Abstract: PO1516
Chicken or the Egg Causality Dilemma: Primary ANCA Vasculitis Complicated by Infective Endocarditis (IE) vs. IE Leading to ANCA Vasculitis
Session Information
- Glomerular Diseases: The Excitement of Clinical Cases
November 04, 2021 | Location: On-Demand, Virtual Only
Abstract Time: 10:00 AM - 12:00 PM
Category: Glomerular Diseases
- 1202 Glomerular Diseases: Immunology and Inflammation
Authors
- Catanese, Benjamin P., Stanford Health Care, Stanford, California, United States
- Anwaar, Ayesha, Stanford Health Care, Stanford, California, United States
- Anand, Shuchi, Stanford Health Care, Stanford, California, United States
Introduction
As the cases of infective endocarditis increase in the Unites States it is important to recognize the associated complications. Glomerulonephritis is a well-recognized but not fully understood consequence. Immune complex deposition is the most common etiology but ANCA-mediated kidney injury is increasingly described and even less understood.
Case Description
A 65 year old male presented with acute onset dysarthria, left facial droop, left sided weakness, and dizziness. 5 months prior he was diagnosed with PR3+ ANCA vasculitis after presenting with 18 lbs weight loss, purpura, anemia, hematuria and sub nephrotic proteinuria. He was treated with methotrexate and a steroid taper, which finished one week prior to the current presentation. Admission vitals were: 145/74 mmHg, heart rate of 90 bpm, afebrile, and 100% oxygen saturation on room air. Lab work revealed: hemoglobin of 10.7 K/uL, creatinine of 1.17 mg/dl (baseline 0.9), low C3: 81 mg/dL, positive PR3 (>8.0), positive c-ANCA (1:128), negative MPO and p-ANCA, and UA: 3+ blood, negative protein, and 11-20 WBC. MRIs of the brain and heart revealed numerous acute and subacute infarcts and severe mitral regurgitation respectively, concerning for small vessel vasculitis, and he was started on high dose steroids. Discovery of streptococcus mutans bacteremia was a surprise. Suspicion was raised that the ANCA vasculitis may have been a consequence of underlying sub-acute endocarditis rather than a primary disease hence a kidney biopsy was planned and he was discharged on steroids and IV antibiotics. Kidney biopsy confirmed the diagnosis of ANCA-mediated endocarditis-associated glomerulonephritis with the presence of glomerulosclerosis with fibrocellular/fibrous crescents, segmental fibrinoid necrosis but no obvious immune deposits on light microscopy. Granular deposits in the mesangial and capillary wall stained for C3, IgM, IgA, kappa and lambda. He underwent 6 weeks of ceftriaxone and mitral valve replacement. His renal function is mildly impaired; he is recovering neurologically.
Discussion
Endocarditis-associated GN typically requires treatment of the underlying infection without immunosuppression, but when the injury is primarily ANCA-mediated, this presents a unique challenge in that end-organ damage from vasculitis may not improve without immunosuppression.