[Cheryl G]

New study re: MGUS and amyloidosis

by Cheryl G on Tue Feb 19, 2019 11:04 am

A study was published recently that looks at the combination of MGUS and amyloidosis. It focuses on the issue of whether an MGUS diagnosis together with a biopsy showing the presence of amyloidosis automatically means the type of amyloidosis present is AL amyloidosis.

Here is the reference for the study:

Monoclonal Gammopathy Plus Positive Amyloid Biopsy Does Not Always Equal AL Amyloidosis
American Journal of Hematology, Feb 17, 2019
https://onlinelibrary.wiley.com/doi/abs/10.1002/ajh.25440

The full text of the article, which technically is a letter to the editors of the journal, is available at this link:

https://onlinelibrary.wiley.com/doi/epdf/10.1002/ajh.25440

I should add that I find the title of the article misleading. I hope others will look at the article closer to see if my interpretation is correct. However, from my quick read of the article, it seems to focus on a type of amyloidosis known as "wild type transthyretin amyloidosis," or ATTRwt amyloidosis. What the authors show is that many people at their center who were diagnosed with this type of amyloidosis also had MGUS (and, in a few instances, multiple myeloma).

To me, the more important question is the one suggested by the article's title, which is: If you're diagnosed with MGUS and have an amyloid-positive biopsy, how likely is it that you have AL amyloidosis versus ATTRwt amyloidosis?

Clearly from the results that authors discuss, it is possible that MGUS combined with an amyloid-positive biopsy could be ATTRwt amyloidosis. However, how often is that the case? Is it something common?

I'm not sure the article answers that question. Again, though, I hope someone else will check my interpretation of the authors' results.