January 10, 2023

Monoclonal Gammopathy of Undetermined Significance – 12/27/2022

Annals of Internal Medicine- In the Clinic


This is complicated and important, and I suggest either reading the article or saving it so it can be available to you at a later point in time.  MGUS is due to either an abnormal intact monoclonal immunoglobulin, or a light chain fragment in the urine or blood. It occurs in more than 3% of patients age 50 or older, and it’s more common in men, and in black patients. MGUS is asymptomatic. There seems to be a predisposition genetically towards development of MGUS.  There are a number of unexplained lab findings that should prompt evaluation for MGUS which include elevated sed rate, elevated total protein level, anemia, renal insufficiency, and hypercalcemia. Testing should include serum protein electrophoresis (SPEP), serum immunofixation electrophoresis, and serum free light chain assay- these 3 tests help to identify more than 97% of patients who have MGUS or a clonal plasma cell disorder.