Induction of organ dysfunction and up-regulation of inflammatory markers in the liver and kidneys of hypotensive brain dead rats: a model to study marginal organ donors

In silico deceased donor intervention research: A potential accelerant for progress

Progress in deceased donor intervention research has been limited. Development of an in silico model of deceased donor physiology may elucidate potential therapeutic targets and provide an efficient mechanism for testing proposed deceased donor interventions. In this study, we report a preliminary in silico model of deceased kidney donor injury built, calibrated, and validated based on data from published animal and human studies. We demonstrate that the in silico model behaves like animal studies of brain death pathophysiology with respect to upstream markers of renal injury including hemodynamics, oxygenation, cytokines expression, and inflammation. Therapeutic hypothermia, a deceased donor intervention studied in human trials, is performed to demonstrate the model's ability to mimic an established clinical trial. Finally, future directions for developing this concept into a functional, clinically applicable model are discussed.

From Inflammation to the Onset of Fibrosis through A2A Receptors in Kidneys from Deceased Donors

Pretransplant graft inflammation could be involved in the worse prognosis of deceased donor (DD) kidney transplants. A2A adenosine receptor (A_2AR) can stimulate anti-inflammatory M2 macrophages, leading to fibrosis if injury and inflammation persist. Pre-implantation biopsies of kidney donors (47 DD and 21 living donors (LD)) were used to analyze expression levels and activated intracellular pathways related to inflammatory and pro-fibrotic processes. A_2AR expression and PKA pathway were enhanced in DD kidneys. A_2AR gene expression correlated with TGF-β1 and other profibrotic markers, as well as CD163, C/EBPβ, and Col1A1, which are highly expressed in DD kidneys. TNF-α mRNA levels correlated with profibrotic and anti-inflammatory factors such as TGF-β1 and A_2AR. Experiments with THP-1 cells point to the involvement of the TNF-α/NF-κB pathway in the up-regulation of A_2AR, which induces the M2 phenotype increasing CD163 and TGF-β1 expression. In DD kidneys, the TNF-α/NF-κB pathway could be involved in the increase of A_2AR expression, which would activate the PKA–CREB axis, inducing the macrophage M2 phenotype, TGF-β1 production, and ultimately, fibrosis. Thus, in inflamed DD kidneys, an increase in A_2AR expression is associated with the onset of fibrosis, which may contribute to graft dysfunction and prognostic differences between DD and LD transplants.

Prolonged Duration of Brain Death was Associated with Better Kidney Allograft Function and Survival: A Prospective Cohort Analysis

BACKGROUND Brain death initiates hemodynamic, immunological, and hormonal changes that potentially compromise organ quality for transplantation. Therefore, it is generally believed that organs should be procured as soon as possible after the declaration of brain death. However, conflicting data exist regarding the impact of brain death duration on long-term graft function and survival. MATERIAL AND METHODS The effect of duration of brain death on graft survival and function of 1869 adult transplant recipients receiving kidneys from deceased donors after brain death was analyzed, using relevant donor and recipient characteristics and allograft related factors. RESULTS Duration of brain death was a significant predictor for long-term graft survival, whilst there was no significant effect of duration of brain death on the incidence of delayed graft function or acute graft rejection after kidney transplantation. After dividing the study population into a "short durBD" (<10.6 hours) group and a "long durBD" (>10.6 hours) group, the 15-year graft survival estimates were significantly higher and the serum creatinine at 3 months after transplantation was significantly lower in the "long durBD" group. CONCLUSIONS Duration of brain death does not affect the incidence of delayed graft function or acute rejection after kidney transplantation. However, longer duration of brain death is associated with better kidney allograft function and survival.

Donor pretreatment with nebulized complement C3a receptor antagonist mitigates brain-death induced immunological injury post-lung transplant

Donor brain death (BD) is an inherent part of lung transplantation (LTx) and a key contributor to ischemia-reperfusion injury (IRI). Complement activation occurs as a consequence of BD in other solid organ Tx and exacerbates IRI, but the role of complement in LTx has not been investigated. Here, we investigate the utility of delivering nebulized C3a receptor antagonist (C3aRA) pretransplant to BD donor lungs in order to reduce post-LTx IRI. BD was induced in Balb/c donors, and lungs nebulized with C3aRA or vehicle 30 minutes prior to lung procurement. Lungs were then cold stored for 18 hours before transplantation into C57Bl/6 recipients. Donor lungs from living donors (LD) were removed and similarly stored. At 6 hours and 5 days post-LTx, recipients of BD donor lungs had exacerbated IRI and acute rejection (AR), respectively, compared to recipients receiving LD lungs, as determined by increased histopathological injury, immune cells, and cytokine levels. A single pretransplant nebulized dose of C3aRA to the donor significantly reduced IRI as compared to vehicle-treated BD donors, and returned IRI and AR grades to that seen following LD LTx. These data demonstrate a role for complement inhibition in the amelioration of IRI post-LTx in the context of donor BD.

C1-Inhibitor Treatment Decreases Renal Injury in an Established Brain-Dead Rat Model

BACKGROUND

Kidneys derived from brain-dead (BD) donors have lower graft survival rates compared with kidneys from living donors. Complement activation plays an important role in brain death. The aim of our study was therefore to investigate the effect of C1-inhibitor (C1-INH) on BD-induced renal injury.

METHODS

Brain death was induced in rats by inflating a subdurally placed balloon catheter. Thirty minutes after BD, rats were treated with saline, low-dose or high-dose C1-INH. Sham-operated rats served as controls. After 4 hours of brain death, renal function, injury, inflammation, and complement activation were assessed.

RESULTS

High-dose C1-INH treatment of BD donors resulted in significantly lower renal gene expression and serum levels of IL-6. Treatment with C1-INH also improved renal function and reduced renal injury, reflected by the significantly lower kidney injury marker 1 gene expression and lower serum levels of lactate dehydrogenase and creatinine. Furthermore, C1-INH effectively reduced complement activation by brain death and significantly increased functional levels. However, C1-INH treatment did not prevent renal cellular influx.

CONCLUSIONS

Targeting complement activation after the induction of brain death reduced renal inflammation and improved renal function before transplantation. Therefore, strategies targeting complement activation in human BD donors might clinically improve donor organ viability and renal allograft survival.

