两种检测抗双链DNA抗体方法对系统性红斑狼疮的诊断价值比较

Abstract

目的 探讨间接免疫荧光法(IIF)和酶联免疫吸附法(ELISA)同时检测对于系统性红斑狼疮(SLE)诊断的价值.方法 回顾性研究,回顾北京大学第一医院2011年6月1日至9月30日所有抗dsDNA抗体检测的病例2712例,记录每份病例的抗dsDNA抗体检测结果及其临床诊断.计算IIF和ELISA方法检测敏感度、特异度,运用Kappa检验进行一致性检验.结果 ELISA方法检测抗dsDNA抗体的阳性率(16.3％)要略高于IIF方法(13.1％),但二者的总体结果基本一致(Kappa=0.641,P＜0.05).在不一致(9.2％)中以IIF法阴性同时ELISA法阳性多见(6.2％).以SLE的临床诊断为金标准,IIF与ELISA检测结果诊断SLE的准确性分别为84.8％和84.4％,差异无统计学意义(x2 =0.25,P＞0.05).IIF诊断SLE的敏感度和特异度为46.1％和99.2％,ELISA诊断SLE的敏感度和特异度为51.3％和96.7％.结论 应将IIF和ELISA 2种方法同时应用于抗dsDNA抗体的检测.若先用ELISA筛查,阳性标本再加测IIF,会将至少3.0％的ELISA阴性IIF阳性标本误判为阴性.IIF阴性ELISA阳性标本应进一步检测抗dsDNA抗体亲和力来辅助SLE的诊断和病情评估.

Objective To investigate the concurrent application value of indirect immunofluorescence (IIF) and enzyme-linked immunosorbent assay (ELISA) in systemic lupus erythematosus (SLE).Methods A retrospective study.All patients who took anti-double stranded DNA (dsDNA) antibody test from June 1 2011 to September 30 2011 in our department were recruited in this study.The patients' anti-dsDNA antibody results and clinical diagnosis were collected and analyzed retrospectively.The consistence,sensitivity and specificity of IIF and ELISA tests were calculated and the consistence was compared by Kappa test.Results The positive rates of detecting anti-dsDNA antibodies by ELISA and IIF tests were 16.3％ and 13.1％ respectively.The consistency between these two tests was 90.8％,and showed good correlation by Kappa test (Kappa =0.641,P ＜ 0.05 ).Of 9.2％ of inconsistent results between IIF andi ELISA,most cases ( 6.2％ ) were ELISA positive and IIF negative.Taking the clinical diagnosis of lupus as a golden standard,the accuracy of IIF and ELISA was 84.8％ and 84.4％ respectively and the difference was no significant (x2 =0.25,P ＞ 0.05 ).The sensitivity and specificity for diagnosing lupus by IIF were 46.1％ and 99.2％,and 51.3％ and 96.7％ by ELISA.Conclusions Our results suggested that anti-dsDNA antibodies in samples should be detected by both ELISA and IIF tests simultaneously.If ELISA was used first and the positive samples were further tested by IIF,at least 3％ of ELISA negative and IIF positive samples would be misdiagnosed as anti-dsDNA antibodies negative.IIF negative and ELISA positive samples should be further analyzed the affinity of anti-dsDNA antibodies in order to help the diagnosis and evaluation of SLE.