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.
DEAR DR. ROACH: I read your recent column on glaucoma with interest. Can you comment on "low pressure glaucoma"? My intraocular pressure was about 15-16 (normal), but my optic nerve was greatly enlarged. Eyedrops lowered that to about 10, but questions about why the nerve is so enlarged and why lowering the intraocular pressure would help do not elicit much of an answer, just that it might help. My concern is the threat of going blind as the optic nerve "cups out." -- C.G.
ANSWER: Glaucoma is a disease of the retina, diagnosed by an enlargement of the optic cup relative to the optic disc when examining the retina. The vast majority of people with glaucoma have elevated pressures inside the eye, and treatment to lower pressure is effective at slowing or stopping progression of the disease. Without treatment, glaucoma will cause progressive and irreversible loss of vision, starting with peripheral vision.
However, some people will develop the retinopathy of glaucoma with normal pressures. This may be associated with medical conditions such as anemia, arrhythmia, hypothyroidism, autoimmune diseases and migraine headaches. An ophthalmologist will typically do a thorough exam to exclude other causes of retinopathy, but lowering the eye pressure, even if normal to begin with, has been shown to reduce progression of visual loss in glaucoma. It's the best treatment we have to prevent blindness.