Hi Julie,
Welcome to the forum.
An elevated IgM level can be associated with a variety of different disorders. See
this article for potential causes:
"1. Increased serum immunoglobulin concentrations occur due to polyclonal or oligoclonal immunoglobulin proliferation in hepatic disease (hepatitis, liver cirrhosis), connective tissue diseases, acute and chronic infections, as well as in the cord blood of neonates with intrauterine and perinatal infections.
2. Elevation of immunoglobulin M may occur in monoclonal gammopathies such as macroglobulinemia, primary systemic amyloidosis, monoclonal gammopathy of undetermined significance, and related disorders."If subsequent tests bear out the presence of monoclonal IgM, then some of the disorders in #2 may apply and then the article below would be relevant.
J Mikhael, "Ask the Hematologist: A Diagnostic Approach to Patients with an IgM monoclonal protein", The Hematologist, Sep 15, 2014 (full text of article)I'm not a doc, but I think you need to first eliminate the potential non-monoclonal IgM causes (those listed in #1 above) since your electrophoresis test registered no monoclonal protein (even though your IgM level is pretty high) and your immunofixation test only detected a "faint band" ... and you have some other issues going on with your kidneys, liver, etc.
There a lot of Canadians on this forum and they can suggest places to seek out top hematologists, including those that are expert in multiple myeloma and related disorders. You might want to let folks know what part of Canada you live in. Hope this helps.