Abstract: SA-PO209
Abnormal Kidney Function in a Patient with Peri-Vascular AL Amyloidosis
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
- Ismail, Abdalla, The Ohio State University Wexner Medical Center, Columbus, Ohio, United States
- Brodsky, Sergey V., The Ohio State University Wexner Medical Center, Columbus, Ohio, United States
- Yau, Amy, The Ohio State University Wexner Medical Center, Columbus, Ohio, United States
Introduction
Classic presentation of renal involvement of amyloidosis includes nephrotic syndrome due to amyloid fibril deposition in the glomerulus giving a “cauliflower” nodular appearance on light microscopy. Rarely amyloid deposits can be seen in a peri-vascular pattern and present with elevated creatinine and non-nephrotic range proteinuria. Patients with vascular limited amyloidosis are well described in AA amyloidosis but information about this pattern in AL amyloidosis is limited.
Case Description
We present a 71 year old white male with hypertension and IgG Kappa monoclonal gammopathy of undetermined significance present for screening colonoscopy. During the colonoscopy, a tubular adenoma was biopsied with findings consistent with AL kappa amyloidosis. On follow up evaluation, his creatinine rose from a baseline of 0.9 mg/dL to 3.5 mg/dL. Upon chart review, 6 months prior his creatinine was already increased at 1.6 mg/dL. His work up was significant for a random urine microalbumin to creatinine ratio of 59 mg/g and urine protein to creatinine ratio of 742 mg/g. Serum kappa was 237 mg/l, serum Lambda 11.5 mg/l and Kappa/Lambda ration 20.6. Serum immunofixation Showed IgG Kappa monoclonal protein 673 mg/dl. Urine immunofixation showed monoclonal free Kappa light chains 73 mg/24hrs. Because of the degree of renal failure in the setting of non-nephrotic proteinuria and AL amyloidosis, he underwent renal biopsy.
Renal biopsy confirmed AL kappa amyloid deposition in the vascular wall with little to no deposition in the glomeruli with 60% of cortex showing interstitial fibrosis and tubular atrophy.
Discussion
Immunoglobulin light chain amyloidosis can be deposited in diffuse pattern or vascular limited pattern. Our patient demonstrates a rare case of AL amyloidosis in a vascular limited pattern. He also had evidence of vascular involvement outside of the kidney as well. Further studies are needed to recognize this pattern of amyloid deposition.
Renal biopsy under Light microscopy shows amorphous hypoeosinophilic deposits in the vascular walls(a), which is positive by Congo red stain and shows bright apple-green birefringence under the polarized light (b).