<scp>PLA2R</scp> ‐Positive Membranous Nephropathy and <scp>AA</scp> Amyloidosis in an Ethiopian Patient With Chronic Hepatitis B: A Case Report

The coexistence of primary phospholipase A2 receptor positive membranous nephropathy and AA amyloidosis in a patient with chronic hepatitis B is an exceedingly rare triad presenting a profound diagnostic and therapeutic challenge. A 38-year-old Ethiopian man with nephrotic syndrome and chronic hepatitis B had dual pathology on renal biopsy. Despite concurrent hepatitis B, C1q negativity and IgG4/PLA2R dominance favored a primary autoimmune process over viral-associated secondary glomerulonephritis. Immunosuppressive therapy (rituximab then cyclophosphamide) achieved complete immunological remission with loss of glomerular PLA2R antigen, yet the patient had persistent heavy proteinuria. Repeat renal biopsy determined that residual proteinuria reflected irreversible structural damage rather than active autoimmune injury. This damage included increased segmentally sclerosed glomeruli (from 11% to 33.3%) with permanent disruption of the filtration barrier from residual amyloid deposits and fibrosis. In multiple pathology settings, outcomes depend on the independent progression of each disease process. Thus, an integrated approach combining longitudinal serology and histological follow-up is essential for managing such complex cases.