肽抗原ELISA检测系统性红斑狼疮患者抗核糖体蛋白P抗体的临床意义

The significance of ribosomal P protein auto-antibodies in systemic lupus erythematosus patients assayed by peptide-antigen based enzyme-linked immunosorbent assay method

目的研究抗核糖体P蛋白(Rib-P)肽抗原抗体对系统性红斑狼疮(SLE)的临床诊断意义。方法用来源于抗核糖体P蛋白的3段表位肽为抗原,用酶联免疫吸附试验(ELISA)法和免疫印迹法(IBT)检测100例SLE病人和100例对照血清中抗Rib-P抗体。其中以90例自身免疫病病人(45例类风湿关节炎、22例强直性脊柱炎、8例干燥综合征、6例多肌炎/皮肌炎和9例其他自身免疫病病人)为疾病对照组和10名健康人为正常对照组。结果以对照组的吸光度(x±3s)设定为阳性临界值,临界值为1.258,SLE病人的阳性率为14%,病人对照组为1%。两组之间差异有统计学意义(P<0.01)。ELISA法的特异性为99%,阳性预测值为93.3%,阴性预测值为53.5%。IBT的阳性率为16%,ELISA和IBT的检测的比较差异无统计学意义(!=0.922,P=0.000)。结论Rib-P抗原肽ELISA与传统的IBT方法相关性好,对SLE病人有高特异性,有较好的诊断价值,与年龄、面部红斑、关节炎、多浆膜炎、肾脏累积、血液累积和神经系统累及等临床症状,以及与抗核抗体(ANA)、抗Sm抗体、抗u1RNP抗体、抗SSA/SSB抗体、抗心磷指抗体(ACL)和病情活动度无关。

Objective To study the diagnosis significance of anti-ribosomal P antibody in systemic lupus erythematosus （SLE）. Method Indirect enzyme-linked immunosorbent （ELISA） assay based on 3 ribsomal P epitope peptides （Pharmarcia） and immunobloting （IBT） method were used to assay anti-ribosomal P antibody. One hundred SLE patients were recruited as study group. Another 100 non-SLE patients were used as control group, which included 45 rheumatoid arthritis patients, 22 ankylosing spondylitis patients, 8 Sjogren syndrome patients, 6 dermotomyositis/polymyositis patients, 9 other autoimmune diseases patients and 10 healthy people. Results The positive cutoff value was determined as 1.258 by the absorbance （A） value of mean plus 3 standard deviation. The positive rate of SLE group was 14% （14 in 100）, and the positive rate of non-SLE group was 1%, and there was significant difference between these two groups （P〈O.001）. There was also a good correlation between ELISA method and IBT method. Conclusion The data shows that antigen peptide based ELISA and traditional IBT method is well correlated. Anti-ribosomal P antibody, which is a specific autoantibody in SLE, has high value in diagnosis. The data has shown a relatively low positive rate in this Chinese cohort than other reported data. And there is no correlation between anti-ribosomal P and clinical manifestations, such as central nervous system involvement, lupus nephritis, arthritis, rash, and disease activity （SLEDAI）. There is no correlation with other autoantibodies.