表达AQP4不同亚型的细胞系检测AQP4抗体敏感性的研究

Sensitivity of Aquaporin-4 Isoforms Binding to Antibody in Neuromyelitis Optica

【目的】研究表达不同亚型的AQP4细胞系检测中国人群视神经脊髓炎患者血清中AQP4抗体的敏感性。【方法】根据纳入标准共获取血清205例,其中包括视神经脊髓炎40例,长节段性脊髓炎39例,复发性视神经炎39例,多发性硬化47例,另设40例健康对照。使用稳定表达水通道蛋白4的四种细胞系HEK293/pcDNA3.1(+)-M23-AQP4、HEK293/pcDNA3.1(+)-M1-AQP4、HEK293/pEGFP-N3-M23-AQP4、HEK293/pEGFP-N3-M1-AQP4通过细胞间接免疫荧光法分别检测以上血清中的AQP4抗体。【结果】NMO-IgG普遍存在于视神经脊髓炎疾病谱中。AQP4抗体同AQP4两种亚型结合敏感性比较发现,M23-AQP4的敏感性高于M1-AQP4。同时绿色荧光蛋白作为标签蛋白,可能干扰抗体同AQP4的结合。【结论】M23-AQP4作为靶抗原检测血清中AQP4抗体优于M1-AQP4,临床中采用细胞间接免疫荧光法对抗体进行检测时应首选表达M23-AQP4亚型的细胞系进行检测。

[ Objective ] To investigate the performance of AQP4 isoform to detect AQP4 antibodies in neuromyelitis optica （NMO） patient＇s sera. [ Methods ] We tested 205 masked serum samples from 40 NMO patients, 39 longitudinally extensive transverse myelitis （LETM） patients, 39 patients with recurrent optic neuritis （rON）, 47 patients with multiple sclerosis （MS） and 40 healthy controls with the indirect immunofluorescence with a composite substrate of HEK293/pcDNA3.1 （＋）-M23-AQP4, HEK293/ pcDNA3.1 （＋）-M1-AQP4, HEK293/pEGFP-N3-M23-AQP4, HEK293/pEGFP-N3-M1- AQP4. [Results] We found antibody to AQP4 was present in NMO spectrums. M23-AQPg was more sensitivity than the M1-AQP4 and while the enhanced green fluorescent protein （EGFP） which was a tag protein may be interfere with the combination between the AQP4 antibody and AQP4. [Conclusion] M23-AQP4 appears to have a higher sensitivity than the M1-AQP4. It is expected to be a first consideration for the detection AQP4 antibody with the cell based assay.