Regulatory T cells

Transplantation is a successful way to treat people whose own organs stop working but to prevent rejection transplant recipients have to take potent immunosuppressive drugs for the rest of their lives. Appropriate combinations of these drugs can be effective, but this requires life-long administration and results in suppression of the entire immune system non-specifically, including in some cases, the development and function of cells that have the potential to control rejection.
As a result, transplant recipients have an increased risk of cancer and infection, suffer from side-effects associated with the drug therapy and require on-going, intensive clinical management.
Understanding how the immune system is controlled when it responds to a transplant, and promoting the development and function of cells that can prevent rejection selectively hold the key to reducing the unwanted side-effects of immunosuppression.

We work with the Transplantation Research Immunology Group at the University of Oxford to address these challenges. Our programme of research focuses on how, when and where specialised cells that can control transplant rejection work and what stops them from working.
The key areas we are currently investigating include:

• Strategies for the induction of tolerance using biological therapeutic agents
• The mechanisms of tolerance particularly the role of regulatory T cells and their therapeutic potential
• Use of regulatory T cells as a cellular therapy in the TWO Study, one of the largest clinical trials in kidney transplantation
• The translation of laboratory findings to clinical transplantation through the development and validation of biomarkers for monitoring the immune status of transplant recipients

The results we obtain will also help develop new treatments for people who have autoimmune diseases, are allergic or have cancer, where controlling the immune system selectively is also critically important.

QUOD: a bio-resource aiming to improve the quality of donated organs for transplantation

Despite the advances made in recent years in organ donation and transplantation, a significant and widening disparity exists between supply and demand. This is predicted to worsen over the next decade, making this a major challenge facing the transplant community today.
Quality in Organ Donation (QUOD) is a national consortium formed of clinicians and scientists from intensive care and transplant units across the United Kingdom, working together with dedicated operational staff from NHS Blood and Transplant (NHSBT) to facilitate research to increase the number and quality of organs available for transplantation.

QUOD has established a national centralised biobank of blood, urine and tissues from DBD (Donation after brain death) and DCD (Donation after circulatory death) donors, collected nationally by transplant professionals throughout the organ donation process and hosted by the University of Oxford. In December 2020, QUOD reached the milestone of 5,000 donors. In addition, QUOD has access to comprehensive donor and recipient clinical data from NHSBT which are invaluable for research studies and multivariate analysis. Together, the samples and the data allow researchers to explore improvements in how we assess a donor organ and match it to the right recipient, thereby increasing the number of transplantable donor organs.

Thanks to funding received in 2017 from the UK Medical Research Council, QUOD has expanded to accept whole organs for study as well. Using these, we will create a searchable library to include genome, proteome and pathology atlases of organs to predict outcomes of transplantation as well as providing data and samples for hypothesis driven work. This will allow us to turn to organs from older and higher risk donors to increase organ utilisation without compromising outcomes. The QUOD infrastructure also aims to be a platform for service development and interventional clinical trials in the donor to improve survival in transplantation. Examples are QUOD’s support at the time of introduction of the Normothermic Regional Perfusion project, the PITHIA trial as well as for the pending study to evaluate the impact of administration of statins on the quality of the donor organs. In addition, the QUOD team has helped to establish the NHSBT COVID Bioarchive, including the sample collections of the RECOVERY and REMAP-CAP trials. 

Combining the enthusiasm and commitment of clinicians and scientists will advance the quality in donation and transplantation widening our horizons in transplantation research.

For more information please visit the QUOD website:
www.quod.org.uk 

COPE Consortium

The COPE Consortium was funded by a European Commission FP7 Award and is the official organ preservation task force of the European Society for Organ Transplantation (ESOT). The Consortium brings together academic institutions, clinical and scientific experts and SMEs from across Europe to work together on advancing organ preservation techniques and is being led by Professor Rutger Ploeg in Oxford.

The COPE Consortium aims to advance and develop organ preservation technologies by performing clinical and translational studies with on-going experimental refinement. Through testing the quality and safety, increasing the efficiency and refining preservation strategies we aim to bring technologies from the bench to the bedside.

