Hello,
The CD57 is a good indicator of chronic Lyme. It measures a specific cell (the natural killer cell) and is useful to determine whether or not your immune system is capable of handling the Lyme infection without the help of antibiotics or other treatments like herbs. Under 20 is definitely indicitive of chronic Lyme. It is not believed that other factors reliably lower the CD57. Some of the co-infections can raise the CD57 so a higher number does not necessarily rule out a Lyme infection.
For the western blot, you have an inderminate on band 31 and 39 which are both specific to Lyme disease. No other infections would cross-react with those bands as far as I know. The IND is seen as a positive because it did show some activity, just not strong enough to be a full positive.
I was highly skeptical about going to a LLMD at first too. I felt like a LLMD might tell me I had Lyme even if I didn't. Fortunately, I did not find that to be the case whatsoever with my doctor. He was the first to actually listen to my concerns and take me seriously and I believe that he would attempt to help even if my problems were not Lyme related. He specializes in another field (he does not treat only Lyme).
Before I got sick last year, I was someone who NEVER went to doctors for anything. I waited until things were really bad before seeking treatment and then I figured out quickly that I was going to have a hard time getting appropriate treatment for Lyme. After I didn't improve on a month of doxy, no doctors would discuss Lyme with me anymore.
I went to many mainstream doctors and they had ruled out everything else and were not willing to help me determine the cause of my symptoms. I progressed very rapidly over the next few months showing signs of major organ involvement (neurological, cardiac, liver) and having seizures, paralysis and jaundice. I test negative on virtually all tests except for Lyme, co-infections and a low (under 20) CD57. My problems started after a reinfection from several known tick bites so I'm pretty confident in the diagnosis, I just needed someone to help me treat it.
The uncertainty regarding Lyme diagnosis and the proper way to treat it is very overwhelming. I hope that you are able to come up with a great plan to ease your symptoms! Good luck!