Antinuclear Antibodies (ANA) Blood Test, from our experts to you.
Dr Natasha Fernando MBBS, MRCGPMedical Director

What is an ANA Blood Test?
Our Antinuclear Antibodies Blood Test sees whether you have auto-antibodies (which attack your cells) to help diagnose several autoimmune conditions, including lupus, rheumatoid arthritis, and Sjögren's syndrome.
What can I learn from this test?
If are you experiencing symptoms, our test can help confirm if you have an autoimmune disease. However, a diagnosis is unlikely to be given from antibodies alone, as antibodies can be raised even if you have no evidence of disease.
What causes autoimmune conditions?
Autoimmune conditions happen if your immune system mistakes your body's cells as foreign cells and starts attacking them. Usually, your immune system is constantly looking for foreign bodies and will send out an army of fighter cells to attack them. However, if you have an autoimmune disease, your immune system mistakes parts of your body, like your joints or skin, as foreign. In this instance, it releases proteins called autoantibodies that attack healthy cells. Read more about this in our blog: Autoimmune disease – why one often follows another.
Limitations of the test
ANA has a very low specificity. This means our test could indicate you may have connective tissue disease, even when you don’t (a false-positive result). Around three in ten people will receive a false positive result. This can lead to unnecessary anxiety and further investigations. One reason for its low specificity is that ANA can be found in other conditions such as liver disease, inflammatory bowel conditions, and chronic infections. Certain drugs, like heart and blood pressure medications, may also increase ANA levels.
Therefore, this test is most suitable when there’s a reasonable suspicion of a connective tissue disease and other more common causes of symptoms have been explored. Results are more clinically significant with ANA titres greater than 1:160.
Although ANA is a good test for ruling out autoimmune disease, there’s a chance you could get a negative result when you do have an autoimmune disease (a false-negative result). False-negative results are less common and occur in about one in twenty cases.