α-胞衬蛋白抗原多肽的筛选及其在干燥综合征临床诊断中的意义

Screen for antigenic polypeptides of α-fodrin and its significance in sjgren’s syndrome

目的:筛选鉴定干燥综合征特异性α-胞衬蛋白抗原多肽,进一步研究该抗原多肽在干燥综合征(SS)疾病临床诊断中的意义。方法:采用固相法合成α-胞衬蛋白第1～59位氨基酸区域的5条多肽,利用酶联免疫吸附法(ELISA)比较合成多肽与干燥综合征患者血清IgG的反应强弱,确定最佳α-胞衬蛋白抗原多肽;以筛选出的最佳α-胞衬蛋白抗原多肽作为包被抗原,检测原发性SS患者135例,继发性SS患者25例,系统性红斑狼疮(SLE)患者48例,类风湿关节炎(RA)患者88例和正常人83例血清中的抗α-胞衬蛋白抗原多肽IgG抗体。结果:合成的5条多肽中有一条(F5)与SS血清IgG反应最强,抗F5多肽抗体(α-F5-PA)在原发性SS患者中的阳性率(78.5%)明显高于SLE(10.4%)、RA(21.6%)患者及正常人(6%)(P<0.01)。抗F5多肽抗体在原发性SS诊断中的敏感性为78.5%,特异性为86.8%,而且该抗体的检测对于SSA抗体、SSB抗体或ANA阴性的原发性SS患者的诊断具有补充作用。结论:F5多肽作为最佳α-胞衬蛋白抗原多肽。

Objective：To screen α-fodrin-specific antigenic polypeptides and investigate its significance in the diagnosis of sjogren＇s syndrome. Methods：Five synthesized α-fodrin polypeptides were compared and the best one was used as target in enzyme- linked immunosorbent assay （ELISA） to detect the specific antibodies in sera of SS, SLE, RA and in normal comtrols. Results：The F5 peptide of α-fodrin was chosen for the best antigenicity. The positive rates for its axtibody in the sera of pSS, SLE, RA patients and norreal individuals were 78. 5%, 10. 4%, 21.6%, 6%, respectively. Conclusion：F5 polypeptide is the best α-fodrin antigenic peptide. Anti-α-FS-PA is much valuable in the diagnosis of primary sjogren＇ s syndrome.