I have a question about MG antibody ranges and false positives. I tested positive for the ACHR modulating antibodies (56% with normal range being 0-20%) and positive for the striational muscle antibodies (1:120 with normal being <1:60).

Does anybody know if its possible to get results like that without having MG? The neuro I just saw told me not to worry about these labs. He seemed annoyed that another doc had turned up these labs and said not to give them another thought.

I'm hesitant to ignore the labs, but I don't know much about MG tests and the possibility of false positives. Do these antibodies confirm a diagnosis? Is there anything else that could make these antibodies turn up positive? Does anyone know what a common range is for an MG-er to have on these labs? (aka, am i only "slightly" positive on these?)

Thanks for any thoughts

Mandy

This is my opinion:

Tests can only and should only be used to support a clinical diagnosis.
It sounds that one physician thought your symptoms could fit myasthenia (and sent those labs) and another thought they couldn't. There is no way for me to know which of them is right.
From reading your other post it seems that you don't have a "classical" disease that nicely fits into a known "box".
I think that the right thing for you to do is not bother yourself with those or any other tests, but find a neurologist you feel you can trust, who will eventually figure it out by putting together all the pieces of the puzzle- the clinical picture, the results of various tests, the response to treatment etc. Not one that carves order by leaving the disorderly parts out.

The name of your illness is much less important than finding the proper treatment that will help you regain as much as possible of your normal life.

My illness initially had no name and I was given inadequate treatment.(mostly symptomatic treatment and more aggressive treatment only when I had potentially dangerous symptoms).
It then had a name and I was given even less adequate treatment. (the treatment that "should" work in patients with an illness with that name, but led to deterioration in my case).
Only now does it have a name and I am given proper treatment. (less commonly used treatment that can work in patients with an illness with that name, but is more commonly used for a very different illness, which I clearly do not have).

As a physician, I see in my clinic healthy people with abnormal test results. I also see very ill people with completely normal test results. I tell the former to keep on enjoying their life, and I take care of the latter.

Some patients respond to commonly used treatments and some don't.

If you trust your neurologist, go with what he says, and let him gradually find with you, the best management approach. If you don't trust him, find another one.

Mandy, 56% is not "slightly" positive. If you had that test done at Mayo, they consider anything above 20% to be abnormal. They invented the test, you know. The AChR modulating antibody test is shown as a percentage. A high percentage is seen in many MGers who have a thymoma. Other labs do this "stepping" of the modulating antibodies where a certain percentage is borderline, etc. That is NOT what Mayo does. You can't compare labs and their results.

Good idea not to "ignore" these results. If you see another neurologist, they may want to retest you to make sure they are both not "false positives." I rather doubt that. If they are retested, it's always good to use the same lab.

Alice is right in that you need to have a neurologist you can trust. But you as a patient need to be your own best advocate, in concert WITH the doctor. If you see too many different neuros, they might start to think you are "doctor s/hopping" to get a diagnosis for something you don't have. Which is utterly ridiculous but that's how some doctors think.

You have a lot going on. You need some help, which we can't give you here! So find those good doctors and get taken care of.

Annie

Alice and Annie, thank you both so much for taking the time to reply and for such thoughtful answers to this and my other post.

Alice--thanks for the advice about not carving order just for the sake of order, and leaving disorderly things out of the picture. It's really great advice for me right now because there are so many pieces and even though i try to stay calm about things, there are times when i really stress about not having a diagnosis or treatment. It sounds like you can really relate to that..I'm sorry you had such a rough time yourself. Thanks for sharing your perspective, it really helps.

Annie--thanks for the insight into the antibody tests, that really helps. I actually didn't know that Mayo invented the ACHR test. Very interesting. I will definitely make sure to have the Barrow's neurologist look a little deeper at this.

You are both wonderful, thanks again!

Mandy