Multiorgan procurement increases systemic inflammation in brain dead donors

Activation of the Innate Immune System in Brain-Dead Donors Can Be Reduced by Luminal Intestinal Preservation During Organ Procurement Surgery - A Porcine Model

Organs obtained from brain dead donors can have suboptimal outcomes. Activation of the innate immune system and translocation of intestinal bacteria could be causative. Thirty two pigs were assigned to control, brain death (BD), BD + luminal intestinal polyethylene glycol (PEG), and BD + luminal intestinal University of Wisconsin solution (UW) groups. Animals were observed for 360 min after BD before organ retrieval. 2,000 mL luminal intestinal preservation solution was instilled into the duodenum at the start of organ procurement. Repeated measurements of plasma C3a, Terminal Complement Complex (TCC), IL-8, TNF, and lipopolysaccharide binding protein were analysed by immunoassays. C3a was significantly higher in the BD groups compared to controls at 480 min after brain death. TCC was significantly higher in BD and BD + UW, but not BD + PEG, compared to controls at 480 min. TNF was significantly higher in the BD group compared to all other groups at 480 min. LPS binding protein increased following BD in all groups except BD + PEG, which at 480 min was significantly lower compared with all other groups. Brain death induced innate immune system activation was decreased by luminal preservation using PEG during organ procurement, possibly due to reduced bacterial translocation.

Induced Coma, Death, and Organ Transplantation: A Physiologic, Genetic, and Theological Perspective

In the clinic, the death certificate is issued if brain electrical activity is no longer detectable. However, recent research has shown that in model organisms and humans, gene activity continues for at least 96 h postmortem. The discovery that many genes are still working up to 48 h after death questions our definition of death and has implications for organ transplants and forensics. If genes can be active up to 48 h after death, is the person technically still alive at that point? We discovered a very interesting parallel between genes that were upregulated in the brain after death and genes upregulated in the brains that were subjected to medically-induced coma, including transcripts involved in neurotransmission, proteasomal degradation, apoptosis, inflammation, and most interestingly, cancer. Since these genes are involved in cellular proliferation, their activation after death could represent the cellular reaction to escape mortality and raises the question of organ viability and genetics used for transplantation after death. One factor limiting the organ availability for transplantation is religious belief. However, more recently, organ donation for the benefit of humans in need has been seen as “posthumous giving of organs and tissues can be a manifestation of love spreading also to the other side of death”.

Severe primary graft dysfunction of the heart transplant is associated with increased plasma and intragraft proinflammatory cytokine expression

INTRODUCTION

Heart transplant results have constantly improved but primary left ventricle graft dysfunction (LV-PGD) remains a devastating complication early after transplantation. Donor and recipient systemic inflammatory response may be involved in immune activation of the transplant, and LV-PGD development. Here, we investigated donor and recipient plasma and intragraft cytokine profiles preoperatively and during LV-PGD and searched for predictive markers for LV-PGD.

METHODS

Donor and recipient plasma samples (n = 74) and myocardial biopsies of heart transplants (n = 64) were analyzed. Plasma and intragraft cytokine levels were determined by multiplexed and next-generation sequencing platforms, respectively. The development of LV-PGD during the first 24 hours, and graft function and mortality up to 1 year after transplantation, were examined.

RESULTS

Severe LV-PGD, but not mild or moderate LV-PGD, was significantly associated with early mortality, plasma high-sensitivity troponin elevation, and an increase in intragraft and plasma proinflammatory cytokines during reperfusion. Preoperative donor and recipient plasma cytokine levels failed to predict LV-PGD. Cytokine network analysis identified interleukins -6, -8, -10, and -18 as key players during reperfusion. Prolonged cold and total ischemia time, and increased need for red blood cell transfusions during operation were identified as clinical risk factors for severe LV-PGD.

CONCLUSIONS

Severe LV-PGD was associated with a poor clinical outcome. Donor and recipient plasma cytokine profile failed to predict LV-PGD, but severe LV-PGD was associated with an increase in post-reperfusion intragraft and recipient plasma proinflammatory cytokines. Identified key cytokines may be potential therapeutic targets to improve early and long-term outcomes after heart transplantation.

Design and Rationale of a Scandinavian Multicenter Randomized Study Evaluating if Once-Daily Tacrolimus Versus Twice-Daily Cyclosporine Reduces the 3-year Incidence of Chronic Lung Allograft Dysfunction After Lung Transplantation (ScanCLAD Study)

Background

A low level of evidence exists regarding the choice of calcineurin inhibitor (CNI) for immunosuppression after lung transplantation (LTx). Therefore, we designed a randomized clinical trial according to good clinical practice rules to compare tacrolimus with cyclosporine after LTx.

