University Medical Center and Faculty of Medicine, Department of Medicine III, Division of Rheumatology, TU Dresden, Dresden, Germany
Policlinic and Hiller Research Unit for Rheumatology, Heinrich-Heine University Düsseldorf, Düsseldorf, Germany.
Ann Rheum Dis. 2021 Jun;80(6):775-781. doi: 10.1136/annrheumdis-2020-219373. Epub 2021 Feb 10.
BACKGROUND/OBJECTIVES: The European League Against Rheumatism (EULAR)/American College of Rheumatology (ACR) 2019 classification criteria for systemic lupus erythematosus system showed high specificity, while attaining also high sensitivity. We hereby analysed the performance of the individual criteria items and their contribution to the overall performance of the criteria.
We combined the EULAR/ACR derivation and validation cohorts for a total of 1197 systemic lupus erythematosus (SLE) and n=1074 non-SLE patients with a variety of conditions mimicking SLE, such as other autoimmune diseases, and calculated the sensitivity and specificity for antinuclear antibodies (ANA) and the 23 specific criteria items. We also tested performance omitting the EULAR/ACR criteria attribution rule, which defines that items are only counted if not more likely explained by a cause other than SLE.
Positive ANA, the new entry criterion, was 99.5% sensitive, but only 19.4% specific, against a non-SLE population that included other inflammatory rheumatic, infectious, malignant and metabolic diseases. The specific criteria items were highly variable in sensitivity (from 0.42% for delirium and 1.84% for psychosis to 75.6% for antibodies to double-stranded DNA), but their specificity was uniformly high, with low C3 or C4 (83.0%) and leucopenia <4.000/mm³ (83.8%) at the lowest end. Unexplained fever was 95.3% specific in this cohort. Applying the attribution rule improved specificity, particularly for joint involvement.
Changing the position of the highly sensitive, non-specific ANA to an entry criterion and the attribution rule resulted in a specificity of >80% for all items, explaining the higher overall specificity of the criteria set.
背景/目的：欧洲抗风湿病联盟（EULAR）/美国风湿病学会（ACR）2019 年系统性红斑狼疮（SLE）分类标准显示出较高的特异性，同时也具有较高的敏感性。在此，我们分析了各标准项目的表现及其对标准整体性能的贡献。
我们将 EULAR/ACR 的推导和验证队列合并，共有 1197 例系统性红斑狼疮（SLE）和 1074 例非 SLE 患者，这些患者患有多种类似于 SLE 的疾病，如其他自身免疫性疾病，并计算了抗核抗体（ANA）和 23 个特异性标准项目的敏感性和特异性。我们还测试了不考虑 EULAR/ACR 标准归因规则的性能，该规则定义，如果不是由 SLE 以外的原因更有可能解释，则不计入项目。
新纳入的标准——阳性 ANA，对非 SLE 人群（包括其他炎症性风湿病、感染性疾病、恶性疾病和代谢性疾病）的敏感性为 99.5%，但特异性仅为 19.4%。特异性标准项目的敏感性差异很大（从谵妄的 0.42%和精神病的 1.84%到双链 DNA 抗体的 75.6%），但其特异性均很高，补体 C3 或 C4 降低（最低值为 83.0%）和白细胞计数 <4000/mm³（83.8%）。在此队列中，原因不明的发热特异性为 95.3%。应用归因规则提高了特异性，特别是对关节受累的诊断。
将高度敏感但特异性不强的 ANA 置于标准的入口标准，并应用归因规则，使所有项目的特异性均>80%，这解释了标准集整体特异性较高的原因。
