Abstract
A 44-year-old man who received allogenic hematopoietic stem cell transplantation after being diagnosed with acute myeloid leukemia developed nephrosis when the dose of tacrolimus was tapered. A renal biopsy showed the granular deposition of immunoglobulin G in the glomerular basement membrane and subepithelial electron-dense deposits, crescent formation, C4d-positive staining of the peritubular capillary, and subendothelial swelling, suggesting that the main pathological diagnosis was membranous nephropathy and that chronic graft-versus-host disease played a role in the etiology of nephrosis. We herein report a case of membranous nephropathy with various pathological findings. C4d deposition suggests complement activation and the involvement of humoral factors.