“I’m not sure how long you’ve had this,” the doctor said as she reviewed the results of my Lyme disease testing.
We were at my daughter’s appointment, so she didn’t explain more at that time. But her comment raised questions of my own and compelled me to do more research.
The CD57 Panel in Lyme Disease Testing
Dr. McIntyre made that remark as she was discussing my HNK1 (CD57) Panel. So, I looked it up online and discovered it’s a test for chronic Lyme. If you have a chronic illness, the panel can help reveal whether your symptoms stem from Lyme.
CD57 is a group of white blood cells—specifically natural killer cells—that’s low in people with chronic Lyme.
Healthy people and those with other chronic illnesses tend to have counts between 60 and 360. Chronic Lyme patients tend to have counts under 60. Severely ill patients tend to have counts under 20.

Since getting Lyme, I’ve had my CD57 counts tested five times. My numbers have been no higher than 42 and as low as 18.
Yet again, blood tests proved I wasn’t crazy, I wasn’t just aging, and I wasn’t a hypochondriac.
What the Test—and My Husband—Revealed
When Dr. McIntyre and I met for my appointment the following week, I learned more. She said it usually takes at least a year or two for someone’s count to go low.
When I first started suspecting I had Lyme in 2018, I had assumed I had just gotten infected that spring or summer. I hadn’t yet examined my journals and medical records from the years before to discover the truth.
After my appointment with Dr. McIntyre, I discussed my test results with my husband, Mark. “Do you remember last year when I was really tired, and I thought I might have Lyme?”
He shrugged. “No.”
I gasped. “How can you not remember? You went with me to the doctor’s appointment!”
“Honey,” Mark said, “you’ve been saying you’re really tired for several years!”
My head jerked back, and I stared at him incredulously. “Several years?”
“At least a year or two,” he insisted. “Maybe more.”
My eyes widened, and my breath caught. That explained a lot. Looking back at the big picture, I hadn’t been feeling well for quite some time. The test and my husband opened my eyes—I had been battling undiagnosed Lyme for three years.
But the test also hinted at something else. Click here to continue reading my story!
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