Background: Chronic graft nephropathy is the most frequent cause of long-term renal transplant loss. Although immunological causes participate in its pathogenesis, other non-immunological factors such as hyperfiltration due to reduced renal mass have been proposed as causal factors of chronic renal graft nephropathy.
Aim: This study aimed to assess the effect of weight disproportion between the donor and recipient in the development of chronic renal graft nephropathy.
Methods: Three weight categories for donors and recipients were established: < 50, 50-75 and > 75 kg. Three groups were distinguished according to the three possible weight combinations between donor and recipient: donor weight (DW)>recipient weight (RW) (N = 133), DW = RW (N = 255) and DW<RW (N = 80). For the study of paired kidneys from the same donor, a multiple Cox regression model was applied to observe the influence of the weight differences between donor and recipient and other variables on the long-term graft and patient survival, and on the level of serum creatinine, proteinuria and arterial hypertension at 3 months after transplantation.
Results: Graft survival at 10 years was significantly lower in the DW<RW group vs the DW = RW and DW>RW groups. In addition, the DW<RW group developed higher proteinuria even by 3 months of evolution. Donor and recipient age, acute rejection and type of immunosuppressive treatment were also independent risk factors to develop chronic nephropathy in this study of paired kidneys.
Conclusions: Weight disproportion between donor and recipient, unfavourable to the recipient, is a risk factor for the development of chronic graft nephropathy. Matching the body weights between the donor and recipient is obligatory to prevent chronic rejection.