Laboratory testing for Lyme Disease, you have heard a little bit about this, the ELISA test which is the screening test, the primary screening test for the disease has less than a 50% sensitivity as Dr Donta showed you, there is also a large variation in how the labs do the test. The Lyme Western Blot is very sensitive but again, there is a problem with that and I will show you that in a minute and also men and women react differently on the Western Blot and I will show you that too in a minute. The Lyme PCR as Dr Donta mentioned is a kind of a controversial area right now. It is highly specific but it is expensive and it doesn’t always come up positive. There is a physician in New Jersey who does PCR tests on all his patients and he does for every 10 tests he may get one positive so very often this test is negative and may not be very useful.
The Lyme Western Blot as you heard – this is an Igenex Western Blot and it’s a little hard to see on here but you can see that it looks at different bands, different protein bands from the bacteria. If you count them here there are 16 bands that are tested for so this is using the patient’s serum and looking at reactivity with 16 of the bands from the bacteria.
Now the problem is though, that this is not the standard Western Blot, the standard Western Blot goes by the so called Dearborn/Dressler criteria that the CDC has adopted to look at Western Blots and what this does is that it takes those 16 bands and it says, OK, now for the IgM Western Blot we are only going to look at 3 bands, we are going to throw out 13 of those bands because they are not important and similarly for the IgG Western Blot we are only going to look at 10 bands, we are going to throw out the other six because they are not important. And then, in order to get a positive, you need at least 2 out of the 3 bands positive on the IgM or at least 5 out of the 10 bands positive for the IgG so this has created a very, very insensitive Western Blot system and, unfortunately, this is the Western Blot that is done by most routine clinical labs and it is what is accepted by the CDC as a positive surveillance Western Blot which is another issue that we can talk about later.
And in contrast to that what IGeneX and MDL and other Lyme Literate laboratories have done is they have said, Well, look, it is really stupid to throw out all of this information on the Western Blot why don’t we just look at the whole Western Blot, look at all 16 bands and then we will say that there are well 6 that are very specific for Borrelia so in order to have a positive Western Blot you either need 2 of those 6 bands positive or 5 of the total bands positive and that is going to be a Western Blot that’s positive. And this really makes a lot more sense, because it makes more physiologic sense that if someone is reacting to all of these bands firstly you don’t want to throw out the ones that are there just because you don’t think they are important you want to see if someone has reacted to that and second of all, it sorts of sets up criteria that are more consistent with what we know about the clinical aspects of the disease. We can talk about that a little later too. So, this is where we have a big problem with testing for Lyme Disease. There is this split in how to do adequate Lyme testing and until that gets resolved we are going to have consistent problems with making a diagnosis.
The other interesting difference with the Western Blot and, this is a study that was done about 10 years ago, is that it turns out that men and women respond differently on Western Blots and this was a study of patients with Chronic Lyme Disease where they did a standard 3/10 Western Blot which is CDC approved and they looked at how many positive bands they got according to whether they were testing men or women.
It turns out that men with symptoms of Chronic Lyme Disease had an average of 6 positive bands on the IgG Western Blot and in contrast to that women with Chronic Lyme Disease had an average of only 4 positive bands on the IgG Western Blot. If you remember, how many bands do you need to have a positive Western Blot? You need 5 positive bands, so girls you are out of luck! Women are at a huge disadvantage doing this test because they tend to have less positive bands on the Western Blot so they tend to be diagnosed less frequently because of this difference. Why do we have this difference? I don’t know but it is also something you can get rid of if you use the IGeneX type Western Blot, it seems to disappear when you consider more of the bands.
So, other ways to test for Lyme Disease, there is the Lyme Dot Assay (LDA) which is a urine test and this has been an excellent monitoring tool if you have a patient who is positive you can actually do the test to see when the bacteria go away. It is based on finding dead bacteria in the urine, which happens when you treat the disease. It is also very useful as a diagnostic test in children where you don’t want to have your staff have to go over to the lab and hold some screaming 2 year old down to draw blood but you can in fact chase them around the house and collect the urine for 3 days and get a test that is very useful. There has been a lot of controversy over this test and we can talk about that too.
