Abstract: SA-PO241
A Case of Combined Light Chain Deposition Disease and Light Chain Cast Nephropathy
Session Information
- Onconephrology: Immunological Cross-Talk
November 04, 2023 | Location: Exhibit Hall, Pennsylvania Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Onconephrology
- 1700 Onconephrology
Authors
- Pemmaraju, Durga, ECU Health, Greenville, North Carolina, United States
- Myers, Iskra, ECU Health, Greenville, North Carolina, United States
Introduction
Light chain cast nephropathy (LCCN) is the most common renal disease caused by multiple myeloma (MM). Light chain deposition disease (LCDD) is characterized by the tissue deposition of non-amyloid immunoglobulin (Ig) light chains. Cases of LCCN with coexistent LCDD remain sporadically documented in literature with reported incidence of 10-50%. Diligent histopathologic analysis is required for correct diagnosis. We report a case of acute renal failure in a patient with MM caused by combined LCCN and LCDD.
Case Description
57-year-old male presented with several weeks duration of bilateral ribs pain requiring multiple doses of ibuprofen. Physical exam was rather unremarkable. Initial blood work indicated creatinine 13.95 mg/dL, potassium 7.5 mg/dL, calcium 14.8 mg/dL, and hemoglobin 9.1 g/dL. The skeletal survey revealed diffuse lytic lesions. Retroperitoneal ultrasound showed bilateral kidneys ~15 cm in size. Serum protein electrophoresis revealed restricted peak in the gamma region, κ- to lambda (λ)-FLC ratio 7501.38. The patient required urgent dialysis followed by 5 treatments with plasmapheresis. Once bone marrow biopsy confirmed myeloma, chemotherapy with Cytoxan-Bortezimib-Dexamethasone regimen was initiated. Renal biopsy showed tubules with hard casts, diffuse linear glomerular and tubular basement membranes all staining for k-LC on IF. Electron dense deposits were not observed on EM. Patient remained dialysis dependent however, passed away 18 months later.
Discussion
Diagnosis of combined LCCN-LCDD is challenging and can be easily missed without meticulous analysis of LM, IF, and EM. Zand’s group at Mayo Clinic, in largest study to date, reported that < 50% of the patients with LCCN-LCDD had evidence of electron dense deposits on EM but had evidence of LCDD by IF. Worse renal and overall survival outcomes are observed in LCCN-LCDD patients compared to those with LCCN or LCDD alone with mortality rate of >50% within the first year of diagnosis. Therefore, early detection and treatment is crucial for renal function stabilization and further studies are needed to establish an optimal mode of therapy.