MS)患者的诊断准确度.方法 选择44例NMO和46例MS患者的血清,采用经典分析法检测血清中的NMO-IgG(AQP4),AQP4抗体分析法检测血清中AQP4抗体.结果 90份血清中,两种方法检测结果均为阳性的36份,两种方法检测结果均为阴性的45份,经典分析法阳性但AQP4抗体分析法阴性血清4份,AQP4抗体分析法阳性但经典分析法阴性血清5份,2种方法的阳性率、阴性率差异无统计学意义(P=1.000).2种方法一致性检验Kappa=0.798,P=0.000.经典分析法检测NMO患者NMO-IgG的灵敏度为77.3%,阳性预测值85.0%,特异度87.0%,阴性预测值87.0%,诊断正确率为82.2%,Youden指数74.3%.AQP4抗体分析法检测NMO患者AQP4抗体的灵敏度为88.6%,阳性预测值95.1%,特异度95.7%,阴性预测值89.8%,诊断正确率为92.2%,Youden指数84.3%.结论 两种AQP4抗体检测方法对区分MS与NMO都具有高灵敏度与特异度,但是抗AQP4抗体分析法对NMO诊断具有更高的诊断准确性,值得推广.     

视神经脊髓炎患者血清 NMO-IgG 检测及其诊断价值

目的 检测神经脊髓炎(neuromyelitis optica,NMO)患者血清NMO-IgG的表达,并探讨其在NMO诊断中的价值.方法 收集北京、辽宁丹东、山西大同三家医疗机构临床诊断为NMO患者26例、多发性硬化(multiple sclerosis,MS)患者32例、神经科其他疾病患者77例;以稳定表达人源水通道蛋白-4(aquaporin-4,AQP4)的人胚肾293(HEK293)细胞株为底物,应用间接免疫荧光法检测患者血清NMO-IgG水平.结果 16例(61.5%)NMO患者血清NMO-IgG阳性,其阳性检出率显著高于MS患者(9.4 %)和MS+神经科其他疾病患者(4.6 %)(P<0.01).NMO-IgG对NMO诊断的灵敏度为61.5%,以MS作为对照时,该抗体对NMO诊断特异度为90.6%,以MS+神经科其他疾病作对照时,其特异度为95.4%.结论 NMO患者血清中普遍存在NMO-IgG,其可作为国内NMO诊断的重要生物学指标.     

水通道蛋白4抗体检测对视神经脊髓炎的诊断价值

目的:探讨水通道蛋白4(AQP4)抗体检测对视神经脊髓炎(NMO)的诊断价值.方法:采用表达人AQP4基因的人胚肾(HEK)293细胞株分别对35例NMO患者(NMO组)、14例NMO高危综合征患者(HRS组)、37例多发性硬化患者(MS组)、23例其他脱髓鞘疾病患者(ODD组)及75例其他神经系统疾病患者(MD组)的血标本进行AQP4抗体检测,比较各组抗体的阳性率.结果:NMO组中31例患者(88.6%)及HRS组中6例患者(42.9%n)AQP4抗体检测为阳性;MS组、ODD组和MD组患者AQP4抗体检测均为阴性.NMO组AQP4抗体检测阳性的敏感性为88.6%,95%CI,73.11%-96.79%;HRS组AQP4抗体检测阳性的敏感性为42.9%,95%CI:16.97%-68.83%;NMO患者AQP4抗体检测阳性的特异性为100%.结论:AQP4抗体检测对NMO及其疾病谱早期确诊有重要意义,且具有较高的敏感性和特异性.     