Links between a biomarker profile, cold ischaemic time and clinical outcome following simultaneous pancreas and kidney transplantation

In sepsis, trauma and major surgery, where an explicit physiological insult leads to a significant systemic inflammatory response, the acute evolution of biomarkers have been delineated. In these settings, Interleukin (IL) -6 and TNF-α are often the first pro-inflammatory markers to rise, stimulating production of acute phase proteins followed by peaks in anti-inflammatory markers. Patients undergoing SPKT as a result of diabetic complications already have an inflammatory phenotype as a result of uraemia and glycaemia. How this inflammatory response is affected further by the trauma of major transplant surgery and how this may impact on graft survival is unknown, despite the recognised pro-inflammatory cytokines' detrimental effects on islet cell function. The aim of the study was to determine the evolution of biomarkers in omentum and serum in the peri-operative period following SPKT. The biochemical findings were correlated to clinical outcomes. Two omental biopsies were taken (at the beginning and end of surgery) and measured for CD68+ and CD206+ antibodies (M1 and M2 macrophages respectively). Serum was measured within the first 72 h post-SPKT for pro- and anti-inflammatory cytokines (IL -6, -10 and TNF-α), inflammatory markers (WCC and CRP) and endocrine markers (insulin, C-peptide, glucagon and resistin). 46 patients were recruited to the study. Levels of M1 (CD68+) and M2 (CD206+) macrophages were significantly raised at the end of surgery compared to the beginning (p = 0.003 and p < 0.001 respectively). Levels of C-peptide, insulin and glucagon were significantly raised 30 min post pancreas perfusion compared to baseline and were also significantly negatively related to prolonged cold ischaemic time (CIT) (p < 0.05). CRP levels correlated significantly with the Post-Operative Morbidity Survey (p < 0.05). The temporal inflammatory marker signature after SPKT is comparable to the pattern observed following other physiological insults. Unique to this study, we find that CIT is significantly related to early pancreatic endocrine function. In addition, this study suggests a predictive value of CRP in peri-operative morbidity following SPKT.

Effects of mechanical ventilation on gene expression profiles in renal allografts from brain dead rats

Pathophysiological changes of brain death (BD) are impairing distal organ function and harming potential renal allografts. Whether ventilation strategies influence the quality of renal allografts from BD donors has not been thoroughly studied. 28 adult male Wistar rats were randomly assigned to four groups: 1) no brain death (NBD) with low tidal volume/low positive endexpiratory pressure (PEEP) titrated to minimal static elastance of the respiratory system (LVT/OLPEEP); 2) NBD with high tidal volume/low PEEP (HVT/LPEEP); 3) brain death (BD) with LVT/OLPEEP; and 4) BD with HVT/LPEEP. We hypothesized that HVT/LPEEP in BD leads to increased interleukin 6 (IL-6) gene expression and impairs potential renal allografts after six hours of mechanical ventilation. We assessed inflammatory cytokines in serum, genome wide gene expression profiles and quantitative PCR (qPCR) in kidney tissue. The influence of BD on renal gene-expression profiles was greater than the influence of the ventilation strategy. In BD, LVT ventilation did not influence the inflammatory parameters or kidney function in our experimental model.

Complement-mediated inflammation and injury in brain dead organ donors

The importance of the complement system in renal ischemia-reperfusion injury and acute rejection is widely recognized, however its contribution to the pathogenesis of tissue damage in the donor remains underexposed. Brain-dead (BD) organ donors are still the primary source of organs for transplantation. Brain death is characterized by hemodynamic changes, hormonal dysregulation, and immunological activation. Recently, the complement system has been shown to be involved. In BD organ donors, complement is activated systemically and locally and is an important mediator of inflammation and graft injury. Furthermore, complement activation can be used as a clinical marker for the prediction of graft function after transplantation. Experimental models of BD have shown that inhibition of the complement cascade is a successful method to reduce inflammation and injury of donor grafts, thereby improving graft function and survival after transplantation. Consequently, complement-targeted therapeutics in BD organ donors form a new opportunity to improve organ quality for transplantation. Future studies should further elucidate the mechanism responsible for complement activation in BD organ donors.

Steatohepatitis is developed by a diet high in fat, sucrose, and cholesterol without increasing iron concentration in rat liver

Iron overload to the liver is known to be a pathogenesis of nonalcoholic steatohepatitis through oxidative stress. High-fat diets have been reported to increase iron concentration in livers that developed steatohepatitis in experimental animals. However, the effect of high-fat diets on hepatic iron concentration is controversial. We hypothesized that a diet high in lard, cholesterol, and sucrose (Western diet) leads to the development of steatohepatitis without increasing hepatic iron concentration. Rats were given either a control or the Western diet for 12 weeks. The Western diet increased triacylglycerol concentration and oxidative stress markers such as the concentration of thiobarbituric acid reactive substances and messenger RNA (mRNA) expression of heme oxygenase-1 in the liver. The Western diet also increased the mRNA expression of macrophage-1 antigen, cluster of differentiation (CD) 45, and CD68 in the liver, and nuclear factor κB level in liver nuclear fraction, suggesting the development of hepatic inflammation. Histological observation also indicated fatty liver and hepatic inflammation in the rats given the Western diet. In contrast, the Western diet decreased iron concentration in the liver. These results clearly indicated that the diet high in lard, cholesterol, and sucrose induces steatohepatitis without increasing hepatic iron concentration.

Dopamine treatment of brain-dead Fisher rats improves renal histology but not early renal function in Lewis recipients after prolonged static cold storage

BACKGROUND

Brain death (BD) and cold preservation are major risk factors for an unfavorable transplantation outcome. Although donor dopamine treatment in brain-dead rats improves renal function and histology in allogeneic recipients, it remains to be assessed if this also holds true for the combinations of BD and prolonged static cold preservation.

METHODS

BD was induced in F344 donor rats, which were subsequently treated with NaCl 1 mL/h (BD, n = 11), NaCl/hydroxy ethyl starch (BD-norm, n = 10), or 10 μg/min/kg dopamine (BD-dopa, n = 10). Renal grafts were harvested 4 h after BD and transplanted into bilateral nephrectomized Lewis recipients 6 h after cold preservation in University of Wisconsin solution. Renal function was evaluated by use of serum creatinine and urea concentrations at days 0, 1, 3, 5, and 10. Ten days after transplantation, recipients were killed and the renal allografts were processed for light microscopy and immune histology.

RESULTS

Serum urea concentrations at days 5 and 10 were significantly lower in recipients that received a renal graft from dopamine-treated rats; for serum creatinine, only a trend was observed at day 10. Immune histology revealed a lower degree of ED1-positive cells in the donor dopamine-treated group. Under light microscopy, Banff classification revealed significantly less intimal arteritis in these grafts (P < .05).

