Navigating testing in lyme disease and the approach I use for most patients (as of fall 2016)
Testing is a changing field in lyme disease, with the advent of increased awareness about the condition in general and recently the more ready availability of different testing methodologies from a variety of labs.
The basics of testing that I wrote about many many years ago here still apply, but for many patients there is a basic relatively cost-effective approach that can be utilized. First and foremost, if lyme disease is suspected, other conditions should be evaluated for and ruled out, and in this type of setting, if other tests are negative, we should remember that if lyme is highly suspected we do not have to rely on testing for therapy. An example might be classic patient who had increased exposure to a tick, had mild flu like symptoms, then over the months developed migratory arthritis, night sweats, pain in soles of feet, impaired cognition, air hunger, etc. In such a patient if all testing is negative, including lyme testing, but the history and exam suggest such a group of infections, a discussion of risk vs benefit should happen and then a trial of 6 weeks of treatment would be my approach.
Back to the testing...
The usual testing for lyme disease in the conventional world is two tiered testing. This, in my opinion, has many limitations in terms of missing many patients. At any rate, it is testing for antibodies against lyme. Anibodies are proteins the immune system makes against foreign structures, including lyme and associated infections. They are classified as humoral immunity and come from B cells. The combination of an ELISA, or IFA and then a western blot is done. In these tests, we indirectly test for lyme by seeing if there are any antibodies in our blood that react with whatever strain of lyme the lab is using. That part is bolded because it really spells out the difference between labs. Most if not all CDC labs will use the B31 strain of lyme, whereas other labs will use that plus another strain or more lyme proteins, depending on the lab. The latter do this to try and increase sensitivity, or likelihood of picking up exposure to the infection. There is also interpretation criteria with this type of testing. For example, CDC would consider an IgG western blot positive if there are at least 5 bands (or antibodies) against a group of selective lyme proteins exists. 4 doesn't count. Other labs will use their own criteria and say perhaps two are needed, depending on how specific the protein is against lyme. (Research does support the latter - see Zoller et al where even just a 41 kda antibody, if very strong, was very specific against lyme... published in the 90s! Mavin et al, in Interpretation criteria in Western blot diagnosis of Lyme borreliosis, British Journal of Biomedical Science also described alternate criteria in which fewer bands may be interpreted as an equivocal or weak positive result, suggesting at least retesting in the future or a trial of treatment and then testing.)
I also use very frequently the Lyme Elispot testing, which is an assay that assesses the other side of the immune system, name the T-cell reactivity against lyme. Here, if the patient does not have a very strong antibody response and their testing from ELISA, or western blot is negative, sometimes we can get valuable information from the T cell assay as to whether or not this side of the immune system is suggesting lyme infection. I also use this test to try and quantify whether there is still substantial lyme-related inflammation or infection that is persisting despite current treatment protocols. As an example, a patient may have made great progress on the herbal or drug antibiotic approach, but has certain lingering symptoms in which we are not clear as to whether they are related to residual infection. Perhaps their elispot was a moderate high positive before - in this example, sometimes their lyme elispot may now be negative but a coinfection elispot may be moderately high, indicating a different treatment course.
I also see a substantial number of patients whom have already seen other practitioners and undergone basic lyme treatment, yet may have not had much benefit. If after re-evaluation of their case, and excluding other diagnoses, we feel that chronic infection is still a likely diagnosis, then often times elispot testing for lyme, and common coinfections (based on history) can help to guide if there is still untreated infection in which we could modify treatment courses. In this scenario, we also evaluate the common roadblocks to cure, eloquently described in Dr Richard Horowitz' book "Why Can't I Get Better." This may include adrenal assessment, thyroid assessment, heavy metal testing, amongst other common lyme-induced changes and/or post lyme changes.