This is topic IGG and IGM question in forum Medical Questions at LymeNet Flash.

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Posted by lmz1100 (Member # 15487) on :
I have been doing lots of reading and have seen that the IGM represents a current infetion and should show within a few weeks of being infected. The IGG shows that one has had the infection for a while. I hope I got that right, without elaborating.

Well, I had what I thought was a Lyme bite in Sept 2006 and tested low positive in a titer test a few weeks later.

I was recently tested through Igenex and tested positive on my IGM but negative on my IGG. The LLMD told me most doctors would consider me negative with those results.

My questions are - why would I show positive when I was allegedly infected over 2 years ago but come up negative in the IGG?

Also, and most importantly to me, are there other diseases/infections that can cause a Western Blot to come back positive - other than Lyme?

I am asking because the more I have thought about it, I realized I had some of my symptoms years before my bullseye rash. I don't want to treat for Lyme (which I already have to an extent and has not worked yet) and have something else that is being overlooked.

Thanks for any advice anyone can give. I tried to break this post up as much as I could, sorry if it wasn't broken up enough.
Posted by sixgoofykids (Member # 11141) on :
Many Lyme patients who have chronic illness end up having their IgM be positive. They think it might have something to do with how the bacteria renews itself or proliferates that the infection shows up as "new."

I was IgG positive and my LLMD told me that was unusual, not the norm.
Posted by KS (Member # 12549) on :
You ask excellent questions....ones I've been seeking answers to as well.

I also have only had a positive IgM response with a negative ELISA and a negative IgG response. However, I will test again to see if with time, more has turned up.

What bands did you actually test positive for?

Based on all of the research I have done, there is little to no scientific data to support that we have lyme disease, without eliciting an IgG response...(unless you are newly infected and treated prior to your immune system making an IgG response).

However, there is plenty of data available that proves the current test methods are not reliable or reproducible and this is important to keep in mind.

Our best LLMDs will report that such test results (IgM positive) are not unusual in their clinical experiences and have said that with treatment, many patients in time will elicit a strong IgG response. There are many good theories as to why this happens but again, very little data is currently available to support such theories.

I personally have chosen to treat....whether I'm treating Lyme or something else, I'm not sure!!

Can other things cross-react, particularly with IgM, yes! Problem is, what is known to cross-react with the lyme western blot usually has a very clear clinical picture (i.e. treponema, leptospira, EBV, HIV, some autoimmune conditions such as RA). Unfortunately not every disease has been evaluated to see if it cross-reacts or to what extent it will cross-react.

Some diseases will cause one or two bands to cross-react but I'm unaware of any other disease that will cross react with all of the lyme antibody bands (actually, very few people WITH lyme will even cross-react will all of the bands anyway). It becomes a game of statistics to determine how likely it is or isn't that we have lyme.

I do know of 2 people who tested IgM positive for lyme and ultimately had Brucella. Brucella can have a chronic presentation and can mimic many symptoms of lyme....just something else to think about excluding.

Ultimately, determining whether you have lyme or not is not easy without a classic positive test result. We need the clinical experience of our LLMDs, a thorough differential diagnosis to be sure we've excluded everything else and ultimately time to see if treatment is helping.

Pardon my rambling...unfortunately, I don't believe there is a concrete answer to your question.
Posted by feelfit (Member # 12770) on :
Check out Dr. C's Western Blot explanation at the top of this page.

He sees more IgM positives and believes it is bacause the infection is chronic and ongoing.

Posted by Deb133 (Member # 18544) on :
This is just so confusing and frustrating. My

daughter has been sick for 7 weeks with lyme type

symptoms. Her WB only showed IGG 58 Postive and

IGM 39 Positive. So if I am understanding this

correctly even with a band very specific to lyme

(Band 39) could show up positive and not having

anything to do with Lyme? Something else could

be causing this? AGGGGGG! I hate this! Because

I don't know whats wrong with her and nobody in our medical community is doing much.

Will see LLMD on Thursday...but its very scary...

if not Lyme then what?????

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