Wayne,
Sorry you're going through something similar too. I don't know if AS contributes to it or not. I just read an interesting article:
"Iodinated contrast media (ICM), a substance commonly used in imaging procedures such as CT scans and cardiac catheterization, may affect patients' thyroid function, according to a new study in the Jan. 23 issue of the Archives of Internal Medicine."
I don't know about you, but I've had several high contrast CT scans since being diagnosed, not to mention all the radiation to my neck via all the chest X-rays I've had too. Probably doesn't help matters.
Good luck to both of us. Keep me posted on how you're doing.
Kelly