The latest rival from the Steere camp is the Lyme C6 Peptide ELISA. This is a test that is supposed to be more specific for Borrelia infection because it looks at a very specific peptide that is in the organism. The problem with it is, it is still an ELISA and as I have shown you, ELISA tests miss 50% of the Lyme patients so this test, even though it is very, very specific, will still miss 50% of the patients and it is just not a good screening test.
And then there is also immunologic testing with CD57 lymphocytes and I will show you that in a minute.
Now, in terms of Neurologic testing, you heard a little bit when Dr Donta talked about MRI and SPECT, cerebrospinal fluid, doing spinal tap, is not very useful because you usually have what is called the ?end spinal fluid. There is not much in it, there are not many proteins, no cells, usually there are no oligoclonal bands which is a diagnostic marker of Multiple Sclerosis (so it may be useful to do it for that reason to show that the patients doesn’t have MS) and Lyme antibodies and PCR are often negative in spinal fluid and I think the reason for that is that the organisms are not in the spinal fluid they are in the brain tissue so when you are looking at spinal fluid you are not really looking at where the bugs are because they are in the brain.
MRI, brain MRI, is also positive in perhaps 50% or less of patients with neurologic Lyme Disease. Often you see these non-specific so called white matter lesions and it resembles other demyelinating diseases such as Multiple Sclerosis. If you saw a brain scan from an MS patient or a Lyme patient, the patients are generally indistinguishable. So MRI has not been that useful.
Now, the SPECT brain scan, you have heard Dr Donta say that 75% of patients have a positive SPECT. It is probably even higher than that with the newer SPECT machines and also with a very important tool which is a radiologist who knows how to read them. You can see inflammatory and perfusion defects with the SPECT scan in Lyme Disease and the lesions usually do resolve with treatment which is nice because you can actually follow your treatment and see if it is working.
A more recent addition is the PET brain scan which is another version of the SPECT. This is still considered experimental.
Neuropsychological testing is also done on patients with neurologic Lyme Disease and it’s always kind of interesting to see how much abnormality there is on this test because patients often don’t even realise how neurologically compromised they are until they try doing this testing and then they see that there is really quite a bit of compromise that may be there. But it also depends a lot on how the test is done and who is doing the test in terms of getting a positive result.
So, you have seen a paediatric version of this, this is Bell’s Palsy, with a 7th nerve palsy on the left here, a very typical symptom of neurologic Lyme Disease. This is an MRI scan – what does this patient have? Anybody know? You can see there are some little white dots here, all over, it could be MS, it could be Lyme, it’s hard to tell, this actually is a Lyme patient but it could also be an MS patient.
This is what a SPECT scan looks like in a child with neurologic Lyme Disease and with SPECT the blue areas are the areas of decreased perfusion whereas the yellow and red areas are the areas of good perfusion and you can see that there is this blue-ish band here which corresponds to the frontal lobe which is over here and also the temporal lobe over here, and those are the areas that are generally involved in neurologic Lyme Disease. This child got hyperbaric therapy and you can see in contrast after hyperbaric treatment there is a lot more yellow in these areas, the blue has decreased, there is better perfusion and hyperbaric treatment does have the ability to do that but it is still an experimental treatment for Lyme and we can talk about that too.
OK, now, the reason I got interested in Lyme Disease is that I really like immunology and I was interested in these cells, this is a kind of funny cell of hair-like projections, a natural killer cell, which has the job of killing tissues and bugs or organisms and tissues that become infected with those organisms. Natural killer cells have certain markers on their surface that can distinguish self from non-self and that is how the body knows not to kill itself and also can detect infected cells and then kill the cells that have been infected.
Ed Winger, who is the director of a lab in San Francisco called Immunodiagnostic Lab had been interested in looking at these cells in patients with AIDS and he developed this whole panel looking at markers on different lymphocytes and natural killer cells and when we were looking at all these AIDS patients we said, well you know, we really need some other patients to look at so why don’t we look at patients with other diseases and one of the diseases happened to be a patient with Lyme Disease. And what we found was that Lyme Disease patients had very normal T cell and T cell panels with the exception of one particular sub-set of natural killer cells called the CD57 natural killer cell subset and so we started looking at more Lyme patients and we found this was a pretty consistent abnormality that patients with Chronic Lyme Disease had this decreased subset and that is kind of how we got interested in the effect of Lyme Disease on this cell population.
