Significance and management of proteinuria in kidney transplant recipients

Proteinuria is common after kidney transplantation and typically urine protein levels are below 500 mg/d. However, even these low levels are associated with reduced graft survival. Most allografts with proteinuria >1500 mg/d have new glomerular pathology. In contrast, lower levels of proteinuria are generally associated with nonglomerular, nonspecific histologic changes. The relationship between proteinuria and graft survival is independent of other variables, including graft function and graft histology. Thus, proteinuria allows stratification of risk in patients with or without glomerular pathology. Proteinuria should be monitored periodically posttransplant and investigation of the cause should be pursued vigorously.