The four strategic objectives of the programme are:
1. To test in clinical trials a number of novel clinical approaches to repairing and preserving high-risk donor organs.
2. To investigate in experimental models a number of novel scientific approaches to organ repair and regeneration.
3. To develop new objective methods to measure and predict the viability and outcome of donated organs.
4. To develop an integrated network of academic clinicians and scientists in Europe that, in collaboration with SMEs and ESOT, will develop and implement new medical therapies and devices in organ transplantation.

The Consortium successfully concluded recruitment for three clinical trials. Results from the first trial lead by Professor Peter Friend were published as the cover article in Nature in spring 2018, revealing that normothermic machine perfusion of the liver results in better liver function and lower organ discard rates. Results from the second trial lead by Professors Paul and Ploeg indicate positive outcomes from oxygenating kidneys during cold machine perfusion with better function, lower graft failure and a significant reduction in rejection; these were published in The Lancet in November 2020. Results from the third trial are currently being assessed.

In addition, the Consortium conducted two experimental work packages aimed at testing and refining novel perfusion techniques and additives. The Consortium also developed a biorepository of samples from the clinical trials to aid in mechanistic and biomarker studies. At present, COPE investigators have initiated over three dozen of these studies using samples from the clinical trials, with research still in progress.

For more information please visit the COPE website www.cope-eu.org

Pancreas Transplantation

Metabolic Outcomes

Pancreas transplantation is an established treatment for selected patients with type 1 diabetes mellitus that returns glucose levels to normal without the need for insulin therapy.  This results in improved quality of life and life expectancy for recipients.  However, some patients suffer from reduced function of their new pancreas following a pancreas transplant, and this can progress to the pancreas transplant failing completely.  At the moment, there is no easy way to monitor the function of a pancreas transplant, and patients must live with the uncertainty of not knowing how long their pancreas might function.  If we had a way of monitoring how well the pancreas transplant is working, we would be able to see when the pancreas is working less well much earlier.  This would allow us to intervene with treatment earlier, and possibly improve graft survival.  We have developed a novel method for monitoring and quantifying pancreas graft function, which could be used routinely in the management of all pancreas transplant recipients.  This study is designed to rigorously test our novel method in pancreas transplant recipients and healthy volunteers.  We have completed the study successfully and in are preparing the results to submit to scientific journals for publication. 

Shruti Mittal

Pancreas Transplantation 

Ischaemia-reperfusion

The NHS BT annual report 2019 has shown current pancreas graft survival at one year in the UK is 87%, with 5-year survival at 79%. The rate of early pancreas graft loss (within the first three months) is substantially greater than other solid abdominal organs (kidney, liver) and the primary reason for this is the severe implications of ischaemia-reperfusion injury. 
In transplantation, the insult of ischaemia, cold storage and the reperfusion of blood following organ implantation trigger an inflammatory cascade. This presents clinically with a range from mild symptoms to life threatening systemic inflammation; the extent and clinical impact of this varies between organs and patients.
Allograft pancreatitis is the commonest major complication following whole organ pancreas transplantation affecting approximately 40-50% of patients. This causes significant morbidity and mortality, both directly and indirectly, leading to more operations, graft loss and substantially increased inpatient hospital stay. In addition, early pancreas graft injury has longer-term implications: data from the Oxford Transplant Centre has shown that the 30% of pancreas graft recipients that exhibit early glucose intolerance, have poor graft survival, with at least 25% returning to insulin therapy within 1- year post-transplant.
Pancreas transplantation is an ideal model in which to examine the potential therapeutic benefit of amelioration of inflammation following ischaemia reperfusion; this is because ischaemia-reperfusion injury in the pancreas has particularly significant clinical impact.
The pathogenesis of pancreatitis involves oxidative stress, which leads to activation of the Tyrosine- Kinase pathway, Janus kinase/signal transducer and cytokines expression. 
We have been studying a novel approach to minimize the incidence and severity of graft pancreatitis after pancreas transplantation. In this clinical trial, the participants will be given a short course of anti-inflammatory drug (Tyrosine Kinase inhibitor). The aim of this study is to assess the safety and anti-inflammatory effect of this intervention on allograft pancreatitis and ischaemia reperfusion injury, by measuring inflammatory markers and imaging of the transplanted pancreas. The study is designed to explore the benefit of this intervention to pancreas transplant patients. We believe this intervention will be able to dampen the inflammatory process, which will improve patient’s outcome and graft survival.  

