Abstract: SA-PO0804
Kappa Amyloidosis Without Nephrotic-Range Proteinuria
Session Information
- Glomerular Diseases: Lupus Nephritis, Monoclonal Gammopathy-Related Disease, and Transplantation
October 24, 2026 | Location: Exhibit Hall A, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Glomerular Diseases
- 1402 Glomerular Diseases: Clinical, Outcomes, and Therapeutics
Authors
- Wissa, Amir, Riverside University Health System Medical Center, Moreno Valley, California, United States
- Heilbronn, Jackson, Riverside University Health System Medical Center, Moreno Valley, California, United States
- Asef, Mark, Riverside University Health System Medical Center, Moreno Valley, California, United States
Introduction
AL amyloidosis is a disease of hyperproliferation of clonal plasma cells that then deposit proteins in various organs such as the heart, kidneys and other tissues. As amyloid disease can affect a wide range of organs, different subtypes of the predominant deposited proteins can change the severity to which an organ is targeted.(1) As the disease progresses, it often presents as a nephrotic syndrome in 60-70% of AL amyloid kidney disease.(2) However, the presence of proteinuria is often dictated by the predominant deposited protein.(1) Most commonly, lambda predominant AL amyloidosis, affects the kidneys and causes profound proteinuria in comparison to kappa predominant disease which often presents with non-nephrotic range proteinuria.(1)
Case Description
A 54 year old female was referred to the hospital by her Nephrologist for rapidly progressing CKD, fatigue and lower extremity edema. Upon admission, her creatinine was 2.66; Elevated from 1.6 the month prior. Spot urine protein excretion was estimated at 1.1g daily. Serum light chain testing demonstrated a free kappa light chain concentration of 1185.4 mg/L and free lambda light chain concentration of 30.8 mg/L with a ratio of 38.49. Serum and urine protein electrophoresis did not show monoclonal proteins. A bone marrow biopsy showed 12% plasma cells consistent with plasma cell malignancy. A kidney biopsy revealed abnormal deposition of Kappa light chains primarily involving the glomerular mesangial cells with only very early interstitial and vascular involvement. The report also noted acute tubular necrosis without evidence of cast nephropathy. Her hospitalization was further complicated by lower gastrointestinal bleeding with a colonoscopy demonstrating diffuse, friable colonic mucosa. In addition she experienced signs of volume overload with transthoracic echocardiogram revealing severely increased wall thickness and restrictive physiology consistent with infiltrative cardiomyopathy. Both of these findings are consistent with systemic amyloidosis.
Discussion
Amyloidosis has a heterogeneous presentation as the light chain subtype predicts affinity for specific organs and the ways in which they are affected.(1) It is important to consider expanded serologic testing even in cases of mild proteinuria as there can be relative sparing of the glomerulus despite severe manifestations in other organs in kappa predominant disease.
Acknowledgment
1. Said SM, Sethi S, Valeri AM, et al. Renal amyloidosis: origin and clinicopathologic correlations of 474 recent cases. Clinical Journal of the American Society of Nephrology. 2013;8(9):1515-1523. doi:10.2215/CJN.10491012.
2. Vaishali Sanchorawala. Systemic Light Chain Amyloidosis. New England journal of medicine/The New England journal of medicine. 2024;390(24):2295-2307. doi:https://doi.org/10.1056/nejmra2304088