Proteinuria in Kidney Transplant Recipients: Prevalence, Prognosis, and Evidence-Based Management

Proteinuria is highly prevalent after kidney transplant, occurring in up to 45% of patients, depending on the definition. In addition to glomerulonephritis, proteinuria in kidney transplant recipients is associated commonly with such transplant-specific diagnoses on biopsy as allograft nephropathy, transplant glomerulopathy, and acute rejection. Proteinuria is associated with decreased patient and allograft survival, as well as an increased risk of cardiovascular events. In proteinuric chronic kidney disease in the nontransplant setting, randomized trials have confirmed that blockade of the renin-angiotensin system is associated with improved clinical outcomes. In proteinuric transplant recipients, treatment with an angiotensin-converting enzyme inhibitor or angiotensin receptor blocker can decrease proteinuria, but there is no evidence from randomized trials that this strategy improves patient or graft survival. This review focuses on the measurement, prevalence, pathological findings, prognostic significance, and evidence-based management of proteinuria in kidney transplant recipients.