How do you interpret Lyme Disease Blood Tests??
The following excerpt is taken from the lyme disease association of
Australia
Www.lymedisease.org.au/about-lyme-disease/interpreting-lyme-disease-blood-tests/
Firstly, it must be stressed that Lyme Disease is NOT diagnosed on the
basis of a blood test. This is because there are currently too many false
negative results. A "negative" Lyme Disease blood test does not rule out a
Lyme bacterial infection. Lyme Disease is a clinical diagnosis based upon
previous medical history and current presenting symptoms blood tests
assist in guiding treatment, but should NOT be used for diagnosis. False
positive blood test results are very rare, especially when specific Lyme
Disease bands are taken into consideration.
We need to note that currently the Lyme Disease Association of Australia
(LDAA) does not recommend being tested in Australia (except privately by PCR
test although it is currently not as accurate as testing performed in the
USA or Germany). Anecdotally, we have found that the vast majority of
testing for Lyme Disease is unreliable. This is based on the fact that many
of our members have tested negative in Australia, but positive in the
specialty Lyme Disease Blood Reference Laboratory IGeneX in the United
States at the same time. There are many different reasons for this
discrepancy, and we hope that testing in Australia will improve in the
future. However we currently can not recommend testing in Australia, as it
is not reliable enough at this stage.
Background : Why is it so hard to test for Lyme Disease? firstly, the
bacteria that causes Lyme Disease often does not reside in the blood, but
rather in tissues, organs, the nervous system, and in collagen and joints,
which makes it very difficult to isolate during a PCR blood test.
Secondly, the vast majority of blood tests currently do not actually test
for the Lyme Disease bacteria itself, but rather the body's immune response
to it. Because of the nature of Lyme Disease and its ability to depress the
immune system, we have found that the sicker the patient is, the less likely
they are to return a positive result, as their body has not been able to
mount a strong immune defence against the Lyme Disease bacteria.
Thirdly, there are many different strains of Lyme Disease all around the
world. Currently there are 14 known genospecies of Borrelia Burgdorferi
senso lato (the bacteria that causes Lyme Disease), with more being
discovered every year the Western Blot blood test, tests for 2 of these
strains. Currently the strain of Borrelia that causes Lyme Disease in
Australia has not been isolated, and so it is not possible to accurately
test for the native Australian strain of Lyme Disease.
Fourthly, due to medical politics in the USA (which affects patients in
Australia), it is difficult to interpret Lyme Disease testing based on
laboratory reporting. This is because the Infectious Diseases Society of
America (IDSA) has recommended that Lyme Disease testing follow a two tier
testing procedure, that firstly tests patients using an ELISA test, and if
this is positive, that it then be further confirmed via a Western Blot blood
test. The problem with this, is that the ELISA is insufficiently sensitive
to test for Lyme Disease [Trevejo R, JID 1999; 179:9318.] and many
infected patients don't get referred on for the Western Blot test. Also,
the US Centre for Disease Control (CDC) has stipulated that certain "bands"
in the Western Blot test must be positive in order for a Lyme test to be
declared positive the problem is that these bands were chosen for
statistical, rather than diagnostic criteria. For example, the most specific
bands for Lyme Disease (bands 31 and 34) were excluded from the CDC criteria
because they were used to create the Lyme Disease vaccine (which is no
longer available), thus eliminating valuable testing data. If you have not
received the Lyme Disease Vaccine and you test positive ("+") or
indeterminate ("IND") to bands 31 and 34, you probably have Lyme Disease.
The CDC testing criteria actually includes a number of bands which are not
specific to Lyme Disease, which increases the chances of a false negative,
but only if the CDC criteria for test reporting is used.
