Autoantibody Testing Test
Autoantibody testing checks your blood for autoantibodies—proteins made by the immune system that mistakenly attack your own healthy tissues. This test helps diagnose or monitor autoimmune diseases.
What this test measures
Autoantibody testing measures the presence and sometimes the amount of autoantibodies in your blood. These are proteins your immune system makes that attack your own healthy cells and organs instead of germs.
What your results mean
Reference ranges vary by laboratory and by your age and sex. MedlinePlus does not publish a single normal range for this test — always read your result against the range printed on your own lab report and discuss it with your provider.
Higher-than-normal results
A positive (abnormal) result means some amount of autoantibodies were found in your blood. This could be a sign of an autoimmune disease, but it does not confirm it. Your provider will consider other tests and your symptoms.
Lower-than-normal results
A negative (normal) result means you have little or no autoantibodies in your blood. However, this does not rule out an autoimmune disease. People with certain autoimmune diseases may still have negative results.
Frequently asked questions
What are autoantibodies?
Autoantibodies are proteins made by your immune system that mistakenly attack your own healthy tissues and organs instead of germs.
Why would I need an autoantibody test?
Your provider may order this test to help diagnose or monitor an autoimmune disease, especially if you have symptoms like joint pain, fatigue, or rash.
What does a positive result mean?
A positive result means autoantibodies were found in your blood. It does not always mean you have an autoimmune disease; some healthy people have them. Your provider will look at your symptoms and other tests.
What does a negative result mean?
A negative result means little or no autoantibodies were found. But it does not rule out an autoimmune disease. For example, some people with rheumatoid arthritis have negative RF tests.
Can autoantibody tests diagnose autoimmune diseases?
Autoantibody tests alone are usually not enough to make a diagnosis. Your provider will also consider your symptoms, medical history, imaging scans, and biopsy results.
Related lab tests
Sources
- MedlinePlus: Autoantibody Testing — NIH MedlinePlus
Last updated . Information is aggregated from official public sources and is not a substitute for professional medical care.