Abstract: PUB171
IgAN with Positive Amyloidosis Genetic Findings: A Diagnostic Challenge
Session Information
Category: Glomerular Diseases
- 1402 Glomerular Diseases: Clinical, Outcomes, and Therapeutics
Authors
- Rosario González, María del Mar, Department of Medicine, University Hospital Dr. Ramón Ruiz Arnau, Bayamón, Puerto Rico, United States
- Colon Lopez, Stephanie, Private Practice Nephrology, Bayamón, Puerto Rico, United States
- Rodriguez, Eddie M., Department of Medicine, University Hospital Dr. Ramón Ruiz Arnau, Bayamón, Puerto Rico, United States
Introduction
IgA nephropathy is the most common primary glomerulonephritis and commonly affects young adults. It presents with microscopic hematuria, episodic gross hematuria, and variable proteinuria, often following upper respiratory infections. Diagnosis requires renal biopsy demonstrating IgA-dominant mesangial deposits after exclusion of secondary causes. We present a case of biopsy-proven IgA nephropathy in a young patient with positive amyloidosis-associated genetic findings, highlighting the importance of clinicopathologic correlation.
Case Description
A 23-year-old woman with hypertension presented for nephrology evaluation due to microscopic hematuria and proteinuria. She also reported intermittent gross hematuria and recurrent ear infections. Laboratory evaluation demonstrated preserved renal function with persistent hematuria and proteinuria. CT imaging showed no acute renal pathology.
Given concern for glomerular disease, a secondary workup was unrevealing. Genetic testing identified amyloidosis-associated mutations, raising concern for hereditary renal involvement; however, cardiac evaluation showed no evidence of systemic amyloidosis.
Renal biopsy demonstrated IgA nephropathy with Oxford classification M1, S1, E0, C0, T0, associated with moderate glomerulosclerosis (40%) and mild interstitial fibrosis (10%). Electron microscopy revealed mesangial and subendothelial immune-type electron-dense deposits.
Because renal function remained preserved and proteinuria was low-grade (UACR <100 mg/g), conservative management was initiated. Immunosuppressive therapy was deferred given the patient’s low-risk disease profile. Follow-up demonstrated stable renal function and improvement in albuminuria.
Discussion
IgA nephropathy is an important cause of chronic kidney disease in young adults, with prognosis influenced by proteinuria, renal function, blood pressure control, and histopathologic findings. Positive amyloidosis genetic findings complicated the diagnostic evaluation and initially raised concern for hereditary renal disease; however, the absence of systemic manifestations together with renal biopsy findings supported the diagnosis of IgA nephropathy.
Despite moderate glomerulosclerosis, preserved renal function and subnephrotic proteinuria favored conservative therapy over immunosuppressive therapy. This case highlights the importance of clinicopathologic correlation when evaluating suspected glomerular disease.