Renal-Limited Anti-GBM Disease in Dual-Antibody Positive RPGN: A Case Report.

Anti-glomerular basement membrane (anti-GBM) disease is a rare autoimmune disorder causing rapidly progressive glomerulonephritis. Early recognition is crucial to prevent irreversible damage. We present a 70-year-old female with hypertension and COPD who had elevated creatinine without respiratory symptoms. Workup revealed elevated anti-GBM antibodies (59 U/mL), anti-MPO antibodies (168 AU/mL), and p-ANCA positivity with kidney biopsy confirming crescentic glomerulonephritis. She was treated with plasmapheresis, corticosteroids, and cyclophosphamide. Her antibody titers declined, and she was discharged on hemodialysis and immunosuppressive therapy. At her 4-week follow-up, renal function had not recovered, and she continued to require hemodialysis. This case highlights the need to consider anti-GBM disease even in isolated renal presentations and emphasizes challenges in managing dual-positive cases. Long-term considerations include maintenance immunosuppression and infection prevention.