Evidence that the ratio of donor kidney weight to recipient body weight, donor age, and episodes of acute rejection correlate independently with live-donor graft function

Background. We demonstrated that higher donor kidney weight-to-recipient body weight (KW/BW) ratio showed better graft function in acute rejection-free renal recipients. Methods. We investigated the impacts of KW/BW ratios on the graft function including acute rejection and donor's age in 259 live-donor renal recipients. Renal parameters were measured yearly. Correlations between the variables and each parameter were assessed by mixed regression and analysis of variance. Results. Renal function showed a positive correlation with the KW/BW ratio, but an inverse correlation with the rejection episodes and donor's age. The regression slope for serum creatinine or creatinine clearance by these covariants was consistent each year. On comparing the lower KW/BW ratios (<3.0) with higher ratios (≥4.5), the higher was associated with better graft function. Increased donor's age was associated with worse graft function. Conclusions. KW/BW ratio, donor's age, and the number of acute rejections are independent covariants for graft function.