Abstract: SA-PO198
Renal IgG Heavy Chain (AH) Amyloidosis as Monoclonal Gammopathy of Renal Significance: From Accurate Diagnosis to Adequate Treatment
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
- Pascoal, Felipe, Universidade de Sao Paulo, Sao Paulo, São Paulo, Brazil
- Machado, Enéias Silva, Universidade de Sao Paulo, Sao Paulo, São Paulo, Brazil
- Vieira, Ana Teresa Pereira, Universidade de Sao Paulo, Sao Paulo, São Paulo, Brazil
- Cavalcante, Livia Barreira, Universidade de Sao Paulo, Sao Paulo, São Paulo, Brazil
- Jorge, Lectícia, Universidade de Sao Paulo, Sao Paulo, São Paulo, Brazil
- Noronha, Irene L., Universidade de Sao Paulo, Sao Paulo, São Paulo, Brazil
- Yu, Luis, Universidade de Sao Paulo, Sao Paulo, São Paulo, Brazil
Group or Team Name
- Division of Nephrology, University of São Paulo.
Introduction
Monoclonal Gammopathy of Renal Significance (MGRS) is a B or plasma-cell clonal disorder that does not meet the criteria for cancer but produces a monoclonal immunoglobulin that leads to kidney injury. It can rarely manifest as AH amyloidosis, in which highly ordered heavy-chain fibrils deposit in the kidneys. We report a case in which a patient with MGRS was diagnosed and treated for renal AH Amyloidosis.
Case Description
A 77-year-old patient was referred to our Nephrology Clinic due to chronic kidney disease (1.4mg/dL baseline creatinine), proteinuria (2.2g/24h), monoclonal gamma spike (0.75g/dL), hypertension and feet paresthesia. Bone marrow biopsy showed 6% plasmocyte clonal proliferation. Eletrocardiogram, echocardiogram, myocardial scintigraphy and bedside kidney ultrasound were unremarkable. Further workup showed 8.7g/dL hemoglobin, 1.28mmol/L ionized calcium, rare eritrocytes and 2+ protein on urinalysis, 6.3 Kappa-to-Lambda ratio and 1058 mg/dL IgG. Renal biopsy was performed for suspected MGRS with glomerular involvement (images attached). AH Amyloidosis was diagnosed and CyBorD chemotherapy started. After 4 sessions, creatinine and blood urea nitrogen levels improved from 2.2mg/dL and 60.2mg/dL to 1.58mg/dL and 30mg/dL respectively. Proteinuria reached 0.86g/24h.
Discussion
This is a case of rare renal AH Amyloidosis diagnosed in a patient with hypertension, subnephrotic proteinuria and isolated kidney injury, which differs from the typical hypotension, nephrotic-range pronteinuria and multi-organ involvement seen in AL Amyloidosis. Since elevated serum free light-chain levels might be seen on both conditions, renal biopsy is vital for precise diagnosis and fibril deposit distinction. As new therapies are surging for MGRS and Amyloidosis, there is a need for prompt suspicion and accurate diagnosis, which can improve renal outcomes, mitigate disease burden and prevent overt malignancy such as multiple myeloma.
Kidney Biopsy