CLIA SS-A/Ro60

SS-A/Ro antigen is a ribonucleoprotein (RNP) complex localized in nucleus and cytoplasm. It consists of hYRNA (small cytoplasmic RNA) and two protein antigens of 52 kDa and 60 kDa (Ro52 and Ro60).

Autoantibodies against Ro60 a Ro52 are often found together; anti-SS-B/La antibodies may also occure. Presence of the SS-A/Ro autoantibodies is typical for Sjögren’s syndrome (50 – 70%) and systemic lupus erythematodes (40 – 50%), especially for certain clinical subunits (subacute cutaneous lupus, neonatal lupus), and rheumatoid arthritis. Anti-SS-A/Ro antibodies can be detected approximately 3 years before the SLE diagnosis is reached. SS-A/Ro antibodies are also associated with features of extraglandular inflammation in SLE patients including vasculitis, purpura, cytopenias, and adenopathy.

While anti-Ro60 antibodies are primarily specific for systemic lupus erythematodes and Sjögren’s syndrome, anti-Ro52 antibodies was proved to be individually present (without anti-Ro60) in systemic scleroderma (20%) and myositis (35%), especially in anti-Jo-1 positive patients. Anti-Ro52 as well as anti-SS-B/La antibodies significantly raise the risk of congenital atrioventricular block (CAVB) development. They may be also present in autoimmune liver disease.

Antigen Used: Highly purified native antigen SS-A/Ro60 (60 kDa) and recombinant antigen SS-A/Ro52 (52 kDa).