posted
The easiest way to remember is that IgG (Gone). A past exposure. Usually a year or more. IgM (More recent). A more recent exposure. Usually within a year.
Unfortunately, many people do not convert from IgM to IgG, so it can be difficult to decifer between the two.
frenchbraid
------------------ Stay positive. Smile. People care.
Posts: 948 | From Northwest, NJ USA | Registered: Jul 2003
| IP: Logged |
posted
So, on the western blot tests, why can you come up IgG positive, if that means it's gone?
Posts: 415 | From Canton, GA United States | Registered: May 2004
| IP: Logged |
posted
I probably didn't explain that right. I remember the "g" as in "g"one. Meaning longer than a year ago. It doesn't mean that it's actually "gone". It just means that the infection ocurred longer than a year ago. Typically.
The "m" I remember as "m"ore recent. The "g" and the "m" by no means mean if the infection is gone or not. It's more of an indicator of how long the patient has been infected.
frenchbraid
------------------ Stay positive. Smile. People care.
Posts: 948 | From Northwest, NJ USA | Registered: Jul 2003
| IP: Logged |
posted
Ok! That makes a lot more sense! I had a doctor (not an LLMD) tell me once that you may never get rid of the IgG. Is this true? Can you be over the disease and still have these bands showing up on your test?
Posts: 415 | From Canton, GA United States | Registered: May 2004
| IP: Logged |
dontlikeliver
Frequent Contributor (1K+ posts)
Member # 4749
posted
Is that right? I had a positive IgM and my Lyme is DEFINITELY OLD,at least 15 years.
I thought IgM was indicative of an old infection.
DLL
Posts: 2824 | From The Back of Beyond | Registered: Oct 2003
| IP: Logged |
It is my understanding that some bands can still remain. Which ones off hand, I do not know. I would have to do some searching to find that answer.
dll,
iGm definately stands for a more recent infection. Like I stated in an earlier reply, some people never convert from IgM to IgG. Why, I just don't know. Just another of life's mysteries I guess.
frenchbraid
------------------ Stay positive. Smile. People care.
Posts: 948 | From Northwest, NJ USA | Registered: Jul 2003
| IP: Logged |
bpeck
Frequent Contributor (1K+ posts)
Member # 3235
posted
An IgM antibody is the first reponse antibody - which is made after the presentation of the antigen.
There is question, as to whether IgM antibodys can kill Lyme or not.
An IgG antibody is much much bigger antibody and it is the antibody that can do major battle with a pathogen. It has a much longer life than IgM.
IgMs life span in measured in weeks - IgG's months and years and sometimes decades.
Barb
PS- in chronic Lyme - The body isn't vaery good at making enough IgG antibodies - (for various reasons) so over the years, IgM spikes at various times....i.e.when ever the bacteria or it's DNA is in the blood.
[This message has been edited by bpeck (edited 07 June 2004).]
[This message has been edited by bpeck (edited 07 June 2004).]
posted
Hi all, The key to your question is in the B-lymphocyte. The B-lymphocyte (a white blood cell)makes antibodies, the Ig's. When you first get infected the B-lymphocyte makes an IgM antibody to the infectious 'antigen'. That IgM antibody attaches to the infectious antigen and helps other cells of the immune system locate and kill the infectious antigen, or the IgM can sometimes kill the infectious cell on it's own. Usually it's a combination of many different cell types.
Once the initial infection has occurred, the B-lymphocyte that recognized the infectious antigen is selectively stimulated to hone in on the infectious antigen. It starts making antibodies much more specific, more able to seek out and bind the infectious antigen, and more lethal in their signaling for help and in their own killing potential. These antibodies are the IgG.
It's these "memory" B-lymphocytes that then stay around in your body forever, constantly reproducing as others die off. And it's these "memory" B-lymphocytes that make only that SPECIFIC IgG TO THAT ONE INFECTIOUS ANTIGEN. The original IgM is not so specific and only functions to hold off the infection until the body's machinery of war starts to crank out the more specific and deadly IgG.
That's why IgG is found much later in the infectious process and years later, even if the infection is gone. The memory B-lymphocytes are constantly on patrol, and when the infection makes a reappearance the memory B-lymphocytes start cranking out the IgG and tries to beat the enemy cells before they can gain a foothold.
posted
I was infected a year ago and tested positive on both IgM and IGG about a month ago. How can I have old and new? Is a year considered old infection or do you think I was infected a long time ago and never showed symptoms till the tick a year ago. As far as I know I was healthy before that and never bitten.
posted
That's a good question! Also, I've read Burrascano's guidelines and he says what bands are positive or negative, but he doesn't mention if those are IgG or IgM. Are you positive with IgG or do you have to have IgM to be considered positive? I'm sorry, I'm just really confused!!!
Posts: 415 | From Canton, GA United States | Registered: May 2004
| IP: Logged |
bpeck
Frequent Contributor (1K+ posts)
Member # 3235
posted
Don't think of them in terms of old and new.
IgM is the first response team - and they can be called up at any time - and they act quickly - but are not as efficient as the IgG team - who have slower response time, better killing power, and around the war zone longer.
Remember - Lyme changes it's outer (protein jacket) all the time to evade the immune system - so that's how you can have both IgG and IgM - they're responding to the differnt proteins expressed by the bug.
posted
Lenny, It's hard to say about the length of time. Sometimes IgM continues to fight on for a while, or it can be that as IgG levels dwindle by a tough fight IgM is brought back again as the reserve army. I'm not really sure about that. It could be a reinfection too. But also the testing is really tricky business.
As these diseases mutate and cause B-lymphocytes to constantly change the details of the Ig they're manufacturing there's, I believe, often a cross-reaction on these tests. A very slight difference in protein configuration or size can cause these proteins to run through the gels used in these tests at rates almost exactly as those for other diseases, or even a variation of the same disease. More complex than I know about I'm sorry to say.
The Lyme Disease Network is a non-profit organization funded by individual donations. If you would like to support the Network and the LymeNet system of Web services, please send your donations to:
The
Lyme Disease Network of New Jersey 907 Pebble Creek Court,
Pennington,
NJ08534USA http://www.lymenet.org/