Extractable Nuclear Antibodies (ENA) Blood Test

Anti-centromere protein (CENP) antibodies are antibodies that target proteins in the centromere, the central part of chromosomes. These antibodies are associated with autoimmune conditions, particularly limited cutaneous systemic sclerosis (also known as CREST syndrome), where the immune system mistakenly attacks the body's own tissues. The presence of these antibodies can help doctors diagnose and classify autoimmune connective tissue diseases. If you have symptoms such as Raynaud's phenomenon, skin thickening, or digestive issues, this test can be useful in identifying the underlying cause.

Anti-Jo1 antibodies are autoantibodies that target an enzyme involved in protein synthesis. They are most commonly associated with polymyositis and dermatomyositis, inflammatory muscle diseases that cause muscle weakness and pain. These antibodies are also linked to a specific syndrome called anti-synthetase syndrome, which can affect the muscles, lungs, joints, and skin. Testing for Anti-Jo1 antibodies helps doctors identify inflammatory muscle conditions.

Anti-Ro antibodies (also called SS-A antibodies) are autoantibodies commonly found in people with Sjögren's syndrome and systemic lupus erythematosus (SLE). These antibodies target proteins found in cell nuclei and are the more common of the two SS antibodies (Anti-Ro and Anti-La), often appearing on their own or alongside Anti-La antibodies.

Anti-Scl-70 antibodies (also called anti-topoisomerase I antibodies) are autoantibodies associated with systemic sclerosis (scleroderma), an autoimmune condition that causes thickening and hardening of the skin and can affect internal organs. These antibodies are particularly linked to the diffuse form of systemic sclerosis, which tends to affect larger areas of skin and has a higher risk of involving internal organs such as the lungs and kidneys. The presence of these antibodies can help confirm a diagnosis of systemic sclerosis and may indicate the need for careful monitoring of organ function.

Anti-Sm antibodies (anti-Smith antibodies) are highly specific autoantibodies associated with systemic lupus erythematosus (SLE). While not everyone with lupus has these antibodies, their presence is considered very specific to the condition. That means if they're found, it strongly suggests SLE. These antibodies target proteins that are part of the cell's machinery for processing genetic information. Testing for Anti-Sm antibodies can help confirm a lupus diagnosis and may be used alongside other tests to build a complete picture of autoimmune activity.

Anti-U1RNP antibodies are autoantibodies that target ribonucleoproteins involved in processing genetic material within cells. These antibodies can be found in several autoimmune conditions, including mixed connective tissue disease (MCTD), systemic lupus erythematosus (SLE), and systemic sclerosis. When found in high levels, they are particularly associated with mixed connective tissue disease, which has features of multiple autoimmune conditions. Testing for these antibodies helps doctors diagnose and differentiate between various autoimmune connective tissue diseases.