*** Hi
@Rossy191276,
[I have edited my original post, where the ++++ are--below]
A criticism of the LTT has been:
"It is often criticized that the detected T-cell reactivity is not specific to borreliosis but simply a general T-cell reactivity of patients with other inflammatory diseases."
*** Well, I have re-read very carefully the large paper on LTT and Lyme in more than 1500 patients, as in the Spanish ME/SFC-investigation forum I run we are treating these issues quite effusively, so it’s a matter I am very interested at:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3474945/#R7
*** first we need to distinguish between the lymphocyte transformation test (LTT) and the ELISPOT Assay. The first measures the number of new T helper cells specific for the borrelia antigens added to the culture of your serum--they are the ones that get activated, so this is a measure of the acquired responsiveness towards the bacteria:
(…) The proliferative response of cultured lymphocytes is measured by quantifying the uptake of tritium-labelled thymidine (3 H- thymidine) into the DNA of antigen-activated T cells. (…):
http://www.jiaci.org/issues/vol15issue04/1.pdf
*** The ELISPOT on the other hand measures the activity of antigens-specific-T cells by quantifying the amount of IFN-gamma secreted when these specific T cells encounter the borrelia antigens:
(…)The enzyme-linked immunospot assay (ELISPOT) has emerged as a superior method for assessment of the magnitude and the quality of T cell immunity. It enumerates at the single cell level the frequency and cytokine signature of activated antigen-specific T cells (…).:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3972671/
*** I have read several studies as well on the ELISPOST, and the results seem to be similar. Also, this is a test approved by the CDC for TB and recommended over other tests in certain cases. Well, for me this is a solid confirmation of the validity of this test to meassure Th responses to antigens:
http://www.cdc.gov/mmwr/pdf/rr/rr5905.pdf
*** So, in response to your question, in my humble opinion these studies make clear how both tests are highly sensitive and specific to detect the specific T responses, with little non-specific stimulation. The immunological bases are described in the first large study:
(…)Each humoral immune response to an infection requires a specific cellular immune response with clonal proliferation of various antigen-specific lymphocyte subpopulations. Of central importance here are antigen-specific T helper lymphocytes (CD4+ TH cells). In addition to effector T cells, long-lived T and B memory lymphocytes are formed. In the presence of antigen-presenting cells and protein antigens, specific CD4+ T memory cells also proliferate in vitro. The lymphocyte transformation test (LTT), also known as the lymphocyte proliferation or lymphocyte activation test, is based on this principle(…)
(…)The results of our study differ in part from some published data which show a low specificity of the Borrelia-LTT [24, 25]. This is very likely due to methodology. The addition of interferon-α to the cell culture medium inhibits nonspecific proliferation of lymphocytes and promotes the function of antigen-presenting cells. This improves the discriminatory power of positive and negative LTT results(…)
I have read widely that it seems ME/CFS patients have a very high positive rate on the LTT test...Of course it would make sense that it is higher given that Lyme could lead to ME/CFS...But is it possible that ME/CFS itself results in false positives without having a lyme infection?
*** Well, most tests (ELISA, PCR, serologies) have demonstrated to show many false negatives, but a high positive predictive value (a positive is most times a real positive). The only tests that have created controversy about the possible false positives are the LTT and the ELISPOT, and both have been improved over the years in order to reduce these non-desirable outcomes. It doesn’t matter if they are used for ME/CFS or for other conditions, they have shown high “reliability” to measure the specific T reactions to antigens in vitro, and this is what determines the sensibility of these tests, regardless of the condition. The large study on LTT noted that false positives due to inflammation, or to other chronic infections had been excluded (although they don’t publish this data). More over, the percentage of Lyme + shed by serology and by LTT in 1480 clinically suspected Lyme patients, was similar, so, given that the positive predictive value of serology is actually high, we can infer the same for the LTT.
For example- I have seen the following quotes on various forum threads:
"What's also interesting is the possibility that the false positive rate for the LTT in ME/CFS patients might be higher than it is in healthy individuals. If that's true, I think it might suggest an underlying problem in some ME/CFS patients that could be mediated by memory T-cells."
*** it could be the other way around given that the acquired Th1 and Th17 responses in ME/CFS are depressed… So I don’t see bases for this assumption. Yes, we do have less T regs and less memory T and B cells, and this means that effector T and B cells over-react to some antigens. But this does not reduce the specificity of a Th cell towards its unique (almost) antigen, it only makes it to react strongly…
Hi
Also here is comment from Dr Edwards: "I personally suspect that a subset of ME is likely to be due to the sort of non-specific T cell overreactivity you see in Reiter's syndrome."
