Relationship between early proteinuria and long term outcome of kidney transplanted patients from different decades of donor age

Abstract

BackgroundProteinuria after kidney transplantation portends a worse graft survival. However the magnitude of proteinuria related to patient and graft survival and its correlation with donor and recipient characteristics are poorly explored.MethodsThis study investigated the impact of post transplant proteinuria in the first year in 1127 kidney transplants analyzing the impact of different donor ages. Proteinuria cut off was set at 0.5 g/day.ResultsTransplants with proteinuria > 0.5 g/day correlated with poor graft and patient outcome in all donor age groups. In addition, 6-month-1-year proteinuria increase was significantly associated with graft outcome, especially with donors > 60 years old (p < 0.05; Odd Ratio 1.8). 1-year graft function (eGFR < or ≥ 44 ml/min) had similar impact to proteinuria (≥ 0.5 g/day) on graft failure (Hazard Ratio 2.77 vs Hazard Ratio 2.46). Low-grade proteinuria (0.2–0.5 g/day) demonstrated a trend for worse graft survival with increasing donor age. Also in kidney-paired analysis proteinuria ≥0.5 effect was more significant with donors > 50 years old (Odd Ratio 2.3).ConclusionsPost-transplant proteinuria was increasingly harmful with older donor age. Proteinuria ≥0.5 g/day correlates with worse outcomes in all transplanted patients. Prognostic value of proteinuria and eGFR for graft and patient survival was comparable and these two variables remain significant risk factors even in a multivariate model that take into consideration the most important clinical variables (donor age, rejection, delayed graft function and cytomegalovirus viremia among others).

Challenges in the Management of the Patient with a Failing Kidney Graft: A Narrative Review

“…A combined approach that includes eGFR trends, proteinuria, the presence of donor-specific antibodies (DSA), recurrent disease and transplant glomerulopathy might be the best predictor of graft failure [ 12 , 13 ]. A multicenter group have evaluated the four-variable (age, sex, eGFR and urine albumin-to-creatinine ratio) kidney failure risk equation in KT recipients, and concluded that the equation accurately predicts graft failure, especially in patients with eGFR < 45 mL/min/1.73 m 2 [ 14 ].…”

Clinical relevance of postoperative proteinuria for prediction of early renal outcomes after kidney transplantation

“…The severity of proteinuria after KT has been shown to be inversely associated with graft survival and favorable patient outcomes [2][3][4][13][14][15][16][17][18][19]. Similarly, a recent large cohort study demonstrated that the severity of proteinuria at 3 months, 1 year, 2 years, and 6 years after KT, as well as at the time of allograft biopsy, was inversely associated with graft survival [16].…”

Acute kidney injury secondary to urinary tract infection in kidney transplant recipients

“…Therefore, in KTRs with significant urine output and significant albuminuria, the supplementation of albumin may frequently be ineffective in terms of normalizing albuminemia and for that reason should not be routinely implemented. However, such an intervention should be considered in KTRs with sepsis and lacking shock-control as an adjunct for fluid resuscitation as stated in SSC 2016 Guidelines 57 – 59 . This allows hypothesizing that the relationship between hypoalbuminemia and late allograft loss is partially due to preexisting glomerulopathy but also secondary to increased incidence of AKI or altered pharmacokinetics of immunosuppressive drugs 60 .…”