Let me clarify all that! There are two issues I brought up.
1. When people with normal amounts of acetylcholine, in other words those without MG, took Mestinon, they did have some destruction at the NMJ. But the Gulf War situation is far more complex than that. They had exposure to pesticides which made the situation worse (because they do the same thing Mestinon does but in a more severe way and they destroy the NMJ).
http://www.gulflink.osd.mil/library/randrep/pb_paper/
2. There simply are not enough studies on how Mestinon affects the humoral immune system (which produces antibodies). Here are the only ones I know of, only one specifically addresses the suppression of the immune system by Mestinon.
http://www.ncbi.nlm.nih.gov/pubmed/1...m&ordinalpos=3
http://www.ncbi.nlm.nih.gov/pubmed/7...m&ordinalpos=4
http://www.ncbi.nlm.nih.gov/pubmed/1...m&ordinalpos=2
The government has done extensive studies on Mestinon, probably more than mainstream medical professionals, due to how they use it and why. It was not Mestinon alone but a combination of factors that they believe caused Gulf War Syndrome, so don't read more into it than there is! It's a complicated issue, again, involving pesticides, Sarin gas, etc.
I hope this answers your questions. Mestinon works, that's the good part.
Annie