Your body’s immune system is responsible for fighting off “foreign invaders” such as bacteria, viruses, fungi and even cancer. One tool that your immune system uses is a protein called an antibody. These antibodies attach to the foreign substance and aid in their removal from the body, usually preventing an illness from establishing itself. Antibodies are often specific to protein markers on the surface of the substance and the antibody will only target that foreign substance; all antibodies that are created against proteins close to those in your own body are usually destroyed. Unfortunately, some antibodies, called autoantibodies can make it past this self-screen and populate the blood. When this happens, inflammation may occur when these autoantibodies come in contact with tissue that it is specific for. This condition can range from mild to very severe and can cause a variety of diseases.
What is an Antinuclear Antibody Test?
The Antinuclear Antibody (ANA) test detects autoantibodies that are specific to the nucleus of the cell. The nucleus of a cell contains DNA and is found in almost every cell in the body.
How is this test performed?
This test is performed by taking a sample of blood, spinning it in a centrifuge and separating the serum (the liquid portion of the blood that contains antibodies) from the red and white cells. The serum is then exposed to cells in the laboratory. Fluorescence is often used to detect the presence of antibodies that have attached themselves to parts of the cell and nucleus.
What is my doctor testing for?
When your doctor orders this test they are checking for autoimmune diseases. Autoimmune diseases occur when the autoantibodies mount a significant response against self tissue, and often a person begins to display symptoms. There are numerous variations of autoimmune diseases known including the following: Crohns disease, Lupus, Hashimoto’s Thyroiditis, Addison’s disease, Multiple Sclerosis, Myasthenia Gravis, and Rheumatoid Arthritis. Your doctor may be suspicious of one of the more than 80 diseases known. The ANA test is a screening test and not necessarily used for specific diagnosis of a disease.
Other tests often ordered with an ANA
Other tests that may also indicate the presence of inflammation caused by autoimmune diseases are:
Erythrocyte sedimentation rate
Are there any medications that can interfere with this test?
Some drugs can induce the production of antinuclear antibodies. Drugs such as procainamide, hydralazine, and dilantin are known to induce these antibodies and even cause what is called drug-induce diseases. For this reason, it is important that your physician knows all medications that you are currently taking.
What if my test is positive?
Your doctor may perform further diagnostic tests to specify which autoimmune disorder you may have. The results of the ANA test are just a piece of the puzzle in which your doctor is solving. Symptoms which you display play a huge part in your doctor making a complete and accurate diagnosis, so it is important to be honest and thorough when explaining your symptoms to your physician.
Self: Medical Laboratory Scientist (4 years) and two Bachelor degrees in medical science