Antinuclear antibodies or ANAs are a group of antibodies produced by the body’s immune system. They are quite rare and related to autoimmune connective tissue diseases. In autoimmune diseases, the immune system turns against the body’s own tissue. Antinuclear antibody levels may also be elevated in connection with inflammation and malignant tumours. In very low concentrations, they also act as part of the natural immune system.
When should ANA be measured?
Antinuclear antibodies are often determined when examining various autoimmune illnesses. They are most commonly used when examining ambiguous joint and muscle pain if suspecting an inflammatory joint disease. However, antinuclear antibodies cannot be used to diagnose a particular illness.
Checking antinuclear antibodies is a good idea when suspecting an autoimmune illness. The symptoms may include:
- Mild fever
- Long-term fatigue, weakness
- Pain similar to arthritis in one or more joints
- Red rash in a butterfly pattern across the nose and cheeks
- Skin sensitive to light
- Hair loss
- Muscle pain
- Numbness or prickling in hands or feet
- Inflammation and damage in organs and tissue, including kidneys, lungs, heart, pericardium, central nervous system and blood vessels
What does the ANA test measure?
The test shows whether the person’s blood contains antinuclear antibodies. Their presence may indicate an autoimmune illness which requires more precise testing.
How to interpret ANA-test result?
Normally, the result is:
- titre less than 320
Interpretation: The antinuclear antibodies are slightly positive (titre 320 or less) in less than 5% of normal population.
The results are reported in titre that is achieved by diluting part of the blood sample with a saline solution (saltwater). For example, a titre result of 1: 320 means that one part blood sample was mixed with 320 parts saline solution and this was the smallest ratio in which ANA was still detected. The smaller the dilution ratio in which ANA is still detected, the higher the titre and the larger the amount of present autonuclear antibodies.
Please contact your physician or other healthcare professional if you suspect an illness or need help interpreting the results.
What can cause elevated ANA values?
Strongly positive antinuclear antibodies (titre 1,000 or higher) are often related to autoimmune illnesses. These include systemic lupus erythematosus or SLE (in 95% of the cases), mixed connective tissue disease or MCTD, Sjögren's syndrome, rheumatoid arthritis, systemic sclerosis (scleroderma) and autoimmune liver diseases. Elevated ANA values may also be caused by the use of some medicinal products.
What can cause decreased ANA values?
The value cannot be decreased. The most common test result is negative. A person who has previously had a positive ANA result may receive a negative result if the autoimmune illness is in remission.
SYNLAB test list: Antinuclear antibodies, IF method, screening (2819 S-ANA) https://www2.synlab.fi/laboratoriokasikirja/tutkimuskuvaukset/ana/
Lab Tests Online: Antinuclear Antibody (ANA) https://labtestsonline.org/tests/antinuclear-antibody-ana
Julkunen H, Miettinen A. Autovasta-aineiden merkitys tulehduksellisissa reumasairauksissa. Duodecim 2008; 124:1637–46.
Fasting is not required
This examination does not require fasting