Abstract: TH-PO270
Morphological Changes in a Nephrectomized End-Stage Kidney 10 Years after Hemodialysis (HD) Initiation for Atypical Hemolytic Uremic Syndrome (aHUS)
Session Information
- Hemodialysis and Frequent Dialysis - 1
October 24, 2024 | Location: Exhibit Hall, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Dialysis
- 801 Dialysis: Hemodialysis and Frequent Dialysis
Authors
- Shah, Kruti, Harbor-UCLA Medical Center, Torrance, California, United States
- Dai, Tiane, Harbor-UCLA Medical Center, Torrance, California, United States
- Nast, Cynthia C., Cedars-Sinai Medical Center, Los Angeles, California, United States
- Adler, Sharon G., Harbor-UCLA Medical Center, Torrance, California, United States
Introduction
A nephrectomy (Nx) for renal cell carcinoma (RCC) in a patient on long-term dialysis receiving C5 inhibitor treatment (C5i) for aHUS afforded the opportunity to morphologically evaluate changes in the end-stage kidney due to end-stage kidney disease (ESKD) milieu, hyperparathyroidism, and treated aHUS.
Case Description
A 23-year-old man presented in 2014 with uremic symptoms and hypertensive emergency (BP 200/120 mmHg). His serum creatinine was 12 mg/dL. He had low complement C3, normal C4, no thrombocytopenia or microangiopathic hemolytic anemia. Renal biopsy showed a large artery with thrombotic microangiopathy (TMA) and immune complex-mediated membranoproliferative Type I pattern of injury. Additional studies showed low Complement Factors B, H (CFH), and I (CFI). Genotyping revealed a novel nonsense mutation in CFI predicted to prematurely truncate the CFI protein and 3 heterozygous polymorphisms in CFH, common in healthy people but enriched in aHUS. Eculizumab was not started because of hematologically silent aHUS and functionally end-stage kidneys. In time, he required parathyroidectomy for tertiary hyperparathyroidism. Subsequently, he presented with right-sided numbness and a cerebrovascular lesion coinciding with the sensory symptom distribution. At this time C5 inhibitor was started for presumptive cerebral TMA, with resolution of aHUS symptoms. After 10 years of dialysis, he developed erythrocytosis, kidney cysts, and renal cell carcinoma (RCC) necessitating nephrectomy (Nx). Nx showed acquired cystic disease, RCC, diffusely calcified glomeruli likely due to tertiary hyperparathyroidism, and chronic TMA with minimal activity, likely reflecting the beneficial effect of long-term complement C5 inhibitor treatment.
Discussion
Nx was done for RCC after 10 years of dialysis and ESKD from aHUS secondary to CFI mutation. This afforded the opportunity to observe the rare finding of diffuse glomerular calcification likely due to tertiary hyperparathyroidism. Additionally, there was chronic and minimally active TMA, likely reflecting long-term complement C5 inhibition.