CONCLUSIONS

Although donor dopamine treatment clearly improves renal histology in this model, the beneficial effect on early renal function was marginal. It remains to be assessed if donor dopamine treatment has a beneficial effect on renal function in long-term follow-up.

Cobalt protoporphyrin protects the liver against apoptosis in rats of brain death

Brain death (BD) leads to a marked increase in apoptosis, which influences the viability of donor organs. Induction of heme oxygenase 1 (HO-1) has been shown to exert beneficial effects in different liver injury models. Therefore, we examined the effect of pretreating rats with cobalt protoporphyrin (CoPP), an HO-1 inducer, on apoptosis in liver during BD and elucidated the mechanisms involved. First, rats were killed at 0, 1, 2, 4 and 6 h after BD induction to examine the expression of hepatic HO-1. Second, rats were randomly divided into four groups (n=6): (S group) rats undergoing sham operation, (CS group) rats pretreated with CoPP for 24 h before the sham operation, (B group) rats undergoing BD for 6 h, (CB group) rats pretreated with CoPP for 24 h before BD induction. The expression levels of hepatic HO-1 mRNA and protein in rats increased at 0, 1, 2, 4 and 6h after BD induction, compared with sham operated rats. In the CB group compared with the B group, the increased hepatic expression of HO-1 correlated with a significant decrease in serum ALT/AST levels, fewer apoptotic cells in liver, increased hepatic expression of Mcl-1 and Bcl-2, and decreased hepatic expression of Bax, cytosolic cytochrome c and cleaved caspase-3. CoPP inhibits apoptosis in liver of BD rats in part via modulating the mitochondrial apoptosis pathway. HO-1 may serve as a potential target for improving the quality of organs from BD donors.

Impact of brain death on ischemia/reperfusion injury in liver transplantation

PURPOSE OF REVIEW

In liver transplantation, the ischemia/reperfusion injury (IRI) is influenced by factors related to graft quality, organ procurement and the transplant procedure itself. However, in brain-dead donors, the process of death itself also thoroughly affects organ damage through breakdown of the autonomous nervous system and subsequent massive cytokine release. This review highlights the actual knowledge on these proinflammatory effects of brain death on IRI in liver transplantation.

RECENT FINDINGS

Brain death affects IRI either through hemodynamical or molecular effects with proinflammatory activation. Immunological effects are mainly mediated through Kupffer cell activation, leading to TNF-α and TLR4 amplification. Proinflammatory cytokines such as interleukin (IL)-6, IL-10, TNF-β and MIP-1α are released, together with activation of the innate immune system via natural killer cells and natural killer T cells, which promote organ damage and activation of fibrosis. Preprocurement treatment regimens attempt to hamper inflammatory response by the application of methylprednisolone or thymoglobulin to the donor. Selective P-selectin antagonism resulted in improved function in marginal liver grafts. Inhaled nitric oxide was found to reduce apoptosis in liver grafts. Other medications like the immunosuppressant tacrolimus produced conflicting results regarding organ protection. Furthermore, improved organ storage after procurement - such as machine perfusion - can diminish effects of IRI in a clinical setting.

SUMMARY

Brain death plays a fundamental role in the regulation of molecular markers triggering inflammation and IRI-related tissue damage in liver transplants. Although several treatment options have reached clinical application, to date, the effects of brain death during donor conditioning and organ procurement remain relevant for organ function and survival.

Complement mediated renal inflammation induced by donor brain death: role of renal C5a-C5aR interaction

Kidneys retrieved from brain-dead donors have impaired allograft function after transplantation compared to kidneys from living donors. Donor brain death (BD) triggers inflammatory responses, including both systemic and local complement activation. The mechanism by which systemic activated complement contributes to allograft injury remains to be elucidated. The aim of this study was to investigate systemic C5a release after BD in human donors and direct effects of C5a on human renal tissue. C5a levels were measured in plasma from living and brain-dead donors. Renal C5aR gene and protein expression in living and brain-dead donors was investigated in renal pretransplantation biopsies. The direct effect of C5a on human renal tissue was investigated by stimulating human kidney slices with C5a using a newly developed precision-cut method. Elevated C5a levels were found in plasma from brain-dead donors in concert with induced C5aR expression in donor kidney biopsies. Exposure of precision-cut human kidney slices to C5a induced gene expression of pro-inflammatory cytokines IL-1 beta, IL-6 and IL-8. In conclusion, these findings suggest that systemic generation of C5a mediates renal inflammation in brain-dead donor grafts via tubular C5a-C5aR interaction. This study also introduces a novel in vitro technique to analyze renal cells in their biological environment.

Evaluating lung injury at increasing time intervals in a murine brain death model

INTRODUCTION

Only 15%-25% of brain death (BD) donors match the ideal donor criteria for lung transplantation. Lung injury may evolve in the hours after onset of brain death, but the evolution over time has not been well studied in lung. The aim of this study was to evaluate lung injury at different time points after BD using a murine model.

MATERIALS AND METHODS

Male C57BL6/J mice (8-10 wk) were anesthetized, tracheotomized, and mechanically ventilated. Mice were randomly assigned to six groups (n=8/group): 1 h, 3 h, and 6 h sham ([SH1], [SH3], [SH6]) and 1 h, 3 h, and 6 h brain death ([BD1], [BD3], [BD6]). BD was gradually induced by a subdural balloon catheter. Heart rate and mean arterial pressure were continuously monitored. At the end of the experiment, bronchoalveolar lavage was performed and the left lung was excised for histopathologic analysis.

RESULTS

The Cushing reflex was characterized by a rapid increase in heart rate and mean arterial pressure after balloon inflation in BD animals. An increase in percentage of neutrophils was seen with a longer follow-up period (P<0.05). Interleukin 6 and interleukin 10 levels in bronchoalveolar lavage progressively increased with longer time intervals after BD ([BD1] versus [BD6]; P<0.01). Histologic signs of lung injury (congestion, hemorrhage, and neutrophilic influx) were more pronounced in [BD3] and [BD6] compared with the other groups; however, this difference did not reach statistical significance.

CONCLUSION

Three hours after brain death, significant signs of inflammation and lung injury were seen compared with sham-operated animals. This murine BD model gives us opportunities for further mechanistic studies regarding treatment of BD-related donor lung injury.

Brain death induces renal expression of heme oxygenase-1 and heat shock protein 70

Background

Kidneys derived from brain dead donors have lower graft survival and higher graft-function loss compared to their living donor counterpart. Heat Shock Proteins (HSP) are a large family of stress proteins involved in maintaining cell homeostasis. We studied the role of stress-inducible genes Heme Oxygenase-1 (HO-1), HSP27, HSP40, and HSP70 in the kidney following a 4 hour period of brain death.

