Fawcett P T, Rose C D, Gibney K M, Emerich M J, Athreya B H, Doughty R A
Department of Pediatrics, duPont Hospital for Children, Wilmington, Delaware 19899, USA.
J Rheumatol. 1999 Aug;26(8):1822-6.
To compare a series of commercial ELISA tests with an indirect immunofluorescent antibody (IFA) test for the detection of antinuclear antibodies (ANA) in children with juvenile rheumatoid arthritis (JRA).
Sera from 178 patients with JRA (88 pauciarticular, 68 polyarticular, 22 systemic) were compared with 26 healthy pediatric subjects. Twenty-one samples from patients with systemic lupus erythematosus (SLE) were also tested. All samples were analyzed by IFA and by 3 commercial ELISA methods. Concordance of ELISA results with IFA results (selected standard) were used as a measure of performance. Sensitivity and specificity were calculated for each test and likelihood ratios (LR) were established for IFA and ELISA in pauciarticular and polyarticular JRA sera. The increment in pretest probability was then obtained for each test as an additional measure of test performance.
IFA rendered positive results on 18-77% of the JRA sera depending upon the subset, 100% of SLE sera, and 15% of normal patient sera. Using IFA as the standard, correspondence with positive results among patients with JRA ranged from 0 to 74% for the 3 ELISA tests, while it ranged from 5 to 73% in IFA negative sera. IFA tests showed intermediate range likelihood ratios (0.3, 0.5, 3.5, and 5) and increments in pretest probability ranging from 25 to 45%. While one of the ELISA tests attained 50% of increment in pretest probability for the positive test, it showed 0% increment as a negative test. The other 2 ELISA tests incremented the pretest probability from 0 to 25%.
Our findings indicate that in JRA, the lack of correspondence with the historic standard IFA precludes the use of ELISA tests for detection of ANA. In addition, IFA out-performs ELISA by a substantial degree when "clinical utility" analysis of test performance is utilized. Detection of ANA in children with JRA should either continue to rely on IFA or be based on a different set of antigens if an ELISA format is chosen.
比较一系列商业化酶联免疫吸附测定（ELISA）试验与间接免疫荧光抗体（IFA）试验在检测幼年类风湿关节炎（JRA）患儿抗核抗体（ANA）方面的效果。
将178例JRA患者（88例少关节型、68例多关节型、22例全身型）的血清与26例健康儿童受试者的血清进行比较。还检测了21例系统性红斑狼疮（SLE）患者的样本。所有样本均采用IFA和3种商业化ELISA方法进行分析。ELISA结果与IFA结果（选定的标准）的一致性用作性能指标。计算每种试验的敏感性和特异性，并确定少关节型和多关节型JRA血清中IFA和ELISA的似然比（LR）。然后获得每种试验的验前概率增量，作为试验性能的额外指标。
根据亚型不同，IFA在18% - 77%的JRA血清中呈阳性结果，在100%的SLE血清和15%的正常患者血清中呈阳性。以IFA为标准，3种ELISA试验在JRA患者中与阳性结果的一致性范围为0至74%，而在IFA阴性血清中为5至73%。IFA试验显示似然比处于中等范围（0.3、0.5、3.5和5），验前概率增量范围为25%至45%。虽然其中一种ELISA试验在阳性试验中验前概率增量达到50%，但作为阴性试验时增量为0%。另外两种ELISA试验的验前概率从0增加到25%。
我们的研究结果表明，在JRA中，与传统标准IFA缺乏一致性使得ELISA试验无法用于ANA的检测。此外，当利用试验性能的“临床效用”分析时，IFA在很大程度上优于ELISA。JRA患儿ANA的检测要么继续依赖IFA，要么如果选择ELISA形式，则基于不同的一组抗原。