水通道蛋白4启动子基因多态性与多发性硬化、视神经脊髓炎遗传易患性的关系

目的 探讨水通道蛋白4(AQP4)启动子区基因多态性与我国南方多发性硬化(MS)、视神经脊髓炎(NMO)患者血清抗AQP4抗体水平及遗传易患性的关系.方法 收集18例NMO、38例MS、13例复发性脊髓炎(RM)、6例复发性视神经炎(RON)患者及39名对照,PCR扩增AQP4外显子0及外显子1启动子基因(即AQP4-promoter0和AQP4-promoter 1),并行DNA测序.结果 共发现14个AQP4-promoter0及6个AQP4-promoter 1基因多态性位点.血清抗AQP4抗体阳性患者AQP4-promoter 0中-1003 bp多态性位点(A突变为G)发生率比血清抗AQP4抗体阴性患者(13/18与20/45,P=0.046)及对照组(13/18与10/39,P=0.001)高,差异有统计学意义.血清抗AQP4抗体阳性患者及血清抗AQP4抗体阴性患者AQP4-promoter 1中- 401 bp与-400 bp之间多态性位点(插入1个C)发生率均比对照组高(5/16与0/28,P=0.008; 8/38与0/28,P=0.027),差异有统计学意义.NMO及MS患者-1003bp多态性位点及-401 bp与-400 bp之间多态性位点发生率均比对照组高,差异有统计学意义(NMO:11/18与10/39,P=0.010;4/15与0/28,P=0.020;MS:19/38与10/39,P=0.027;8/34与0/28,P=0.018).结论 AQP4启动子区基因存在多态性位点,且与NMO、MS易患性有一定的关系;AQP4外显子0启动子中- 1003 bp多态性位点可能与血清抗AQP4抗体的出现有关.     

免疫荧光检测人血清视神经脊髓炎免疫球蛋白G的实验方法

目的 建立检测神经脊髓炎免疫球蛋白G(NMO-IgG)的间接免疫荧光方法,描述其注意事项.方法 选择C57小鼠小脑、中脑、肾脏和胃冰冻切片作为基质.人血清经稀释、豚鼠肝粉预处理后,滴加于封闭液处理的上述切片,4℃过夜后滴加荧光素结合的羊抗人IgG的抗体,封片、荧光显微镜观察.实验通过荧光双标技术确定NMO-Igc结合部位与AQP4表达位置是否一致.结果 测定了182份人血清,通过间接免疫荧光法证实部分NMO、MS、脊髓炎、视神经炎患者血清有NMO-IgG结合到小鼠的软脑膜、脑膜下和脑、脊髓的毛细血管部位.荧光双标技术显示NMO-IgG的结合位置与AQP4表达的位置完全一致.豚鼠肝粉-PBS液对照及空白对照无特异荧光.结论 以C57小鼠的小脑、肾脏和胃冰冻切片作为基质,通过间接免疫荧光法能成功检测出人血清中的NMO-IgG抗体,有助于我们对NMO进行诊断与鉴别诊断.     

视神经脊髓炎与多发性硬化的临床表现和视神经脊髓炎IgG抗体阳性率的对比

目的 比较视神经脊髓炎(NMO)和多发性硬化(MS)在临床表现、辅助检查等方面的不同;比较NMO和MS等脱髓鞘疾病患者血清NMO-IgG抗体的阳性率,判断该抗体能否作为鉴别诊断的一项实验室依据.方法 对34例NMO、22例MS、24例高危综合征、5例临床孤立综合征以及35例其他神经科疾病患者进行NMO-IgG检测,并对其中NMO、MS患者的人口学、临床表现、免疫学指标、脑脊液、头颅MRI等资料进行对比.结果 NMO的起病年龄较MS大且年龄跨度更广;从年复发率和进展指数来看,NMO更为严重,预后更差;NMO长节段脊髓损害者比MS多.NMO-IgG在NMO组和高危综合征组的阳性率分别为58.8%(20/34)和45.8%(11/24),高于MS组(1/22)、临床孤立综合征组(1/5)和其他疾病组(1/35;X2=37.2,P<0.01).NMO-IgG阳性率与脊髓病变长度相关.结论 NMO和MS在临床表现、辅助检查等方面都有所不同,提示NMO与MS可能是2种不同的疾病.NMO-IgG在NMO患者中的阳性率高于MS患者,可以作为鉴别诊断的一项实验室依据.     

