Creatinine clearance and proteinuria as early markers of kidney graft survival

In patients who receive a kidney transplant from expanded criteria donors (ECDs), few studies are available concerning the relation between the clinical characteristics, pretransplant biopsies, and graft outcomes.

To identify early clinical markers predicting worse graft survival in recipients of kidneys from ECDs.

Between 1999 and 2006, we performed a prospective, observational study in 180 recipients of kidney grafts from ECDs that had undergone a preoperative biopsy to evaluate viability. The patients received immunosuppression with basiliximab, late introduction of tacrolimus, mycophenolate mofetil, and steroids. Data were gathered on demographic and posttransplantation clinical characteristics at 1, 3, 6, and 9 months, including estimates of proteinuria and of the glomerular filtration rate using the Modification of Diet in Renal Disease (MDRD) formula.

The mean age of the donors was 63.54 years and of the recipients, 58.38 years. A creatinine clearance below the median (40 mL/min, interquartile range 32-50 mL/min) in the first posttransplant year was significantly associated with worse death-censored graft survival (log-rank 14.22, P<.0001). A proteinuria value above the median (100 mg/24 h, interquartile range 40-275 mg/24 h) at 1 year posttransplant significantly reduced the death-censored graft survival (log-rank 14.3, P<.0001). Multivariate Cox analysis showed that a creatinine clearance<40 mL/min in the first year (hazards ratio [HR] 5.7, 95% Confidence Interval [CI] 1.62-20.37; P=.007) and proteinuria at 1 year greater tan 100 mg/24 h (HR 8.3, 95% CI 2.15-32.06; P=.002) were independent risk factors for death-censored graft loss after adjusting for donor age and acute rejection episodes.

Limited renal function and/or low proteinuria at 1 year posttransplant were associated with worse kidney graft survival among recipients of kidneys from ECDS.