What is the difference between "+", "++", "+++" and "IND"? These are the
level to which the laboratory technician can see the immune response to the
specific part of the bacteria. Both "++" and "+++" results are very rare,
and show a strong immune response to the Lyme Disease bacteria. If a
patients immune response is compromised (as it is in most Lyme Disease
patients and particularly in patients with neurological, late stage or
severe Lyme Disease), a "IND" result is a weak positive immune response to
Lyme Disease and should be treated as a positive result. After treatment,
many patients who are retested return stronger results, as their immune
system has been able to mount a more effective response against the Lyme
Disease bacteria.
What is the difference between the Western Blot IgG and IgM tests? IgM is
generally regarded as the body's response to recent exposure to Lyme
Disease. IgG is generally regarded as the body's response over time (ie.
longer term) to Lyme Disease. Because the immune system is compromised in
Lyme Disease, often the IgG and IgM responses can become mixed up.
When should I test for Lyme Disease? It takes the body 6 weeks to 6 months
to make antibodies to Lyme Disease therefore testing straight after a tick
bite is not recommended. Also, patients with late stage Lyme Disease will
have an impaired immune response due to the interaction by the Lyme Disease
bacteria in depressing the immune system, making testing unreliable as well.
So, how do I interpret the Lyme Disease Blood test results??
Currently there are 9 identified bands specific to Lyme Disease 18, 23-25,
31, 34, 37, 39, 83 and 93. A "+" or "IND" to one of these bands is
considered a positive result. A "+" or "IND" to two or more of these bands
is considered a strong positive result.
Other bands on the Western Blot report such as 22, 28, 30, 41, 45, 58, 66, &
73, all add significant weight to the result, but at this stage are not
necessarily considered as absolute specific for Lyme bacteria.
NOTE : It must be stressed that a Lyme Disease diagnosis is not based on a
blood test result, but is rather based on medical history and current
presenting symptoms blood tests can assist in diagnosis, but should not be
used to base a diagnosis on. Also, almost all Lyme Disease patients have
co-infections such as Ehrlichia, Rickettsia, Babesia, Bartonella, Mycoplasma
Fermentans, Chlamydia Pneumonia, etc these have their own testing and
diagnostic problems, but should be considered in the diagnosis and treatment
of a patient with Lyme Disease.
For more information regarding the bands
31 (also written as 31kDa) is the outer surface protein A (ospA) this
is a classic Lyme Disease band, used in the Lyme Disease vaccine
34 (also written as 34kDa) this is the outer surface protein B (ospB)
this is also a hallmark Lyme Disease antibody, but is excluded from CDC
criteria.
23-25 (also written as 23-25 kDa) these are the outer surface protein C.
Patients that have a 31 or 34, or 23-25 band have a 97% response rate to the
correct antibiotic treatment in conjunction with correct treatment for
co-infections.
The following is taken from the website of the California lyme disease
assocication:
Lyme Disease Diagnosis
Diagnosis is clinical and is based primarily on recognition of the typical
symptoms of Lyme disease in a person who lives in a high-risk area. Doctors
like to have hard evidence to back up their opinions, but testing is not an
exact science: the tests for Lyme disease may sometimes be negative in cases
where disease is actually present, and false positive tests, though less
common, are also possible. Therefore, experienced doctors recommend that
Lyme disease be diagnosed clinically, meaning they base the diagnosis on an
evaluation of your risk and your symptoms.
To view the Center For Disease Control's, "Lyme is a clinical diagnosis",
click here.
People with chronic Lyme disease may be misdiagnosed with more familiar
conditions with symptoms that mimic Lyme disease.
Since scientists have not figured out the cause of these diseases and
treatment does not call for antibiotics, the underlying Lyme infection is
allowed to progress unchecked.
Diagnostic tests
Some doctors consider a bull's-eye rash diagnostic and don't require further
tests. Others, however, require laboratory confirmation before treatment.
Culture is the "gold standard" test for identifying bacteria. A sample of
the organism is taken from the patient is allowed to grow in a medium and
then identified. Culture is accepted as proof of infection. While culture is
used to diagnose many infections, it is not practical for Lyme because the
bacteria grow too slowly. There are no commercially available culture tests
for Lyme.