视神经脊髓炎与多发性硬化的临床表现和视神经脊髓炎IgG抗体阳性率的对比

目的 比较视神经脊髓炎(NMO)和多发性硬化(MS)在临床表现、辅助检查等方面的不同;比较NMO和MS等脱髓鞘疾病患者血清NMO-IgG抗体的阳性率,判断该抗体能否作为鉴别诊断的一项实验室依据.方法 对34例NMO、22例MS、24例高危综合征、5例临床孤立综合征以及35例其他神经科疾病患者进行NMO-IgG检测,并对其中NMO、MS患者的人口学、临床表现、免疫学指标、脑脊液、头颅MRI等资料进行对比.结果 NMO的起病年龄较MS大且年龄跨度更广;从年复发率和进展指数来看,NMO更为严重,预后更差;NMO长节段脊髓损害者比MS多.NMO-IgG在NMO组和高危综合征组的阳性率分别为58.8%(20/34)和45.8%(11/24),高于MS组(1/22)、临床孤立综合征组(1/5)和其他疾病组(1/35;X2=37.2,P<0.01).NMO-IgG阳性率与脊髓病变长度相关.结论 NMO和MS在临床表现、辅助检查等方面都有所不同,提示NMO与MS可能是2种不同的疾病.NMO-IgG在NMO患者中的阳性率高于MS患者,可以作为鉴别诊断的一项实验室依据.     

视神经脊髓炎与多发性硬化的临床表现和视神经脊髓炎IgG抗体阳性率的对比

目的 比较视神经脊髓炎(NMO)和多发性硬化(MS)在临床表现、辅助检查等方面的不同;比较NMO和MS等脱髓鞘疾病患者血清NMO-IgG抗体的阳性率,判断该抗体能否作为鉴别诊断的一项实验室依据.方法 对34例NMO、22例MS、24例高危综合征、5例临床孤立综合征以及35例其他神经科疾病患者进行NMO-IgG检测,并对其中NMO、MS患者的人口学、临床表现、免疫学指标、脑脊液、头颅MRI等资料进行对比.结果 NMO的起病年龄较MS大且年龄跨度更广;从年复发率和进展指数来看,NMO更为严重,预后更差;NMO长节段脊髓损害者比MS多.NMO-IgG在NMO组和高危综合征组的阳性率分别为58.8%(20/34)和45.8%(11/24),高于MS组(1/22)、临床孤立综合征组(1/5)和其他疾病组(1/35;X2=37.2,P<0.01).NMO-IgG阳性率与脊髓病变长度相关.结论 NMO和MS在临床表现、辅助检查等方面都有所不同,提示NMO与MS可能是2种不同的疾病.NMO-IgG在NMO患者中的阳性率高于MS患者,可以作为鉴别诊断的一项实验室依据.     

水通道蛋白4与视神经脊髓炎的发病机制

视神经脊髓炎(neuromyelitis optica,NMO)是视神经和脊髓主要受累的中枢神经系统脱髓鞘疾病.特异性NMO-IgG抗体~([1])[也称抗水通道蛋白4(AQP4)抗体]的发现支持NMO是一独立疾病,而非多发性硬化(multiple sclerosis,MS)的亚型,开辟了NMO研究的新领域.NMO-IgG诊断NMO的敏感度为50%～91%,特异度85%～99%~([2]),2006年已被纳入NMO修订的诊断标准.     

