Fenger Mogens, Wiik Allan, Høier-Madsen Mimi, Lykkegaard Jens J, Rozenfeld Teresa, Hansen Michael S, Samsoe Bente Danneskjold, Jacobsen Søren
Department of Clinical Biochemistry, University Hospital of Copenhagen, Hvidovre, Denmark.
Clin Chem. 2004 Nov;50(11):2141-7. doi: 10.1373/clinchem.2004.038422. Epub 2004 Sep 2.
Antinuclear antibodies (ANAs) are associated with several inflammatory rheumatic diseases. The aim of the present work was to evaluate enzyme immunoassays (EIAs) and compare them with classic immunofluorescent analysis (IFA) for the detection of ANA.
Seven enzyme immunoassays were used in this study. All assays were applied as described by the manufacturers. Three populations were included in the study: (a) a population of patients with well-established autoimmune inflammatory disease (n = 102); (b) a population in which a rheumatic disease was diagnosed up to 5 years after an IFA was performed (n = 164); and (c) a population of consecutive outpatients suspected to have a rheumatic disease (n = 101). The current clinical diagnoses of the patients served as the standard against which performance of the assays was evaluated.
In patients with well-established rheumatic disorders, the newly developed EIA in which HEp-2 extracts were included had sensitivities and specificities comparable to or in some instances better than the IFA. The assays without HEp-2 extracts included had significantly lower sensitivities and specificities. In the outpatient population, up to 51% of patients had positive ANA tests that did not correspond to classic ANA-associated disease. However, in the assays in which the HEp-2 extracts were not included, the false-positive rate was <10%. The false-negative rate judged against IFA differed from assay to assay and disease to disease and was mostly <10%.
In this study, the sensitivities of EIAs and IFA were largely comparable. However, EIAs without HEp-2 extracts included had a low sensitivity but a high specificity, particularly in nonselected populations. The choice of test is highly dependent on the clinical setting in which the ANA test is to be used and on laboratory policy.
抗核抗体（ANA）与多种炎性风湿性疾病相关。本研究的目的是评估酶免疫测定法（EIA），并将其与经典免疫荧光分析（IFA）用于ANA检测进行比较。
本研究使用了七种酶免疫测定法。所有测定均按照制造商的说明进行。研究纳入了三组人群：（a）确诊为自身免疫性炎性疾病的患者群体（n = 102）；（b）在进行IFA后5年内被诊断出患有风湿性疾病的人群（n = 164）；（c）连续的疑似患有风湿性疾病的门诊患者群体（n = 101）。以患者当前的临床诊断作为评估测定性能的标准。
在确诊的风湿性疾病患者中，新开发的包含人喉癌上皮细胞（HEp-2）提取物的EIA的敏感性和特异性与IFA相当，在某些情况下甚至优于IFA。不包含HEp-2提取物的测定法的敏感性和特异性显著较低。在门诊患者群体中，高达51%的患者ANA检测呈阳性，但不符合经典的ANA相关疾病。然而，在不包含HEp-2提取物的测定法中，假阳性率<10%。根据IFA判断的假阴性率因测定法和疾病而异，大多<10%。
在本研究中，EIA和IFA的敏感性在很大程度上相当。然而，不包含HEp-2提取物的EIA敏感性低但特异性高，尤其是在非选择性人群中。检测方法的选择高度依赖于使用ANA检测的临床环境和实验室政策。
