Monoclonal gammopathies of renal significance: interdisciplinary management of a multiorgan disease. Highlights from Session on Monoclonal gammopathies of renal significance at the 56th SIBioC Congress, 2024

The term monoclonal gammopathy of renal significance (MGRS) encompasses any kidney impairment and injury due to the production of a monoclonal immunoglobulin by a non-malignant B-cell clone. Despite the benign origin of the hematological disorder, the spectrum of MGRS is associated with high morbidity related to the deposition of a nephrotoxic monoclonal immunoglobulin in the kidneys, with distinct localization and pattern of ultrastructural organization. At the 56th SIBioC Congress (Bologna, October 2024), a group of experts elucidated and debated recent acquisitions in the clinical and laboratory management of patients with MGRS. The session provided specific indications on the MGRS classification, pathological alterations, clinical approach, laboratory investigation, therapeutic protocols, and emerging technologies for improving the course of the disease and patient outcome. The first key point in the discussion was to clarify that MGRS can neither be treated with immunosuppressive protocols commonly used for autoimmune-mediated kidney diseases nor with kidney transplantation; the primary therapeutic treatment should eliminate the monoclonal protein. The second key point was to establish the laboratory test panel for the diagnosis and monitoring of MGRS. The closer the multidisciplinary coordination, the more effective the laboratory test panel. Finally, the development of novel molecular methods for the fully characterization of monoclonal immunoglobulin sequences allows the accurate detection of clonal sequences even at very low tumor burdens, providing new insights into post-translational modifications, such as N-glycosylation, which has been recently implicated in the progression of the disease, particularly in AL amyloidosis.