Hi Cinusti -
Your story sounds so familiar - as others have said, getting a diagnosis is so difficult. I have had negative and positive AChR antibody tests. There are actually different blood tests that they do - the first one is usually for binding (the antibodies bind to the receptor sites for acetycholine and prevent it from getting to where it needs to go) - there are two other AChR antibodies that they test for - modulating and blocking. You may want to find out if they did the full test or just the binding. There are also other antibodies that they can test for (MuSK antibodies) that some people who test negative for AChR have. Maybe they need to do a few more things before just ruling it out. Don't give up. I have posted a link to an article that may explain the antibody tests more clearly. - Gabe

http://www.nature.com/nm/journal/v7/...m0301_365.html