TITLE:
A Mystery Intensive Care Admission with Renal Failure: A Rare Case of Monoclonal Gammopathy of Renal Significance
AUTHORS:
Pritha Mohanta, Gurpreet Chawla, Palak Grover, Gurleen Kaur, Bipneet Singh
KEYWORDS:
Renal Failure, Kidney Injury
JOURNAL NAME:
Journal of Biosciences and Medicines,
Vol.14 No.9,
September
28,
2026
ABSTRACT: This report presents the case of a 54-year-old woman admitted to the intensive care unit with severe acute kidney injury of an initially undetermined source, complicated by hypotension and lactic acidosis requiring continuous renal replacement therapy. An unexplained protein gap and markedly elevated serum free kappa light chains prompted a paraprotein workup and kidney biopsy, which demonstrated proliferative glomerulonephritis with monoclonal immunoglobulin deposits (PGNMID) with IgG3-kappa restriction. Because the bone marrow contained only a small (approximately 5%) kappa-restricted plasma cell clone that did not meet criteria for multiple myeloma, and the glomerular deposits matched the circulating clone, the patient was diagnosed with monoclonal gammopathy of renal significance (MGRS). Competing causes of shock-associated renal failure, light chain cast nephropathy, ischemic acute tubular necrosis, sepsis, nephrotoxin exposure, and obstruction, were systematically excluded. The patient was treated with a bortezomib-based clone-directed regimen. This case highlights the protein gap as a diagnostic clue, the indispensability of kidney biopsy in linking a monoclonal protein to renal injury, the reconciliation of an MGRS diagnosis with a low-burden clone, and the role of clone-directed therapy in preserving kidney function.