Effective management of necrotizing crescentic glomerulonephritis using an aggressive combination therapy including avacopan in a patient double-seropositive for anti-GBM antibodies and ANCA: a case report

The prognosis of anti-glomerular basement membrane (anti-GBM) nephritis, often accompanied by the presence of antineutrophil cytoplasmic antibodies (ANCA), is poor, and even with aggressive therapeutic approaches, kidney replacement therapy (KRT) is typically required. Here, we present a case of necrotizing crescentic glomerulonephritis in a patient double-seropositive for anti-GBM antibodies and ANCA who successfully achieved dialysis independence following aggressive treatment, including avacopan. The patient was a 77-year-old woman with rapidly progressive glomerulonephritis and double seropositivity for myeloperoxidase-ANCA and anti-GBM antibodies. A kidney biopsy revealed diffuse cellular crescents with necrosis and immunoglobin (Ig)G1 and IgG3 positivity on immunofluorescence staining, leading to a histological diagnosis of anti-glomerular basement membrane nephritis. Our treatment approach involved a novel combination of glucocorticoids, rituximab, low-dose cyclophosphamide, and plasma exchange complemented by avacopan. Temporary hemodialysis was required, and the patient successfully discontinued dialysis after 12 sessions despite a poor histological prognosis. This case underscores the significance of considering aggressive therapeutic strategies, including avacopan, for severe anti-GBM nephritis, even in the absence of lung involvement, to avert the need for KRT.