Blood is typically drawn from a vein, usually from the inside of the elbow or the back of the hand. The site is cleaned with germ-killing medicine (antiseptic). The health care provider wraps an elastic band around the upper arm to apply pressure to the area and make the vein swell with blood.
Next, the health care provider gently inserts a needle into the vein. The blood collects into an airtight vial or tube attached to the needle. The elastic band is removed from your arm. Once the blood has been collected, the needle is removed, and the puncture site is covered to stop any bleeding.
In infants or young children, a sharp tool called a lancet may be used to puncture the skin and make it bleed. The blood collects into a small glass tube called a pipette, or onto a slide or test strip. A bandage may be placed over the area if there is any bleeding.
The blood sample is sent to the laboratory for testing.
No special preparation is necessary for this test.
When the needle is inserted to draw blood, some people feel pain, while others feel only a prick or stinging sensation. Afterward, there may be some throbbing.
Autoimmune disorders, in which cells from the immune system attack tissues or organs, are one possible cause of liver disease. The most common autoimmune liver diseases are autoimmune hepatitis and primary biliary cirrhosis.
This group of tests helps your health care provider diagnose liver disease.
The normal range for protein levels in the blood will change with each laboratory. Please check with your health care provider for the normal ranges in your particular laboratory.
Negative results on all antibodies are normal.
Note: Normal value ranges may vary slightly among different laboratories. Talk to your doctor about the meaning of your specific test results.
Blood tests for autoimmune diseases are not completely accurate. They can have false negative results (you have the disease, but the test is negative) and false positive results (you do not have the disease, but the test is positive).
A “weakly positive” or “low titer positive” test for autoimmune disease is often not due to any disease.
A positive test on the panel may indicate autoimmune hepatitis or other autoimmune liver disease.
If the test is positive mostly for anti-mitochondrial antibodies, there is a high probability of primary biliary cirrhosis.
If the immune proteins are high and albumin is low, you may have liver cirrhosis or chronic active hepatitis.
Veins and arteries vary in size from one patient to another and from one side of the body to the other. Obtaining a blood sample from some people may be more difficult than from others.
Other risks associated with having blood drawn are slight but may include:
- Excessive bleeding
Fainting or feeling light-headed
- Hematoma (blood accumulating under the skin)
- Infection (a slight risk any time the skin is broken)