Methods

The ScanCLAD study is an investigator-initiated, pragmatic, controlled, randomized, open-label, multicenter study evaluating if an immunosuppressive protocol based on anti-thymocyte globulin (ATG) induction, once-daily tacrolimus dose, mycophenolate mofetil, and corticosteroid reduces the incidence of chronic lung allograft dysfunction (CLAD) after LTx, compared to a cyclosporine-based protocol with all other immunosuppressive and prophylactic drugs being identical between groups. All patients will be followed for 3 years to determine the main endpoint of CLAD. The study is designed for superiority, and power calculations show that 242 patients are needed. Also, the study is designed with more than 10 substudies addressing other important and unresolved issues in LTx. In addition, the ScanCLAD study enabled the synchronization of the treatment and follow-up protocols of the lung transplantation programs of all five Scandinavian lung transplantation centers.

Planned Outcomes

Recruitment started in 2016. At the end of April 2019, 227 patients were randomized. We anticipate the last patient to be randomized in autumn 2019, and thus the last patient visits will be in 2022. The ScanCLAD study is enrolling and investigates which CNI is to be preferred from a CLAD perspective after LTx.

Trial Registry Number

ScanCLAD trial registered at ClinicalTrials.gov before patient enrollment (NCT02936505). EUDRACT number 2015-004137-27.

Structural differences in the diaphragm of patients following controlled vs assisted and spontaneous mechanical ventilation

PURPOSE

Ventilator-induced diaphragm dysfunction or damage (VIDD) is highly prevalent in patients under mechanical ventilation (MV), but its analysis is limited by the difficulty of obtaining histological samples. In this study we compared diaphragm histological characteristics in Maastricht III (MSIII) and brain-dead (BD) organ donors and in control subjects undergoing thoracic surgery (CTL) after a period of either controlled or spontaneous MV (CMV or SMV).

METHODS

In this prospective study, biopsies were obtained from diaphragm and quadriceps. Demographic variables, comorbidities, severity on admission, treatment, and ventilatory variables were evaluated. Immunohistochemical analysis (fiber size and type percentages) and quantification of abnormal fibers (a surrogate of muscle damage) were performed.

RESULTS

Muscle samples were obtained from 35 patients. MSIII (n = 16) had more hours on MV (either CMV or SMV) than BD (n = 14) and also spent more hours and a greater percentage of time with diaphragm stimuli (time in assisted and spontaneous modalities). Cross-sectional area (CSA) was significantly reduced in the diaphragm and quadriceps in both groups in comparison with CTL (n = 5). Quadriceps CSA was significantly decreased in MSIII compared to BD but there were no differences in the diaphragm CSA between the two groups. Those MSIII who spent 100 h or more without diaphragm stimuli presented reduced diaphragm CSA without changes in their quadriceps CSA. The proportion of internal nuclei in MSIII diaphragms tended to be higher than in BD diaphragms, and their proportion of lipofuscin deposits tended to be lower, though there were no differences in the quadriceps fiber evaluation.

CONCLUSIONS

This study provides the first evidence in humans regarding the effects of different modes of MV (controlled, assisted, and spontaneous) on diaphragm myofiber damage, and shows that diaphragm inactivity during mechanical ventilation is associated with the development of VIDD.

Direct peritoneal resuscitation reduces inflammation in the kidney after acute brain death

Brain death is associated with significant inflammation within the kidneys, which may contribute to reduced graft survival. Direct peritoneal resuscitation (DPR) has been shown to reduce systemic inflammation after brain death. To determine its effects, brain dead rats were resuscitated with normal saline (targeted intravenous fluid) to maintain a mean arterial pressure of 80 mmHg; DPR animals also received 30 cc of intraperitoneal peritoneal dialysis solution. Rats were euthanized at 0, 2, 4, and 6 h after brain death. Pro-inflammatory cytokines were measured using ELISA. Levels of IL-1β, TNF-α, and IL-6 in the kidney were significantly increased as early as 2 h after brain death and significantly decreased with DPR. Levels of leukocyte adhesion molecules ICAM and VCAM increased after brain death and were decreased with DPR (ICAM 2.33 ± 0.14 vs. 0.42 ± 0.04, P = 0.002; VCAM 82.6 ± 5.8 vs. 37.3 ± 1.9, P = 0.002 at 4 h) as were E-selectin and P-selectin (E-selectin 25,605 vs. 16,144, P = 0.005; P-selectin 82.5 ± 3.3 vs. 71.0 ± 2.3, P = 0.009 at 4 h). Use of DPR reduces inflammation and adhesion molecule expression in the kidneys, and is associated with reduced macrophages and neutrophils on immunohistochemistry. Using DPR in brain dead donors has the potential to reduce the immunologic activity of transplanted kidneys and could improve graft survival.

