ANA Test
Overview
The antinuclear antibody test, or ANA test, is a blood test that checks for antinuclear antibodies in the body. These antibodies are made by the immune system when it mistakenly attacks the body’s own cells, which can happen in certain autoimmune diseases.
Doctors often order the ANA test to help identify or rule out conditions like lupus, rheumatoid arthritis, or scleroderma. They may suggest this test when a person shows symptoms that could be caused by autoimmune disorders.
The test looks for antibodies that often target the nucleus inside the body’s own cells. A positive result may indicate an autoimmune reaction, though some healthy people also test positive.
Key Points to Remember:
- Detects antibodies linked to autoimmune issues.
- A positive test can appear in both sick and healthy people.
- Main target is nuclear antigens inside cells.
Purpose of This Test
Doctors use this test when symptoms like joint pain, tiredness, or fever may point to an autoimmune problem. It helps them find autoantibodies in the blood, which can signal inflammation or an autoimmune disease. A positive ANA result often leads to more testing for certain autoantibodies tied to specific conditions.
Common Reasons for Testing
- Unexplained joint pain or swelling.
- Ongoing fatigue not explained by other causes.
- Repeated low-grade fevers.
- Suspicion of autoimmune diseases such as lupus or rheumatoid arthritis.
Getting Ready for the Test
You do not need to follow a special diet or avoid drinks before an ANA test unless your doctor tells you otherwise. If the blood sample will be checked for other things, your doctor may ask you to stop eating or drinking for a certain time.
Share a list of all medicines you use with your doctor before the test. Some medications can affect your results. Keeping your doctor informed helps make sure the test is accurate.
What Happens During the Test
A healthcare provider takes a small blood sample from a vein in your arm using a needle. This process usually takes just a few minutes. After collecting the sample, the provider sends it to a lab for testing. Most people can continue normal activities right away. Symptoms during the test may include:
- A brief pinch when the needle goes in.
- Mild soreness or bruising where the needle was inserted.
Laboratory Findings
A positive antinuclear antibody (ANA) test means antinuclear antibodies are present in the blood. However, this result does not confirm a specific illness. Healthy people, especially women over 65, can have positive ANA tests.
Some infections, certain cancers, and medication use can also cause increased ANA levels. Doctors often order additional tests if they suspect an autoimmune condition. These extra tests look for diseases like lupus (systemic lupus erythematosus or SLE), rheumatoid arthritis, and dermatomyositis.
ANA test results can also include a titer, which shows the concentration of antibodies in the blood. People with autoimmune disorders generally have higher titers, but lower levels can appear in healthy individuals as well.
Key Points
- A positive result alone does not diagnose a disease.
- ANA titers help doctors track the degree of antibodies.
- Related conditions: Lupus (SLE), rheumatoid arthritis, dermatomyositis.
| Test | Can Indicate | Notes |
|---|---|---|
| ANA | SLE, rheumatoid arthritis, dermatomyositis | Needs more testing to confirm diagnosis. |
