@roxanablue, welcome. I'm tagging fellow members @blt054 @modens @pepin31219, who have experience with cryoglobulinemia and may be able to provide more insight for you.

Roxana, you ask about a bone marrow biopsy as a possible treatment. I think you might be referring to a bone marrow or stem cell transplant. (Bone marrow biopsy is a test, not a treatment. See more here: https://www.mayoclinic.org/tests-procedures/bone-marrow-biopsy/about/pac-20393117)

From what I could gather through an internet search bone marrow or stem cell treatment is not the standard treatment option, but is being studied.

Plasmapheresis (plasma exchange) is an option when patients have life-threatening, or organ-threatening cryoglobulinemia. This procedure filters clumps of cryoglobulins from the blood plasma, helping to prevent cryoglobulins from blocking the arteries and restricting blood flow to organs.

Has your team suggest a bone marrow biopsy for further testing?