S-ANA is a blood test used to detect antinuclear antibodies – autoantibodies that can occur when the immune system mistakenly attacks the body's own cells. The test can provide important information when investigating autoimmune diseases and help identify whether the body is attacking its own tissues.
In case of suspicion of autoimmune disease
Analysis of S-ANA is particularly important when suspecting systemic lupus erythematosus (SLE), since almost everyone who has this disease receives a positive test result. A positive test result is therefore a strong indicator when suspecting SLE.
At the same time, it is important to know that ANA can also occur in completely healthy individuals – that is, without any underlying disease. This applies primarily in low concentrations, and the occurrence increases slightly with age. A positive ANA test is therefore not in itself proof of disease, but it is an important piece of the puzzle in the overall assessment when there is suspicion of rheumatic or autoimmune conditions such as SLE, Sjögren's syndrome, scleroderma and other connective tissue diseases.
ANA is also more frequent in women than men. It is also possible that ANA occurs transiently during an ongoing infection, without it meaning that one has an autoimmune disease. The analysis is used as part of the investigation of the following diseases;
- Systemic lupus erythematosus (SLE)
- Sjögren's syndrome
- Mixed connective tissue diseases (MCTD)
- Scleroderma
- Myositis
When might an ANA test be appropriate?
The S-ANA blood test may be appropriate if you experience unexplained symptoms such as:
- Fatigue and body aches.
- Prolonged fever without infection.
- Joint problems or swelling.
- Skin rash, sun sensitivity, or hair loss.
- Dry mouth or dry eyes.
Important things to know before ordering the ANA test
- A positive ANA is relatively common, especially in women and occurs in 5% of the normal population.
- To make a diagnosis, more tests are usually required, such as ENA, dsDNA, or complement factors.
- The test can be combined with other blood tests when investigating inflammation or autoimmune disease.
Note! The ANA test is not a general health test and should only be taken if autoimmune disease is suspected. A positive result may require further analysis and medical follow-up. If you are unsure about your symptoms, you should contact your doctor.
