Early Graft Function Defined by Area Under the Curve Serum Creatinine 7 Days Post-Transplant in a Series of Live Donor Kidney Transplantation

BackgroundThere is a degree of variability in early graft function that is often not highlighted in live kidney donor transplantation. We used the calculation of area under the curve of serum creatinine (AUC Cr) in the first 7 d post-transplant to assess early graft function and examine the influence on longer term outcome.MethodsA total of 188 live donor renal transplants performed between 1998 and 2007 were analyzed. AUC Cr was calculated over the first 7 d post-transplant and 12 mo serum creatinine levels recorded. Donor and recipient demographics were recorded, and univariable and multivariable analyses were used to determine influencing factors. The sensitivity and specificity of AUC Cr for the detection of reduced serum creatinine at 12 mo (cut-off 130 μmol/L) were assessed by the receiver operating characteristic (ROC) curve.ResultsThere was a significant variation in levels of AUC Cr over the first 7 d post-transplant (range, 692–5765 μmol/L.d). The ROC curve had a relatively low predictive value for the AUC Cr calculation (AUC = 0.735). However, multivariable analysis showed that higher levels of AUC Cr were associated with higher serum creatinine levels at 12 mo (slope 0.012; P = 0.0005). The need for dialysis, lower kidney weight, and higher recipient weight were significant independent predictors of a higher serum creatinine at 12 mo.ConclusionThe calculation of AUC serum creatinine 7 d post-transplant highlighted the significant variation in early graft function following live donor transplantation and was associated with creatinine levels at 12 mo. This calculation may be used as a simple prognostic marker to highlight poorer graft outcome.