Antibody tests
The most common tests measure the patient's antibody response to infection.
When your body is invaded by the Lyme spirochetes, your immune system makes
antibodies to fight the infection. Tests that measure antibody levels are
indirect tests because they measure the body's response to infection rather
than the presence of the bacteria themselves.
During the first 4-6 weeks after exposure, most people have not developed
the antibody response that the test measures. Treatment should not be
delayed pending a positive test result if the suspicion of Lyme disease is
high (exposure, tick bite, possible rash).
Two primary antibody tests are used to diagnose Lyme disease, the ELISA and
the western blot. Doctors commonly order an ELISA first to screen for the
disease and then confirm the disease with a western blot. However, current
ELISA tests are not sensitive enough for screening and may miss over half
the true cases. Because of this, the best antibody test to use for diagnosis
is the western blot. To learn more about the tests, click here.
The read-out from the western blot looks like a bar code. The pattern
produced by running the test with your blood is compared to a template
pattern that represents known cases of Lyme disease. If your blot has bands
in the right places, and the right number of bands, it is positive. Some of
the bands are more significant than others and your doctor may decide you
have Lyme disease even if your western blot does not have enough bands or
the right bands to be reported to the Centers for Disease Control and
Prevention (CDC) for surveillance purposes.
Different laboratories use different methods and criteria, so you can have a
positive test result from one lab and a negative test result from another.
Lyme disease is known to inhibit the immune system and twenty to thirty
percent of patients have falsely negative antibody tests. To view
interpretation of the western blot test, click here.
To view Seronegativity Fast Facts, click here.
Other tests
Two other tests that may be used to diagnose Lyme disease are PCR and
antigen detection tests. Polymerase chain reaction (PCR) multiplies a key
portion of DNA from the Lyme bacteria so that it can be detected. While PCR
is highly accurate when the Lyme DNA is detected, it produces many false
negatives. This is because Lyme bacteria are sparse and may not be in the
sample tested. Antigen detection tests look for a unique Lyme protein in
fluid (e.g. blood, urine, joint fluid). Sometimes people whose indirect
tests are negative are positive on this test.
Recommended labs
CALDA recommends that you use a CLIA- and Medicare-approved lab that
specializes in testing for tickborne diseases and reports all bands on the
western blot. The healthcare professional ordering the test must ask the lab
to report all bands except in the case of IGeneX, which automatically
reports all bands. Blots may still vary in sensitivity.
IGeneX www.igenex.com 800-832-3200
Stony Brook
631-444-3824
MDL www.mdlab.com 877-269-0090
Taken from www,betterhealthguy.com
It is important to differentiate between tests that look for antibodies and
tests that look for antigens, or the actual organisms (or DNA of the
organisms themselves). Antibody testing can be highly unreliable (as can
antigen testing). Lyme disease often evades the immune system and thus
false-negatives are not uncommon. It may be only after the start of
treatment that one finds a Western Blot, for example, becoming positive.
This is generally due to the recovery of the immune system and the immune
system's ability to now begin to mount an attack and recognize the foreign
invaders.
2) Western Blot - This is likely the most commonly used test for Lyme
disease. It is still an antibody test and thus false negatives are not
uncommon, but it is, in my opinion, the best place to start. Western Blot
test results will include both IgG and IgM assays. In many traditional
infections, IgM is an indication of recent infection whereas IgG is an
indicator of late infection. With Lyme Disease, there appears to be a
cycling between IgM and IgG and thus, these are not accurate indicators of
the length of time the infection has been present in most cases. In my
opinion, IGeneX is the best place to have this test performed.
