question about reliability of testing circumstances
I have been tested for positive for Lyme bacteria & a co-infection last fall through Quest Diagnostics, Western Blot.
Then my doc ordered a re-test through Igenix. However, no antibiotics were delivered as I thought were a prerequisite to diagnose the bacterium (Lyme & co) in chronic conditions.
Welcome -- sorry to hear you have need to be tested! ... but your doc sounds on the ball, which isn't always the case.
Others here will also likely weigh in, and none of us is medically trained, but here's my initial take:
The first round of tests you had (W. blot, and possibly its companion, ELISA) are the basic, standard Lyme tests that look for your immune system's reaction to the infection, measuring antibodies against the bacteria. These tests do not look directly for evidence of Lyme bacteria, but W.blot and ELISA have been the standard test for a long time, so most docs will start with them.
Because those tests are not very precise, however, it is not uncommon to have a 'false negative' result -- meaning you are infected, but the test shows no indication that you are. Your doc may have been thinking that your symptoms were strongly indicating Lyme, however, so the doc went for the next level of testing, through IgeneX. The IgeneX tests don't look for your immune system reaction, but instead look for the actual DNA of the Lyme bacteria themselves: a direct test. And you came up positive, it seems. (Why docs don't just go straight to the IGeneX test is a mystery to me, since it's more accurate, to my understanding.)
About why you were not given antibiotics before the IGeneX test: it's not necessary to do so, because the purpose of giving an 'antibiotic challenge' is to stir up the immune system and get it to produce antibodies against an infection, so that the test will locate the antibodies and show up as positive. (An 'antibiotic challenge' is sometimes necessary in the W.blot/ELISA tests, because the human immune system is made to kill bacteria that have a short life cycle and so can be wiped out in a couple weeks of antibiotic treatment, but Lyme is tricky -- its life cycle is much longer than most bacteria, so it needs longer treatment to be able to slam the bacteria while they are dividing and are much more susceptible to the antibiotics.)
Sorry if this is more detail than you want ... but it's the long way of saying that the IgeneX test doesn't need your immune system to be stimulated with antibiotics to show a positive result if you are infected. The IgeneX test will look directly for the bacteria, not for the immune system's reaction to the bacteria.
So it sounds like your doc says you have Lyme .... and a co-infection. Which co-infection were you positive for? It may well need different antibiotic treatment than Lyme needs, and Lyme itself is usually treated with a combination of antibiotics because of Lyme's ability to hide in slimy shields they make inside your body, called biofilms. One antibiotic is used to pierce the biofilm, and another one to kill the Lyme. And then the co-infection is treated.
Different docs have different approaches, since Lyme is an area of medicine still developing, but your doc's approach sounds like that used by my doc, and he's pretty much cutting edge. My treatment for Lyme plus one co-infection took about a year, and that's pretty common.
Let us know if we can help -- we've all been where you are! Take care and best wishes --
I just re-read what I wrote above and this part in particular does say what I meant to convey:
"(An 'antibiotic challenge' is sometimes necessary in the W.blot/ELISA tests, because the human immune system is made to kill bacteria that have a short life cycle and so can be wiped out in a couple weeks of antibiotic treatment, but Lyme is tricky -- its life cycle is much longer than most bacteria, so it needs longer treatment to be able to slam the bacteria while they are dividing and are much more susceptible to the antibiotics.)"
So let me tear it into bits and explain it a little more, if it's useful. What's in quotes below are the same words I wrote above, but broken into pieces and with better explanation:
"An 'antibiotic challenge' is sometimes necessary in the W.blot/ELISA tests" -- so far so good.
"... because the human immune system is made to kill bacteria that have a short life cycle and so can be wiped out in a couple weeks of antibiotic treatment" -- also accurate.
"but Lyme is tricky -- its life cycle is much longer than most bacteria, so it needs longer treatment to be able to slam the bacteria while they are dividing and are much more susceptible to the antibiotics." -- meaning that when the bacteria are reproducing [dividing], their cell wall is disrupted, and when the cell wall is split like that, it's easiest for the antibiotics to kill the bacteria. Just like if bad guys are holed up in a hiding place, it's easier for the cops to take them out if the front door is open.
The human immune system is set up to assume that bacteria reproduce about every 20 minutes, I think I read some place, and after about 2 or 3 weeks of antibiotics, there have been disrupted cell walls every 20 minutes for 24 hours a day (3 times an hour for 24 hours) for 14 to 21 days. That's a lot of opportunity for the antibiotics to kill the relatively defenseless bacteria.
However there are some bacteria that reproduce very slowly, such as tuberculosis. Their reproductive cycle is measured in hours, not minutes, and the standard antibiotic treat needs to be longer to have enough opportunities at the ruptured cell wall to kill the bacteria. That's why standard antibiotic treatment for TB is 18 months or so.
Lyme has a similar slow reproductive cycle, so a few weeks of antibiotics will not make much of a dent in a Lyme infection. That's why Lyme specialists treat for a longer time, just as they would with TB.
I am curious as to why your doctor is retesting you at IGeneX. Quest does a less thorough job, not to mention that odds of a false positive are quite low.
Five of the ten bands considered in the IgG portion of the test are not Lyme specific. It is possible to have the right combination of other antibodies to other bugs to make those five bands positive. But if any of the five Lyme specific bands are positive, then there's really no question. Unfortunately, lab results don't tell you which bands matter more than others, so even most doctors don't know. If you have a doc informed enough to know exactly which 5 are not Lyme specific, and you have only those 5, this could explain why he wants a second opinion from a more advanced lab.
If you only have an IgM response and you're early in the disease, a positive there isn't controversial. If you're late in the disease, like I was, and you only have an IgM response, like I did, then it is more controversial.
Don't you love how complicated this is! This is why the CDC and IDSA tried to "simplify" the process and just give doctors a positive or negative answer. Unfortunately, they made it so strict and narrow, the official testing misses lots of cases.
Don't be too concerned if the IGeneX WB results are different than the Quest results. IGeneX uses two different strains of the bug in their testing, which sometimes shows different bands. But even at the same lab, you can test once a month and be different every time. This is known about Lyme, but not well publicized. Some people go from "positive" to "negative" even when they haven't been treated and are still sick.
Any positive test indicates Lyme, regardless of how many negatives you have, so don't let your doctor conclude that a subsequent "negative" results means you don't have it. (Do you see why I am confused as to why your doctor wants to test you again after a positive? )
In the book "Cure Unknown", the author explains how the researchers arrived at the test interpretation. Confirmed early Lyme patients had blood drawn four times before, during, and after treatment. If they met the criteria any one time of those four, they were considered positive. Unfortunately, that means that a patient could have tested "negative" on this criteria THREE TIMES before showing positive, but they don't tell doctors that.
Doctors think the test is definitive, because that's what the CDC and IDSA say on their websites and guidelines. Both these organizations also warn of false positives in supposedly non-endemic areas, in spite of the fact that false positives are extremely rare, and false negatives are common and documented in their own research and studies. Just a sample of the craziness around Lyme Disease.
Feel free to share your WB results with us. We'd be happy to chime in.
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