a Laboratory of Clinical Pathology , San Antonio Hospital , Tolmezzo , Italy.
b Azienda Sanitaria Universitaria Integrata , Udine , Italy.
Autoimmunity. 2018 Jun;51(4):152-156. doi: 10.1080/08916934.2018.1469013. Epub 2018 May 6.
The correct identification of anti-dense fine speckled-70 (DFS70) antibodies represents an important issue in the detection of anti-nuclear antibodies (ANAs) as performed by the indirect immunofluorescence (IIF) test on HEp-2 substrates. In this study, we have evaluated a new method for anti-DFS70 antibody detection employing HEp-2 cells knocked-out for the DFS70 antigen.
We studied 148 sera with a DFS70-like pattern (91 positive and 57 negative when tested for anti-DFS70 antibodies by a specific chemoluminescence [CLIA] method); 116 sera with infectious disease; 100 healthy donors (HDs), 139 samples from patients with a defined diagnosis of autoimmune rheumatic disease (ARD), and 242 consecutive unselected samples screened for ANA during the routine work-up.
The HEp2 DFS70-Ko substrate recognized anti-DFS70 antibodies in 86/91 (94.5%) of the DFS70 CLIA-positive sera and in 9/57 (15.8%) of the DFS70 CLIA-negative samples. None of the 116 infectious diseases were positive for DFS70 using the engineered IIF substrate. Two samples (2%) were positive among HDs and were then confirmed by CLIA. The 139 ANA-positive sera from patients with ARD displaying a defined antibody specificity showed their expected patterns also on DFS70-Ko HEp-2 substrate. Five of the 242 (2.1%) consecutive samples tested in the routine ANA-screening were identified as DFS70-positive using the HEp2 Ko-substrate and were then confirmed by CLIA.
The use of DFS70 HEp-2 Ko cells may offer the unique possibility of simultaneously identifying and confirming the presence of anti-DFS70 antibodies during the standard ANA evaluation, while keeping the expression of other autoantibody markers intact.
在使用 HEp-2 底物进行间接免疫荧光（IIF）检测抗核抗体（ANA）时，正确识别抗密体细斑点-70（DFS70）抗体是一个重要问题。在这项研究中，我们评估了一种新的方法，使用 DFS70 抗原敲除的 HEp-2 细胞检测抗-DFS70 抗体。
我们研究了 148 份具有 DFS70 样模式的血清（148 份血清中，91 份经特定化学发光[CLIA]方法检测抗-DFS70 抗体阳性，57 份阴性）；116 份传染病血清；100 名健康供体（HD），139 名自身免疫性风湿病（ARD）明确诊断患者的样本，以及 242 份在常规工作中筛选的连续未选择的 ANA 样本。
HEp2 DFS70-Ko 底物在 91 份 DFS70 CLIA 阳性血清中的 86/91（94.5%）和 57 份 DFS70 CLIA 阴性样本中的 9/57（15.8%）中识别出抗-DFS70 抗体。使用工程化 IIF 底物，116 份传染病血清均未呈 DFS70 阳性。在 HD 中，有 2 份样本（2%）为阳性，然后通过 CLIA 确认。139 份来自 ARD 患者的 ANA 阳性血清显示出明确的抗体特异性，也在 DFS70-Ko HEp-2 底物上显示出预期的模式。在常规 ANA 筛选中，242 份连续样本中的 5 份（2.1%）使用 HEp2 Ko 底物鉴定为 DFS70 阳性，然后通过 CLIA 确认。
使用 DFS70 HEp-2 Ko 细胞可能提供独特的可能性，即在进行标准 ANA 评估时同时识别和确认抗-DFS70 抗体的存在，同时保持其他自身抗体标志物的表达完整。
