Progression of urinary protein excretion after kidney transplantation: A marker for poor long-term prognosis

Abstract

IntroductionPost-transplantation proteinuria is a risk factor for graft failure. A progressive decline in renal graft function is a predictor for mortality in kidney transplant patients. ObjectivesTo assess the development and the progression of urinary protein excretion (UPE) in the first year post-transplant in recipients of kidney transplants and its effect on patient and graft outcomes. Materials and methodsWe analysed 1815 patients with 24-h UPE measurements available at 3 and 12 months post-transplant. Patients were divided based on their UPE level: below 300mg, 300–1000mg and over 1000mg (at 3 and 12 months), and changes over time were analysed. ResultsAt 3 months, 65.7% had UPE below 300mg/24h, 29.6% 300–1000mg/24h and 4.7% over 1000mg/24h. At one year, 71.6% had UPE below 300mg/24h, 24.1% 300–1000mg/24h and 4.4% over 1000mg/24h.In 208 patients (12%), the UPE progressed, in 1233 (70.5%) it remained stable and in 306 (17.5%) an improvement was observed.We found that the level of UPE influenced graft survival, particularly if a progression occurred.Recipient's age and renal function at one year were found to be predictive factors for mortality, while proteinuria and renal function were predictive factors for graft survival. ConclusionsProteinuria after transplantation, essentially when it progresses, is a marker of a poor prognosis and a predictor for graft survival. Progression of proteinuria is associated with poorer renal function and lower graft survival rates.