Anti-Ro52 Ab (SSA)

Anti-Ro antibodies are among the most frequently detected autoantibodies directed against extractable nuclear antigens (ENA) and were initially described in patients with systemic lupus erythematosus (SLE) and Sjögren’s syndrome (SS). Two distinct antibody specificities are recognized: anti-Ro52 (SS-A 52), directed against the TRIM21 protein, and anti-Ro60 (SS-A 60). Although historically considered part of a single autoantibody system, Ro52 and Ro60 are distinct antigens with different clinical associations.

Anti-Ro52 antibodies are commonly detected in patients with SS and SLE and may also occur, including as an isolated antibody specificity, in systemic sclerosis (SSc) and idiopathic inflammatory myopathies (IIM). In patients with IIM, particularly those positive for anti-Jo-1 antibodies, the presence of anti-Ro52 has been associated with interstitial lung disease and may be associated with more severe pulmonary involvement. Maternal anti-Ro antibodies are also clinically significant because of their association with neonatal lupus and congenital heart block.

Anti-Ro52 and anti-Ro60 antibodies should be evaluated as separate specificities because assays using a mixture of Ro52 and Ro60 antigens may fail to detect isolated reactivity to either antigen. Anti-Ro52 results should be interpreted in conjunction with the patient’s clinical presentation and other relevant autoantibody findings. [Based on information from the QUANTA Flash® Ro52 Directional Insert, Werfen]