Elevated ANA sparks search for associated conditions
DEAR DR. ROACH: I am a 58-year-old healthy female. I am 6 feet tall, and weigh 130 pounds. My last blood pressure reading was 100/58. I have Raynaud’s phenomenon. I exercise every day (walk, bike, snowshoe).
All of my medical laboratory results are within the normal range with the exception of my antinuclear antibody. In 2012, it was at 1:640 titer (speckled pattern). In 2020, it was at 1:1280 titer (speckled pattern). The rheumatologist ordered additional blood tests which showed a strong positive for ANA IgG (95 units) and positive for ANA by HEp-2 titer at 1:160. All other tests were negative.
According to the doctor, the tests determined that I did not have systemic lupus, rheumatoid arthritis or a connective tissue disease. But he could not say why my ANA is elevated, only that I most likely had inflammation somewhere in my body. My research shows that some normal, healthy people just have elevated ANA, and it does not mean anything is wrong. I would like to know your thoughts on this. — T.O.
ANSWER: The antinuclear antibody is indeed a common finding, and its meaning can sometimes be very confusing. While the majority of people with systemic lupus will have a positive ANA, you are correct that some people will have a positive ANA test without any indication of illness. The pattern of ANA can be helpful, but just “speckled” may or may not be associated with autoimmune diseases. A high titer (1:1280 is high) is more likely to be associated with autoimmune diseases.
Rheumatologists will usually try to get more information, using specific tests in people with such high titers, looking for lupus or rheumatoid arthritis, and it sounds like yours did so and got negative results, which is good news.
Raynaud’s phenomenon is associated with positive ANA titers up to 40% of the time. Raynaud’s may also occur as part of other autoimmune diseases. Since you don’t seem to have any symptoms, and a thorough evaluation was negative, I would not look further unless you develop new issues.