Proteinuria after renal transplantation affects not only graft survival but also patient survival

Background. Proteinuria is associated with an increased risk of renal failu re. Moreover, proteinuria is associated with an increased death risk in pat ients with diabetes mellitus or hypertension and even in the general popula tion. Methods. One year after renal transplantation, we studied the influence of the presence of proteinuria on the risk of either graft failure or death in all 722 recipients of a kidney graft in our center who survived at least 1 year with a functioning graft. Proteinuria was analyzed both as a categori cal variable (presence versus absence) and as a continuous variable (quanti fication of 24 hr urine). Other variables included in this analysis were: d onor/recipient age and gender, original disease, race, number of HILA-A and HILA-B mismatches, previous transplants, postmortal or living related tran splantation, and transplantation year. At I year after transplantation, we included: proteinuria, serum cholesterol, serum creatinine, blood pressure, and the use of antihypertensive medication. Results. In the Cox proportional hazards analysis, proteinuria at I year af ter transplantation (both as a categorical and continuous variable) was an important and independent variable influencing all endpoints. The influence of proteinuria as a categorical variable on graft failure censored for dea th showed no interaction with any of the other variables. There was an adve rse effect of the presence of proteinuria on the graft failure rate (RR=2.0 3). The influence of proteinuria as a continuous variable showed interactio n with original disease. The presence of glomerulonephritis, hypertension, and systemic diseases as the original disease significantly increased the r isk of graft failure with an increasing amount of proteinuria at I year. Th e influence of proteinuria as a categorical variable on the rate ratio for patient failure was significant, and there was no interaction with any of t he other significant variables (RR=1.98). The death risk was almost twice a s high for patients with proteinuria at I year compared with patients witho ut proteinuria. The influence of proteinuria as a continuous variable was a lso significant and also without interaction with other variables. The deat h risk increased with increasing amounts of proteinuria at 1 year. Both the risks for cardiovascular and for noncardiovascular death were increased. Conclusion. Proteinuria after renal transplantation increases both the risk for graft failure and the risk for death.