Avacopan in Double-Positive Vasculitis...Why Not Consider It?: A Case Report.

Rapidly progressive glomerulonephritis (RPGN) secondary to antineutrophil cytoplasmic antibody-associated vasculitis and antiglomerular basement membrane disease has a poor prognosis, influenced by the dual positivity of both antibodies. Despite the use of aggressive immunosuppressive treatments, the outlook remains bleak, with a high percentage of patients progressing to advanced chronic kidney disease or requiring renal replacement therapy. We present the case of a 72-year-old patient with RPGN associated with vasculitis and double positivity, confirmed by immunological testing and renal histology. The patient was initially treated with a combination of glucocorticoid pulses, rituximab, cyclophosphamide, and plasmapheresis. Shortly thereafter, however, she experienced a relapse, which led to the addition of avacopan to the treatment regimen, with progressive improvement in clinical status and kidney function. This case highlights the importance of considering aggressive therapeutic strategies in antiglomerular basement membrane disease, including avacopan as part of immunosuppressive therapy to prevent progression to advanced chronic kidney disease.