JessieP said...
Ive been doing some reading and i’ve read that if you have been feeling unwell for longer than 6 months and you are only igm positive and igg negative that this could be a false positive. Anyone know anything about this?
i would say that is false - based on poor understanding of how the lyme causing borrelia organism work.
More detail on IgM vs IgG in lyme
the lyme disease organism has the largest genome of any bacteria so far discovered.
the large majority of this extra genetic material is dedicated to making different outer surface proteins
this enables it to change the proteins it has on its outer membrane - this is important as these are the ones the immune system is in contact with and trying to make antibodies to, which takes time - maybe 1 month and are initially IgM antibodies ( it later learns from these IgM antibodies what to make IgG antibodies to )
by the time the body has figured out what proteins to make antibodies to the organism has changed the proteins in the outer membrane and now looks like a new infection to the immune system - and so off the immune system goes again, trying to make new (IgM) antibodies to that - and so the cycle continues.....
you can see what an effective an immune avoidance mechanism this is - as the body never quite catches up to the microbe with its learned immunity.
you can also see how this would result in IgM antibodies being present on an ongoing basis in chronic infection
it is not always this way however - as the organism also has other immune disrupting strategies and one of these is it interferes with the bodies ability to make antibodies at all - and so we instead tend to see a somewhat randomised picture of: no antibodies, only IgM antibodies or a random mix of IgG and IgM antibodies.