A Case of Proliferative Glomerulonephritis with Monoclonal IgG Deposits (PGNMID) with Crescent Formation that Responds Favorably to Low-Dosage Daratumumab

Introduction: Proliferative glomerulonephritis with monoclonal immunoglobulin deposits (PGNMID) is a rare renal disease without standardized treatment modalities. Daratumumab is a human IgG monoclonal anti-CD38 antibody that has been demonstrated to be highly effective and safe in treating PGNMID. Case Description: The patient is a middle-aged woman whose first kidney biopsy suggested proliferative glomerulonephritis. Despite receiving treatment with glucocorticoids, glucocorticoids combined with immunosuppressants, and rituximab, her condition continued to progress. Upon a second kidney biopsy, she was diagnosed with proliferative glomerulonephritis associated with monoclonal immunoglobulin deposition (IgG3 κ). The patient received a total dose of 400-800 mg of daratumumab every two weeks. After the first dose of daratumumab, her 24-hour proteinuria decreased from 12g to 4.38g, and serum creatinine levels dropped from 616umol/L to 342.8umol/L. Two months later, she was able to discontinue hemodialysis. After six months of follow-up, the kidney disease achieved complete remission, with no serious adverse reaction. Discussion: In conclusion, this case underlines the potential of low-dose daratumumab as a viable option for PGNMID, even in severe cases presenting as rapidly progressive glomerulonephritis.Fig1. Images from the renal biopsyFig2. Trends in patient urine protein and serum creatinine changes