Abstract: PUB132
When the Kidneys Speak Loudest: Atypical Presentation of c-ANCA Vasculitis
Session Information
Category: Glomerular Diseases
- 1402 Glomerular Diseases: Clinical, Outcomes, and Therapeutics
Authors
- Karrothu, Vishnu Vardhan, Baton Rouge General Medical Center, Baton Rouge, Louisiana, United States
- Kudithi, Revathi, Baton Rouge General Medical Center, Baton Rouge, Louisiana, United States
- Kumbala, Damodar R., Renal Associates of Baton Rouge LLC, Baton Rouge, Louisiana, United States
Introduction
We present a case of C-ANCA vasculitis presenting as severe Acute Kidney injury, highlighting the importance of early recognition.
Case Description
A 74-year-old male with hypertension initially presented to urologist with hematuria attributed to renal stones and urinary tract infection and was treated with levofloxacin. He then developed a facial rash and was prescribed valacyclovir by his dermatologist, but the culture was later negative for HSV. Two weeks later, he saw his ophthalmologist for eye redness and was found to have a significantly elevated serum creatinine of 6.08 mg/dL (baseline was 1.07 mg/dL one month ago). He reported fatigue, fevers, night sweats, bilateral lower extremity swelling, and a weight loss of 30 pounds over two months. Urinalysis showed 2+ proteinuria, 3+ blood with multiple red blood cells and casts, and a urine protein-to-creatinine ratio of 3.3 g/day. Serology showed negative antinuclear antibody with reflex and nonreactive HCV. Given worsening renal function and active urinary sediment, he was started empirically on intravenous Solumedrol 1 g for three days, suspecting acute glomerulonephritis. The patient underwent renal biopsy; preliminary results were consistent with pauci-immune crescentic glomerulonephritis with minimal fibrosis. Serologic testing showed C-ANCA positivity at a 1:160 titer with elevated PR3. He was transitioned to oral prednisone 60 mg daily and received IV rituximab 1 g, with the next dose in two weeks. Avacopan was considered but deferred due to pharmacy issues. At discharge, significant improvement in renal function was noted with adequate urine output.
Discussion
C-ANCA vasculitis usually affects multiple organs, but renal-predominant presentations remain a diagnostic challenge. This case illustrates a renal-predominant presentation in which early systemic features were subtle, transient, and misattributed to unrelated conditions, resulting in a delayed diagnosis. Diagnosis involves clinical presentation, serologic testing, and histopathological confirmation, with kidney biopsy as the gold standard. Current guidelines recommend induction therapy with glucocorticoids combined with rituximab or cyclophosphamide. Rituximab is increasingly chosen due to similar efficacy and a better safety profile. This case highlights that delayed diagnosis of ANCA vasculitis in some patients can present as severe renal dysfunction, requiring timely diagnosis and management.