Methods

Brain death was induced in rats (n=6) by inflating a balloon catheter in the epidural space. Kidneys were analysed for HSPs using RT-PCR, Western blotting, and immunohistochemistry.

Results

RT-PCR data showed a significant increase in gene expression for HO-1 and HSP70 in kidneys of brain dead rats. Western blotting revealed a massive increase in HO-1 protein in brain dead rat kidneys. Immunohistochemistry confirmed these findings, showing extensive HO-1 protein expression in the renal cortical tubules of brain dead rats. HSP70 protein was predominantly increased in renal distal tubules of brain dead rats treated for hypotension.

Conclusion

Renal stress caused by brain death induces expression of the cytoprotective genes HO-1 and HSP70, but not of HSP27 and HSP40. The upregulation of these cytoprotective genes indicate that renal damage occurs during brain death, and could be part of a protective or recuperative mechanism induced by brain death-associated stress.

Graft-specific immune cells communicate inflammatory immune responses after brain death

BACKGROUND

Donor brain death (BD) triggers inflammatory graft activation that leads to impaired graft quality and outcome. We used a mouse BD model to investigate graft inflammation in cardiac transplants from immune-competent and immune-deficient donor animals. Effects of donor T-cell depletion were tested in an additional group of cardiac transplant recipients.

METHODS

We analyzed systemic and graft-specific inflammatory activation after BD in donors and in syngeneic recipients of hearts retrieved from BD donors. To dissect the role of donor-specific immune cells in communicating BD-triggered inflammation, immune-deficient T-cell-, B-cell-, and natural killer cell-deficient Rag2/double knockout mice and naïve C57BL6 treated with anti-thymocyte globulin (Thymoglobulin; Genzyme Transplant, Cambridge, MA) were observed.

RESULTS

Donor BD boosted lymphocyte activation in donors and recipients of syngeneic BD grafts. Lymphocyte activation was mitigated in recipients of immune-deficient and Thymoglobulin-treated BD donor grafts. Likewise, systemic and intra-graft levels of inflammatory cytokines interleukin -1, interleukin-6, interferon-γ, and tumor necrosis factor-α were significantly reduced in immune-deficient and anti-thymocyte globulin-treated recipients. Dense lymphocyte infiltrates were detected in the hearts from untreated BD donors; in contrast, the hearts from donors treated with Thymoglobulin demonstrated a preserved structure with minimal infiltrates comparable with naïve controls.

CONCLUSION

BD triggers inflammatory graft activation communicated through intra-graft immune cells. Donor treatment with Thymoglobulin prevented inflammatory immune activation and improved graft quality to levels comparable to living donor organs.

Effects of brain death on organ quality and transplant outcome

The inferiority of organs from brain dead donors is reflected by impaired graft survival and patient outcome. Brain death effects hemodynamic stability, hormonal changes, and neuroimmunologic effects and unleashes a cascade of inflammatory events. Despite considerable efforts in experimental and clinical research, most of the mechanisms linked to brain death are only appreciated on a descriptive level. This overview presents our current understanding of the pathophysiology and consequences of brain death on organ injury and summarizes available therapeutic interventions.

The effect of steroid pretreatment of deceased organ donors on liver allograft function: a blinded randomized placebo-controlled trial

BACKGROUND & AIMS

Brain death-associated inflammatory response contributes to increased risk of impaired early liver allograft function, which might be counterbalanced by steroid pretreatment of the organ donor. The aim of this randomized controlled trial was to elucidate whether steroid pretreatment of liver donors improves early liver allograft function, prevents rejection and prolongs survival.

METHODS

A placebo-controlled blinded randomized clinical trial was performed in three different centers in Austria and Hungary between 2006 and 2008. Ninety deceased organ donors received either 1000 mg of methylprednisolone or placebo 6h before recovery of organs. The primary end point was the concentration slope of transaminases within the first week. The secondary end point included survival and biopsy-confirmed acute rejection (BCAR) within 3 years after transplantation.

RESULTS

Of the 90 randomized donors, 83 recipients were eligible for study. The trajectories of ALT and AST were not different between treatments (p=0.40 and p=0.13, respectively). Eight subjects died in the steroid and 13 in the placebo group within 3 years after engraftment (RR=0.63 95% CI [0.29,1.36], p=0.31). Eleven recipients experienced biopsy-confirmed rejection (BCAR) in the steroid and 11 in the placebo group (RR=1.02 95% CI [0.50,2.10], p=1.00). No effect modification could be identified in the predefined strata of donor age, sex, cold ischemic time, and cause of donor death.

CONCLUSIONS

Steroid pretreatment of organ donors did not improve outcomes after liver transplantation.

Fluoro-D-glucose-micro positron emission tomography as a diagnostic tool to confirm brain death in a murine donor lung injury model

PURPOSE

Because brain death (BD)-related donor lung injury is still poorly understood, a reliable mouse model can help in understanding the immunologic mechanisms behind this lung injury. The purpose of our study was to validate BD in mice using small-animal positron emission tomography.

PROCEDURES

BD was induced in male Balb/c mice (27.1 ± 0.9 g) with an intracranial balloon catheter inflated rapidly (<1 min) [BD](R) or gradually (36 ± 5 min) [BD](G), and compared with sham-operated [SH] and control animals [C] (n = 6/group). Ten minutes after balloon insertion 10.4 ± 1.0 MBq 2-deoxy-2-[(18)F]-fluoro-D-glucose ((18)FDG) was administered intravenously and static images were performed and quantified.

RESULTS

Coronal, sagittal, and transaxial sections of cerebral (18)FDG activity revealed significant differences when comparing [BD](R) and [BD](G) with [C] and [SH] animals. No significant (18)FDG uptake was visually detectable in [BD](R) and [BD](G). The percentage injected dose showed significant differences between BD groups and [C] and [SH] (P < 0.0001). No significant difference was seen between [C] versus [SH] nor between [BD](R)versus [BD](G) (P > 0.05).

CONCLUSIONS

(18)FDG micro positron emission tomography imaging is a valuable tool to demonstrate brain functionality and can therefore be used as a surrogate test to confirm BD in mice.

