After spending a bit of time trying to track down any new information, I came across a post by Dr. Garth Nicolson stating, "Low CD57 is associated with Lyme disease, but it can also be associated with Mycoplasma infections without Lyme Borrelia. So it is not necessarily diagnostic for Lyme. "
www.medhelp.org/posts/Autoimmune-Disorders/CD57-and-lyme-disease/show/1099856 So I would suggest you take a good look at your symptoms and see if they match up with one infection or the other (Lyme or Myco) or you could have both.
And I would suggest that you stay away from ID docs - should you have one of these infections - their track record on treating them appropriately isn't good at all. We usually have a handful of people that end up here due to having treated with an ID doc and still have the infections. I won't say that there is no such thing as an ID that is really savvy about
Lyme & co-infections - only that they are like finding a needle in a haystack.