AB1336B PERFORMANCE EVALUATION OF PARTICLE-ENHANCED TURBIDIMETRIC IMMUNOASSAY FOR ANTINUCLEAR ANTIBODIES DETECTION IN COMPARISON WITH LINE IMMUNOASSAY
Authors: Yan Qin, Jing Luo, Xiang-Cong Zhao
Journal: Annals of the Rheumatic Diseases (2019)

<h3>Background:</h3> Detection of antinuclear antibodies (ANAs) supports the clinical diagnosis of ANA-associated rheumatic diseases, such as systemic sclerosis (SSc), systemic lupus erythematosus (SLE), primary sjogren's syndrome (SjS) and mixed connective tissue disease (MCTD) [1-3]. Throughout history, a number of autoantibody detection methods have emerged, for instance, indirect immunofluorescence (IIF), radioimmunoassay (RIA), enzyme-linked immunosorbent assay (ELISA) and line immunoassay (LIA) [4]. With the development of detection technology, new methods to detect ANAs were continuously developed by numerous manufacturers, for example, particle-enhanced turbidimetric immunoassay (PETIA). Therefore, in the current study, we evaluated for the first time the performance of PETIA in the detection of anti-nuclear antibody and compared it with commercial LIA. <h3>Objectives:</h3> To evaluate the clinical performance of PETIA for the detection of ANAs in comparison to the currently commonly used LIA. <h3>Methods:</h3> Total 606 serum samples from diseased and healthy controls were assayed to simultaneously determine SSA, Sm/RNP, SSB, Sm and U1-SnRNP antibodies by the PETIA and LIA. The sensitivity, specificity, consistency and area under curve (AUC) were analyzed for each antibody between PETIA and LIA. <h3>Results:</h3> The positive rate and specificity of PETIA and LIA for ANA specific target antibodies were comparable. Compared with LIA, the sensitivity of SSA, SSB and Sm were 100.00%, 88.89% and 90.00%, while Sm/RNP and U1-SnRNP were 75.00%, 70.59%, respectively; Sm/RNP, SSB, Sm and U1-SnRNP have high specificity, respectively 97.87%, 98.90%, 97.80% and 94.68%, while SSA specificity is general, 81.52%. Under manufacturer's cut-off values, the consistent rates of SSA, Sm/RNP, SSB, Sm, and U1-SnRNP between PETIA and LIA were 87.22% (116/133), 92.06% (116/126), 96.61% (114/118), 97.03% (98/101) and 88.28 (113/128), respectively. Excellent consistencies were found between PETIA and LIA for the detection of Sm/RNP, SSB and Sm antibodies (kappa&gt;0.75), and kappa coefficients were 0.776 (p&lt;0.001), 0.901 (p&lt;0.001) and 0.841 (p&lt;0.001), while the coincidence for anti-SSA and U1-SnRNP detection were moderate (0.40&lt;kappa&lt;0.75), and Kappa coefficient was 0.731 (p&lt;0.001) and 0.685 (p&lt;0.001), respectively. <h3>Conclusion:</h3> The performance of PETIA for the detection of antibodies to nuclear specific antigen was satisfying to correlate with that of LIA. With the additional benefits of short detection time, quantitative output and high universality. PETIA can better meet the requirements of quantitative detection of specific target antibodies. <h3>References</h3> [1] Kapsogeorgou E K, Tzioufas A G. Autoantibodies in Autoimmune Diseases: Clinical and Critical Evaluation[J]. Israel Medical Association Journal, 2016, 18(9):519-524. [2] Routsias J G, Tzioufas A G. B-cell epitopes of the intracellular autoantigens Ro/SSA and La/SSB: Tools to study the regulation of the autoimmune response[J]. Journal of Autoimmunity, 2010, 35(3):0-264. [3] Suurmond J, Diamond B. Autoantibodies in systemic autoimmune diseases: specificity and pathogenicity[J]. Journal of Clinical Investigation, 2015, 125(6):2194-2202. [4] Fritzler M, Fritzler M. The Emergence of Multiplexed Technologies as Diagnostic Platforms in Systemic Autoimmune Diseases[J]. Current Medicinal Chemistry, 2006, 13(21):2503-2512. <h3>Disclosure of Interests:</h3> None declared