Mine changed. I had two positives at Mayo in 1/09, 1 negative at ARUP labs in 11/09 and another negative at an unknown lab in 3/10. I have something strange going on though because my symptom pattern is like that of a Musk patient though I test positive for the AchR binding antibodies (and the titer on that was low). Notice also that my pattern was backwards: my first tests were positive and subsequent ones were negative. Thanks to the good advice of this board I didn't take mestinon or anything else that could affect the tests.

Just my opinion: I think they say they know a lot about this disease and I think they actually know very little. And I think there are a lot of people out there who have the disease but don't fit a typical pattern and so don't get treated.

Also, I've had two negative and one positive single fiber emg. That test, though, I really believe is completely dependent on the experience and skill of the neuro who is doing the test. The first neuro was well meaning but inexperienced, the second neuro was a moron, the third was a brilliant guy who had been doing the test for decades.

A.