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.

Detection of aquaporins-4:methods comparison and clinical significance for the diagnosis of neuromyelitis optica

Objective To compare the efficiency of original neuromyelitis optica(NMO)-IgG assay of detecting NMO-IgG with a new anti-aquaporin-4(AQP4)assay of detecting AQP4,and to explore the accuracy of the method in the diagnosis of NMO and multiple sclerosis(MS).Methods The sera were obtained from 44 patients with NMO and 46 patients with MS and were tested by both NMO-IgG and antiAOP4 assays.NMO-IgG was identified by original NMO-IgG assay with a substrate from mouse brain.AntiAQIP4 was detected by anti-AQP4 antibody assay.The results from the two assays were statistically analyzed to compare accuracy and specificity of the methods.Results The results of the two assays were concordant in 45 testing negative cases and 36 positive cases(Kappa=0.798.P=0.000).The McNemar test showed that the positive rate of the two assays were not significantly different(P=1.000).The NMO-IgG assay showed 77.3% sensitivity,87% specificity,82.2% diagnosis accuracy,85%positive predictive value,87% negative predictive value.and 74.3%Younden index. The anti-AOP4 antibody assay showed 88.6% sensitivity,95.7%specificity,92.2% diagnosis accuracy,98.1% positive predictive value,89.8% negative predictive value.and 84.3% Younden index.Conclusions This study demonstrated that NMO-IgG and AQP4 antibody detection have high sensitivity and specificity to detect NMO and MS.Anti-AQP4 detected by anti-AQP4 antibody assay may be more useful for NMO diagnosis.