Early and accurate diagnosis is the most important factor in a person’s ability to overcome Lyme and other tick-borne diseases. This means access to high quality Lyme disease tests is crucial – something all too many patients unfortunately struggle to find. The CDC’s Lyme disease test recommendations are limited and flawed, leaving many patients understandably in search of better options.
However, without a medical background, it can be tough to understand the differences between the many types of Lyme disease tests. In this article, learn about the most common tests for Lyme and their various advantages and limitations.
Understanding how Lyme disease tests work
Antibody tests
The most popular type of test for Lyme disease is an indirect testing method known as an antibody test. This test doesn’t detect the pathogens themselves, but rather antibodies produced by the immune system in response to a Lyme infection. This has important implications for how the tests are used for diagnosis.
One important consideration is that the human immune system produces more than one type of antibody. Different types of antibodies show up for a vast range of illnesses, including viral infections (like COVID-19), other tick-borne infectious diseases, and some autoimmune conditions (such as Rheumatoid Arthritis).
A Lyme infection causes the immune system to produce two different types of antibodies: IgM and IgG. The presence of either will result in a positive Lyme test. IgM antibodies are the first antibodies to show up after infection and stick around for a short time. (PDF) If your Lyme disease test results show a high number of IgM antibodies, you likely have a new or recent Lyme infection.
IgG antibodies, which are smaller than IgM antibodies, are produced later on in the infection and can even remain after the infection resolves. Testing positive for a high number of IgG antibodies can be indicative of late-stage or chronic Lyme.
Antibody test quick facts
- The timing of the test is crucial. It takes 4-6 weeks for the body to develop enough antibodies to show up on a positive Lyme test, so if you test too early, you could get a false negative.
- Most antibody tests are blood tests. Also known as serological tests, they require that a patient have a small sample of blood taken, and they detect antibodies in the patient’s serum or plasma.
- Not every test is able to detect every type of Lyme Borrelia. In fact, most tests – like those recommended by the CDC – are only designed to detect one or two species of Borrelia, even though at least 18 distinct types of Lyme-causing Borrelia are active in North America. This is a major cause of mis- and missed diagnoses.
Common antibody tests and how they work
ELISA
The Enzyme-Linked Immunosorbent Assay (ELISA) is the first-tier test, or “screening” test, recommended by the CDC’s two-tier testing strategy. This plate-based test works by taking a sample of the patient’s blood and then placing it in a petri dish containing a specific Lyme antigen. If the patient’s sample contains Lyme antibodies, they will bind to the antigens in the petri dish, resulting in a positive Lyme test. This process is revealed when the lab technician adds an enzyme to the dish and observes the reaction.
The ELISA has been heavily criticized in the Lyme community for its limitations as a screening test. In two-tier testing, screening tests should be as sensitive as possible. If the test isn’t sensitive enough, it can fail to detect infections. Since the CDC only recommends performing a Western Blot if the first test (the ELISA) was positive, someone who has Lyme that was not detected in their screening test can be left with an infection that will worsen and become much harder to treat.
According to Lymedisease.org, the CDC’s current screening system indeed misses up to 54% cases of Lyme.
Western Blot
The Western Blot is the second-tier test recommended by the CDC. In this test, the lab separates proteins from the patient’s blood sample into bands, then compares the pattern – which resembles a bar code – to a template pattern based on confirmed cases of Lyme.
The CDC recommends that patients who test positive on the ELISA confirm their results with a Western Blot. One of the many problems with this approach is that Western Blots are often only designed to detect one or two species of Lyme, meaning that even after an initial positive Lyme test from the ELISA, a patient may come up negative on the Western Blot. Additionally, different labs have different standards for which bands they consider indicative of a Lyme infection, which can lead to conflicting results.
ImmunoBlot
To increase the specificity of Western Blot-style testing without sacrificing sensitivity, IGeneX developed the ImmunoBlot. This test uses a similar method of separating proteins onto bands and comparing them to a template pattern. However, the ImmunoBlot uses specifically created recombinant proteins from multiple species and strains of Lyme Borreliae, and tests for all Borrelia-specific antigens relevant in North America and Europe. The result – a single test that replaces at least 8 Western Blots – also reduces inconsistencies in reading and interpreting the test bands.
Other types of indirect tests do exist, including the Indirect Immunofluorescent Assay (IFA) and the IgXSpot. Learn more about these methodologies at IGeneX’s testing page.
Other types of Lyme disease tests
Though indirect tests are the most common, the following are also available:
- Molecular tests: Molecular tests include the Polymerase Chain Reaction (PCR) and the Fluorescent In Situ Hybridization (FISH). Like the most common tests for COVID-19, traditional and real-time (RT) PCR tests detect active infections in patient samples using Lyme DNA. The FISH test, on the other hand, detects bacteria, fungi, and intraerythrocytic parasites (piroplasts) in red blood cells.
- Antigen tests: These detect proteins in blood, urine, or joint fluid. The presence of certain proteins from these samples constitute a positive Lyme test.
- Culture tests: These work by attempting to grow Lyme spirochetes in a special medium using patient samples of blood or other fluids. This type of test can be highly accurate but it is a relatively new technology, so it is not yet widely available in the U.S.
Get tested with IGeneX today
If you’ve been experiencing symptoms of a possible tick-borne disease, it’s crucial to get tested as soon as possible from a reputable lab. You may want to work with your primary care doctor, or find a trusted Lyme-literate doctor to help you understand your test results.
If you’re interested in a Lyme disease test for IGeneX, get started today.
