
How Accurate are Lyme Disease Tests?
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Time to read 5 min
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Time to read 5 min
Most Lyme disease testing administered by commercial laboratories and hospitals are only about 50% accurate. This rate of accuracy would never be acceptable in testing for other diseases, such as HIV. The main reason for the low accuracy is because these tests only identify one species of Lyme disease. These tests are also prone to user error. However, newer tests coming to market test for more species, and use more reliable methodologies, resulting in a more accurate Lyme disease test.
An accurate Lyme disease test is determined by the methodology and what is being tested.
The most common Lyme disease testing methodologies include the following:
1. Enzyme-linked immunosorbent assay (ELISA): This blood test detects antibodies produced by the immune system in response to the Lyme bacteria (Borrelia burgdorferi). ELISA is often the initial screening test for Lyme disease. However, it can produce false positives and false negatives, particularly in the early stages of infection. It also looks for antibodies to only one protein, B. burgdorferi B31, which is why it misses many cases.
2. Western blot: The Western blot is more specific than ELISA, but is still not considered a high quality test because it is built using lysed BB cultures, and therefore, depending on the culture conditions, can result in antigens being over-expressed or under-expressed. This, in turn, can affect the ability to detect antibodies from patients’ blood. It also looks for antibodies to only one protein, B. burgdorferi B31, which is why it misses many cases.
3. ImmunoBlot: Unlike a Western blot, an ImmunoBlot is a very accurate Lyme disease test that uses recombinant proteins instead of proteins from natural sources. The recombinant DNA technology provides a more efficient method to obtain large amounts of proteins (i.e. billions of copies). Additionally, by using recombinant technology, scientists are able to create DNA sequences that would not naturally exist under normal circumstances and environmental conditions, leading to more sensitive and specific tests. An ImmunoBlot also looks for antibodies to multiple borrelia species, which increases sensitivity.
4. Polymerase chain reaction (PCR): This test detects the genetic material (DNA) of the Lyme bacteria in blood, joint fluid, or tissue samples. PCR can be useful in the early stages of infection when antibodies may not yet be detectable, or in cases where the infection has spread to other tissues.
5. Culture: Culturing the Lyme bacteria from a blood sample or other bodily fluids or tissues is another diagnostic method. It is the most specific type of testing. However, it's less commonly used due to its low sensitivity and the slow growth of the bacteria in culture.
6. EliSpot: An ELISPOT test for Lyme disease is a type of immunoassay used to detect specific immune responses (like the production of certain cytokines). The test is primarily used to assess T-cell immunity, which is part of the body's immune response to the infection. The ELISPOT test is considered more sensitive than some other Lyme disease tests, especially in detecting early-stage or chronic Lyme disease.
7. IFA: In some cases, healthcare providers may measure antibody levels over time to look for changes that suggest active infection or treatment response. Although IFA can be sensitive, it may not always be as specific as other tests like Western blot. This means that while it can detect the presence of antibodies, it might not always distinguish Lyme disease from other conditions with similar symptoms.
Common Lyme two-tier testing has a sensitivity of just above 50% because it detects only one Borrelia species, B. burgdorferi B31. The IGeneX ImmunoBlot detects antibodies to nine different species of Borrelia.
Sources- The Accuracy of Diagnostic Tests for Lyme Disease in Humans, A Systematic Review and Meta-Analysis of North American Research. PLoS ONE 11(12): e0168613.- Pilot Study of Immunoblots with Recombinant Borrelia burgdorferi Antigens for Laboratory Diagnosis of Lyme Disease- The Lyme Disease Polymerase Chain Reaction Test Has Low Sensitivity. Vector Borne Zoonotic Dis.
Lyme disease tests can be categorized into direct tests and indirect tests.
Direct Lyme Disease Tests
Direct Lyme Disease tests look for the bacteria or pathogen in a specimen. Common direct tests are PCR and Culture.
Indirect Lyme Disease Tests
Indirect tests measure the immune system's response to being invaded by a pathogen. Common indirect Lyme disease tests are Western blots, ImmunoBlot, Elispot, ELISA, and IFA.
Both testing methods can produce and accurate Lyme disease test, but the majority of testing methods today are indirect. Some of the indirect tests, such as ELISA and Western blot, have limitations and are no longer recommended, but other indirect tests such as ImmunoBlots are still considered the best. Direct tests become more important if a patient is immunosuppressed and doesn't make adequate antibodies. Adding a direct test such as PCR or Culture can be important because these direct tests are very specific. That is, if they detect the pathogen, there is a near certainty that you have Lyme disease. Unlike some older indirect tests, which can trigger false positives.
The reason tests such as ELISA and Western blot are not very accurate Lyme disease tests is because they look for only one Lyme causing species, B. burgdorferi B31. In reality there are many Lyme disease causing species that must be tested, including species from across the country and the world. According to Wikipedia, there are at least 53 known species of Borrelia, the genus of bacteria that cause Lyme disease.
A more modern and technologically advanced Lyme disease test that detects antibodies to multiple Lyme causing species is an ImmunoBlot. The Lyme ImmunoBlot from IGeneX Laboratory, for example, detects antibodies to nine borrelia species: B. burgdorferi B31, B. burgdorferi 297, B. californiensis, B. mayonii, B. afzelii, B. garinii, B. spielmanii, B. bissettii and B. valaisianaa. This results in a much more accurate Lyme disease test.
It's important to note that when searching for an accurate Lyme disease test, no single test is 100% accurate, and false positives and false negatives can occur. A combination of testing methods, including both direct and indirect methods, and those testing methods that look for multiple species of the disease, are recommended.
Further, diagnosis should be based on a combination of clinical findings and test results, interpreted by a healthcare professional experienced in diagnosing and treating Lyme disease. Early diagnosis and treatment are essential for preventing complications of Lyme disease. If you suspect you have Lyme disease or have been bitten by a tick and are experiencing symptoms, it's important to consult a healthcare provider promptly for evaluation and appropriate management.