Glomerular vasculopathy after unrelated cord blood transplantation.

A 1-year-old boy with hemophagocytic lymphohistiocytosis exhibited proteinuria 1 month after unrelated cord blood cell transplantation, which persisted without hematuria. Laboratory study showed an increase of factor VIII-related antigen and total plasminogen activator inhibitor, suggesting endothelial injury. Histological examination of autopsy materials showed increased mesangial matrices and double-contoured basement membranes, and ultrastructurally, swelling of the endothelial cells and widening of the subendothelial space with mesangial interposition. Thrombosis was not observed at any of the sites. This case may be vasculopathy distinct from thrombotic microangiopathy (TMA) or a variant form of TMA following blood stem cell transplantation (BSCT). This vasculopathy should be considered in the differential diagnosis of proteinuria in the early stages after BSCT.