Clinical Information

SS-A/Ro is 1 of 4 autoantigens commonly referred to as ENAs. The other ENAs are SS-B/La, RNP (ribonucleoprotein), and Sm (Smith). Each ENA is composed of one or more proteins associated with small nuclear or cytoplasmic RNA species (snRNP) ranging in size from 80 to 350 nucleotides. Antibodies to ENA are common in patients with connective tissue diseases (systemic rheumatic diseases) including SLE, mixed connective tissue disease, SjS, scleroderma (systemic sclerosis), and polymyositis/dermatomyositis. A positive result for SS-A/Ro antibodies may be suggestive of connective tissue disease (CTD) such as Sjogren syndrome, systemic lupus erythematosus (SLE), systemic sclerosis (SSc), inflammatory myopathies especially in patients with anti-synthetase syndrome, CTD-associated with interstitial lung diseases (CTD-ILD), or rheumatoid arthritis. A positive result for SSA antibodies in a woman with LE prior to delivery indicates an increased risk of congenital heart block in the neonate.