CD57 tests are not a good
Why? Because at least two studies show CD57 can’t tell the difference between people who would be considered to have chronic Lyme disease and others. Therefore, relying on a CD57 test could result in false positives or false negatives. That’s why the CDC warns against CD57 and other unvalidated tests.
In 2015, scientists in British Columbia, Canada compared 4 groups of patients: 13 patients with the “Alternatively diagnosed chronic Lyme syndrome” (ADCLS), 25 patients with Chronic Fatigue Syndrome (CFS), 25 matched healthy control patients, and 11 Lupus control patients. The researchers found none of the ADCLS patients had signs of Lyme disease and noted that they “have a similar phenotype to that of CFS patients.” They also discussed CD57 tests:
Some practitioners employ CD57 cell count as an additional criterion to support diagnosis of ADCLS. Our finding of no significant difference in CD57 cell counts between ADCLS and CFS patients and healthy controls is consistent with another study that could not replicate the findings on which such practice is based.
In 2009, NIH scientists published the paper “Natural Killer Cell Counts Are Not Different between Patients with Post-Lyme Disease Syndrome and Controls.” The scientists compared three groups of patients: 9 patients with post-Lyme disease syndrome (PLDS), 12 patients who recovered from Lyme disease, and 9 healthy volunteers. The results were definitive:
We conclude that the numbers of NK cells do not differ between patients with PLDS, individuals who have recovered from Lyme disease, and healthy volunteers and that the number of CD57+ non-T (CD3−) cells is not helpful in evaluation or management of these patients.
Conclusion: Use the recommended testing
Online groups, many with the word “Lyme” in their names, have spread false and misleading information about well-established testing for Lyme disease.
Established testing is accurate when used correctly. According to the CDC:
- Patients who have had Lyme disease for longer than 4-6 weeks, especially those with later stages of illness involving the brain or the joints, will almost always test positive.
- A patient who has been ill for months or years and has a negative test almost certainly does not have Lyme disease as the cause of their symptoms.
- Serologic testing is generally not useful or recommended for patients with single EM rashes. For this manifestation, a clinical diagnosis (alone) is recommended.