The CD57 marker is present on natural killer cells (NK) and T lymphocytes.  In cases of chronic diseases such as Lyme disease the number of CD57 NK cells has been shown to be below normal. Following treatment the count can return to normal (Stricker and Winger, 2001.  Immunol Letter. 76:43-48). However, the utility of this test is controversial.  Marques et. al. (2009 Clin. Vaccine Immunol. 16:1249-50) reported that there was no difference between the CD57 NK cell counts among patients with Lyme disease and normal controls.  This test measures only the CD57 NK cells and may be useful for patients with known Lyme disease who present with chronic symptoms.   If the count is low, the cause of the symptoms may be from Borrelia burgdorferi.  If the count is normal, the cause may still be from Lyme disease, or it may be from some other agent.

CD57 NK Cell Test

Test Number 295

CPT Code 86356

Methodology:  Flow Cytometry

Ordering Information

  • Collection and Shipping Instructions: See whole blood collection procedure. Sample must be stored and sent at room temperature.
  • Shipping: Sample must be shipped 2 day FedEX on the same day specimen is collected.
  • Sample Stability: 48 hours at ambient temperature
  • Rejection Criteria refer to general collection procedure. Specimens older than 48 h Frozen/refrigerated samples will not be accepted)

Reference Range

CD57 NK Cells (Absolute Count/µl) % CD57 NK Cells of total
<40 Low <2.26 Low
40 to 98 Borderline 2.26 to 4.65 Borderline
>98 Normal >4.65 Normal

Clinical Significance

The CD57 is expressed on both natural killer (NK) cells and T lymphocytes.   The CD57 test measures CD57 positive NK cells only. The test is performed on EDTA whole blood.  In patients with low CD 57 counts, Lyme disease and Chlamydophila pneumoniae infections should be included in differential diagnosis.

Limitations: If laboratory tests are positive for Lyme disease in a chronically ill patient, this test can be useful prior to antimicrobial therapy, to suggest that the cause of the symptoms is due to Lyme disease.   If the count is low, repeat testing after therapy can also be useful.

FOR HEALTHCARE PROFESSIONAL:  Click here for more information on the type of diagnostic tests to measure CD57 NK cells.  In addition, physicians may want to consider having blood tested for other possible causes of their patient’s symptoms, including other tick-borne infections, such as Lyme disease.

Click here on how to order a test kit from IGeneX.

Click here for result interpretations of CD57.

Special Instructions:  Medicare patients, download ABN forms here.  This test is not available for New York residents.

Disclaimer:  This test was developed and its performance characteristics determined by IGeneX, Inc. It has not been cleared or approved by the FDA. The FDA has determined that such approval is not necessary. This test is used for clinical purposes and should not be regarded as investigational or for research. IGeneX Inc. is licensed by CMS and NYS to perform high complexity clinical laboratory testing.