It is critically important that one not look at the NEGATIVE or POSITIVE
summary result of the Western Blot test. That criterion is based on CDC
guidelines which many argue are not appropriate for Lyme disease. Instead,
it is important to look at all of the bands and map those to the known
Lyme-specific bands (those bands that represent evidence of serological
exposure to Borrelia Burgdorferi). According to Dr. Charles Ray Jones,
these are: 18 23 30 31 34 37 39 83 93 Reference Other doctors focus on
23-25, 31, 34, 39, 83-93 as the most specific bands. Additional information
on the specific bands and what they mean can be found here.
If any of these bands appear in either IgG or IgM, that is an indication of
past or present infection with the causative agent in Lyme disease. Thus,
that is NOT a clear "negative" test result; "something" consistent with
infection with Borrelia was observed. Some labs reports only + (positive)
and - (negative) and ignore equivocal or IND (indeterminate) bands. This
is, in my opinion, an error. If anything is visible, this is not negative.
Quest, for example, does not report IND bands whereas IGeneX does. In my
opinion, testing for Lyme disease via Quest, and most other major labs, is a
waste of time and money as they do not test for bands 31 and 34 which where
used for Lyme vaccine production. Something else to consider is that most
labs in the US only test for Borrelia burgdorferi. This may miss many
strains of the Borrelia organisms, especially those from Europe.
IGeneX also now offers a new 30-31kDa Confirmation IgG and IgM test. If
results from the initial Western Blot are positive for bands 30 or 31 only,
it is possible that these could be due to cross-reactivity with several
different types of viruses. In this confirmatory test, highly specific
recombinant antigens are used to validate that the positive result is not
due to cross-reaction with viruses.
3) PCR (polymerase chain reaction) - a sensitive method of testing where
minute amounts of DNA are looked for. Though many consider this method of
testing to be useful, I have not found that to be the case. In a
presentation that I attended by Dr. Aristo Vojdani (head of Immunosciences
Lab), it was noted that PCR tests are positive somewhere between 6% and 15%
of the time. Thus, it was stated that this is not generally a useful test
for the evaluation of Lyme Disease. For PCR to be useful, it should be
expected that it may take repeated tests in order to get a positive result.
4) Lyme DOT-BLOT is an assay for the direct detection of Lyme antigen in the
urine. The Reverse Western Blot is an antigen detection test in urine where
the urine is exposed to rabbit antibodies for Borrelia Burgdorferi.
5) IGeneX offers the IFA (immunofluorescence assay) for Borrelia. It has
shown many people that have had consistently equivocal or negative results
that, in fact, they do have results consistent with Lyme disease. IGeneX
also offers a Babesia FISH and a Bartonella FISH (Fluorescent In Situ
Hybridization). I'm excited about these options as they are antigen
detection tests and not antibody tests.
6) CD-57 - We have all likely heard of people with HIV/AIDS getting their
T-cell counts or CD-4 cell counts checked on a regular basis. Current
information suggests that there is a similar population of NK (natural
killer) cells called CD-57 cells that are known only to be suppressed in the
presence of Lyme disease. Generally guidelines are that a score of < 20
indicates advanced or highly active Lyme disease. Scores of 20-60 are
indicative of active Lyme disease where scores > 60 start to suggest that
the Lyme infection is less active. A normal test result would be > 200. It
is the opinion of some doctors that treatment is necessary until the CD-57
test score is 150 or above. The lower the result, the more likely a relapse
if treatment is terminated.
The test can be an indication of progression of disease or of progress in
treatment. However, it should be noted that it is not uncommon to see only
small changes in the results until the end of treatment where the results
often then jump quickly to higher levels. It may be the case that this test
can both be used as an indicator of Lyme disease presence and as a marker
for when to consider stopping treatment. Unfortunately, there are people
that feel they are recovering and still have low CD-57 scores as well as
those that have high scores and are still quite ill. The test doesn't seem
to provide consistent value for every patient. For more information on the
CD-57 test from a recent article in the Public Health Alert, go here. The
test is now available through both LabCorp and, as of late 2010, IGeneX.
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