Saturday, February 28, 2015
Blood tests for Lupus...positive or negative?
for years I have had off and on positive ANA blood tests..been told I have lupus then I don't..then I was told I had fibromyalgia(a bad case of it due to the positive ANA,which was not high enough to be considered lupus)is this possible, and why would the levels be so varied? last one was 180....and now it is negative again.please explain
The ANA (anti-nuclear antibody test) is very non-specific. A publication in Arthritis & Rheumatism showed that approximately 30% of adults without any known disease can be ANA positive and almost 40% of persons who satisfy the American College of Rheumatology criteria for Fibromyalgia are ANA positive. The study did not indicate any relationship between the degree of abnormality of the ANA and the severity of Fibromyalgia symptoms.
The American College of Rheumatology (A.C.R.) has criteria for the diagnosis of S.L.E. (Systemic Lupus Erythematosus). If an individual does not fulfill the criteria, the diagnosis of SLE can not be made with certainty regardless of the results to the ANA. The A.C.R. has criteria for Fibromyalgia as well.
However, further complicating the interpretation of the presence of anti-nuclear antibodies (positive ANA) is the coexistence of Fibromyalgia and S.L.E. Individuals with S.L.E. have a greater risk of developing Fibromyalgia. Accordingly, these disorders can co-exist. Because of this, most clinicians make a diagnosis based on criteria rather than the results of an ANA.
Larry Houk, MD
Professor of Clinical Medicine and Rheumatology
College of Medicine
University of Cincinnati