Tests for autoimmune diseases measure the amount of certain antibodies in your blood. Your body makes antibodies to attack and destroy substances such as bacteria and viruses. But in autoimmune diseases, the antibodies attack and destroy your body's tissues. This can lead to diseases such as rheumatoid arthritis, scleroderma, and lupus. These health problems affect the connective tissues, such as the skin and joints, and blood vessels and other tissues.
Autoimmune tests may include anti-dsDNA, anti-RNP, anti-Smith (or anti-Sm), anti-Sjogren's SSA and SSB, anti-scleroderma or anti-Scl-70, anti-Jo-1, and anti-CCP. Antibody against cardiolipin also may be tested.
If you have several of these antibodies—or have them in high amounts—you may have an autoimmune disease.
You may have had an antinuclear antibody test, or ANA. This test is often done first to look for antibodies that can cause autoimmune problems. A rheumatoid factor test is also done to look for rheumatoid arthritis.
Your doctor will look at several things to decide if you have one of these conditions. He or she will look at your symptoms and the results of these and other tests.
Why It Is Done
These tests help your doctor see if you have an autoimmune disease, such as:
Your doctor may want you to have these tests if you have symptoms such as joint pain, muscle aches, and fever.
Your doctor will use these tests and your symptoms to see if you have a health problem.
How To Prepare
You do not need to do anything special to prepare for this test.
How It Is Done
The health professional taking a sample of your blood will:
Wrap an elastic band around your upper arm to stop the flow of blood. This makes the veins below the band larger so it is easier to put a needle into the vein.
Clean the needle site with alcohol.
Put the needle into the vein. More than one needle stick may be needed.
Attach a tube to the needle to fill it with blood.
Remove the band from your arm when enough blood is collected.
Put a gauze pad or cotton ball over the needle site as the needle is removed.
Put pressure on the site and then put on a bandage.
How It Feels
The blood sample is taken from a vein in your arm. An elastic band is wrapped around your upper arm. It may feel tight. You may feel nothing at all from the needle, or you may feel a quick sting or pinch.
There is very little chance of a problem from having a blood sample taken from a vein.
You may get a small bruise at the site. You can lower the chance of bruising by keeping pressure on the site for several minutes.
In rare cases, the vein may become swollen after the blood sample is taken. This problem is called phlebitis. You can use a warm compress several times a day to treat this.
Tests for autoimmune diseases measure the amount of certain antibodies in your blood.
A normal (negative) result means that antibodies for these conditions were not found. An abnormal (positive) result means that one or more of these antibodies were found.
What Affects the Test
Your doctor will talk with you about anything that might keep you from having the test or that may change the test results.
What To Think About
Your doctor won't use tests alone to diagnose a condition. Some people who have an autoimmune disease have normal test results. So your symptoms, your medical history, and family medical history are also important.
Some of these tests also may be done to watch a condition after a person has been diagnosed.
Medical Review:Adam Husney MD - Family Medicine & E. Gregory Thompson MD - Internal Medicine & Martin J. Gabica MD - Family Medicine & Jeffrey N. Katz MD, MPH - Rheumatology
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