Now CD57 natural killer cells are a subset of natural killer cells but they are distinct from the main subset of natural killer cells which has the CD56 marker on them. CD57 cells have the CD57 marker which is just another protein on the cell’s surface. Their function is poorly understood. We know that they are down-regulated by so-called Thl cytokines (such as IL-2, IFN-gamma, TNF-alpha) and also they are found on other cells including T cells and also interesting on nerve cells in the brain which is something that we can also discuss.
So, we looked at a series of patients with Lyme Disease and looked for CD57 cells in those patients and that is shown on the next few slides. For controls we had 10 patients with acute Lyme Disease: 5 men and 5 women. All of those patients had musculoskeletal symptoms primarily. In contrast, we had 73 patients with Chronic Lyme Disease shown here, most of those patients – most of the men had musculoskeletal symptoms actually most of both groups had musculoskeletal symptoms but some did have neurological symptoms primarily and then as another control group we had a group of 22 AIDS patients and what we found was the following:
The 10 patients with acute Lyme Disease that we tested for CD57 natural killer cells, all had normal levels of these cells - none of the patients had low levels of CD57 natural killer cells. Now in contrast, when we looked at the patients with Chronic Lyme Disease, there were 31 patients who were tested before any antibiotic treatment; all of those patients had low levels of CD57 natural killer cells. When we looked at the group of patients who were on treatment, and there were 37 of those, about half the patients had low levels of these cells and half the patients had normal levels. So there was kind of a mixed bag in the patients who were being treated. And we also had a group of 5 patients who had been treated for Lyme Disease and had recovered and all of those patients had normal levels of these natural killer cells so there seemed to be a correlation between decreased levels of these natural killer cells and active Chronic Lyme Disease.
Now, in contrast, when we looked at the AIDS patients, the 22 AIDS patients, 82% of those had normal levels of these cells and this was in spite of the fact that they virtually no CD4 T cells which is the marker of AIDS. So, even though their T cells were compromised, their natural killer cells by and large were pretty normal. So here was a defect that was very specific for Lyme Disease and didn’t cross over, by and large, to another disease which was HIV infection.
We also looked at the difference between patients with musculoskeletal symptoms versus the patients with neurologic symptoms and what we found on this slide is that patients with musculoskeletal symptoms by and large had much higher levels of the CD57 natural killer cells than the patients with neurological symptoms, so the patients with neurologic Lyme Disease seemed to be sicker than the patients with muscular-skeletal symptoms by immunologic testing.
And, finally, when we looked at patients on treatment over time, what we found was pretty much like what we found in the original data, some of these patients had increases in their CD57 cells back up to normal but some patients had persistently low levels of these CD57 cells and these were the patients who were chronically ill with Lyme Disease and generally didn’t respond to treatment.
So here we had a very nice marker of Chronic Lyme Disease and we also serendipitously found another patient who had been treated by Joe Burrascano about 10 years previously and was tested for this subset sort of by accident and I happened to inherit her 10 years later and she was still sick with Chronic Lyme Disease and over the next, its actually now up to 12 years, we have a series of the CD57 levels, the normal level by the way is 60, and starting in 1991 she had a slightly low level of these cells and she has had persistently low levels of these natural killer cells even though she tends to go almost back to normal when her symptoms improve but when she goes off treatment and her symptoms get worse her levels also go down. So, here there is evidence that this immunologic defect can persist over 10 years or more in a patient with Chronic Lyme Disease and it is pretty good evidence for the existence of Chronic Lyme Disease. I mean, here you have this immunologic defect that correlates with that entity.
So a decrease in the CD57 lymphocyte subset may be an important marker of Chronic Lyme Disease and also changes in the subset may be useful to monitor therapy in patients with Lyme Disease and of course the take home message is that the CD57 natural killer cells may be like the “CD4 T cells” of Chronic Lyme Disease just as we use CD4 T cells to monitor patients with AIDS and to see how patients with HIV infection are doing monitoring CD57 natural killer cells can be useful for patients with Chronic Lyme Disease.
Lyme Disease Action, Registered Charity Number 1100448, Registered Company Number 4839410
Home | Terms and Conditions | Site map