Endothelial precursor cell cross-match using Tie-2-enriched spleen cells

BACKGROUND

Non-HLA antibodies against human endothelial progenitor cells (EPC) in pre-transplant recipient serum can have a deleterious influence on the graft. EPC enriched from peripheral blood have been commonly used for EPC cross-matching. In the present study, we describe cross-matches using EPC enriched from fresh or frozen-thawed spleen cell preparations, thereby widening the sample source for deceased-donor cross-matching and retrospective studies.

METHODS

EPC cross-matches were performed retrospectively using spleen cells and the flow cytometric XM-ONE cross-match test kit.

RESULTS

Healthy controls (n = 28) showed no IgG antibodies against EPC. When sera of 11 random dialysis patients were studied, 2 patients (18%) exhibited IgG EPC antibodies. When pre-transplant sera of 20 kidney graft recipients with good long-term graft outcome (serum creatinine 1.0 ± 0.2 mg/dL measured 2463 ± 324 days post-transplant) were investigated using frozen-thawed and then separated Tie-2-enriched spleen cells of the original transplant donor, 3 patients (15%) had pre-transplant IgG EPC antibodies. When pre-transplant sera of 5 patients with intra-operative graft loss were studied employing the original donor spleen cells, 4 (80%) patients showed IgG EPC antibodies.

CONCLUSIONS

Cross-matches with spleen cell-derived EPC using the XM-ONE assay are technically possible. Our very preliminary experience suggests clinical relevance.

Gene expression in the twilight of death: The increase of thousands of transcripts has implications to transplantation, cancer, and forensic research

After a vertebrate dies, many of its organ systems, tissues, and cells remain functional while its body no longer works as a whole. We define this state as the "twilight of death" - the transition from a living body to a decomposed corpse. We claim that the study of the twilight of death is important to ethical, legal and medical science. We examined gene expression at the twilight of death in the zebrafish and mouse reaching the conclusion that apparently thousands of transcripts significantly increase in abundance from life to several hours/days postmortem relative to live controls. Transcript dynamics of different genes provided "proof-of-principle" that models accurately predict an individual's elapsed-time-of-death (i.e. postmortem interval). While many transcripts were associated with survival and stress compensation, others were associated with epigenetic factors, developmental control, and cancer. Future studies are needed to determine whether the high incidence of cancer in transplant recipients is due to the postmortem processes in donor organs.

Proteomic analysis of differentially expressed proteins in kidneys of brain dead rabbits

A large number of previous clinical studies have reported a delayed graft function for brain dead donors, when compared with living relatives or cadaveric organ transplantations. However, there is no accurate method for the quality evaluation of kidneys from brain-dead donors. In the present study, two-dimensional gel electrophoresis and MALDI-TOF MS-based comparative proteomic analysis were conducted to profile the differentially-expressed proteins between brain death and the control group renal tissues. A total of 40 age- and sex-matched rabbits were randomly divided into donation following brain death (DBD) and control groups. Following the induction of brain death via intracranial progressive pressure, the renal function and the morphological alterations were measured 2, 6 and 8 h afterwards. The differentially expressed proteins were detected from renal histological evidence at 6 h following brain death. Although 904±19 protein spots in control groups and 916±25 in DBD groups were identified in the two-dimensional gel electrophoresis, >2-fold alterations were identified by MALDI-TOF MS and searched by NCBI database. The authors successfully acquired five downregulated proteins, these were: Prohibitin (isoform CRA_b), beta-1,3-N-acetylgalactosaminyltransferase 1, Annexin A5, superoxide dismutase (mitochondrial) and cytochrome b-c1 complex subunit 1 (mitochondrial precursor). Conversely, the other five upregulated proteins were: PRP38 pre-mRNA processing factor 38 (yeast) domain containing A, calcineurin subunit B type 1, V-type proton ATPase subunit G 1, NADH dehydrogenase [ubiquinone] 1 beta subcomplex subunit 10 and peroxiredoxin-3 (mitochondrial). Immunohistochemical results revealed that the expressions of prohibitin (PHB) were gradually increased in a time-dependent manner. The results indicated that there were alterations in levels of several proteins in the kidneys of those with brain death, even if the primary function and the morphological changes were not obvious. PHB may therefore be a novel biomarker for primary quality evaluation of kidneys from brain-dead donors.

