Pediatr Nephrol (2009) 24:475–484 of LRD transplants in adolescents, and pre-emptive grafts were associated with a 50% reduction in the risk of graft failure. Delaying transplantation in adolescents may expose them to increased risk of poorer outcomes [51]. Recurrent diseases Diseases that recur after transplantation and, therefore, have a potential to affect outcome include FSGS, membranopro- liferative glomerulonephritis (MPGN) and haemolytic urae- mic syndrome (HUS) [42, 47, 52, 53]. Oxalate will continue to be deposited in the transplant if liver transplantation is not undertaken in patients with hyperoxaluria. Nephrotic syndrome can recur in patients with congenital nephrotic syndrome, and anti-glomerular basement membrane (anti- GBM) nephritis in patients with Alport’s syndrome, both due to the development of antibody to the ‘missing’ protein. FSGS is the most feared of all, as it recurs in approximately 30% of transplants, conferring a relative risk of transplant loss of 1.27 in comparison to other diseases [42, 47, 54]. Readers are referred to a review of this subject [55]. Human leukocyte antigen matching Donor-specific HLA mismatching is a risk for poor outcome [17]. Worst outcome has been observed for two HLA-DR mismatched grafts, while 000 and favourably matched kidneys (100, 010, 110 HLA-A, -B, -DR mis- matches) survived longest [56]. Sensitised patients [panel reactive antibodies (PRA) > 40%] [11] also have a poorer outcome, and donor antigen-specific hyporeactivity corre- lates with better graft function [57]. Immunosuppression There have been considerable changes in the use of immunosuppression over the years. NAPRTCS has reported that the use of ciclosporin has decreased from 82.3% in 1996 to 20.7% in 2003. In contrast, use of tacrolimus has increased from 5.5% to 67.1% over the same period. There has also been a move away from azathioprine (AZA), from 56.4% to 1.9%, towards mycophenolate mofetil (MMF), use of which is now approximately 57.4%. Antibody induction has also moved away from antithymocyte globulins (ATGs) and OKT3 to anti-IL2 receptor blockers. The use of steroid- sparing regimens is also becoming common [17]. Clearly, changes in immunosuppression to more powerful agents over the years will have affected transplant outcome. There is evidence that the use of MMF in association with ciclosporin is associated with better outcome at 5 years than a similar regimen using AZA, transplant survival’s being 90.7% for MMF and 68.5% for AZA patients. Cumulative rejection-free survival was also better in the MMF group, at 479 51.2% versus 37.0% in AZA patients [58]. As absence of rejection is associated with better outcome [49], the projected half-life was 14.4/4.5 years in patients with rejection and 18.7/14.5 years without rejection in the MMF/AZA groups, respectively [58]. There is also evidence that tacrolimus is more effective than ciclosporin: a randomised trial of steroids and azathioprine with either tacrolimus or ciclosporin demon- strated that tacrolimus was significantly more effective than ciclosporin in both preventing acute rejection and main- taining graft function, with a 4-year transplant survival rate of 86% and 69%, respectively, and glomerular filtration rates (GFRs) of 71.5 ml/min/1.73 m2 and 53.0 ml/min/ 1.73 m2 body surface area, respectively [59]. Concordance with therapeutic regimens Non-concordance with therapeutic regimens is a difficult problem to deal with. It affects patients and families at all ages, but particularly so at adolescence. A study of concordance evaluated by cyclosporine levels, attendance at clinic visits, individual interviews and unexplained late graft dysfunction identified that non-concordance was the main factor in late graft loss, accounting for 71% of cases, and was a particular problem in Afro-American recipients [60]. Hypertension Hypertension is very common after transplantation, and its incidence varies with time, ranging from 46%, 40%, and 66% of children at 1, 5, and 10 years, respectively [9]. Other studies give similar results [8, 33, 61]. The presence of hypertension is a significant and independent predictor of poor long-term transplant function, regardless of the number of rejection episodes or transplant function at 1 year [62]. Bladder dynamics Transplantation into an abnormal urinary tract is associated with a high incidence of urological and infectious compli- cations [63]. However, despite this, several studies have found no effect on patient survival or transplant outcome [63–66]. Based on a review of 25 articles on the subject, it has been suggested that bladder reconstruction should be performed before transplantation when clinically indicated [66], although one study suggests that there is no adverse outcome on long-term allograft survival or function from transplantation into the unaugmented valve bladder [67]. Because of the high urological complication rates, careful surveillance of lower urinary tract function by urodynamic evaluation is essential before transplantation. Reflux does not need to be corrected before transplantation, unless it is causing symptoms or infection [68–70].