The Reward is Worth the Wait: A Prospective Analysis of 100 Consecutive Organ Donors

Aggressive donor management protocols have evolved to maximize the number of procured organs. Our study assessed donor management time and the number and types of organs procured with the hypothesis that shorter management time yields increased organ procurement and transplant rates. We prospectively analyzed 100 donors managed by a regional organ procurement organization (OPO) during 2007 to 2008. Data included patient demographics, number and types of organs procured and transplanted, patient management time by the OPO, and achievement of donor pre-procurement goals. One hundred consecutive organ donors were managed with a mean age 41 ± 18 years and mean management time 23 ± 9 hours; 376 organs were procured and 327 successfully transplanted. Donors managed greater than 20 hours yielded significantly more heart (5 vs 26, P < 0.01) and lung (6 vs 40, P < 0.01) procurements, more organs procured per donor (3.2 ± 1.4 vs 4.2 ± 1.6, P < 0.01), and more organs transplanted per donor (2.6 ± 1.5 vs 3.7 ± 1.8, P < 0.01) than those managed 20 hours or less. No difference in the attainment of donor management goals was observed between these populations. Contrary to our initial hypothesis, donor management times greater than 20 hours yielded increased organ procurement and transplant rates, particularly for hearts and lungs, despite no differences in the achievement of donor preprocurement management goals.

Early activation of the inflammatory response in the liver of brain-dead non-human primates

BACKGROUND

Donor brain death (BD) triggers a systemic inflammatory response that reduces organ quality and increases immunogenicity of the graft. We characterized the early innate immune response induced by BD in the liver and peripheral blood of hemodinamically stable non-human primates (NHP).

METHODS

Rhesus macaques were assigned to either brain death or control group. BD was induced by inflation of a subdurally placed catheter and confirmed clinically and by cerebral angiography. Animals were monitored for 6 h after BD and managed to maintain hemodynamic stability.

RESULTS

Cortisol, epinephrine, nor-epinephrine, and IL-6 levels were elevated immediately after BD induction. Neutrophils and monocytes significantly increased in circulation following BD induction, while dendritic cells were decreased at 6 h post-induction. Flow cytometry revealed increased expression of chemokine receptors CxCR1, CxCR2, CCR2, and CCR5 in peripheral blood leukocytes from NHP subjected to BD. Microarray analysis demonstrated a significant up-regulation of genes related to innate inflammatory responses, toll-like receptor signaling, stress pathways, and apoptosis/cell death in BD subjects. Conversely, pathways related to glucose, lipid, and protein metabolism were down-regulated. In addition, increased expression of SOCS3, S100A8/A9, ICAM-1, MHC class II, neutrophil accumulation, and oxidative stress markers (carboxy-methyl-lysine and hydroxynonenal) were detected by immunoblot and immunohistochemistry.

CONCLUSIONS

Activation of the innate immune response after BD in association with a down-regulation of genes associated with cell metabolism pathways in the liver. These findings may provide a potential explanation for the reduced post-transplant function of organs from brain dead donors. In addition, this work suggests potential novel targets to improve donor management strategies.

Local renal complement C3 induction by donor brain death is associated with reduced renal allograft function after transplantation

BACKGROUND

Kidneys derived from brain-dead donors have inferior outcomes after transplantation compared to kidneys from living donors. Strikingly, early and profound serum levels of IL-6 in brain-dead donors are observed. IL-6 is the main regulator of the acute phase response (APR). The aim of this translational study was to investigate the expression of renal acute phase proteins (APPs) following brain death (BD) and to assess the association with renal allograft outcome after transplantation.

METHODS

BD was induced in rats by inflating a subdurally placed balloon catheter. Kidney biopsies were obtained from human living and brain-dead donors at donation, after cold preservation and reperfusion. In vitro, renal proximal tubular epithelial cells (HK-2 cells) were stimulated with IL-6.

RESULTS

Both in human and rat brain-dead donors, C3 and FBG expression was enhanced at donation compared to living donors and sham-operated animals. In human donors, no additional expression was found after cold ischaemia or reperfusion. C3 expression after reperfusion was independently associated with decreased short-term function after transplantation in grafts from brain-dead donors. In cultured HK-2 cells, C3 production was induced in the presence of IL-6.

CONCLUSIONS

In conclusion, BD induces renal C3 and FBG expression. Moreover, C3 expression is associated with a worse allograft function early after transplantation. Therefore, targeting renal APPs in brain-dead donors, especially complement C3, may improve transplant outcome.

NFkappaB, cytokines, TLR 3 and 7 expression in human end-stage HCV and alcoholic liver disease

BACKGROUND/AIMS

Conflicting observations exist concerning the role of nuclear factor kappa B (NFjB) in alcoholic liver disease (ALD) in animal models. To date no studies have examined this aspect in human liver tissue. We here assessed cytokines and toll-like receptors (TLRs) expressions in conjunction with NFkappaB activation in non-active end-stage human ALD compared with normal livers and hepatitis C virus (HCV) related end-stage disease.

METHODS

mRNA and protein expression were examined by quantitative PCR and Western blotting, DNA-binding by electrophoretic mobility shift assays and NFkappaB sub-cellular localization by immunofluorescent staining of livers.

RESULTS

NFkappaB mRNA and protein expression as well as strong DNA-binding were preserved in ALD but significantly down-regulated in HCV compared with normal livers. P50 immunofluorescence was found in hepatocytes and bile ducts in ALD and normal livers, whereas a shift was observed in p65 staining from non-parenchymal cells in normal livers to hepatocytes in ALD. NFkappaB responsive genes mRNA levels IkBalpha and interleukin 6 were significantly higher in ALD compared with HCV. Tumour necrosis factor alpha (TNFalpha), TLRs 3 and 7 mRNA were up-regulated in ALD and HCV compared with normal liver with TNFalpha and TLR7 being the highest in HCV. Strong induction of interferon beta was found in HCV but not in ALD or normal liver tissue.

CONCLUSIONS

Persistent NFkappaB activation together with high pro-inflammatory cytokine expression and upregulation of TLR3 and TLR7 is associated with end-stage ALD in humans and could contribute to disease progression even in absence of alcohol intake.

Organ donation and utilization in the United States, 1999-2008

Despite the Organ Donation Breakthrough Collaborative's work to engage the transplant community and the suggested positive impact from these efforts, availability of transplanted organs over the past 5 years has declined. Living kidney, liver and lung donations declined from 2004 to 2008. Living liver donors in 2008 dropped to less than 50% of the peak (524) in 2001. There were more living donors that were older and who were unrelated to the recipient. Percentages of living donors from racial minorities remained unchanged over the past 5 years, but percentages of Hispanic/Latino and Asian donors increased, and African American donors decreased. The OPTN/UNOS Living Donor Transplant Committee restructured to enfranchise organ donors and recipients, and to seek their perspectives on living donor transplantation. In 2008, for the first time in OPTN history, deceased donor organs decreased compared to the prior year. Except for lung donors, deceased organ donation fell from 2007 to 2008. Donation after cardiac death (DCD) has accounted for a nearly 10-fold increase in kidney donors from 1999 to 2008. Use of livers from DCD donors declined in 2008 to 2005 levels. Understanding health risks associated with the transplantation of organs from 'high-risk' donors has received increased scrutiny.