Study of the Role of Transforming Growth Factor β-1 in Organ Damage Protection in Porcine Model of Brain Death

BACKGROUND

From the medical and ethical points of view, donation after brain death is a more acceptable organ source than that from a living donor because it has the advantage of providing multiple organs from a single donor source. Hence, it has become a more promising field of research which focuses on the protection of organs at brain death Here we investigated the role of transforming growth factor (TGF)-β1 in a porcine model of brain death.

METHODS

A porcine model of brain death was established by increasing the intracranial pressure (ICP) after which TGF-β1 was monitored by immunofluorescence at the following time points: before ICP was performed (t1), at brain death (t2), and at 3 (t3), 6 (t4), 9 (t5), and 18 (t6) hours after brain death. The data were analyzed using the fixed effect regression method and the correlation between the results was determined by Pearson analysis.

RESULTS

Our results showed that there was a significant increase in the levels of TGF-β1 (P < .05), urea (P < .01), creatinine (P < .01), and aspartate aminotransferase (AST; P < .01) during the 18-hour brain death process. There were negative correlations between TGF-β1 and urea, creatinine, alanine aminotransferase, AST, and total bilirubin. The negative correlations between TGF-β1 and creatinine and AST achieved statistical significance (P < .05).

CONCLUSIONS

These findings taken together confirm that significant damages are caused to the myocardial fiber cell and kidney glomerulus during brain death process, and that TGF-β1 is associated with the protection of these organs.

Circulating resistin levels are early and significantly increased in deceased brain dead organ donors, correlate with inflammatory cytokine response and remain unaffected by steroid treatment

INTRODUCTION

Resistin is a pro-inflammatory adipokine that increases after brain injury (trauma, bleeding) and may initiate an inflammatory response. Resistin was found increased in deceased, brain dead organ donors (DBD) and correlated with delayed graft function after kidney transplantation. The kinetics of resistin during brain death (BD), its impact on the inflammatory response and the influence of several donor variables on resistin levels are still unknown.

METHODS

Resistin along with a panel of Th1/Th2 cytokines [interferon (IFN)-gamma, interleukin (IL)-1beta, IL-2, IL-6, IL-8, IL10, IL-12, IL-13 and tumor necrosis factor (TNF)] was analyzed in 36 DBDs after the diagnosis of BD and before organ procurement and in 12 living kidney donors (LD). The cytokine levels and resistin were analyzed in relation to donor parameters including cause of death, donors' age and steroid treatment.

RESULTS

Resistin levels were higher in DBDs both at BD diagnosis and before organ procurement compared to LD (p < 0.001). DBDs had significantly increased IL-1beta, IL-6, IL-8, IL-10 and TNF levels at both time points compared with LD. In DBDs, resistin at BD diagnosis correlated positively with IL-1beta (rs 0.468, p = 0.007), IL-6 (rs 0.511, p = 0.002), IL-10 (rs 0.372, p = 0.028), IL-12 (rs 0.398, p = 0.024), IL-13 (rs 0.397, p = 0.030) and TNF (rs 0.427, p = 0.011) at procurement. The cause of death, age over 60 and steroid treatment during BD did not affect resistin levels. However, steroid treatment significantly decreased pro-inflammatory cytokines IL-1beta, IL-8, TNF and IFN-gamma at the time of organ procurement.

CONCLUSIONS

Resistin is increased early in DBDs, remains increased throughout the period of BD and correlates strongly with pro-inflammatory mediators. Resistin level, in contrast to cytokines, is not affected by steroid treatment. Resistin increase is related to the BD but is not influenced by age or cause of death. Resistin may be one of the initial triggers for the systemic inflammatory activation seen in DBDs.

Treating the donor

PURPOSE OF REVIEW

Current pressures of organ supply and demand require maximization of potential for organ donation. The donor population is older and has more significant comorbidity than in the past.Optimal management of the donor after brain death (DBD) is essential to ensure that the greatest number of organs can be transplanted per donor. Defining evidence-based drugs and techniques to assist this has never been more important.

RECENT FINDINGS

Care of patients with catastrophic brain injury incorporating supportive therapy targeted at specific goals and delivered by experienced specialists provides the best donation outcomes. Such pathways represent best practice critical care applied to this population. In this context, the value of some previously recommended therapies appears questionable and warrants reassessment. Prolonged (>24 h) incorporeal organ conditioning may have significant benefits.Extracorporeal support in the resuscitation arena is emerging and, in patients who fail to respond, may yield a new source of donors.

SUMMARY

Early identification of potential DBD, best practice critical care, and achieving defined treatment goals are associated with more transplantable organs. Study of a complex intervention like donor management presents significant problems of organization, ethics and consent. This situation is recognized internationally and progress is being made.