Because of a worldwide shortage of renal grafts, kidneys procured from donors after cardiac death (DCD) have recently become an important source of renal transplants. However, DCD kidneys often have complications with delayed graft function (DGF) and recipients require hemodialysis (HD) in the early period after kidney transplantation (KTx). This study evaluated serum NGAL as a potential specific parameter to predict early functional recovery of transplanted DCD kidneys. The average serum neutrophil gelatinase-associated lipocalin (NGAL) level in normal samples was 53 ± 30 ng/ml, while that in patients with chronic renal failure requiring HD was markedly raised at 963 ± 33 ng/ml. In patients undergoing a living-related KTx from a living donor (n = 11), serum NGAL level decreased rapidly after KTx, and only in two cases, with serum NGAL levels over 400 ng/ml on postoperative day 1 (POD1), was HD required due to DGF. In contrast, all patients undergoing a KTx from a DCD (n = 5) required HD due to DGF. Even in these cases, serum NGAL levels decreased rapidly several days after a KTx prior to the recovery of urine output and preceding the decrease in serum creatinine level. The pattern of decline in serum NGAL was biphasic, the decrease after the second peak indicating a functional recovery within the next several days. These data suggest that monitoring of serum NGAL levels may allow us to predict graft recovery and the need for HD after a KTx from a DCD.

Background. It has been well documented that two factors, brain death (BD) and ischemia/reperfusion (I/R) injury, have distinct but overlapping adverse influences on the clinical outcome of renal transplantation. Method. We previously established a rat model of renal isografting from brain dead donors. In the present study, we performed genomic expression profiling with a high-density oligonucleotide microarray to identify genes that were upregulated or downregulated by BD and/or I/R injury. Results. Among a total of 20,550 genes, most of those upregulated by BD were genes for adhesion molecules and cytokines or for chemokines such as Gro1 and IP-10. When overexpression of these genes was assessed by real-time reverse transcriptase–polymerase chain reaction, it was only observed one hr after the engraftment of kidneys from BD donors and returned to baseline thereafter, indicating the presence of an acute systemic inflammatory response to BD. Analysis of biologic networks demonstrated the activation of specific pathways that were clearly different for BD and I/R injury. The p53 and NFκB pathway was involved in the acute response to BD, whereas the Myc, Jun, and c-fos pathway was involved in I/R injury. Investigation of secretory protein genes identified LCN2 and SPP1 as candidate genes for biologic markers. Conclusion. Because our experimental system is a good model of renal transplantation from brain dead or living human donors, our data may be useful for elucidating the pathologic processes involved and for identification of novel markers for graft dysfunction of renal transplantation.

Kidneys procured from donors after cardiac death hold great potential to expand the donor pool. However, they have not yet been fully used, in part due to the high incidence of delayed graft function. Although urine neutrophil gelatinase-associated lipocalin is a well-known early biomarker for renal injury after kidney transplantation, its usefulness is limited in cases with delayed graft function because of the unavailability of a urine sample. We evaluated serum neutrophil gelatinase-associated lipocalin as a potential biomarker to predict the functional recovery of kidneys transplanted from donors after cardiac death. Consecutive patients transplanted with a kidney from a living related (39), brain dead (1) or post-cardiac death (27) donor were retrospectively enrolled in the study. Serum samples were collected serially before and after kidney transplantation. Serum neutrophil gelatinase-associated lipocalin was measured using the ARCHITECT® assay. Average serum neutrophil gelatinase-associated lipocalin was markedly high during the pre transplantation period. It decreased rapidly after transplantation. The slope of the decrease correlated well with the recovery period. By analyzing ROC curves we determined cutoffs to predict immediate, slow or delayed graft function requiring hemodialysis for longer than 1 week with high sensitivity and specificity. These data suggest that serial monitoring of serum neutrophil gelatinase-associated lipocalin may allow us to predict graft recovery and the need for hemodialysis after kidney transplantation from a donor after cardiac death.