Signal transduction pathways involved in brain death-induced renal injury

Kidneys derived from brain death organ donors show an inferior survival when compared to kidneys derived from living donors. Brain death is known to induce organ injury by evoking an inflammatory response in the donor. Neuronal injury triggers an inflammatory response in the brain, leading to endothelial dysfunction and the release of cytokines in the circulation. Serum levels of interleukin-6, -8, -10, and monocyte chemoattractant protein-1 (MCP-1) are increased after brain death. Binding with cytokine-receptors in kidneys stimulates activation of nuclear factor-kappa B (NF-kappaB), selectins, adhesion molecules and production of chemokines leading to cellular influx. Mitogen-activated protein kinases (MAP-kinases) mediate inflammatory responses and together with NF-kappaB they seem to play an important role in brain death induced renal injury. Altering the activation state of MAP-kinases could be a promising drug target for early intervention to reduce cerebral injury related donor kidney damage and improve outcome after transplantation.

Systemic inflammation in the brain-dead organ donor

Brain death itself impairs organ function in the potential donor, thereby limiting the number of suitable organs for transplantation. In addition, graft survival of kidneys obtained from brain-dead (BD) donors is inferior to that of kidneys obtained from living donors. Experimental studies confirm an inferior graft survival for the heart, liver and lungs from BD compared with living donors. The mechanism underlying the deteriorating effect of brain death on the organs has not yet been fully established. We know that brain death triggers massive circulatory, hormonal and metabolic changes. Moreover, the past 10 years have produced evidence that brain death is associated with a systemic inflammatory response. However, it remains uncertain whether the inflammation is induced by brain death itself or by events before and after becoming BD. The purpose of this study is to discuss the risk factors associated with brain death in general and the inflammatory response in the organs in particular. Special attention will be paid to the heart, lung, liver and kidney and evidence will be presented from clinical and experimental studies.

Hepatic IL-8 release during graft procurement is associated with impaired graft function after human liver transplantation

In experimental models, brain death induces inflammatory cascades, leading to reduced graft survival. Thus far, factors prior to graft preservation have gained less attention in clinical setting. We studied pre-preservation inflammatory response and its effects on graft function in 30 brain dead liver donors and the respective recipients. Before donor graft perfusion, portal and hepatic venous blood samples were drawn for phagocyte adhesion molecule expression and plasma cytokine determinations. Donor intensive care unit stay correlated with donor C-reactive protein (R = 0.472, p = 0.013) and IL-6 (R = 0.419, p = 0.026) levels, and donor (R = 0.478, p = 0.016) and recipient gamma-glutamyl transferase (R = 0.432, p = 0.019) levels. During graft procurement, hepatic IL-8 release was observed in 17/30 donors. Grafts with hepatic IL-8 release exhibited subsequently higher alkaline phosphatase [319 (213-405) IU/L vs. 175 (149-208) IU/L, p = 0.006] and bilirubin [101 (44-139) micromol/L vs. 30 (23-72) micromol/L, p = 0.029] levels after transplantation. Our findings support the concept that inflammatory response in the brain dead organ donor contributes to the development of graft injury in human liver transplantation.

Impact of innate and adaptive immunity on rejection and tolerance

Until recently, research on transplantation rejection and tolerance has been directed toward deciphering the mechanisms of the adaptive immune system. However, the emergence that the innate immune system, the body's first-line defense against pathogens, has a strong influence on adaptive immunity has galvanized interest in elucidating the interplay between these two arms of the immune system. The discovery of Toll-like receptors and the characterization of the cellular mediators involved in innate immunity have provided growing evidence that innate immunity affects the adaptive immune response. Emerging evidence has also shown that early "danger signals"' associated with ischemia-reperfusion injury or brain death contribute to innate immune activation, promoting rejection, and inhibiting tolerance induction. In addition, nonspecific stimuli such as increased donor age or patient disease may also serve to exert a synergistic influence on innate immune activation. Ultimately, controlling the events in innate immune activation may help drive tolerance induction and reduce the rate of rejection.

Ischemic preconditioning of the liver: a few perspectives from the bench to bedside translation

Utilization of ischemic preconditioning to ameliorate ischemia/reperfusion injury has been extensively studied in various organs and species for the past two decades. While hepatic ischemic preconditioning in animals has been largely beneficial, translational efforts in the two clinical contexts--liver resection and decreased donor liver transplantation--have yielded mixed results. This review is intended to critically examine the translational data and identify some potential reasons for the disparate clinical results, and highlight some issues for further studies.

Complement and renal transplantation: from donor to recipient

Long-term kidney graft survival is affected by different variables including donor condition, ischemia-reperfusion injury, and graft rejection during the transplantation process. The complement system is an important mediator of renal ischemia-reperfusion injury and in rejecting allografts. However, donor complement C3 seems to be crucial in renal transplantation-related injury as renal injury is attenuated in C3 deficient kidney grafts. Interestingly, before ischemia-reperfusion induced C3 expression, C3 is already induced in donors suffering from brain death. Therefore, strategies targeting complement activation in the brain-dead donor may increase graft viability and transplant outcome.

High levels of donor CCL2/MCP-1 predict graft-related complications and poor graft survival after kidney-pancreas transplantation

In this study we analyzed the role of CCL2, a member of the chemokine family, in early graft damage. Using simultaneous kidney-pancreas transplantation (SPK) as a model, we showed that brain death significantly increases circulating CCL2 levels in humans. We found that in such situations, high donor CCL2 levels (measured before organ recovery and at the onset of cold preservation) correlate with increased postreperfusion release of CCL2 by both the graft and recipient throughout the week following transplantation (n = 28). In a retrospective study of 77 SPK recipients, we found a significant negative association between high donor levels of CCL2 and graft survival. Decreased survival in these patients is related to early posttransplant complications, including a higher incidence of pancreas thrombosis and delayed kidney function. Taken together our data indicate that high CCL2 levels in the donor serum predict both an increase in graft/recipient CCL2 production and poor graft survival. This suggests that the severity of the inflammatory response induced by brain death influences the posttransplant inflammatory response, independent of subsequent ischemia and reperfusion.

