Current technologies for anti-ENA antibody detection: State-of-the-art of diagnostic immunoassays

• Published in: Journal of immunological methods 2022-08, Vol.507, p.113297-113297, Article 113297
• Main Authors: Infantino, Maria, Carbone, Teresa, Brusca, Ignazio, Alessio, Maria-Grazia, Previtali, Giulia, Platzgummer, Stefan, Paura, Giusi, Castiglione, Caterina, Fabris, Martina, Pesce, Giampaola, Porcelli, Brunetta, Terzuoli, Lucia, Bacarelli, Maria-Romana, Tampoia, Marilina, Cinquanta, Luigi, Villalta, Danilo, Buzzolini, Francesca, Palterer, Boaz, Pancani, Silvia, Benucci, Maurizio, Manfredi, Mariangela, Bizzaro, Nicola
• Format: Article
• Language: English
• Subjects: Agreement; Autoimmune rheumatic diseases; Cohen's kappa; Diagnostic accuracy; ENA; Immunologic methods
• ISSN: 0022-1759; 1872-7905
• DOI: 10.1016/j.jim.2022.113297

Autoantibodies against extractable nuclear antigens (ENA) play a pivotal role in the diagnosis and classification of systemic autoimmune rheumatic diseases (SARD). In recent years, newly developed methods have enabled the simultaneous and quantitative detection of multiple anti-ENA reactivities. However, data regarding the comparability of results obtained using different technologies across different platforms are scarce. In this study we compared eight different immunoassays, commonly used in current laboratory practice for detection of anti-ENA antibodies. Sixty patients suffering from different SARD, 10 inflammatory arthritis patients (disease controls) and 10 healthy blood donors were included in this comparative study. Sera were collected in 15 centers belonging to the Study Group on Autoimmune Diseases of the Italian Society of Clinical Pathology and Laboratory Medicine. We evaluated the analytical sensitivity, specificity and diagnostic accuracy of each method for antibodies to Sm, RNP, Ro60, Ro52, Scl70, CENP-B and Jo1. Cohen's kappa was used to analyze the agreement among methods. Average agreement among methods was 0.82, ranging from substantial (k = 0.72) to almost perfect (k = 0.92). However, while the specificity was very good for all methods, some differences emerged regarding the analytical sensitivity. Diagnostic performance of current technologies for anti-ENA antibody detection showed good comparability. However, as some differences exist among methods, laboratory scientists and clinicians must be aware of the diagnostic accuracy of the testing method in use. •Antibodies to ENA are important in the diagnosis of autoimmune rheumatic diseases.•Many different immunological methods are available to the clinical laboratory.•Diagnostic performance of current immunoassays show good comparability.•Though agreement among assays is good, differences exist in diagnostic accuracy.•Clinicians and laboratory scientists should be aware of these differences.