Kidney Transplantation and Monoclonal Gammopathy of Undetermined Significance

Plasma cell disorders are one of the most common hematologic malignancies. Monoclonal gammopathy of undetermined significance (MGUS) is defined by a serum monoclonal protein <3 g/dL, bone marrow plasma cell infiltration <10%, and most importantly absence of end-organ damage. The prevalence of MGUS in general population is estimated to be 1%–4% and its frequency increases with age with 3% among people above 50 y of age. The risk of progression to clinically significant plasma cell dyscrasia is estimated to be 1% per year. With aging population and increasing use of transplantation for the management of kidney disease in older adults, MGUS is being identified during the evaluation for kidney transplant candidacy or during the postkidney transplant follow-up. MGUS in patients with end-stage renal disease (ESRD) undergoing evaluation for kidney transplant can pose a complex management dilemma. In this article, we review the current state of knowledge about the prevalence of MGUS in ESRD population and the impact of kidney transplantation on the progression of MGUS to clinically significant plasma cell disorder. We make recommendations for the screening of ESRD patients undergoing kidney transplant evaluation and the management of MGUS after renal transplant.