You’ve discovered you have some symptoms of Lyme disease. In fact, you’ve already made a doctor’s appointment with your primary care provider (PCP). Unfortunately—or, rather, fortunately—you also know most only order one unreliable test. So, which other Lyme tests should you ask your PCP to order?
Standard Tests: Lyme Ab/Western Blot Reflex
The Centers for Disease Control and Prevention (CDC) recommends a two-tiered test. First, you take an enzyme assay (EIA) or an immunofluorescence assay (IFA). More specifically, you usually take an enzyme-linked immunosorbent assay (ELISA). This screening test is the only Lyme test most PCPs order. Sadly, it has a low sensitivity rate.
According to Lab Tests Online, “Diagnostic Sensitivity is the ability of a test to correctly identify people who have a given disease or disorder.”
In other words, a test with a low sensitivity rate will yield many false negatives. As a result, many people with Lyme go undiagnosed, allowing the bacteria to multiply.
In the CDC process, if your screening test is positive or equivocal, only then will your PCP order the western blot. If the western blot is positive, you are then diagnosed with Lyme disease.
For two reasons, I recommend you ask your doctor to order both tests right away:
1. You won’t have to wait for your screening test results before getting the western blot. Why is this important? Especially with Lyme, the quicker you’re diagnosed and begin treatment, the better.
2. You may test positive on the western blot, but negative on the screening test.
A Better Test: C6 B. burgdorferi (Lyme)
The newer C6 Lyme ELISA is a more sensitive test that’s still highly specific.
According to Lab Tests Online, “Diagnostic Specificity is the ability of a test to correctly exclude individuals who do not have a given disease or disorder.”
In other words, a test with a high specificity rate will yield few false positives. The C6 scores almost as high on specificity (98.9 percent) as the two-tiered test (99.5 percent). Yet, the C6 test scores higher on sensitivity. In other words, false positives are rare for both, but false negatives are less common with the C6.
Chronic Lyme Test: HNK1 (CD57) Panel
This white blood cell test helps reveal whether your chronic symptoms stem from Lyme. How? Because chronic Lyme patients tend to have low CD57+ natural killer (NK) counts. Like CD56 counts in Chronic Fatigue Syndrome or CD4 T-cell counts in AIDS, it can also reveal the illness’s severity.
But what if your doctor only orders the CDC’s standard screening test, and it comes back negative? Continue reading to discover four possible reasons!