This site is intended for healthcare professionals

Go to /sign-in page

You can view 5 more pages before signing in

Monoclonal gammopathy of undetermined significance (MGUS)

Last reviewed dd mmm yyyy. Last edited dd mmm yyyy

Authoring team

MGUS patients have M proteins (IgG kappa or lambda; or IgA kappa or lambda) in the serum but without features of multiple myeloma, macroglobulinemia, amyloidosis, or lymphoma (1).

  • they have fewer than 10% of plasma cells in the bone marrow
  • patients are asymptomatic and should avoid treating them (1)

In smouldering myeloma, patients have similar characteristics but may have more than 10% of marrow plasma cells (1)

MGSU can be seen in 2% of people older than 50 years (2) and around 1% to 2% of MGUS patients per year will progress to myeloma (most commonly), amyloidosis, lymphoma, or chronic lymphocytic leukemia.

  • they must be followed carefully because patients who develop these diseases require treatment
  • almost all patients with multiple myeloma are preceded by a gradually rising level of MGUS
  • the following risk factors suggest disease progression
    • an abnormal serum-free light chain ratio
    • non-IgG class MGUS.
    • a high serum M protein level (≥15 g/L) (1)

The following criteria are used for the diagnosis of MGUS (all three are required):

  • serum monoclonal protein low *
  • monoclonal bone marrow plasma cells of 10%
  • no evidence of end-organ damage attributable to the clonal plasma cell disorder:
    • normal serum calcium, haemoglobin level and serum creatinine
    • no bone lesions on full skeletal X-ray survey and/or other imaging if performed
    • no clinical or laboratory features of amyloidosis or light chain deposition disease (1)

* low is defined as serum M protein of 3.0 g per 100 ml (3).

Reference:


Create an account to add page annotations

Add information to this page that would be handy to have on hand during a consultation, such as a web address or phone number. This information will always be displayed when you visit this page

The content herein is provided for informational purposes and does not replace the need to apply professional clinical judgement when diagnosing or treating any medical condition. A licensed medical practitioner should be consulted for diagnosis and treatment of any and all medical conditions.

Connect

Copyright 2024 Oxbridge Solutions Limited, a subsidiary of OmniaMed Communications Limited. All rights reserved. Any distribution or duplication of the information contained herein is strictly prohibited. Oxbridge Solutions receives funding from advertising but maintains editorial independence.