Glomerular and extraglomerular immune complex deposits in a bone marrow transplant recipient

A 44-year-old man developed nephrotic syndrome 9 months after HLA-identical sibling bone marrow transplantation. Membranous changes consisted mainly of alterations of glomeruli, which were interpreted as chronic graft-versus-host disease (GVHD) caused by lodging of the circulating immune complex. In the tubules, a lumpy deposition of IgG and complement breakdown products was distributed along the tubular basement membrane, which coincided with the peculiar deposits ascertained by electron microscopy. These findings suggest that an extraglomerular reaction should be considered in evaluating renal involvement of GVHD.