While studies in animal models have linked Toll-like receptor (TLR) 4 signaling to kidney injury induced by ischemia and reperfusion, the relevance of TLR4 activation to allograft injury in human kidney transplants is unknown. Here we show that TLR4 is constitutively expressed within all donor kidneys but is significantly higher in deceased-, compared with living-donor organs. Tubules from deceased-but not living-donor kidneys also stained positively for high-mobility group box-1 (HMGB1), a known endogenous TLR4 ligand. In vitro stimulation of human tubular cells with HMGB1, in a TLR4-dependent system, confirmed that HMGB1 can stimulate proinflammatory responses through TLR4. To assess the functional significance of TLR4 in human kidney transplantation, we determined whether TLR4 mutations that confer diminished affinity for HMGB1 influence intragraft gene-expression profiles and immediate graft function. Compared with kidneys expressing WT alleles, kidneys with a TLR4 loss-of-function allele contained less TNF␣, MCP-1, and more heme oxygenase 1 (HO-1), and exhibited a higher rate of immediate graft function. These results represent previously undetected evidence that donor TLR4 contributes to graft inflammation and sterile injury following cold preservation and transplantation in humans. Targeting TLR4 signaling may have value in preventing or treating postischemic acute kidney injury after transplantation.delayed graft function ͉ high mobility group box-1

Abstract. Prevention of contrast agent-induced nephropathy is of crucial importance for a number of diagnostic studies. N-Acetylcysteine (NAC) was recently reported to decrease serum creatinine levels in this setting, and its administration before radiocontrast medium administration has been widely recommended. The objective of this prospective study was to investigate whether there are effects of NAC on serum creatinine levels that are independent of alterations in GFR. Volunteers with normal renal function who did not receive radiocontrast medium were studied. Fifty healthy volunteers completed the study protocol. NAC was administered orally at a dose of 600 mg every 12 h, for a total of four doses. Surrogate markers of renal function, such as serum creatinine, urea, albumin, and cystatin C levels, were measured and estimated GFR (eGFR) was assessed immediately before the administration of NAC and 4 and 48 h after the last dose. There was a significant decrease in the mean serum creatinine concentration (P Ͻ 0.05) and a significant increase in the eGFR (P Ͻ 0.02) 4 h after the last dose of NAC. The cystatin C concentrations did not change significantly. In several studies, a protective effect of NAC on renal function after radiocontrast medium administration has been postulated. This is the first study to demonstrate an effect of NAC on creatinine levels and eGFR, surrogate markers of renal injury, without any effect on cystatin C levels. Before renoprotective effects of NAC against contrast agent-induced nephropathy are considered, the direct effects of NAC on creatinine levels, urea levels, and eGFR should be assessed.Nephropathy and subsequent renal failure constitute a major concern when radiocontrast agents are administered to patients. With the use of radiocontrast agents in more then 10 million procedures annually in the United States, an incidence of radiocontrast agent-induced nephropathy of 0.5%, and mortality rates reported to be as high as 34% among those patients (1,2), the occurrence and prevention of adverse events have substantial medical and economic effects. Hydration of the patient and administration of N-acetylcysteine (NAC) are currently recommended to prevent renal injury (3). In studies to establish the protective effects of any given regimen, serum creatinine levels serve as a surrogate marker of GFR and changes are thought to reflect renal injury. However, any changes in serum creatinine levels that are not based on corresponding alterations of GFR should raise significant concerns regarding application of the model.A recent study suggested additive protective properties of NAC used in conjunction with hydration. Interestingly, that advantage was based on a decrease in serum creatinine concentrations among patients exposed to contrast agent plus NAC, whereas unchanged serum creatinine concentrations were observed after radiocontrast agent exposure among patients without NAC (3). This decrease in serum creatinine concentrations might reflect either an increase in creatinine excretion or...

The 2 year study results confirm that tacrolimus is a highly efficacious cornerstone immunosuppressant in kidney transplantation. Tacrolimus-based immunosuppression may induce long-term benefits with regard to graft function and graft survival. The overall side-effect profile is considered to be favourable.

Summary Aging of the population and improvements in diabetes therapy have led to an increased number of older pancreas transplant candidates. The aim of our retrospective study was to evaluate pancreas transplantation (PT) outcomes in patients ≥50 years, as limited data exist in these patients. We analyzed 398 consecutive pancreas transplant patients from June 1994 to June 2009 for different outcomes (patient/graft survival, rejection rate, and surgical complications) between the age groups ≥50 years (n = 69) and <50 years (n = 329). Donor and recipient characteristics were similar except for recipient age (54.0 vs. 38.8 years), BMI (24.6 vs. 22.9 kg/m2), and duration of diabetes mellitus (36.0 vs. 27.7 years). One‐, 5‐, and 10‐year patient and graft (kidney/pancreas) survival were not significantly different between the groups with patient survival rates reaching 84% and pancreas graft survival up to 67% after 10 years. Surgical complications such as relaparotomy rate (34% vs. 33%) or pancreas graft thrombosis (14% vs. 11%) as well as 1‐year rejection rates (35% vs. 31%) were not significantly different. PT in selected patients aged ≥50 years resulted in survival comparable with that of younger patients. In conclusion, advanced age should no longer be considered as an exclusion criterion for PT. However, good medical assessment and careful patient selection are necessary.