Kidney Transplantation After Rituximab Treatment for End-Stage Renal Failure With Myeloperoxidase Anti-neutrophil Cytoplasmic and Anti-glomerular Basement Membrane Antibody Positivity: A Case Report.

Double positivity for myeloperoxidase anti-neutrophil cytoplasmic antibody (MPO-ANCA) and anti-glomerular basement membrane (anti-GBM) antibody is associated with distinct clinical features, including older age at onset, prolonged symptom duration, and a combination of severe renal involvement and pulmonary hemorrhage. Although kidney transplantation in patients with isolated anti-GBM disease carries a low risk of recurrence, the risk in double-positive patients remains uncertain, warranting careful immunosuppressive management and close monitoring. Herein, we report the case of a 28-year-old female patient who developed end-stage kidney disease due to rapidly progressive glomerulonephritis with MPO-ANCA and anti-GBM double positivity. Following hemodialysis and infection-related complications, treatment with rituximab was initiated to suppress the progression of MPO-ANCA-associated vasculitis. Subsequently, she underwent ABO-compatible kidney transplantation, with her father as the donor. One year after transplantation, graft function remained stable, without evidence of recurrence or rejection on protocol biopsy. This case highlights the safety of kidney transplantation in double-positive patients with appropriate immunosuppressive strategies, including pretransplant rituximab, even when performed relatively early after diagnosis. Our experience suggests the potential for favorable outcomes in this high-risk subgroup, although further data are needed to establish optimal timing and treatment approaches.