Published online Sep 25, 2025. doi: 10.5527/wjn.v14.i3.109400
Revised: May 28, 2025
Accepted: July 10, 2025
Published online: September 25, 2025
Processing time: 131 Days and 6 Hours
This case report describes myeloperoxidase-anti-neutrophil cytoplasmic antibody associated vasculitis with kidney involvement in a patient with relapsing polychondritis, which was successfully treated with Avacopan. Although relapsing polychondritis has been associated with anti-neutrophil cytoplasmic antibody-associated vasculitis, overlap can result in severe organ involvement, particularly renal damage progressing to end-stage kidney disease. This case presents a unique opportunity to evaluate the potential role of Avacopan as an alternative therapeutic option in managing myeloperoxidase-anti-neutrophil cytoplasmic antibody-associated vasculitis in the context of relapsing polychondritis highlighting a positive renal response despite treatment challenges.
This is a case of a 69-year-old Caucasian woman who presented to our hospital’s emergency department with a 4 week history of inflammatory polychondritis affecting the auricular cartilage, accompanied by acute kidney injury. On admission, serum creatinine was elevated at 4.0 mg/dL, which progressively increased to 6.07 mg/dL on day 6. The renal biopsy revealed necrotizing and crescentic glomerulonephritis affecting more than 50% of the glomeruli. She was treated with a total of 2500 mg intravenous methylprednisolone over 3 days followed by oral prednisone. Induction treatment included intravenous cyclophosphamide induction, with plans for a total of 2 doses followed by transition to rituximab. However the patient was unable to tolerate rituximab due to allergic reaction so intravenous cyclophosphamide was continued for a total of 6 doses (cumulative dose 3000 mg). In the setting of persistent acute kidney injury, Avacopan was added to the regimen 3 months after diagnosis. Maintenance therapy included azathioprine in addition to Avacopan. Prednisone gradually tapered off at 6 months.
Avacopan may be beneficial in treating anti-neutrophil cytoplasmic antibody-associated vasculitis with coexisting relapsing polychondritis, especially in cases where preservation of kidney function is critical. Further research will be essential to validate these findings and refine treatment protocols for such complex cases.
Core Tip: This case report presents a rare overlap of relapsing polychondritis and myeloperoxidase anti-neutrophil cytoplasmic antibody associated vasculitis, complicated by severe acute kidney injury. The patient demonstrated sustained renal improvement following treatment with Avacopan, a complement 5a receptor antagonist, after intolerance to rituximab. This case highlights the potential role of Avacopan in preserving renal function and achieving disease control in complex autoimmune syndromes, especially when conventional immunosuppressive regimens are contraindicated or poorly tolerated.