I do believe I had that tested twice, once for my CIDP diagnosis and a second time for my cancer. But little, if anything was made of it or about it. Mostly they looked at the IGa and IGg and subclasses....
You bringing up this issue is a good kick to my backside to take another look...as I am sure nothing was ever mentioned about the two being connected...except by my specialist surgeon. Go figger. But then she'd worked at NIH? The assurances were that it was highly unlikely and not related {HAH!} We know better about ourselves at times and I, too, have been pooh-poohed about other connections to that pesky thyroid issue as well. You are not alone?
Hang in there, maybe some doc will get a lightbulb moment? One can always hope.
's - j