Department of Laboratory Medicine, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.
Department of Oral Biology, University of Florida, Gainesville, FL, United States.
Front Immunol. 2020 Oct 2;11:562138. doi: 10.3389/fimmu.2020.562138. eCollection 2020.
Anti-DFS70 antibodies correlating with the nuclear dense fine speckled (DFS) pattern in the HEp-2 indirect immunofluorescence assay (IFA) are less common in patients with systemic autoimmune rheumatic disease (SARD) than in healthy subjects and their clinical associations remain elusive. We hosted a multi-center HEp-2 IFA training program to improve the ability of clinical laboratories to recognize the DFS pattern and to investigate the prevalence and relevance of anti-DFS70 antibodies.
DFS pattern sera identified by HEp-2 IFA in 29 centers in China were redirected to a central laboratory for anti-DFS70 testing by line immunoblot assay (LIA), enzyme-linked immunosorbent assay (ELISA), and IFA with HEp-2 ELITE/DFS70-KO substrate. Anti-extractable nuclear antigen antibodies were measured by LIA and the clinical relevance was examined in adult and pediatric patients.
HEp-2 IFA positive rate and DFS pattern in positive sera were 36.2% (34,417/95,131) and 1.7% (582/34,417) in the patient cohort, and 10.0% (423/4,234) and 7.8% (33/423) in a healthy population, respectively. Anti-DFS70 prevalence among sera presenting the DFS pattern was 96.0, 93.7, and 49.6% by ELISA, LIA, and HEp-2 ELITE, respectively. 15.5% (52/336) of adult and 50.0% (20/40) of pediatric anti-DFS70 positive patients were diagnosed with SARD. Diseases most common in anti-DFS70 positive patients were spontaneous abortion (28.0%) in adults and juvenile idiopathic arthritis (22.5%) in pediatric patients.
Accurate DFS pattern identification increased the detection rate of anti-DFS70 antibodies by ELISA and LIA. Anti-DFS70 antibodies are remarkably high in cases of spontaneous abortion and in pediatric SARD patients, but not prevalent in adult SARD patients.
与 HEp-2 间接免疫荧光检测（IFA）中的核密集细斑点（DFS）模式相关的抗-DFS70 抗体在系统性自身免疫性风湿病（SARD）患者中比在健康受试者中更为常见，其临床相关性仍不清楚。我们举办了一个多中心的 HEp-2 IFA 培训计划，以提高临床实验室识别 DFS 模式的能力，并研究抗-DFS70 抗体的流行率和相关性。
在中国 29 个中心通过 HEp-2 IFA 鉴定的 DFS 模式血清被重新定向到一个中央实验室，通过线免疫印迹检测（LIA）、酶联免疫吸附试验（ELISA）和使用 HEp-2 ELITE/DFS70-KO 底物的 IFA 进行抗-DFS70 检测。通过 LIA 测量抗可提取核抗原抗体，并在成年和儿科患者中检查其临床相关性。
患者队列中 HEp-2 IFA 阳性率和阳性血清中的 DFS 模式分别为 36.2%（34,417/95,131）和 1.7%（582/34,417），健康人群中分别为 10.0%（423/4,234）和 7.8%（33/423）。通过 ELISA、LIA 和 HEp-2 ELITE，DFS 模式血清中的抗-DFS70 患病率分别为 96.0、93.7 和 49.6%。15.5%（52/336）的成年和 50.0%（20/40）的儿科抗-DFS70 阳性患者被诊断为 SARD。在抗-DFS70 阳性患者中最常见的疾病是成人自发性流产（28.0%）和儿科青少年特发性关节炎（22.5%）。
准确识别 DFS 模式可提高 ELISA 和 LIA 检测抗-DFS70 抗体的检出率。抗-DFS70 抗体在自发性流产和儿科 SARD 患者中显著升高，但在成年 SARD 患者中并不常见。
