Change in serum creatinine levels between 6 and 12 months and kidney graft survival: influence of proteinuria.

ABSTRACT

Renal function within the first year after transplantation has been shown to be an important parameter influencing long-term survival. In this study, we examined the relationship between long-term outcome in 365 renal transplants and renal function in the first year, expressed as serum creatinine (SCr) level at 6 months and at 1 year as well as namely deltaCr, the change in SCr between 6 months and 1 year. In addition, we examined the influence of the presence of proteinuria as a predictive factor for a worse evolution. Graft survival was worse among patients with higher deltaCr, especially among those who developed proteinuria. In a Cox regression analysis of long-term graft survival, both deltaCr and proteinuria were important predictors of half-life. The risk of graft loss when deltaCr >0.3 was 2.65 (1.8-3.8; P < .000), whereas the risk increased to 5.67 (3.3-9.4; P < .00) when proteinuria was present. In conclusion, deltaCr values predict long-term graft survival. Patients who developed proteinuria were at higher risk for graft loss compared with those without proteinuria. By using a combination of SCr and deltaCr with proteinuria, it is possible to identify a subset of transplant recipients with a predictably shortened half-life.