Faysal Elgilani

European liver perfusion trial  

The global shortage of livers for transplantation has necessitated the use of increasingly marginal organs. Normothermic machine perfusion (NMP) of the liver is a technique of organ preservation in which the liver is perfused with oxygenated blood, medications and nutrients at normal body temperature in order to preserve it in a physiological functioning state. Previous animal work has suggested that this could improve the quality of organs and so potentially enable more marginal livers to be transplanted successfully. The trial is the first multinational randomized controlled trial to compare the efficacy of normothermic machine perfusion with conventional static cold storage in human liver transplantation. 
This investigator-initiated, multinational, open-label, randomised controlled trial was sponsored by the University of Oxford and funded through COPE. The seven trial sites included four UK transplant centres (Addenbrooke’s Hospital, Cambridge; King’s College Hospital, London; Queen Elizabeth Hospital, Birmingham; Royal Free Hospital, London) and University Hospital, Essen, Germany; University Hospitals, Leuven, Belgium; and Hospital Clinic, Barcelona, Spain. 
Livers from adult donors after neurological (DBD) and cardiovascular (DCD) certification of death were randomly assigned to NMP or SCS. The trial was powered (90%) to show a 33% difference in the primary endpoint, peak AST (a clinically accepted biomarker for graft and patient survival). Secondary endpoints included: organ utilisation; preservation time; reperfusion haemodynamics; early allograft dysfunction (EAD); hospital stay; cholangiopathy seen on MRCP; graft and patient survival. 
Between 26th June 2014 and 8th March 2016, 272 livers (135 SCS, 137 NMP) were enrolled, consisting of 194 DBD and 78 DCD organs. 48 livers were discarded (32 SCS [15 DBD, 17 DCD] vs 16 NMP [10 DBD, 6 DCD]; p=0.01). NMP livers experienced significantly longer preservation times than SCS (7hr 21min vs 11hr 39min; p< 0.01). Despite this, better early graft function was observed in the NMP group with regards to peak AST (974 IU/L SCS vs 485IU/L NMP; p< 0.001) and EAD (29.9% SCS vs 12.6% NMP; p=0.002) with the magnitude of these effects being greater for DCD organs (p=0.02). 
Only one patient in each arm developed clinically significant evidence of ischaemic cholangiopathy within the first year after transplant, both of whom required re-transplantation. On MRI scan at 6 months there was no difference seen in the radiological rate of non-anastomotic biliary strictures in DBD livers (5.4% SCS vs 7.4% NMP; p=0.678) or DCD livers (5/19 (26.3%) SCS vs 3/27 (11.1%) NMP; p=0.18).  
There was no measurable difference between the two trial arms in ITU stay, hospital stay, or one year graft and patient survival. 
This study was the first randomized trial to compare any form of machine perfusion with static cold storage in human liver transplantation. It showed the technique to be safe and feasible in clinical practice across four European countries. NMP was associated with considerably lower markers of preservation injury (peak-AST) despite these livers being preserved for substantially longer durations and more NMP livers going on to be transplanted than in the SCS arm. Peak-AST is a clinical biomarker of long-term graft and patient survival, although no difference was seen in this outcome at one year; a much larger study would be required to measure a difference in this outcome. 
Beyond the clinical outcomes, perhaps the most important findings from this study are the implications for future work in this area. Now that the efficacy of NMP has been demonstrated against conventional storage techniques in standard criteria livers, the next step is to apply the technology to livers outside conventional acceptance criteria.  
These results have now been published in the journal Nature and can be found at: 
https://www.nature.com/articles/s41586-018-0047-9

 
Nasralla D, Coussios CC, Mergental H, Akhtar MZ, Butler AJ, Ceresa CDL, Chiocchia V, Dutton SJ, García-Valdecasas JC, Heaton N, Imber C, Jassem W, Jochmans I, Karani J, Knight SR, Kocabayoglu P, Malagò M, Mirza D, Morris PJ, Pallan A, Paul A, Pavel M, Perera MTPR, Pirenne J, Ravikumar R, Russell L, Upponi S, Watson CJE, Weissenbacher A, Ploeg RJ, Friend PJ; on behalf of the Consortium for Organ Preservation in Europe.   A randomized trial of normothermic preservation in liver transplantation   Nature. 2018 May;557(7703):50-56. 
 