New Insights into Neuromyelitis Optica

Neuromyelitis optica (NMO) is an idiopathic inflammatory disorder of the central nervous system (CNS) that preferentially affects the optic nerves and spinal cord. In Asia, NMO has long been considered a subtype of multiple sclerosis (MS). However, recent clinical, pathological, immunological, and imaging studies have suggested that NMO is distinct from MS. This reconsideration of NMO was initially prompted by the discovery of a specific antibody for NMO (NMO-IgG) in 2004. NMO-IgG is an autoantibody that targets aquaporin-4 (AQP4), the most abundant water channel in the CNS; hence, it was named anti-AQP4 antibody. Since it demonstrated reasonable sensitivity and high specificity, anti-AQP4 antibody was incorporated into new diagnostic criteria for NMO.The spectrum of NMO is now known to be wider than was previously recognized and includes a proportion of patients with recurrent, isolated, longitudinally extensive myelitis or optic neuritis, and longitudinally extensive myelitis or optic neuritis associated with systemic autoimmune disease or with brain lesions typical of NMO. In this context, a new concept of "NMO spectrum disorders" was recently introduced. Furthermore, seropositivity for NMO-IgG predicts future relapses and is recognized as a prognostic marker for NMO spectrum disorders. Humoral immune mechanisms, including the activation of B-cells and the complement pathway, are considered to play important roles in NMO pathogenesis. This notion is supported by recent studies showing the potential pathogenic role of NMO-IgG as an initiator of NMO lesions. However, a demonstration of the involvement of NMO-IgG by the development of active immunization and passive transfer in animal models is still needed. This review focuses on the new concepts of NMO based on its pathophysiology and clinical characteristics. Potential management strategies for NMO in light of its pathomechanism are also discussed.     

Antibodies against aquaporin-4 in neuromyelitis optica: distinction between recurrent and monophasic patients

The detection of antibodies against aquaporin-4 (AQP4) has improved the diagnosis of neuromyelitis optica (NMO). We evaluated a recently established cell-based anti-AQP4 assay in 273 patients with inflammatory CNS demyelination. The assay had a specificity of 99% and a sensitivity of 56% to detect all NMO patients and of 74% to detect the recurrent NMO patients, similar to the initial studies reported. AQP4 antibodies were absent in monophasic NMO patients, while samples in recurrent cases remained positive during follow-up. We conclude that the pathogenesis of monophasic NMO may be different from that of relapsing NMO.     

Anti-aquaporin 4 antibody in selected Japanese multiple sclerosis patients with long spinal cord lesions

Multiple sclerosis (MS) in Asian populations is often characterized by the selective involvement of the optic nerve (ON) and spinal cord (SP) (OSMS) in contrast to classic MS (CMS), where frequent lesions are observed in the cerebrum, cerebellum or brainstem. In Western countries, inflammatory demyelinating disease preferentially involving the ON and SP is called neuromyelitis optica (NMO). Recently, Lennon et al. discovered that NMO-IgG, shown to bind to aquaporin 4 (AQP4), could be a specific marker of NMO and also of Japanese OSMS whose clinical features were identical to NMO having long spinal cord lesions extending over three vertebral segments (LCL). To examine this antibody in larger populations of Japanese OSMS patients in order to know its epidemiological and clinical spectra, we established an immunohistochemical detection system for the anti-AQP4 antibody (AQP4-Ab) using the AQP4-transfected human embryonic kidney cell line (HEK-293) and confirmed AQP4-Ab positivity together with the immunohistochemical staining pattern of NMO-IgG in approximately 60% of Japanese OSMS patients with LCL. Patients with OSMS without LCL and those with CMS were negative for this antibody. Our results accorded with those of Lennon et al. suggest that Japanese OSMS with LCL may have an underlying pathogenesis in common with NMO.     

Biomarkers in neuromyelitis optica

Recently, the disease-specific neuromyelitis optica (NMO) autoantibody NMO-IgG was detected in the sera of NMO patients, as the specific immunohistochemical pattern of human IgG on mouse brain slices. Aquaporin-4 (AQP4), mainly expressed in astroglial foot processes, was identified as the target for NMO-IgG. For diagnosing NMO, serological tests are mainly performed using a cell-based assay with HEK293 cells transfected with AQP4; this assay has the highest sensitivity (>70%) and specificity (>90%) for diagnosing NMO. However, several assays, such as immunoprecipitation assay, and ELISA systems, for detecting the AQP4 antibody have been reported. Several papers focus on inflammatory and pathological biomarkers, including cytokines, chemokines, and astrocyte markers, for NMO. Pleocytosis in the cerebrospinal fluid (CSF) and an increased CSF IgG: serum IgG/albumin ratio are useful markers of inflammation and blood-brain barrier leakage in NMO patients. Increased concentrations of cytokines such as IL-17, IL-6, and BAFF in the CSF may be key factors that induce the formation of NMO lesions, mainly by promoting the infiltration of neutrophils or plasma cells. Astrocytic damage, reflected by a marked increase in CSF-GFAP levels, was evident in NMO patients, but not in classical multiple sclerosis (MS) patients, indicating that CSF-GFAP is a good marker of lysis during autoimmune astrocytopathy. Therefore, the assessment of such useful biomarkers may become a supportive criterion for diagnosing NMO and NMO spectrum disorders.     

