Diagnostic and Therapeutic Aspects of Monoclonal Gammopathies of Renal Significance (MGRS): An Update
Giuseppe Stefano Netti,
Dario Troise,
Michele Rossini,
Valeria Catalano,
Federica De Luca,
Javeria Khalid,
Valentina Camporeale,
Fabiana Ritrovato,
Barbara Infante,
Francesca Sanguedolce,
Giovanni Stallone,
Elena Ranieri
Affiliations
Giuseppe Stefano Netti
Unit of Clinical Pathology, Department of Medical and Surgical Sciences, University of Foggia, University Hospital “Policlinico Riuniti”, Viale Luigi Pinto, 71122 Foggia, Italy
Dario Troise
Center for Research and Innovation in Medicine (CREATE), Department of Medical and Surgical Sciences, University of Foggia, University Hospital “Policlinico Riuniti”, Viale Luigi Pinto, 71122 Foggia, Italy
Michele Rossini
Unit of Nephrology, Dialysis and Transplantation, Department of Precision and Regenerative Medicine and Ionian Area (DiMePRe-J), University of Bari “Aldo Moro”, Piazza Giulio Cesare 11, 70124 Bari, Italy
Valeria Catalano
Unit of Clinical Pathology, Department of Medical and Surgical Sciences, University of Foggia, University Hospital “Policlinico Riuniti”, Viale Luigi Pinto, 71122 Foggia, Italy
Federica De Luca
Unit of Clinical Pathology, Department of Medical and Surgical Sciences, University of Foggia, University Hospital “Policlinico Riuniti”, Viale Luigi Pinto, 71122 Foggia, Italy
Javeria Khalid
Unit of Clinical Pathology, Department of Medical and Surgical Sciences, University of Foggia, University Hospital “Policlinico Riuniti”, Viale Luigi Pinto, 71122 Foggia, Italy
Valentina Camporeale
Unit of Clinical Pathology, Department of Medical and Surgical Sciences, University of Foggia, University Hospital “Policlinico Riuniti”, Viale Luigi Pinto, 71122 Foggia, Italy
Fabiana Ritrovato
Unit of Clinical Pathology, Department of Medical and Surgical Sciences, University of Foggia, University Hospital “Policlinico Riuniti”, Viale Luigi Pinto, 71122 Foggia, Italy
Barbara Infante
Unit of Nephrology, Dialysis and Transplantation, Advanced Research Center on Kidney Aging (A.R.K.A.), Department of Medical and Surgical Sciences, University of Foggia, University Hospital “Policlinico Riuniti”, Viale Luigi Pinto, 71122 Foggia, Italy
Francesca Sanguedolce
Unit of Pathology, Department of Clinical and Experimental Medicine, University of Foggia, University Hospital “Policlinico Riuniti”, Viale Luigi Pinto, 71122 Foggia, Italy
Giovanni Stallone
Center for Research and Innovation in Medicine (CREATE), Department of Medical and Surgical Sciences, University of Foggia, University Hospital “Policlinico Riuniti”, Viale Luigi Pinto, 71122 Foggia, Italy
Elena Ranieri
Unit of Clinical Pathology, Department of Medical and Surgical Sciences, University of Foggia, University Hospital “Policlinico Riuniti”, Viale Luigi Pinto, 71122 Foggia, Italy
Monoclonal gammopathy of renal significance (MGRS) refers to a group of renal disorders caused by a monoclonal immunoglobulin (MIg), secreted by a non-malignant B-cell clone. Unlike overt multiple myeloma or B-cell proliferation, MGRS does not meet those diagnostic criteria. However, it is associated with significant morbidity, due to severe renal, and sometimes systemic, lesions induced by the MIg. Early recognition is crucial, as chemotherapy to suppress MIg secretion often improves outcomes. The spectrum of renal diseases in MGRS is broad, including both well-known conditions like AL amyloidosis and newly described lesions. Kidney biopsy is essential to determine the specific lesion associated with MGRS and assess its severity. Diagnosis involves integrating morphologic alterations using techniques such as light microscopy, immunofluorescence (IF), electron microscopy, and, in some cases, IF staining for Ig isotypes, immunoelectron microscopy, and proteomic analysis. Additionally, a complete hematologic evaluation, including serum and urine protein electrophoresis, immunofixation, and a serum-free light-chain assay, is necessary.
