Good evening doctors. does immunofixation serum blood test with no monoclonal proteins found rule out multiple kidney myeloma? is there a similar blood or urine test to rule out or rule in renal kidney amyloydosis?

Serum electrophoresis may miss some instances of myeloma, but serum immunofixation& urine immunofixation will usually detect the abnormal kappa or lambda light chains. This will most likely diagnose multiple myeloma with light chain nephropathy or actual systemic amyloidosis with proteinura &kidney involvement, but bone marrow biopsy is the gold standard for diagnosis though.