Dr. Bartley Cryan:

One can get positive Lyme disease serology with rheumatoid arthritis or autoimmune conditions. Many conditions make it very difficult for one to diagnose anything serologically. In the reference laboratory in which I worked, if we had a positive test for Lyme disease, we tested for three or four other illnesses to exclude them because one can have cross-reacting antibodies. We ensured the antibodies were due to the borreliaand not due to another spirochete, rheumatoid arthritis or a connective tissue infection.