Yu Liping, Wang Jian, O'Dell James R, Oates James, Arend William P, Eisenbarth George S
Barbara Davis Center for Childhood Diabetes and the Division of Rheumatology, School of Medicine, University of Colorado Health Sciences Center, Denver, Colorado, USA.
J Rheumatol. 2007 Apr;34(4):734-9.
To evaluate whether a new fluid-phase filtration radioassay possesses both high sensitivity and specificity compared with the currently used ELISA and Farr assays.
Sequential sera (25 samples) from 9 patients with systemic lupus erythematosus (SLE), sera from 20 patients with SLE possessing anti-dsDNA antibodies by the Crithidia assay, 75 patients with rheumatoid arthritis possessing rheumatoid factors, 50 healthy control subjects, 767 from patients with type 1 diabetes, and a commercial standard serum sample were tested for anti-dsDNA antibodies with the 3 different assays.
Of serial dilutions of a standard anti-dsDNA antibody sample, only the highest positive sample (50 IU/ml) in the ELISA and the highest 2 positive samples (50 and 25 IU/ml) in the Farr assay were above the normal range. In contrast, all dilutions (to 2.5 IU/ml) of the standard anti-dsDNA antibody sample were above the normal range in the filtration radioassay. Using the values of 50 healthy control subjects in each assay to define the normal range, all 25 sequential sera from 9 patients with SLE were positive. In addition, 20/20 of the SLE individual sera, 2/75 (2.7%) of the RA sera, and 12/767 (1.6%) of the diabetes sera were positive (signal above normal range) in the filtration radioassay. The SLE sera were further examined in 2 additional assays, ELISA and Farr assay, and both assays were less sensitive and specific compared with the filtration radioassay.
The fluid-phase filtration radioassay demonstrated high sensitivity and specificity for the detection of anti-dsDNA antibodies in SLE, with the standard ELISA exhibiting lower specificity. We suggest that testing for anti-dsDNA antibodies can be improved using a fluid-phase filtration radioassay in comparison to commercial assays.
评估一种新的液相过滤放射分析方法与目前使用的酶联免疫吸附测定（ELISA）和法尔（Farr）测定相比是否具有高灵敏度和特异性。
对9例系统性红斑狼疮（SLE）患者的连续血清（25份样本）、通过利什曼原虫检测法检测出具有抗双链DNA抗体的20例SLE患者的血清、75例具有类风湿因子的类风湿关节炎患者的血清、50名健康对照者的血清、767例1型糖尿病患者的血清以及一份商业标准血清样本，采用3种不同的测定方法检测抗双链DNA抗体。
在标准抗双链DNA抗体样本的系列稀释液中，ELISA中只有最高阳性样本（50 IU/ml）以及Farr测定中最高的2个阳性样本（50和25 IU/ml）高于正常范围。相比之下，标准抗双链DNA抗体样本的所有稀释液（至2.5 IU/ml）在过滤放射分析中均高于正常范围。利用每种测定方法中50名健康对照者的值来定义正常范围，9例SLE患者的所有25份连续血清均呈阳性。此外，在过滤放射分析中，20/20的SLE个体血清、2/75（2.7%）的类风湿关节炎血清以及12/767（1.6%）的糖尿病血清呈阳性（信号高于正常范围）。对SLE血清进一步采用另外两种测定方法（ELISA和Farr测定）进行检测，与过滤放射分析相比，这两种测定方法的灵敏度和特异性均较低。
液相过滤放射分析在检测SLE患者抗双链DNA抗体方面显示出高灵敏度和特异性，而标准ELISA的特异性较低。我们建议，与商业测定方法相比，使用液相过滤放射分析可改进抗双链DNA抗体的检测。
