What does it mean to have a raised ANA titre?
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As noted in previous answers, the acronym ANA stands for anti-nuclear antibody. When your doctor suspects you may have an autoimmune disorder, he or she will test for the presence of anti-nuclear antibodies in your blood.
To perform the ANA test, serum from your blood specimen is added to microscope slides which have commercially prepared cells on the slide surface.
If your serum contains antinuclear antibodies (ANA), they bind to the cells (specifically the nuclei of the cells) on the slide.
A second antibody, commercially tagged with a fluorescent dye, is added to the mix of patient's serum and commercially prepared cells on the slide. The second (fluorescent) antibody attaches to the serum antibodies and cells which have bound together. When viewed under an ultraviolet microscope, antinuclear antibodies appear as fluorescent cells.
If fluorescent cells are observed, the ANA test is considered positive. If fluorescent cells are not observed, the ANA test is considered negative.
The ANA titer is determined by repeating the positive test with serial dilutions until the test yields a negative result. The last dilution which yields a positive result (flourescence) is the titer which gets reported. For example, if a titer performed for a positive ANA test is:
1:10 positive
1:20 positive
1:40 positive
1:80 positive
1:160 positive
1:320 negative
The reported titer would be 1:160.
Generally, an ANA titre of 1:80 or higher is considered positive.
At least 5% of the population has a positive ANA titre with no disease activity.
For those with disease activity, the ANA titre does not indicate the absolute amount of disease activity (e.g. one person with an ANA titre of 1:640 may have very little disease activity, while another with a titre of 1:320 may have significant disease activity). The ANA titre must be evaluated in the context of the individual.
The ANA test by itself is not specific for any disease. Your clinical presentation, as well as tests for additional antibodies, complements and factors in your blood will also be used to determine what condition, if any, is present, and how to treat it.
ANA ( anti nuclear antibody) shows the presence of an autoimmune disorder. Because there are soooo many your doctor will have to determine where to go from here. Good luck.
To add to G I's response, the ANA level of a healthy person is 0.
From there, it's a geometric progression that stops at 640 (2,4,8,16,32,64, 128...). There are many autoimmune diseases that raise one's ANA level: rheumatoid arthritis and lupus are probably the two most common. It will take some more testing of various sorts to determine which disease is responsible for the rise in ANA level. Be patient, and ask your doctor lots of questions. If s/he is dismissive, seek another doctor. You have the right to be informed, and this includes the right to read your medical chart and have things explained to you in language you understand.
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