SchnitzMD > Knowledge Base > ANA Testing
ANA is a test for a group of diseases known as connective tissue diseases. The problem with this test is that about 20% of all normal women test positive for this antibody. This makes it confusing when someone has symptoms that are pretty common in the general public like fatigue or joint pains and then tests positive for ANA. Is it just coincidence of several common things or is it a sign of an uncommon disease like lupus?
| CONNECTIVE TISSUE DISEASES | TITERS | Other Antibodies to Test For |
|---|---|---|
| LUPUS SJOGREN’S SYNDROME SCLERODERMA POLYMYOSITIS MIXED CONNECTIVE TISSUE DISEASE UNSPECIFIED CONNECTIVE TISSUE DISEASE |
Unlike a lot of other test results ANA tests are often reported as a titer. Remember from science when you dilute serum in water. If the amount of an antibody in serum is very high the test will stay positive at a high number or dilution. An ANA titer of 1 to 40 is low while over 1 to 640 is high. | DNA Sm RNP Ro La |
ANA = antinuclear antibody
ANA is usually reported as three pieces of information:positive or negative, a titer or level and as a pattern. Just because it is positive does not mean something is wrong. Low titers are often seen in the general population. Most patients with connective tissue diseases will have ANA titers. The pattern is what the ANA test looks like under a microscope.
Antibodies are usually thought of as good. Our bodies have millions of antibodies whose job is to watch for and fight off infections of things foreign to your body. But, some antibodies are associated with certain diseases. The ANA antibody is identified by knowing that it attaches to a nucleus of a cell.
It is the rheumatologist’s job to figure out if the ANA means anything. This is done by questioning for symptoms of connective tissue diseases like arthritis, rash, dry eyes, dry mouth, difficulty swallwoing, pleurisy (see each disease in the knowledge base for more features.); by examining for features of these diseases and by doing more testing. More testing means testing for other antibodies that are usually present in connective tissue diseases.
Antibody
noun: an-ti-bod-y
A Y-shaped protein on the surface of cells that neutralizes antigen
ETYMOLOGY:
anti-, against + body