title: Monoclonal gammopathy of renal significance: when MGUS is no longer undetermined or insignificant.
abstract: Multiple myeloma is the most frequent monoclonal gammopathy to involve the kidney; however, a growing number of kidney diseases associated with other monoclonal gammopathies are being recognized. Although many histopathologic patterns exist, they are all distinguished by the monoclonal immunoglobulin (or component) deposits. The hematologic disorder in these patients is more consistent with monoclonal gammopathy of undetermined significance (MGUS) than with multiple myeloma. Unfortunately, due to the limitations of the current diagnostic schema, they are frequently diagnosed as MGUS. Because treatment is not recommended for MGUS, appropriate therapy is commonly withheld. In addition to end-stage renal disease, the persistence of the monoclonal gammopathy is associated with high rates of recurrence after kidney transplantation. Preservation and restoration of kidney function are possible with successful treatment targeting the responsible clone. Achievement of hematologic complete response has been shown to prevent recurrence after kidney transplantation. There is a need for a term that properly conveys the pathologic nature of these diseases. We think the term monoclonal gammopathy of renal significance is most helpful to indicate a causal relationship between the monoclonal gammopathy and the renal damage and because the significance of the monoclonal gammopathy is no longer undetermined.
authors.affiliation: Division of Nephrology and Hypertension, Mayo Clinic, Rochester, MN, USA. leung.nelson@mayo.edu
authors.forename: Nelson
authors.initials: N
authors.lastname: Leung
authors.forename: Frank
authors.initials: F
authors.lastname: Bridoux
authors.forename: Colin A
authors.initials: CA
authors.lastname: Hutchison
authors.forename: Samih H
authors.initials: SH
authors.lastname: Nasr
authors.forename: Paul
authors.initials: P
authors.lastname: Cockwell
authors.forename: Jean-Paul
authors.initials: JP
authors.lastname: Fermand
authors.forename: Angela
authors.initials: A
authors.lastname: Dispenzieri
authors.forename: Kevin W
authors.initials: KW
authors.lastname: Song
authors.forename: Robert A
authors.initials: RA
authors.lastname: Kyle
mesh_terms: D018906:Antineoplastic Agents, Alkylating / Q000009:adverse effects / Q000627:therapeutic use; D018450:Disease Progression; D006801:Humans; D007674:Kidney Diseases / Q000209:etiology* / Q000473:pathology; D007676:Kidney Failure, Chronic / Q000209:etiology / Q000517:prevention & control; D016030:Kidney Transplantation / Q000706:statistics & numerical data; D008998:Monoclonal Gammopathy of Undetermined Significance / Q000473:pathology* / Q000628:therapy*; D010265:Paraproteinemias / Q000150:complications* / Q000175:diagnosis / Q000473:pathology / Q000628:therapy
chemical_list: D018906:Antineoplastic Agents, Alkylating