1.
Intern Med
; 63(5): 693-698, 2024 Mar 01.
Article
En
| MEDLINE
| ID: mdl-37438138
A 70-year-old woman with acute kidney injury, a high serum Creatinine (Cr) level (3.91 mg/dL), and proteinuria (protein/Cr ratio 1.59 g/gCr) was admitted. Serum IgG λ-type and urinary λ-type M proteins were observed. A bone marrow examination indicated monoclonal gammopathy of undetermined significance (MGUS). A renal biopsy showed distended proximal tubular cells, and immunofluorescence identified tissue positive for proximal tubular cell λ light chains. Electron microscopy identified fibril-like structures in the lysosomes. The patient was diagnosed with light chain proximal tubulopathy without crystals in IgG λ-type MGUS and treated with bortezomib and dexamethasone therapy, which improved her renal function.
Kidney Diseases , Monoclonal Gammopathy of Undetermined Significance , Paraproteinemias , Female , Humans , Aged , Bortezomib/therapeutic use , Monoclonal Gammopathy of Undetermined Significance/drug therapy , Monoclonal Gammopathy of Undetermined Significance/diagnosis , Paraproteinemias/complications , Paraproteinemias/drug therapy , Dexamethasone/therapeutic use , Immunoglobulin G