David Nasralla  
 

Novel strategies to enhance fatty livers for transplantation

Liver transplantation has become a victim of its own success and 20% of patients on the UK waiting list die without a liver transplant. Steatotic (fatty) livers derive particularly poor outcomes when transplanted and a result a large number are discarded. With the global obesity epidemic, an increasing number of steatotic livers in the donor pool is inevitable and identifying methods to salvage these livers is of great importance.

Normothermic machine perfusion (NMP) is a novel preservation technique which maintains the liver in a fully functioning state outside the body; providing it with oxygen and nutrition at normal body temperature. This facilitates extended preservation times, functional liver assessment and the potential for liver-directed therapeutic interventions.

At the Oxford Transplant Centre, Professor Friend’s liver perfusion group are performing perfusion studies of steatotic human livers which have been deemed too high risk for transplantation. By perfusing the livers for 48 hours with de-fatting agents and other adjuncts, the group hope to gain an understanding of NMP’s potential in the enhanced preservation and de-fatting of steatotic livers. If successful, this will increase the number of livers available for transplantation and take significant steps to abolish waiting list deaths.

Carlo Ceresa

Normothermic Kidney Perfusion

 We developed of a transportable normothermic kidney preservation device which is able to perfuse discarded human and porcine kidneys for up to 24 hours. Recirculation of the urine to facilitate maintenance of perfusate volume and homeostasis is a novel approach and applied successfully. Utilisation of this perfusion device could enable viability assessment, decrease organ discard rate and improve transplantation logistics. Thirty-six clinically declined human kidneys were perfused: n=4 kidneys were perfused using Ringer’s lactate to replace excreted urine volume, and n=32 using urine recirculation. In all cases, normothermic perfusion either maintained or slightly improved the histopathologically assessed tubular condition, achieved physiological arterial flow levels and effective urine production. Biomarkers were detected and quantified in the perfusates with and without urine recirculation. Only kidneys with urine recirculation were readily perfused up to 24 hours and exhibited physiological perfusate sodium levels, whilst kidneys without urine recirculation achieved reduced normothermic perfusion time and significantly higher perfusate sodium. Metabolomics analyses of perfusate samples detected urea and two sugars as the main difference between kidneys with and without urine recirculation. Proteomics analyses not only revealed that human kidneys have become metabolically active during normothermic perfusion, but they also detected that damage-associated molecular patterns known to contribute to ischaemia-reperfusion-injury, were significantly downregulated in biopsies from kidneys with urine recirculation compared to kidneys without. Porcine perfusion studies were performed with the aim to revisit the findings obtained during the human experiments and to render a valid comparison between urine recirculation and urine replacement in undamaged kidneys.

Annemarie Weissenbacher

1) Weissenbacher A, Lo Faro L, Boubriak O, Soares MF, Roberts IS, Hunter JP, Voyce D, Mikov N, Cook A, Ploeg RJ, Coussios CC, Friend PJ. Twenty-four-hour normothermic perfusion of discarded human kidneys with urine recirculation.
Am J Transplant. 2019 Jan;19(1):178-192.
2) Weissenbacher A, Voyce D, Ceresa CDL, Soares MF, Roberts IS, Hunter JP, Cook A, Ploeg RJ, Coussios CC, Friend PJ. Urine Recirculation Improves Hemodynamics and Enhances Function in Normothermic Kidney Perfusion.
Transplant Direct. 2020 Mar 13;6(4):e541.
3) Weissenbacher A, Huang H, Surik T, Lo Faro ML, Ploeg RJ, Coussios CC, Friend PJ, Kessler BM. Urine recirculation prolongs normothermic kidney perfusion via more optimal metabolic homeostasis-a proteomics study.

Sentinel Skin

Sentinel Skin Grafts 

The observation that the abdominal wall transplanted skin could be seen to develop a rash when acute rejection was occurring led to the development of the sentinel skin flap. This is a skin bearing Vascularised Composite Allograft (VCA) from the same donor and transplanted simultaneously as the intestinal, pancreas or kidney pancreas transplants and used to monitor these transplants for acute rejection.
Research in the utility of these sentinel skin flaps for monitoring the unseen buried solid organ transplants is continuing, particularly trying to unravel the immunological mechanisms.

