Successful Treatment of Monoclonal Gammopathy of Renal Significance With Bortezomib in the Setting of Post- Viral SARs-CoV-2 Infection: Case Report

Introduction: Monoclonal Gammopathy of Renal Significance (MGRS) is an immunoglobulin proliferative disorder that leads to the destruction of the renal glomerular basement membrane and progression to end-stage renal disease. The pathogenesis of MGRS is similar to that of multiple myeloma and chronic lymphocytic lymphoma but lacks criteria for either disease. This inability to characterize the disease creates a gap in diagnostic and treatment recommendations. Recent studies and observations suggest that the pathogenesis of MGRS correlates with an acute inflammatory reaction as seen in postviral SARS-CoV-2 (COVID-19) patients. Case presentation: Here, we present a 61-year-old male with MGRS following a COVID-19 diagnosis with signs of acute kidney injury (AKI). The diagnosis was one of exclusion following kidney and bone marrow biopsy that showed four percent plasma cells and monoclonal protein IgG lambda light chains which did not meet the criteria for multiple myeloma. Historically the treatment of MGRS has targeted the underlying kidney pathology; however, evidence now supports treatment customization to the nature of the clonal M protein proliferation involved in the pathogenesis of the disease. Conclusion: This case study demonstrates the novel finding of COVID-19-induced MGRS, which was successfully treated with dexamethasone and bortezomib to reduce the progression of kidney injury in MGRS.