CD57+ immune cells are measured with an established method of flow cytometry for cell characterization. They are a type of lymphocyte, called Natural Killer (NK) cells. These NK cells contain CD57, a cell-surface marker correlated with clinical prognosis in chronic infections (Kared 2016). CD57+ NK cells measure at a lower frequency in patients suffering from chronic disease.
Normal CD57 results do not necessarily rule out nor do abnormal results necessarily confirm Lyme disease. CD57 results, in conjunction with other testing methods and symptomology, provide information potentially guiding Health Care Practitioners in determining the stage of the illness or treatment of Lyme disease or other infections.