The Antinuclear Antibody Test: What It Means
There is no way to hurry the diagnosis of lupus. The length of time it takes can be highly variable; it may take weeks, months or years. In some cases, it can take as long as 10 years before enough evidence accumulates indicating that it is, in fact lupus.
Learn the signs and symptoms of lupus so that if you develop something new, you can tell your doctor so s/he can determine if you have satisfied enough criteria for a diagnosis.
What about a "borderline" ANA?
All tests have a normal range of values. If a test value is at the upper limit of the normal range or slightly over, it's often referred to as "borderline." The importance of a borderline ANA test depends on the other criterion that are present. A borderline positive ANA will probably be ignored by the doctor if there are only one or two other criterion suggesting lupus, yet could clinch the diagnosis if there are already three or four positive criterion.
Is it possible to have lupus with a negative ANA?
More than 95% of people with systemic lupus have a positive ANA. Only a small percentage have a negative ANA, and many of those have other antibodies (such as anti-phospholipid antibodies, anti-Ro, anti-SSA) or their ANA converted from positive to negative from steroids, cytotoxic medications, or uremia (kidney failure).
How high does my ANA have to get before the doctor says it's lupus?
It is not a question of how high the ANA titre is. Even a very high "titre' ANA by itself is never sufficient to diagnose lupus. Other criteria must be satisfied.
A titre (ti-ter) is the number of times a solution (such as a person's blood) can be diluted before a substance (such as an antibody) can no longer be detected. Thus, an ANA titre of 1:80 means that the blood can be diluted to one in eighty parts and the lab technician can still detect the ANA antibody. The dilutions are usually two-fold, so that the next dilution would be 1:160, and the one after 1:320.
Because normal ranges for ANA titres vary from lab to lab, there is no universal normal range. There is no limit to how high the ANA can go.