"IgM antibodies are the first antibodies to be produced in the body in response to an infection, and is produced in great quantity.[...]
IgM antibodies, when present in high numbers, represent a new active infection or an existing infection that has become reactivated. Over time, the number of IgM antibodies will decline as the active infection is resolved.
IgG antibodies are produced once an infection has been going on for a while, and may be present after the infection has been resolved.
Generally speaking, the presence of IgG antibodies to an organism when accompanied by a negative IgM test for the same organism means that the person was exposed to that organism at one time and developed antibodies to it, but does not have a current active infection of that organism.
When it comes to Borrelia burgdorferi (Bb), the organism responsible for Lyme disease, that is not necessarily the case.
To recap, depending on the numbers,
IgM is a sign of a current infection.
IgG is a sign of a current infection, or of a past exposure to or past infection by the organism."
Please note the last sentence:
" When it comes to Borrelia burgdorferi (Bb), the organism responsible for Lyme disease, that is not necessarily the case."
I am not a doctor but I found out from my tests tha IgG means that you have antibodies for an infection and you are now past that infection, I mean it happened in the past, whereas IgM means that antibodies are now forming cause you are now going through an infection and your body fights it. I haven't heard about a case when both are positive, but from the above I would assume that it means either you have gone through that infections in the past and now as well or that you are halvway past the present infection, and slowly the percentage of antibodies are going for the ongoing status(IgM) to the past illness(IgG)- the latter seems more possible to me. I hope I helped
" Patients infected with Epstein-Barr virus and other spirochetal diseases may give false positive results"
The site above, about IgM and IgG for Lyme, has a lot of medicalese in it.
A site for toxoplasmosis (which may or may not be pertinent for Lyme or EBV ) states if both IgM and IgG are positive the blood should be drawn and then sent to another lab that uses a different reference lab which employs a different IgM testing system for confirmation.
I'd send another blood draw to your lab to see if results differ. They often do. That's if your insurance would pay for a 'repeat' test----sometimes they won't.
BUT before getting too immersed in the results of your IgM and IgM for EBV I would suggest that you try to forget about the results of that test. There're so many things that can result in false pos. and false negs. that's it's a wonder they're even done! (Sorta an exaggeration there, but you get what I mean.)
Instead, let's focus on whether or not you have Lyme disease and forget about the EBV titers since absolutely no one can agree on them.
The belief that IgG indicates a "past" infection is a misunderstanding that has unfortunately resulted in unknown numbers of patients going undiagnosed and untreated. In the case of Lyme, active infection past the 4 week mark is expected to show IgG antibodies. After treatment and resolution of the illness, tests can still show IgG antibodies. And so, IgG can represent either current or "past" infection.
Our bodies usually start producing IgG antibodies about a month or so after initial recognition of an infection and production of IgM antibodies. Unfortunately for Lyme patients, the medical establishment has declared a hard "rule" that all patients produce IgG antibodies at the one month mark and therefore, anybody with a tick bite/rash/symptoms over a month ago MUST show IgG antibodies. But some immune systems didn't get the memo. In my case, I'd been infected almost exactly 6 years and I showed only IgM antibodies for Lyme (except for the very common band 41) when I got tested.
But for your EBV titers, postive IgM indicates that your immune system is in "first response" mode to the virus. It could mean you were infected recently (but more than a month ago given the IgG +), or it could mean the virus has reactivated thanks to a suppressed/stressed immune system.
Many Lyme patients show postive EBV tests as the virus takes advantage of the Lyme suppressed immune system to start reproducing again. Of course this gives the feeling of having mono on top of the Lyme, just to add to the misery.
Some Lyme patients have been misdiagnosed with EBV and the so-called illness "chronic mononucleosis" given these tests. But this does not exclude Lyme. Have you been tested for Lyme?
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