Nephron Dosing and Low-Grade Proteinuria

We congratulate Halimi et al. for an interesting article highlighting the importance of early low-grade proteinuria. They have concluded that it is a strong predictor of graft loss, and that short-term reduction in proteinuria is associated with improved graft survival. Early low-grade proteinuria was shown to be associated with elderly donors, cardiovascular cause of donor death, prolonged cold and warm ischemia times and acute rejection episodes (1). We believe nephron dosing, which is defined as the ratio of donor kidney weight to recipient body weight, should also be considered as one of the important causes of early low-grade proteinuria. It has been well reported in the literature that kidneys with insufficient nephron mass for the recipient may be damaged by hyperfiltration injury resulting in proteinuria and chronic allograft nephropathy (2-4). With this background, it would be interesting if the authors go back and look for any correlation between nephron dosing, early low-grade proteinuria and graft loss which was reported in 98 recipients in this study. In short, our intention is to highlight Nephron dosing as one of the potential causes of early low-grade proteinuria and an important predictor of graft survival.