Early events in kidney donation: progression of endothelial activation, oxidative stress and tubular injury after brain death

Cerebral injury leading to brain death (BD) causes major physiologic derangements in potential organ donors, which may result in vascular-endothelial activation and affect posttransplant graft function. We investigated the kinetic of pro-coagulatory and pro-inflammatory endothelial activation and the subsequent oxidative stress and renal tubular injury, early after BD declaration. BD was induced by slowly inflating a balloon-catheter inserted in the extradural space over a period of 30 min. Rats (n = 30) were sacrificed 0.5, 1, 2 or 4 h after BD-induction and compared with sham-controls. This study demonstrates immediate pro-coagulatory and pro-inflammatory activation of vascular endothelium after BD in kidney donor rats, proportional with the duration of BD. E- and P-Selectins, Aalpha/Bbeta-fibrinogen mRNA were abruptly and progressively up-regulated from 0.5 h BD onwards; P-Selectin membrane protein expression was increased; fibrinogen was primarily visualized in the peritubular capillaries. Plasma von Willebrand factor was significantly higher after 2 h and 4 h BD. Urine heart-fatty-acid-binding-protein and N-acetyl-glucosaminidase, used as new specific and sensitive markers of proximal and distal tubular damage, were found significantly increased after 0.5 h, with a maximum at 4 h. Unexpectedly, oxidative stress was detectable only late, after the installation of tubular injury, suggesting only a secondary role for hypoxia in triggering these injuries.

Cytokine gene expression in kidney allograft biopsies after donor brain death and ischemia-reperfusion injury using in situ reverse-transcription polymerase chain reaction analysis

BACKGROUND

This study focuses on the cytokine genes expression after brain-death, ischemia-reperfusion injury, and during allograft rejection.

METHODS

A total of 49 needle core biopsies from kidney transplant recipients, performed before and during transplantation procedures were studied. The first biopsy was taken during procurement of the organ, the second after cold ischemia, and the third after approximately 30 min of reperfusion. We also assessed 34 allograft biopsies obtained during acute rejection. Tubular and glomerular expression of interferon (IFN)-gamma, transforming growth factor (TGF)-beta1, platelet-desired growth factor-B (PDGF-B), interleukin (IL)-2, IL-6, IL-10 mRNA was analyzed with reverse-transcription polymerase chain reaction (RT-PCR) in situ technique, which allows to detect a few copies of the target gene without destruction of the tissue architecture.

RESULTS

Compared with normal kidney tissue from living donor, high gene expression of IFN-gamma, TGF-beta1, PDGF-B, IL-2, IL-6, and IL-10 was detected in all procurement specimens. After reperfusion gene expressions of IL-2, IL-6, and IL-10 were significantly upregulated in renal tubules compared to biopsies taken after cold ischemia. The gene expression of IFN-gamma, TGF-beta1, and PDGF-B remained stable after organ procurement, during cold ischemia, and after reperfusion. Gene expression of IFN-gamma, IL-2, IL-6, IL-10, and PDGF-B in procurement biopsies, as well as in those taken after cold ischemia and reperfusion, were significantly higher than during the period of acute rejection.

CONCLUSION

The data presented herein strongly point out the importance of the immunological and morphological injury that occurs before and during transplantation. The increase of inflammatory response after brain death is important for further stimulation of the immune response and long-term kidney survival.

Dopamine treatment in brain-dead rats mediates anti-inflammatory effects: the role of hemodynamic stabilization and D-receptor stimulation

Brain death (BD) is associated with profound inflammation in end-organs. Dopamine (DA) treatment reduces this inflammatory response, but the underlying mechanisms remain thus far largely unknown. In this study, we investigated if the anti-inflammatory effect of DA was related to hemodynamic stabilization and by which receptors it was mediated. BD was induced in F344 donor rats. DA was given either before BD for 24 h or after BD induction during a definite time. Adrenergic or D-receptor blockers were administered to inhibit the receptor stimulation mediated by DA. Hemodynamic changes were recorded and kidneys were harvested after 6 h of BD. Mean arterial pressure was completely normalized by DA treatment. DA pretreatment before BD induction and treatment during BD both significantly inhibited the monocyte infiltration. The anti-inflammatory as well as its blood pressure stabilizing effect was abrogated by concomitant application of adrenergic receptor blockers. In contrast, concomitant application of D-receptor blockers only abrogated the anti-inflammatory effect, but did not affect blood pressure stabilization. In contrast, pergolide and adrenergic receptor blockers completely normalized the blood pressure, but did not affect renal inflammation. Hence, DA might reduce BD-induced monocyte infiltration possibly by hemodynamic stabilization, D-receptor activation, or a combination of both.

Influence of Donor Histology on Outcome in Patients Undergoing Transplantation for Hepatitis C

BACKGROUND

Risk factors for graft loss and recipient death in liver transplantation for hepatitis C virus (HCV) have been extensively investigated. Donor age was defined as one of the most important predictors of outcome in these patients; however, the mechanism leading to more severe recurrent hepatitis has not yet been investigated.

METHOD

In a retrospective analysis, histological findings of 79 donor liver grafts were assessed according to criteria inflammation, fibrosis, fatty degeneration, and necrosis. These findings were correlated with the histological and clinical course of HCV-positive liver graft recipients.

RESULTS

The overall 1-, 5- and 10-year graft survival figures were 85%, 77%, and 60%, respectively. We could not identify any correlation between outcome, fat content, and necrosis in the donor liver. However, stage 3 and 4 fibrosis 1 year after liver transplantation was significantly increased in the group of patients receiving a graft from a donor with portal inflammation (P<0.05). Additionally, the occurrence of intrahepatic inflammation was significantly increased in older donors (P<0.05) and donors with prolonged intensive care hospitalization (P<0.05).

CONCLUSION

A number of risk factors for detrimental outcome in HCV-positive patients after liver transplantation have been identified. In particular, older donor age significantly impaired outcome in recent analysis, but due to donor shortage it is not possible to provide young grafts for all HCV-positive patients. Our data show that donor histology is helpful in identifying patients with more severe recurrent hepatitis prior to transplantation, and that especially in older donors, prolonged intensive care hospitalization should be avoided.

Kidney grafts from brain dead donors: Inferior quality or opportunity for improvement?

