Renal function: defining long-term success.

One of the leading causes of late graft loss is chronic allograft nephropathy, characterized in part by deteriorating renal function. Registry data have demonstrated that renal function within the first year post-transplant is an important predictor of long-term transplant outcome, with serum creatinine concentrations < or =1.5 mg/dl at 6 or 12 months being associated with the highest rate of 5 year graft survival. These findings are supported by a retrospective, pooled analysis of two multicentre trials in the USA, as well as by our own data showing that serum creatinine concentrations may be predictive of long-term survival as early as 1 month post-transplant. Analysis of 216 renal transplantations carried out at our centre (1996-2000) using immunosuppressive therapy based on tacrolimus, corticosteroids and azathioprine (n = 51) or mycophenolate mofetil (MMF; n = 70) vs ciclosporin microemulsion, azathioprine and corticosteroids (n = 95) showed that the best 3 year graft survival was achieved with tacrolimus/MMF therapy. While serum creatinine concentrations at this time point were similar for the tacrolimus and ciclosporin treatment groups (1.69 and 1.65 mg/dl, respectively), the proportion of patients with functioning grafts was significantly higher in the tacrolimus group (84 vs 67%, P = 0.007). Similar findings of improved renal function or graft outcomes with tacrolimus- vs ciclosporin-based therapy have been reported in other single-centre and multicentre trials and a USRDS registry survey. Accumulating data suggest that renal function compares well between tacrolimus-based and calcineurin inhibitor (CNI)-sparing regimens. Consequently, the vast majority of renal transplant recipients maintain good long-term renal function with tacrolimus cornerstone immunosuppression without adopting CNI minimization or withdrawal strategies.