*** I agree, but let’s try to clarify this: more and more evidence supports that the origin of autoimmune arthritis is a cross-reaction, and some pathogens have been indentified as possible culprits. These process involves T over-reactivity (loss of tolerance, mainly of Tregs), in different forms, including polyclonal T cell proliferation, what entails many T cells attacking many antigens that shouldn’t, what subsequently causes autoimmunity. But the specificity of these T cells towards their specific antigens (let’s say, a protein of the joint tissue) does not change. This is the key idea to keep in mind.
Personally, I have tested positive to LTT tests from 2 different labs (Armin + Australian Biologics) but I am seronegative on 3 different Western Blots (with band 41 the only band ever positive once which i have now read is quite common without having lyme)...In the study of LTT testing they reported that only 2.2% of the 1500 cases was seronegative and LTT positive...
*** Well, serology test shave shown very clearly that they are just not reliable for chronic Lyme disease. For example (you can find many studies showing this):
(…)Seronegative cases with late stage Lyme borreliosis have also been recently described(…):
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3474945/#R7
(…)The standard two-tier tests used to detect specific antibodies to B. burgdorferi include an enzyme-linked immunosorbent assay (ELISA) and a Western Blot assay (WB) [13]. However, the limitation of these assays is that they have low sensitivity and specificity, frequently producing false negative and false positive results (…):
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3972671/#B27-cells-02-00607
*** About that 2.2% of patients seronegative and LTT-positive,
++++ EDITED:
***the paper states:
(...)In 1182 out of 1480 patients (79.8%), the Borrelia serology and Borrelia-LTT showed corresponding results. 37,8% (n=560) showed a positive serology and a positive LTT whereas 42% (n=622) were LTT as well as serology negative. The combination of a positive serology with a negative Borrelia-LTT was found in 266 patients (18.0%). 32 patients (2.2%) were seronegative and LTT-positive.(...)
*** As for the seronegative and LTT-positive being so low, my explanation given in the paragraph edited (below, with ++++) I think explains these findings: because with these cohorts of patients (an average of "sub-acute" stages, where their immune systems are still quite reactive and able to form specific Igs), we should expect the serologies to be reliable, so, in agreement to this, we see a 37.8% with serology+ and LTT+ (LTT equally reliable to serology when this is +, confirming its high PPV).
*** In the same vein, and for the very same reason, when the serology is -, because of its high NPV, the LTT shows similar results conforming thus also its ability to discard the disease: a 40% of serology - and LTT-
*** But, when does concur a serology - and a LTT+?? Well, this is VERY NORMAL to be observed in late states of chronic Lyme disease, not assessed in this study (more than 3-5 years sick, and severe symptoms). This study shows the other occasion when this combination occurs: In more "sub-acute" states. As I explain below, at this early point, the reliability of serology is still high, so the discrepancies between serology and LTT at this point are almost insignificant--hence the 2.2%!!!! Alright, now this makes more sense!
++++ [paragraph complemented with the new info I've written above] out of the 1480, it makes sense, as in that study they define late stage Lyme as those who have been sick for more than a year, and early Lyme for those who have been sick for less than a year. Alright, This is a too early cut-off point. If you read studies on chronic Lyme, you can see that after a year they are still very reactive, with a Th1 dominance. These patients will for sure shed high percentage of real positive results from serological tests. The problem comes over time, after more years of disease, or when the symptoms become severe. At this time the immune response has evolved towards a Th2 dominance, and the capacity of secreting antibodies has diminished greatly (borrelia b. does attack and destroy the lymph nodes, then the B cells cannot convert into plasmatic cells, or their ability to form specific IgGs from IgMs (change of class process) has been haltered, etc.). In short, the study uses the ELISA and the Wetern Blot tests in order to asses positive or negative cases of lyme by serology. Putting together both techniques sensitivities and a mixture of patients comprising early Lyme patients and late ones (taking into account that their definition of late does not really fit what a late chronic stage lyme disease means), then it is understandable that both serology and LTT show high sensibility.
My clinical picture is classic severe ME/CFS- extreme exertion intolerance, PEM, cyclical, extreme ANS disregulation, other neural symptoms, and much more.... But from a lyme perspective this can be seen as chronic lyme...(I realise I could also have both)...I have been doing antibiotic/herb combo treatment for lyme for 3 months...
But it seems to me that if ME/CFS spikes T Cell reactivity my positive results may be due to ME/CFS...What are peoples' current thoughts on whether ME/CFS without Lyme is causing/can cause False positives on the Armin LTT?
Thank you in advance for your insights!
*** Well, I think I have answered to these questions above. I do hope this is helpful!
*** Best!
Sergio