EMRAH SALMAN
Turkish Journal of Immunology - 2025;13(2):90-98
Objective: Systemic autoimmune rheumatic diseases (SARDs) are associated with antinuclear antibodies (ANAs). This study aimed to retrospectively assess the outcomes of extractable nuclear antigen (ENA) tests in patients with rheumatologic disorders who tested positive for antinuclear antibodies. Materials and Methods: The study included 542 patients with a positive ANA result, no mixed pattern, and a positive immunoblot (IB) test. An ANA indirect immunofluorescence (IIF) test was performed on the same slide using the Hep-20-10/liver tissue kit (Euroimmun AG, Lübeck, Germany). Antibodies targeting ENAs were investigated using the EUROLINE ANA Profile 3 plus DFS70 (IgG) test kit (Euroimmun AG, Germany). Results: The homogeneous pattern (AC-1), Sm-RNP, and ribosomal P protein exhibited significant associations with systemic lupus erythematosus (SLE) (p<0.001, p=0.002, p<0.001, respectively). The speckled pattern (AC 4/5), SS-A, SS-B, and Ro52 showed a strong association with Sjögren’s syndrome (p<0.001 for each). The centromere pattern (AC-3), CENP-B, and Scl-70 were significantly correlated with systemic sclerosis (p<0.001 for all). The homogeneous pattern (AC-1) and Mi-2 were significantly associated with rheumatoid arthritis (p=0.019, p=0.035, respectively). The speckled pattern (AC-4/5), Jo-1, and Mi-2 exhibited significant associations with polymyositis/dermatomyositis (p<0.001, p=0.006, p<0.001, respectively). Systemic sclerosis was substantially correlated with mixed connective tissue disease (p=0.021). Conclusion: Antinuclear antibody IIF testing should be used to evaluate autoimmune disorders. Extractable nuclear antigen testing is essential for identifying and confirming the presence of the antigen. Extractable nuclear antigen tests detect specific antigens, making them diagnostically and prognostically valuable in rheumatological diseases. Through rational laboratory use, these tests can enhance efficiency and provide more accurate clinical guidance.
