Diagnosing acute Lyme disease is often straightforward. If someone develops flu-like symptoms following a tick bite or spending time in nature, the diagnosis of Lyme disease is often considered. However, when someone is sick with multiple symptoms for an extended period of time, it can take years to get a correct diagnosis. There are many nuances associated with Lyme disease testing. Read below to learn about accurate testing for chronic or late-stage Lyme disease.
Where did Lyme Disease Testing Criteria Come From?
There may not be an infection that is more complex to diagnose than chronic Lyme disease. When Lyme disease was first discovered in the 1970s, the Center for Disease Control (CDC) wanted to track the number of cases in the US, so they developed diagnostic criteria for surveillance reporting to local public health departments. The criteria needed to be narrow to increase the sensitivity of cases reported. Unfortunately, the surveillance criterion made its way into doctor’s offices, and physicians used the narrow criteria as diagnostic parameters for Lyme disease.
If someone had symptoms following a tick bite – or even years after a tick bite – but did not have a large bullseye rash, meningitis, facial paralysis, or encephalomyelitis, they were told they did not have Lyme disease.
Another limitation of the Lyme disease surveillance criteria is it only includes symptoms often seen in acute cases of Lyme disease and excludes many symptoms consistent with late-stage Lyme disease. Throw in the misconception that people can only contract Lyme disease in the northeastern US, and Lyme disease is not typically considered as a possible cause of symptoms in the rest of the country.
Poor Sensitivity of Traditional Lyme Disease Testing
If a physician considers Lyme disease as a possible diagnosis as the cause of a patient’s symptoms, standard laboratory testing has poor sensitivity so many cases are missed. The traditional laboratory test used to diagnose Lyme disease is a “two-tiered” test. This means an ELISA test is run first, and if it is positive, a second test called a western blot is performed to confirm the accuracy. If the ELISA test is negative, the western blot is not performed. The sensitivity of the ELISA test is so poor that it reports a false-negative about half of the time. This means the more sensitive western blot never gets tested.
Physicians that specialize in treating tick-borne infections consider the diagnosis of late-stage Lyme disease a clinical diagnosis. A patient has these signs and symptoms consistent with a tick-borne infection and other diagnoses that could explain the signs and symptoms have been ruled out.
Many times other diagnoses have been ruled out, there has been a possible exposure to ticks (including the distant past with chronic Lyme disease), and the pattern of symptoms is consistent with Lyme disease. Specialized laboratory testing that is more sensitive than general national laboratory testing should be used to confirm the diagnosis.
Additional Challenges with Lyme Disease Testing
Another obstacle with many Lyme disease tests are they rely on detecting antibodies produced by the immune system against the Borrelia bacteria. In some circumstances, the level of antibodies may be low due to immune suppression which compromises the accuracy of the test. In addition, if a test is performed too soon after a tick bite, antibodies may have not yet formed. Also, if antibiotics are taken early in an infection, the medication can prevent antibody formation resulting in future negative tests.
In late-stage Lyme disease, the Lyme spirochete has burrowed into tissues like muscles, joint spaces, and organs. The bacteria can also form a protective structure around itself called a biofilm. These immune-privileged locations prevent the immune system from detecting the bacteria and do not make antibodies for tests to detect.
ELISA (Enzyme-Linked Immunosorbent Assay)
ELISA methodology of testing works by attaching Lyme antigens to a surface in a laboratory. If a blood sample has Lyme antibodies, the antibodies will bind to the antigen. This creates an antigen/antibody complex that is linked to an enzyme (which is another antibody). In the last step, a substrate is added that allows the result to be measured.
The limitation of the ELISA test is the cut-off for a positive result is set extremely high to make the test highly specific. However, the high specificity comes at the cost of the sensitivity of the test. A review of research studies looking at the sensitivity of ELISA testing for Lyme disease revealed it is accurate less than half the time. Because of this, the standard two-tiered test for Lyme disease should not be relied upon to identify Lyme disease.
Immunofluorescence Assay (IFA)
Like the ELISA, the IFA methodology for Lyme disease testing is an indirect test looking for antibodies formed against the bacteria that causes Lyme disease – Borrelia burgdorferi. In the laboratory, blood is added to a slide that contains the Borrelia antigens. If the blood contains antibodies to Borrelia, they will bind to the antigens on the slide. The final step is to view the slide under a fluorescent microscope (hence the name). Antibodies bound to the antigens will light up if they are present.
The IFA lacks specificity and sensitivity, so it is not a preferred method for diagnosing Lyme disease. Antibodies from other infections can bind to the antigens on the test strip (called cross-reactivity) leading to a false-positive result.
The Western Blot for Lyme Disease
The western blot is also an antibody-based test but is more sensitive and specific than the ELISA and IFA tests. For a western blot test, specific surface proteins from the Lyme bacteria are produced on strips. If there are Lyme antibodies in a blood sample they will bind to the surface protein antigens. The pattern of binding indicates whether or not the result is positive. In Lyme disease, there are specific outer surface proteins (called bands) and the specific pattern formed on the blot increases the specificity of the test.
