Amyloidosis can be tested with a fat pad biopsy. They take a small bit of abdominal fat for testing. Mine was negative. I'm 71 and have MGUS, but asymptomatic with 378 kappa and 32 kappa/lambda. High creatinine (a marker for eGFR, kidney disease) showed up on a 1/24 test and because kidney amyloidosis is a risk when someone has MGUS, I also had a kidney biopsy and it showed no amyloidosis, IgA nephropathy, or MGRS (also risks), but did show scarring from Acute Kidney Injury (AKI). Turns out, it was from norovirus on 12/23. Go to the ER if you have projectile vomiting/diarrhea and high fever; by the time Urgent Care got around to me that day, the damage was done. Other than that, I have no risk factors for kidney disease. Oh well.