Allergologia e Immunologia Clinica, DML, A.O. S. Maria degli Angeli, Pordenone, Italy.
Clin Chim Acta. 2010 May 2;411(9-10):710-3. doi: 10.1016/j.cca.2010.01.037. Epub 2010 Feb 4.
Anti-fibrillarin (AFA), anti-RNA polymerase (anti-RNAP), and anti-PM-Scl autoantibodies are useful markers for the diagnosis of systemic sclerosis (SSc) in patients who are anti-centromere- (ACA) or anti-topoisomerase I (anti-topo I)-negative, but, until recently, the only specific method for their identification was the radio-immunoprecipitation assay. The aim of this study was to evaluate the clinical accuracy of the new enzyme-linked immunosorbent assays (ELISA) developed by Phadia for their detection.
Sera of 50 ACA and anti-topo I-negative SSc patients, and, as control group, sera of 122 patients (42 with SSc, ACA or anti-topo I-positive, 40 with systemic lupus erythematosus and 40 with rheumatoid arthritis) were studied.
Using the cutoff proposed by the manufacturer (10 AU/mL), sensitivity and specificity were: for AFA, 22% and 92.6%; for anti-RNAP, 16% and 97.5%; and for anti-PM-Scl, 8% and 98.8%, respectively. Using a cutoff corresponding to 98.8% specificity for all three antibodies, sensitivity was 10%, 14% and 8%, respectively. The combined use of these three antibody assays enabled identification of 32% of ACA- and anti-topo I-negative SSc patients.
These new ELISA methods for AFA, anti-RNAP III and anti-PM-Scl detection have good diagnostic specificity, and may help identify a subset of SSc patients ACA and anti-topo I-negative.
抗纤维蛋白（AFA）、抗 RNA 聚合酶（抗-RNAP）和抗 PM-Scl 自身抗体是抗着丝点（ACA）或抗拓扑异构酶 I（抗-topo I）阴性的系统性硬化症（SSc）患者的有用诊断标志物，但直到最近，唯一确定这些自身抗体的特异性方法是放射免疫沉淀测定法。本研究旨在评估由 Phadia 开发的新酶联免疫吸附测定法（ELISA）用于检测这些自身抗体的临床准确性。
检测了 50 例 ACA 和抗-topo I 阴性的 SSc 患者的血清，并以 122 例患者（42 例 SSc，ACA 或抗-topo I 阳性，40 例系统性红斑狼疮，40 例类风湿关节炎）作为对照组。
使用制造商建议的临界值（10 AU/mL），AFA、抗-RNAP III 和抗 PM-Scl 的灵敏度和特异性分别为：22%和 92.6%；16%和 97.5%；8%和 98.8%。使用对应于三种抗体特异性为 98.8%的临界值，灵敏度分别为 10%、14%和 8%。这三种抗体检测方法的联合使用可识别 32%的 ACA 和抗-topo I 阴性的 SSc 患者。
这些新的抗 AFA、抗-RNAP III 和抗 PM-Scl ELISA 检测方法具有良好的诊断特异性，可能有助于识别 ACA 和抗-topo I 阴性的 SSc 患者亚群。
