An HNK-1 CD57 panel is used to measure levels of lymphocytes (cells that fight infection) in the blood. An HNK1 CD57 panel is also used to diagnose chronic Lyme disease. Lyme disease tends to suppress a person’s immune system and many people with Lyme disease show a low level of the CD57 lymphocyte.
This test may be used for screening for Lyme disease but it is not a definitive confirmation of having the disease. Some people with Lyme disease do not have a lower level of CD57 and other conditions may also cause a lower level. This test should be combined with both the C3a and C4a complement protein tests.