ENA Panel | Autoantibodies – SS-A, SS-B, RNP, Sm, Scl-70, Jo-1

General Information

Systemic autoimmune rheumatic diseases are characterized by elevated levels of autoantibodies produced against intracellular proteins and nucleic acids (DNA, RNA). These are called autoantibodies Antinuclear Antibodies (ANA), Because they are directed mainly against nuclear antigens.

ENA extractable nuclear autoantibodiesIt is a part of antinuclear antibodies and is directed against different classes of nuclear proteins:

Anti-SS-A

Anti-SS-B

Anti-RNP

Anti-SM

Anti-SCL-70

Anti-JO-1

Anti-SS-A – The most commonly detected ENA antibody. It is associated with systemic lupus erythematosus, its subacute subcutaneous course, neonatal lupus, etc.

Anti-SS-B    It is a typical marker of autoimmune connective tissue diseases. It occurs in Sjogren's disease, scleroderma, myositis, systemic lupus erythematosus.

Anti-RNP     Autoantibodies against ribonucleoproteins. It occurs in 45% of patients with systemic lupus erythematosus, however, it is also characteristic of other connective tissue diseases: Sjogren's syndrome, scleroderma and polymyositis.

Anti-SM   Smith's autoantibodies are formed against small nuclear ribonucleoprotein - Smith, which consists of B, B1, D, E, G protein subunits. Smith's autoantibodies are typical of systemic lupus erythematosus and are present in 30% of patients.

Anti-SCL-70   Autoantibodies are present in 20% of patients with systemic scleroderma and often indicate a poor clinical prognosis.

Anti-JO-1  It is an autoantibody characteristic of myositis, which occurs in patients with idiopathic inflammatory myopathies. These antibodies are directed against histidyl transport RNA synthetase and inhibit histidyl attachment to transport RNA during protein synthesis.

It is often associated with a form of polymyositis and dermatomyositis with lung damage. The anti-JO-1 antibody titer correlates directly with disease activity.