Abstract: SA-PO223
An Unusual Case of Kidney Infiltration by Heavy Chain Disease with Lamellar Inclusion Bodies
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
- Cojuc, Gabriel, Instituto Nacional de Ciencias Medicas y Nutricion Salvador Zubiran, Ciudad de Mexico, Ciudad de México, Mexico
- Tinajero Sánchez, Denisse Nayely, Instituto Nacional de Ciencias Medicas y Nutricion Salvador Zubiran, Ciudad de Mexico, Ciudad de México, Mexico
- Ramirez-Sandoval, Juan Carlos, Instituto Nacional de Ciencias Medicas y Nutricion Salvador Zubiran, Ciudad de Mexico, Ciudad de México, Mexico
Introduction
Heavy chain diseases (HCDs) are rare B-cell proliferative disorders characterized by the production of a monoclonal protein composed of incomplete immunoglobulin heavy chains. To the best of our knowledge, we report the first case of renal HCD infiltrated by plasmacytic cells exhibiting distinctive lamellar inclusion bodies.
Case Description
A 65-year-old woman with systemic lupus erythematosus in remission with hydroxychloroquine and low-dose prednisone presented with fatigue, weakness, weight loss, and shortness of breath. Examination revealed pallor, hepatosplenomegaly, and inguinal lymphadenopathy. Laboratory tests showed anemia (Hb 5.2 g/dL), elevated creatinine (3.9 mg/dL, baseline 0.6), nephrotic-range proteinuria (6.2 g/day), and increased IgG levels (12,267 mg/dL). Imaging demonstrated bilateral kidney enlargement. Extensive workup for multiple potential etiologies was negative.
Further analysis revealed a spike in the beta-1 region in serum protein electrophoresis and gamma-heavy chain presence in serum and urine immunofixation, with a normal free k/l light chain ratio. Bone marrow aspirate showed 6% plasmatic cells and a B-cell lymphoproliferative process with plasma cell differentiation and gamma heavy chain expression without light chain restriction. A kidney biopsy was performed (Fig 1).
The patient underwent treatment with cyclophosphamide, bortezomib, and dexamethasone, resulting in kidney function improvement.
Discussion
The observed lamellar bodies are residual lysosomes often seen in lysosomal storage diseases, in subjects receiving lysosomotropic drugs, and rarely in plasma cell dyscrasias. In this case, they were located in the cytoplasm of plasma cells rather than in the tubules or podocytes, corresponding to heavy chain deposits.
Kidney involvement is uncommon in HCDs, and its coexistence with lamellar inclusion bodies is even rarer, providing additional insights into this disease.
Kidney Biopsy