Why and when are autoantibody tests performed?
Autoantibody tests are performed, along with x-rays, other imaging scans, and biopsies, to help diagnose an autoimmune disorder. In some cases, they are used to help evaluate the severity of the condition, monitor progress of the disease, and assess the effectiveness of treatments.
Autoantibody tests may be ordered when a person presents with chronic, progressive arthritic symptoms, fever, fatigue, muscle weakness, and/or a rash that cannot readily be explained.
One of the most commonly ordered tests is the antinuclear antibody (ANA) test. ANA may be positive with a variety of autoimmune diseases, including lupus, Sjögren syndrome, rheumatoid arthritis, and autoimmune hepatitis. When someone has a positive ANA, other autoantibody tests are used to help make a diagnosis. For example, an anti-dsDNA and a panel of 4 or 6 autoantibody tests called extractable nuclear antigens (ENA) are typically ordered. The pattern of results for these autoantibodies helps to determine if a particular autoimmune disorder is likely to be present.
Results of these autoantibody tests must be interpreted with care and in context. This is because not everyone with an autoimmune disease will have detectable autoantibodies. A health practitioner will consider the results in conjunction with an individual's personal and medical history along with signs and symptoms when making a diagnosis.