Enocsson Helena, Sjöwall Christopher, Wirestam Lina, Dahle Charlotte, Kastbom Alf, Rönnelid Johan, Wetterö Jonas, Skogh Thomas
From the Department of Clinical and Experimental Medicine, Linköping University, Linköping, and the Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden.H. Enocsson, Postdoctoral, PhD; C. Sjöwall, MD, PhD, Associate Professor; L. Wirestam, MSc, PhD-student; C. Dahle, MD, PhD, Associate Professor; A. Kastbom, MD, PhD; J. Wetterö, PhD, Associate Professor; T. Skogh, MD, PhD, Professor, Department of Clinical and Experimental Medicine, Linköping University; J. Rönnelid, MD, PhD, Professor, Department of Immunology, Genetics and Pathology, Uppsala University.
J Rheumatol. 2015 May;42(5):817-25. doi: 10.3899/jrheum.140677. Epub 2015 Feb 15.
Analysis of antibodies against dsDNA is an important diagnostic tool for systemic lupus erythematosus (SLE), and changes in anti-dsDNA antibody levels are also used to assess disease activity. Herein, 4 assays were compared with regard to SLE specificity, sensitivity, and association with disease activity variables.
Cross-sectional sera from 178 patients with SLE, of which 11 were followed consecutively, from a regional Swedish SLE register were analyzed for immunoglobulin G (IgG) anti-dsDNA by bead-based multiplex assay (FIDIS; Theradig), fluoroenzyme-immunoassay (EliA; Phadia/Thermo Fisher Scientific), Crithidia luciliae immunofluorescence test (CLIFT; ImmunoConcepts), and line blot (EUROLINE; Euroimmun). All patients with SLE fulfilled the 1982 American College of Rheumatology and/or the 2012 Systemic Lupus International Collaborating Clinics (SLICC-12) classification criteria. Healthy individuals (n = 100), patients with rheumatoid arthritis (n = 95), and patients with primary Sjögren syndrome (n = 54) served as controls.
CLIFT had the highest SLE specificity (98%) whereas EliA had the highest sensitivity (35%). When cutoff levels for FIDIS, EliA, and EUROLINE were adjusted according to SLICC-12 (i.e., double the reference limit when using ELISA), the specificity and sensitivity of FIDIS was comparable to CLIFT. FIDIS and CLIFT also showed the highest concordance (84%). FIDIS performed best regarding association with disease activity in cross-sectional and consecutive samples. Fisher's exact test revealed striking differences between methods regarding associations with certain disease phenotypes.
CLIFT remains a good choice for diagnostic purposes, but FIDIS performs equally well when the cutoff is adjusted according to SLICC-12. Based on results from cross-sectional and consecutive analyses, FIDIS can also be recommended to monitor disease activity.
抗双链DNA抗体分析是系统性红斑狼疮（SLE）的一项重要诊断工具，抗双链DNA抗体水平的变化也用于评估疾病活动度。在此，对4种检测方法在SLE特异性、敏感性以及与疾病活动度变量的相关性方面进行了比较。
对来自瑞典某地区SLE登记处的178例SLE患者的横断面血清进行分析，其中11例患者进行了连续随访，采用基于微珠的多重检测法（FIDIS；Theradig）、荧光酶免疫分析法（EliA；Phadia/赛默飞世尔科技）、路氏锥虫免疫荧光试验（CLIFT；ImmunoConcepts）和线性印迹法（EUROLINE；Euroimmun）检测免疫球蛋白G（IgG）抗双链DNA。所有SLE患者均符合1982年美国风湿病学会和/或2012年系统性红斑狼疮国际协作临床中心（SLICC-12）分类标准。健康个体（n = 100）、类风湿关节炎患者（n = 95）和原发性干燥综合征患者（n = 54）作为对照。
CLIFT的SLE特异性最高（98%），而EliA的敏感性最高（35%）。当根据SLICC-12调整FIDIS、EliA和EUROLINE的临界值时（即使用酶联免疫吸附测定法时为参考限值的两倍），FIDIS的特异性和敏感性与CLIFT相当。FIDIS和CLIFT的一致性也最高（84%）。在横断面和连续样本中，FIDIS在与疾病活动度的相关性方面表现最佳。Fisher精确检验显示，不同方法在与某些疾病表型的相关性方面存在显著差异。
CLIFT仍是诊断的良好选择，但根据SLICC-12调整临界值时，FIDIS表现同样出色。基于横断面和连续分析的结果，FIDIS也可推荐用于监测疾病活动度。
