Treatment of ANCA-Associated Glomerulonephritis in a Patient with Bacteremia and Vertebral Osteomyelitis: A Challenging Clinical Dilemma

Introduction: ANCA-associated vasculitis (AAV) involves an autoimmune response that produces antibodies targeting neutrophil antigens, leading to necrotizing and crescentic glomerulonephritis. While modern immunosuppressive therapies have improved outcomes, infections remain a significant risk. Older age and high disease activity at diagnosis are critical prognostic factors. This case highlights the challenge of balancing immunosuppression with infection management. Case Description: A 77-year-old man with a history of anti-glomerular basement membrane disease leading to chronic kidney disease (CKD) stage 3a was admitted for a burn injury, which worsened his kidney function. He was readmitted with acute kidney injury (AKI) and diagnosed with microscopic polyangiitis and crescentic glomerulonephritis with IgA deposits. Despite treatment with Rituximab and high-dose corticosteroids, he developed Enterobacter Cloacae bacteremia and vertebral osteomyelitis. His condition further complicated with disseminated Herpes Zoster infection and progression to end-stage kidney disease (ESKD), requiring dialysis. He ultimately succumbed to refractory septic shock three months after diagnosis. Discussion: The treatment of ANCA-associated small vessel vasculitis and glomerulonephritis primarily involves high-dose corticosteroids and cyclophosphamide. However, balancing immunosuppression with infection risk is challenging, especially in elderly patients. Despite remission in the majority of patients, relapse is common, particularly in those with anti-PR3 positivity. This case underscores the need for accurate prognostic tools and strategies to mitigate infection risks while managing AAV. Lower dose steroid regimens and new agents like Avacopan may offer safer alternatives without compromising efficacy. Labs - 7/30/2023 7/29/2023 6/12/2023 Na 134 135 138 K 4.2 4.4 4.3 Cl 100 99 105 CO2 22 22 24 Anion Gap 12 14 9 BUN 54 56 36 Creatinine 6.15 5.91 1.62 eGFR 9 9 44 Calcium 8.4 8.1 8.5 Phosphorus 4.9 4.5