IgA is an antibody belongs to immunoglobulin, which is a part of the immune system, so when there is an inflammatory response in the body, it may lead to elevated IgA antibodies. In IgA nephropathy, IgA levels in the blood may be elevated, and at this time there may be abnormalities in the urine such as red blood cells and protein. IgA is polyclonal at this time, and if there is an elevated monoclonal IgA in the blood, it may also indicate that the patient has a proliferation of clonal plasma cells, such as in multiple myeloma. A large number of clonal plasma cells produce too much IgA, at which point the patient needs to have a bone marrow aspiration to clarify the presence of myeloma.