The outer surface proteins are numbered by weight in kilodaltons. Specific bands for Lyme disease include 23-25 kDa, 31 kDa, 34 kDa, 39 kDa, 41 kDa, and 83-93 kDa. The CDC criteria require at least two of three positive IgM bands and five out of ten positive IgG bands for a western blot result to be positive. The CDC criteria are stringent so some Lyme specialty laboratories have established their own criteria after performing thousands of tests.
If someone was possibly exposed to ticks, had many clinical signs and symptoms of Lyme disease, but did not have the exact pattern considered to be positive by the CDC, they were told by their doctor they do not have Lyme disease.
One nuance with the CDC criteria for a Lyme disease western blot is they do not take bands 31 and 34 into consideration. The CDC excludes these two bands because a person might be positive for these bands if they received a Lyme vaccine. Ironically, very few people received the Lyme vaccine because it was only available for a couple of years before it was removed from the market due to adverse reactions (and lawsuits). Based on over 25 years of experience and validation studies, the Lyme specialty laboratory Igenex requires two out of six bands to be positive for an IgM positive result.
Western blot tests offered by national commercial laboratories such as Quest and LabCorp develop their testing strip using a synthetic laboratory strain of Borrelia called B31. Igenex uses the synthetic B31 strain as well as the wild (occurs in nature) 297 strains to increase the sensitivity of their western blot
Because Igenex uses more inclusive criteria than the CDC and two strains of Borrelia for testing, their western blot may diagnose Lyme disease that is missed by commercial laboratories.
It is common for doctors such as general practitioners (GP’s) and pediatricians, or specialists such as neurologists and rheumatologists that do not routinely treat Lyme disease, to dismiss Igenex results. Their misunderstanding comes from a lack of knowledge about what makes Igenex’s tests more sensitive and specific. Some claim Igenex test results are always positive. I have ordered hundreds of Igenex tests on people suspected of having Lyme disease and it is not uncommon to get back a negative Lyme test.
ImmunoBlot fro Lyme Disease
The Lyme immunoblot uses recombinant proteins on the blot so it is more sensitive than western blots that use native proteins. Igenex’s immunoblot is the main Lyme disease test I use in my practice. This test can detect Lyme disease as early as one week after exposure to the Borrelia bacteria and detect late-stage Lyme when antibodies are typically low.
Igenex includes multiple Borrelia species in their immunoblot test that increases the sensitivity of detecting other species of Borrelia that are not included in other Lyme tests. These include B. burgdorferi B31, B. burgdorferi 297, B. californiensis, B. mayonii, B. spielmanii, B. afzelli, B. garinii, and B. valaisiana. Like the western blot, an immunoblot result has to meet the criteria for a positive result.
Additional species of Borrelia bacteria fall into the Tick-Borne Relapsing Fever Group (TBRF). The TBRF group causes symptoms similar to Lyme disease, and some species may be more common in other parts of the United States, like California. This may be why some Californians test negative on a traditional Lyme test. The Igenex TBRF Immunoblot test detects antibodies to B. miyamotoi, B. hermsii, B. turicatae, and B. coriaceae. Two or more species in this panel need to be positive for a positive result. If only one species is positive, it is labeled as indeterminate (Ind). However, this finding needs to be correlated with the patient’s symptoms.
EliSPOT / T-Lymphocyte Test
In recent years, the sensitivity of T-lymphocyte testing for Lyme disease has improved. This methodology detects an immune system cell (called a T-lymphocyte) that has formed in response to the Borrelia bacteria. T-lymphocytes are part of the cellular immune response, unlike antibodies that are created as part of a humoral immune response.
Early in an infection T-cells can develop before antibodies are formed so an EliSpot test may help with the early detection of Lyme disease. As the disease progresses, some people’s immune system does not convert from a cellular to a humoral response. This would prevent antibodies from forming, so a T-lymphocyte test would be informative in this scenario.
A positive Lyme antibody test makes it difficult to determine if someone has an active infection, or if memory antibodies have persisted after the infection has been successfully treated.
A challenge with antibody testing is memory antibodies can remain in the blood long after an infection has resolved. A positive Lyme antibody test makes it difficult to determine if someone has an active infection, or if memory antibodies have persisted after the infection has been successfully treated. One of the great debates about long-term symptoms associated with Lyme disease is whether it is a chronic active infection or a persistent immune response driving the symptoms. The presence of T-lymphocytes against the Borrelia bacteria indicates an active infection.
Putting Lyme Disease Testing Together
Late-stage Lyme disease can be difficult to diagnose. The CDC criterion was established for surveillance purposes only, so should not be used for diagnostic purposes. Lyme disease tests at national reference laboratories have poor sensitivity and specificity and laboratories that specialize in Lyme disease testing provide a more accurate result. No one testing methodology is perfect, so results need to be taken into consideration with symptoms.
Combining Igenex’s Lyme and TBRF IgM / IgG Immunoblots, with a sensitive EliSPot test provides a comprehensive, objective assessment to aid in determining if Lyme disease is an underlying cause of someone’s symptoms. A complete co-infection panel including Bartonella, Babesia duncani and microti, Ehrlichia, Anaplasma, Rickettsia, Mycoplasma, Brucella, and other bacteria should also be included for a complete diagnostic workup of tickborne infections.