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Dec 27, 2024, 10:31

Vincent Rajkumar: We need to interpret testing for monoclonal proteins correctly

Vincent Rajkumar, Professor of Medicine at the Mayo Clinic, shared a post on X:

“MGUS: With increased testing and with mass spectrometry to detect monoclonal (M) proteins, we are increasingly finding smaller and smaller monoclonal gammoapthies of near zero significance.

We need to interpret testing for monoclonal proteins correctly:

1) Low risk MGUS (see figure) doesn’t need bone marrow, bone survey, or annual follow up. They don’t need Hematology referral unless there is a clinical concern.

2) An M protein that is not measurable on SPEP but seen only on immunofixation is likely to be of limited significance unless there’s a specific concern for myeloma, amyloid, etc.

3) A new M protein detected on mass spectrometry that is tiny (less than 0.2 gm/dl) unless there is clinical concern for amyloid, is probably of little significance. I’d rather we don’t report these tiny ones in clinical labs.

4) In contrast to above, mass spectrometry is useful in tracking a known M protein to levels below 0.2 gm/dl in patients with myeloma or amyloid where we have a prior M protein signature to track. In this scenario we are using mass spec in a different way, to detect minimal residual disease post therapy.
In this context the ultra sensitive test is useful.”

Vincent Rajkumar: We need to interpret testing for monoclonal proteins correctly

Monoclonal Gammopathy of Undetermined Significance

Authors: Wilson I. Gonsalves, and S. Vincent Rajkumar

Vincent Rajkumar: We need to interpret testing for monoclonal proteins correctly

Vincent Rajkumar is a Professor of Medicine at the Mayo Clinic in Rochester, Minnesota, and Chair for the Mayo Clinic Myeloma, Amyloidosis, and Dysproteinemia Group. He also chairs the Board of directors of The International Myeloma Foundation and the Eastern Cooperative Oncology Group (ECOG) Myeloma Committee.

His extensive contributions include over 230 peer-reviewed publications, predominantly focusing on multiple myeloma and related plasma cell disorders. Furthermore, Dr. Rajkumar is a Section Editor for multiple myeloma and related disorders for Leukemia and an Associate Editor for the Mayo Clinic Proceedings.