A Case of Concurrent Anti-Glomerular Basement Membrane Antibody Disease and Immunoglobulin A Nephropathy

Anti-glomerular basement membrane (GBM) antibody disease is a rare autoimmune disorder characterized by autoantibodies directed against antigens within the GBM, primarily affecting the kidneys and lungs. This severe form of glomerulonephritis has an incidence of less than two cases per million individuals with crescentic glomerulonephritis. The coexistence of immunoglobulin A (IgA) nephropathy and anti-GBM disease is rare. Here, we present a case of concurrent anti-GBM antibody disease and IgA nephropathy. A 49-year-old male presented with fever, azotemia, proteinuria, and hematuria. Biopsy of the kidney revealed crescentic glomerulonephritis with linear IgG deposition along the GBM and IgA deposition in the mesangium. Elevated serum levels of anti-GBM antibody (311 U/mL) confirmed the diagnosis of concurrent anti-GBM antibody disease and IgA nephropathy. Despite treatment with methylprednisolone, cyclophosphamide, and plasma exchange, renal function deteriorated, necessitating hemodialysis.