Major improvements in immunosuppressive treatment, surgical techniques, and treatment of post-transplant complications have contributed considerably to improved outcome in renal transplantation over the past decades. Yet, these accomplishments have not led to similar improvements in transplant outcome when the results of living and deceased donors are compared. The enormous demand for donor kidneys has allowed for the increase in acceptance of suboptimal donors. The use of brain dead patients as organ donors has had a tremendous positive influence on the number of renal transplants. Unfortunately, the physiologically abnormal state of brain death has a negative effect on transplant outcome. The fact that transplanted kidneys derived from brain dead donors have a decreased viability indicates that potential grafts are already damaged before retrieval and preservation. In this review, we present an overview of the current knowledge of (patho)-physiological effects of brain death and its relevance for renal transplant outcome. In addition, several options for therapeutic intervention during brain death in the donor with the goal to improve organ viability and transplant outcome are discussed.

Non-heart beating organ donation: overview and future perspectives

New indications for organ transplantation combined with a stagnating number of available donor grafts have severely lengthened the waiting list for almost all types of transplantations. This has led to a renewed interest in non-heart beating (NHB) donation, as a possible solution to bridge the gap between supply and demand. In this review, we present an overview of current NHB donation practice, outcome, existing problems and future perspectives. We focus on possible improvements in donor management, recipient care and new methods of organ preservation that may be better suited for these marginal organs. Successful institution of NHB protocols depends on adapting current transplantation practice at all levels, which is one of the greatest challenges for researchers and professionals in this interesting re-emerging field.

Brain death activates donor organs and is associated with a worse I/R injury after liver transplantation

The majority of transplants are derived from donors who suffered from brain injury. There is evidence that brain death causes inflammatory changes in the donor. To define the impact of brain death, we evaluated the gene expression of cytokines in human brain dead and ideal living donors and compared these data to organ function following transplantation. Hepatic tissues from brain dead (n = 32) and living donors (n = 26) were collected at the time of donor laparotomy. Additional biopsies were performed before organ preservation, at the time of transplantation and one hour after reperfusion. Cytokines were assessed by real-time reverse transcriptase-polymerase chain reaction (RT-PCR) and cytometric bead array. Additionally, immunohistological analysis of tissue specimens was performed. Inflammatory cytokines including IL-6, IL-10, TNF-alpha, TGF-beta and MIP-1alpha were significantly higher in brain dead donors immediately after laparotomy compared to living donors. Cellular infiltrates significantly increased in parallel to the soluble cytokines IL-6 and IL-10. Enhanced immune activation in brain dead donors was reflected by a deteriorated I/R injury proven by elevated alanin-amino-transferase (ALT), aspartat-amino-transferase (AST) and bilirubin levels, increased rates of acute rejection and primary nonfunction. Based on our clinical data, we demonstrate that brain death and the events that precede it are associated with a significant upregulation of inflammatory cytokines and lead to a worse ischemia/reperfusion injury after transplantation.

Early hemodynamic injury during donor brain death determines the severity of primary graft dysfunction after lung transplantation

Sympathetic discharge and hypertensive crisis often accompany brain death, causing neurogenic pulmonary edema. Progressive systemic inflammatory response develops, which can injure the lung further. We investigated whether (a) early hemodynamic injury during donor brain death increases reperfusion injury after lung transplantation and (b) delaying lung recovery would augment reperfusion injury further, because of the progressive systemic inflammatory response in the donor. Brain death was induced by intracranial balloon inflation in rats, with or without alpha-adrenergic blockade pretreatment to prevent the hypertensive crisis. Another group of rats had a sham procedure. Lungs were retrieved 15 min after brain death or sham procedure and reperfused using recipient rats. In a fourth group, brain death was induced and the lungs were retrieved 5 h after brain death and reperfused. Postreperfusion, lungs retrieved early from untreated brain-dead donors developed more severe reperfusion injury, as assessed by functional parameters and inflammatory markers, than those from sham or alpha-blockade-treated donors. Lungs retrieved late from brain-dead donors had similar inflammatory markers after reperfusion to those retrieved early, but significantly lower pulmonary vascular resistance. Early hemodynamic damage during donor brain death increases reperfusion injury after lung transplantation. Delaying retrieval may allow the lung to recover from the hemodynamic injury.

Time-dependent changes in donor brain death related processes

Donor brain death (BD) affects kidney function and survival after transplantation. Studies on brain dead kidney donors indicate that, besides inflammation and coagulation, cytoprotective gene expression is activated as well. Here, we evaluated in a time-course experiment progression of these renal BD-related processes. Animals were sacrificed 0.5, 1, 2 or 4 h after BD and compared to sham-operated controls. Proinflammatory genes (E-selectin, MCP-1, II-6) were massively up-regulated (p < 0.05) already 0.5 h after BD. Inducers of proinflammatory gene expression were either activated (NF-kappaB) or induced in expression (Egr-1) after 0.5 h of BD. Increased numbers of infiltrating granulocytes were seen in the interstitium from 0.5 h on. Also, expression of protective genes HO-1 and HSP70 were increased within 0.5 h. Remarkably, reactive oxygen species formation was detectable only in the later phase of BD. Among 14 measured serum cytokines, MCP-1 and KC-protein were significantly elevated from 0.5 h on. In conclusion, a fast induction of proinflammatory and stress-induced protective processes in brain dead donor kidneys was demonstrated, probably triggered by changes occurring during BD induction. Importantly, hypoxia appeared not to be one of the initial triggers, and early increased systemic levels of chemokines MCP-1 and KC may be regarded as the starting point for the inflammatory cascade in brain dead donor kidneys.

Improved long-term graft survival after HO-1 induction in brain-dead donors

Brain death (BD) of the donor, a risk factor uniquely relevant for organs derived from cadaver donors, influences organ quality by induction of various inflammatory events. Consequently ischemia/reperfusion injury is deteriorated and acute and chronic rejections accelerated. Donor treatment might be an approach to improve the quality of the graft. The induction of heme oxygenase 1 (HO-1) has been shown to exert beneficial effects in living-donor transplantation models. Therefore, we examined the impact of donor treatment with the selective inducer of HO-1, cobalt protoporphyrin (CoPP), on organ quality and transplant outcome in a standardized BD model in a F344-->LEW kidney transplant rat model. Immediately after BD induction, donor animals were administered a single dose of CoPP (5 mg/kg) and in control groups, HO-1 activity was blocked with zinc protoporphyrin (ZnPP, 20 mg/kg). Recipients of organs from brain-dead donors treated with CoPP survived significantly better than those from untreated brain-dead donors (p < 0.05) and intra-graft analysis showed improved histology (p < 0.05). Blockade of HO-1 with ZnPP decreased the survival rates (p < 0.05) comparable to untreated brain-dead donors. Our results demonstrate that HO-1 induction by one single treatment of CoPP in brain-dead donors leads to enhanced allograft survival.