The Oxford Transplant Centre is the World’s biggest and busiest centre for VCA transplantation having performed over 60 of the World’s 300 reported cases. It is co-host to the NHSE funded UK hand transplant programme.

Henk Giele

Quality of Life and Outcomes

Over the past few years we have been collecting quality of life data to understand how an intestinal transplant impacts on our patients. We have used three different questionnaires to record this including both generic, that have the advantage of being applicable across many different conditions, and condition specific questionnaires, allowing us compare patients with the same condition. From the generic ones, we have found that following intestinal transplant patients overall score with life rises from an average of 40% (+/- 21%) to 73% (+/- 7%), with an improvement in move around, to do everyday activities including caring for themselves and their pain or discomfort levels. In addition, from the disease specific questionnaire there were marked improvement in ability to travel, body image, concerns regarding their health and the future and the ability to eat food again. This is incredibly exciting to see the improvement that intestinal transplant brings. We are continuing to collect data and our aim in the next few years is to develop a short patient centred questionnaire that reflects what patients feel are important questions for us to ask them.

The Centre for Evidence in Transplantation

The Centre for Evidence in Transplantation (CET) (www.transplantevidence.com) was established at the beginning of 2005 by Professor Sir Peter Morris with the aim of providing a source of high quality evidence-based information on all aspects of solid organ transplantation. The Centre is devoted to evaluating the quality of evidence in organ transplantation (kidney, heart, lung, pancreas, liver, etc.) and defines gaps in our knowledge in these different areas. The CET is based within the Nuffield Department of Surgical Sciences and the Oxford Transplant Centre.
The CET has been involved in a number of projects since its establishment, one of which is the development and maintenance of the Transplant Library (www.transplantlibrary.com). The Transplant Library is an electronic library of all randomised controlled trials (RCTs) in solid organ transplantation, including congress abstracts, from 1970 to the present and more recently includes systematic reviews that are regarded as of reasonable quality, and clinical practice guidelines. We have also added invited expert commentaries to key articles and the ability for users to comment on and discuss articles on the site. Since March 2020 the Library includes published evidence and other information, such as webinars, on COVID-19 in solid organ transplantation.
To promote the Transplant Library CET produces the Transplant Trial Watch, a monthly overview of RCTs that were recently added to the Transplant Library. The Trial Watch includes a summary of the RCT, critical commentary written by CET and critical appraisal. 
The Centre has also carried out and is carrying out a large number of systematic reviews and meta-analyses in all aspects of solid organ transplantation. Many of these have been published in peer reviewed journals and are well cited. The CET staff have expertise in literature searching, risk of bias assessment and meta-analysis, including handling missing data, mixed effects analysis and network meta-analysis.
More recently, the CET has been involved in the design and reporting of clinical trials in transplantation, including the management and design of the Consortium for Organ Preservation in Europe (COPE) clinical trials in partnership with the Surgical Interventional Trials Unit (SITU).
The CET also has an agreement with the European Society for Organ Transplantation (ESOT) and provides research support to the society, and its members and scientific working groups.

www.transplantevidence.com

www.transplantlibrary.com

www.nds.ox.ac.uk/research/centre-for-evidence-in-transplantation

The Transplant Immunology and Immunogenetics Laboratory provides consultant-lead specialist regional services for clinical transplantation within the Oxford Transplant Centre and for haematopoietic stem cell transplants performed within the OUH. Currently these services include HLA typing to the DNA sequence level, antibody screening and specification and crossmatching.  The laboratory provides a 24-hour on-call service for transplantation and post-transplant monitoring.  Immunogenetics services are also provided to clinicians to define disease susceptibility genes as an aid to patient diagnosis and treatment. The laboratory is accredited by the UK Accreditation Service (UKAS) and the European Federation for Immunogenetics (EFI). Referrals are received from within the OUH and externally from Primary Care Trusts and other Trusts and Institutions.  In order to maintain the highest standards of the services in a continually developing field, the laboratory supports research and development in histocompatibility and immunogenetics testing and in the broader field of clinical transplantation.