Igs can be elevated to compensate for other, lowered Igs. You seemed to be referring to that in your post,
@justy , but the relationship isn't only IgG(low):IgM(high)... that is just the most commonly found combo.
For example, my IgG subclasses are borderline low, but it's my IgA that's clinically low every time. Supposedly, IgM should be elevated in response. My IgM is dead-center normal. Instead, it's my IgE that's through the roof, which may be to compensate.
This could be due to infection alone, but in context it seems to be directly proportional to my IgA.
I've read about this a bit recently, so I can say with relative confidence that any elevated Ig can be in response to any lowered Ig.
Therefore, it could be that what you have is IgA(low):IgM(high). Maybe. Have you gotten your IgA checked?
Oh, and let's not forget that you and I have a LOT of the same symptoms and a LOT of the same bloodwork values. If you haven't had it checked to see, it is definitely worth doing!
Also, low IgA is helped by IgG replacement therapy, since IgG infusions contain small amounts of IgA as well.
-J