Revised diagnostic criteria for neuromyelitis optica (NMO)

We analyzed neuromyelitis optica (NMO) IgG in the serum or CSF samples from 46 patients with suspected NMO (28) and limited forms of NMO (18). One hundred and fifteen samples from multiple sclerosis (MS) patients were included as controls. The final clinical diagnosis after follow-up was 16 NMO, 12 MS, 11 transverse myelitis (TM) and seven recurrent optic neuritis (RON). NMO-IgG was detected in 62.5% of NMO, 50% of the recurrent longitudinally extensive TM, 14.3% of the RON but in none of the MS patients. The authors then compared the newly revised diagnostic criteria for NMO with the criteria published in 1999, in the 28 patients with suspected NMO. The revised criteria had higher specificity, and positive and negative predictive value (83.3% vs. 25%; 87.5% vs. 62.5; 83.3% vs. 75%), but slightly lower sensitivity (87.5% vs. 93.7%). Our study confirms NMO-IgG as a highly specific marker of NMO, and the usefulness of the revised diagnostic criteria in predicting a diagnosis of NMO.     

Neuromyelitis optica: Diagnosis,pathogenesis, and treatment

Although the co-occurrence of myelitis and optic neuritis that characterizes neuromyelitis optica (NMO) was recognized over a century ago, distinguishing NMO from multiple sclerosis relied solely on clinical criteria until recently. The identification of a biomarker that has high specificity for NMO is clinically useful for distinguishing NMO from multiple sclerosis and identifying patients at high risk for recurrent myelitis and optic neuritis. That fact that the biomarker is an autoantibody that recognizes aquaporin 4 (AQP4), a water channel expressed on astrocyte podocytes, has substantially contributed to the hypothesis that NMO is a humorally mediated autoimmune disease. This review discusses the discovery of the NMO-IgG biomarker, the identification of AQP4 as its target, the clinical applications of these advances, the pathologic implications for the anti-AQP4 antibody, and advances in NMO treatment.     

Antibodies to CV2/CRMP5 in neuromyelitis optica-like disease: case report and review of the literature

Neuromyelitis optica (NMO) is associated with antibodies to aquaporin-4 (termed NMO-IgG or AQP4-Ab) in 60-90% of cases. Little is known about the aetiology of NMO in NMO-IgG/AQP4-Ab negative patients. Here we report on CV2/CRMP5 antibodies in a 69-year-old male patient with NMO-IgG/AQP4-Ab negative NMO. The association of CV2/CRMP5-Ab with prostate cancer suggests a paraneoplastic aetiology of NMO in our patient. Our report strengthens the case of antibodies other than AQP4-Ab being involved in the immunopathogenesis in a subset of patients with NMO. We conclude that CV2/CRMP5-Ab should be included in the differential diagnosis of NMO, in particular if AQP4-Ab are negative and irrespective of whether a tumour is known or not. We recommend that recombinant tests, which are increasingly used because of their higher sensitivity and specificity, should always be accompanied by standard indirect immunofluorescence employing brain tissue sections in order to avoid CV2/CRMP5-Ab or other paraneoplastic antibodies being overlooked. In addition, we provide a comprehensive review of all patients with CV2/CRMP5-Ab and NMO-like disease published in the English literature so far.