Hi, Lesmom96. Welcome.
Did your doctor do the MuSK Antibody test? Did you get copies of the test that was done?
If you are concerned about the high WBC, you should see your internist. They can do more testing and try to figure out the cause. It's not something that would directly be related to MG. MG is all about fatigable muscle weakness that gets worse with sustained or repetitive activity and relatively better with rest.
Since some MG patients can have a thymoma, a tumor of the thymus gland, neurologists usually order a chest CT to check for that. It's "possible" that if you had one, you MIGHT have an elevated WBC. But, again, it could be completely unrelated!
Only a doctor can tell you what's going on.
I had to giggle when you talked about Mestinon having a placebo effect. For those of us who've had MG a long time, it's very obvious that Mestinon has a very REAL effect.
Good luck in figuring out the WBC. There's a lot to learn about MG. I hope you'll ask as many questions as you need to.
Annie