A Natural Killer Cell that is Uniquely Attracted to Borrelia
The human immune system consists of several different types of white blood cells with one category being called Lymphocytes. Lymphocytes consists of 3 subcategories of white blood cells known as B-Cells, T-Cells, and Natural Killer Cells. B-Cells are responsible for antibody production, while T-Cells and Natural Killer Cells are responsible for killing foreign invaders.
CD57 is a natural killer cell. "CD" stands for "Cluster Designation" which is simply a molecule on the cell that gives the CD57 cell its identity. The "57" in CD57 is just an implication of the numerical order it was discovered in.
CD57 and Lyme Disease
CD57 natural killer cells are designed to kill many types of bacteria, but are uniquely attracted to Borrelia burgdorderi (i.e., the Lyme bacteria) due to its type of cell wall. Borrelia's cell wall consists of lipopolysaccharide which is a lattice type of structure. Unlike other CD natural killer cells, CD57 specifically responds to this type of foreign invader.
CD57 Testing and Lyme Disease
Borrelia are believed to be capable of reducing the total amount of CD57 natural killer cells in the human body. It's currently unknown how Borrelia accomplishes such a task, but the results of this action are used as a means of confirming a diagnosis or determining remission of Lyme Disease by some physicians. Testing CD57 cell counts can be done through Labcorp.
It is generally believed that the lower the amount of CD57 natural killer cells in the body, the more chronic or progressive Lyme disease is, and the higher the amount, the closer a person is to remission. There have been instances where high amounts of CD57 natural killers cells have been found in those with chronic Lyme disease, and low amounts of CD57 natural killer cells have been found in those who were believed to be in remission. While the CD57 test is not 100% accurate in terms of diagnosing chronic Lyme disease, it is an incredibly useful test in doing so when it is compared with other diagnostic Lyme tests such as a western blot test or the c3a and c3a complement protein test, as well as a person's symptoms.
The progression of Lyme Disease is discretionarily determined by the graph below:
A CD57 natural killer cell level of about 200 is believed to be the area in which it is safe to discontinue use of a protocol without the risk of encountering a relapse.
Even if your symptoms disappear, you should still continue with treatment until your CD57 reaches about 200 to avoid a relapse.
200 is also the level where CD57 natural killer cells should naturally reside.
High CD57 levels with symptoms could be an indication that one is actually dealing with a co-infection as opposed to Lyme itself.
Note: A CD57 test is used by some physicians to discretionarily confirm suspicions of chronic Lyme disease and remission. The test is not an official or 100% accurate means of diagnosing chronic Lyme or determining stage of infection.
SAVELY, GINGER, RN, and FNP-C. "Understanding The CD 57 Test « HOPE TO HEAL." HOPE TO HEAL. N.p., n.d. Web. 14 Feb. 2012. <http://heallyme.wordpress.com/2009/01/28/understanding-the-cd-57-test/>