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 considered. However, when someone has been sick with multiple symptoms for a long time, it can take years to get an accurate diagnosis. There are many nuances associated with Lyme disease testing. Read below to learn more about accurate testing for chronic or late-stage Lyme disease.
How Did We Come Up With Lyme Disease Testing Criteria?
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 for reporting a case of Lyme disease. However, the surveillance criterion was carried over into the doctor’s offices, and physicians used these narrow criteria as the 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 challenge with the Lyme disease surveillance definition 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 Tests
However, if a physician considers Lyme as a possible diagnosis, the testing is so insensitive that many cases are missed. The traditional laboratory testing for Lyme disease is a two-tiered approach. This means an ELISA test is run first, and if it is positive, a second test called a western blot is performed. If the ELISA is negative, the sample does not get tested by western blot. The sensitivity of the ELISA test is so low that it reports a false-negative about half the time. This means the more sensitive western blot never gets tested.
For physicians who specialize in tick-borne infections, the diagnosis of chronic Lyme disease is considered a clinical diagnosis
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
The biggest challenge with indirect tests such as ELISA, IFA and western blot tests is they rely on detecting antibodies produced by the immune system against the Borrelia bacteria. In some circumstances, antibodies may not form in the body decreasing the accuracy of the results. For example, if a test is performed too soon after a tick bite, antibodies may have not yet formed. Also, if antibiotics are taken early on in an infection, the medication can prevent antibody formation resulting in negative future tests.
In addition, the Lyme spirochete likes to burrow into tissues like muscles, joint spaces, and organs. The bacteria can also form a protective structure around itself called a biofilm. So, if the immune system does not detect the bacteria because the bacteria is in tissue or a biofilm, the immune system will not make antibodies for the test to detect.
ELISA (Enzyme-Linked Immunosorbent Assay)
The ELISA methodology works by attaching Lyme antigens to a surface in the laboratory, then antibodies from a blood sample bind to the antigen. The antigen/antibody complex is linked to an enzyme (which is another antibody), and finally, 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 very 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 only 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.
IFA (Immunofluorescence Assay)
Like the ELISA, the IFA methodology for Lyme disease testing is an indirect test looking for antibodies made against the bacteria that causes Lyme disease – Borrelia burgdorferi. Blood is added to a slide that contains the Borrelia antigens. If there are 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 (and immunoblot test) are also antibody-based tests but are more sensitive and specific than ELISA and IFA tests. Specific surface proteins from the Lyme bacteria are produced on strips. Antibodies from blood samples bind to the specific antigens, and the pattern of positive binding indicates whether or not the result is positive. There are specific outer surface proteins on the Lyme bacteria (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 for an IgM positive western blot is at least two of three positive bands (23-25, 39, 41). The CDC criteria require five out of ten positive bands on an IgG western blot to be considered positive which can be limiting.
If someone has had a possible exposure to ticks, has many clinical symptoms of Lyme disease, but does not have the exact pattern considered to be positive by the CDC, they are told by their doctor they do not have Lyme disease.
Another nuance with the CDC western blot requirement is the criteria does not take bands 31 and 34 into consideration 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).
Western blot tests offered by national commercial laboratories such as Quest and LabCorp develop their testing strip using a synthetic lab strain of Borrelia called B31. The Lyme-specific laboratory Igenex in Palo Alto, CA uses two Lyme antigens – B31 and 297 strains – to increase the sensitivity of their western blot. Based on over 25 years of experience and validation studies, Igenex criteria for a positive IgM and IgG results are 2 out of 6 possible bands. This criterion is more inclusive than the CDC criteria mentioned above. Due to both of these variables, Igenex testing may pick up 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’s results. Their misunderstanding comes from a lack of knowledge about the details of Igenex’s tests that make it more sensitive and specific. Some claim Igenex test results are always positive. I have ordered hundreds of Igenex tests over the years – in a population suspected of having Lyme disease – and it is not uncommon to get back a negative Lyme test.
The Lyme immunoblot uses recombinant proteins on the blot so it is more sensitive than western blot tests 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 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 have a certain number of bands 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 early Lyme disease detection. 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.
Another 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 would indicate 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, so laboratories that specialize in Lyme disease testing should be used. No one testing methodology is perfect, so results need to be taken into consideration with symptoms. Many times other diagnoses have been ruled out, or patients have additional symptoms than explained by an incorrect diagnosis.
Combining Igenex’s Lyme and TBRF IgM / IgG Immunoblots, with a sensitive EliSPot test such as one offered by Igenex or Armin Labs, 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, erlcihia, anaplasma, rickettsia, mycoplasma, brucella and other bacteria should also be included for a complete diagnostic work-up of tickborne infections.