Step 4: Read and complete the decision guide to learn more about your symptoms.
Nearly all people with systemic lupus erythematosus (SLE) have a positive (abnormal) ANA -- that is, the sensitivity of the ANA for SLE is quite high. That also means that it is very rare to have lupus with a negative (normal) ANA. If you or your doctors are concerned you may have SLE, a negative ANA should be quite reassuring. However, there are other arthritic, autoimmune and rheumatic conditions that have a negative ANA.
Not everyone with a positive ANA has a disease. In fact, specificity is low, meaning that many healthy people have a positive result.
Here is a partial list of common rheumatic and non-rheumatic diseases associated with a positive ANA. Because many of these conditions are relatively rare, many -- perhaps most-people with a positive ANA have none of them and have no disease or condition related to this test result.
ANA in rheumatic disease: SLE , drug-induced lupus erythematosus, Sjogren's syndrome, mixed connective tissue disease, progressive systemic sclerosis (scleroderma)
ANA in non-rheumatic disease: autoimmune hepatitis, primary biliary cirrhosis, Graves' disease, Hashimoto's thyroiditis, hepatitis C, HIV infection
Finally, some specific details about the ANA are important. The ANA is reported as a ratio, as in 1:80 or 1:640. In general, the more abnormal result, (that is, the higher the second number), the more likely it is to be meaningful; however, exceptions are common. In addition, there are several types of ANAs and, when necessary, additional testing can identify the specific type of ANA (also called subtype). Among the most helpful are the anti-Sm and anti-ds-DNA, because when positive, they strongly suggest SLE.
Remember: just because you have a positive ANA does not mean you have lupus or other specific rheumatologic disease. It all depends on your symptoms, your physical examination, other routine test results and why the ANA was checked in the first place.