What does having a high serum IgA mean?

Usaully gut! Inflammation of the GI tract, usually subclinical, is present in all the seronegative arthopathies and IgA is frequently elevated. It is mostly made from lymph tissue ligning the small intestine, called peyer's patches. It is also elevated in regional enteritis and crohn's of the small intestine. In an older person, multiple myeloma must be excluded.