Donation after circulatory death today: an updated overview of the European landscape.

Donation after circulatory death (DCD) has become an accepted practice in many countries and remains a focus of intense interest in the transplant community. The present study is aimed at providing a description of the current situation of DCD in European countries. Specific questionnaires were developed to compile information on DCD practices, activities and post-transplant outcomes. Thirty-five countries completed the survey. DCD is practiced in 18 countries: eight have both controlled DCD (cDCD) and uncontrolled DCD (uDCD) programs, 4 only cDCD and 6 only uDCD. All these countries have legally binding and/or nonbinding texts to regulate the practice of DCD. The no-touch period ranges from 5 to 30 min. There are variations in ante and post mortem interventions used for the practice of cDCD. During 2008-2016, the highest DCD activity was described in the United Kingdom, Spain, Russia, the Netherlands, Belgium and France. Data on post-transplant outcomes of patients who receive DCD donor kidneys show better results with grafts obtained from cDCD versus uDCD donors. In conclusion, DCD is becoming increasingly accepted and performed in Europe, importantly contributing to the number of organs available and providing acceptable post-transplantation outcomes.

Emerging technologies in organ preservation, tissue engineering and regenerative medicine: a blessing or curse for transplantation?

Since the beginning of transplant medicine in the 1950s, advances in surgical technique and immunosuppressive therapy have created the success story of modern organ transplantation. However, today more than ever, we are facing a huge discrepancy between organ supply and demand, limiting the potential for transplantation to save and improve the lives of millions. To address the current limitations and shortcomings, a variety of emerging new technologies focusing on either maximizing the availability of organs or on generating new organs and organ sources hold great potential to eventully overcoming these hurdles. These advances are mainly in the field of regenerative medicine and tissue engineering. This review gives an overview of this emerging field and its multiple sub-disciplines and highlights recent advances and existing limitations for widespread clinical application and potential impact on the future of transplantation.

Emerging approaches and technologies in transplantation: the potential game changers.

Newly emerging technologies are rapidly changing conventional approaches to organ transplantation. In the modern era, the key challenges to transplantation include (1) how to best individualize and possibly eliminate the need for life-long immunosuppression and (2) how to expand the donor pool suitable for human transplantation. This article aims to provide readers with an updated review of three new technologies that address these challenges. First, single-cell RNA sequencing technology is rapidly evolving and has recently been employed in settings related to transplantation. The new sequencing data indicate an unprecedented cellular heterogeneity within organ transplants, as well as exciting new molecular signatures involved in alloimmune responses. Second, sophisticated nanotechnology platforms provide a means of therapeutically delivering immune modulating reagents to promote transplant tolerance. Tolerogenic nanoparticles with regulatory molecules and donor antigens are capable of targeting host immune responses with tremendous precision, which, in some cases, results in donor-specific tolerance. Third, CRISPR/Cas9 gene editing technology has the potential to precisely remove immunogenic molecules while inserting desirable regulatory molecules. This technology is particularly useful in generating genetically modified pigs for xenotransplantation to solve the issue of the shortage of human organs. Collectively, these new technologies are positioning the transplant community for major breakthroughs that will significantly advance transplant medicine.

T Follicular Regulatory Cells and Antibody Responses in Transplantation.

De novo donor-specific antibody (DSA) formation is a major problem in transplantation, and associated with long-term graft decline and loss as well as sensitization, limiting future transplant options. Forming high-affinity, long-lived antibody responses involves a process called the germinal center (GC) reaction, and requires interaction between several cell types, including GC B cells, T follicular helper (Tfh) and T follicular regulatory (Tfr) cells. T follicular regulatory cells are an essential component of the GC reaction, limiting its size and reducing nonspecific or self-reactive responses.An imbalance between helper function and regulatory function can lead to excessive antibody production. High proportions of Tfh cells have been associated with DSA formation in transplantation; therefore, Tfr cells are likely to play an important role in limiting DSA production. Understanding the signals that govern Tfr cell development and the balance between helper and regulatory function within the GC is key to understanding how these cells might be manipulated to reduce the risk of DSA development.This review discusses the development and function of Tfr cells and their relevance to transplantation. In particular how current and future immunosuppressive strategies might allow us to skew the ratio between Tfr and Tfh cells to increase or decrease the risk of de novo DSA formation.

[Advances in tracheal transplantation].

The length of tracheal defect or stenosis exceeded 5 cm could not be treated by simple resection and end-to-end anastomosis of the remaining trachea. Various ways of tracheal replacement had appeared sequentially, such as radial forearm free flap with cartilage grafts, tracheal tissue-engineering and tracheal allotransplantation. Among these methods, tracheal allotransplantation displayed a better long-term result. In this review, we are focused on recent advances in tracheal allotransplantation, particularly on revascularization and reepithelialization of graft, as well as on the application of immunosuppressive agents.

The role of nanomaterials in cell delivery systems.

In more than one decade, cell transplantation has created an important strategy to treat a wide variety of diseases characterized by tissue and cell dysfunctions. In this course of action, cell delivery to target site has been always one of the most important constraints and complications, as only a small proportion of the cells are housed in the target sites. Nanotechnology and nanoscale biomaterials have been helpful for cell transplantation in various fields of regenerative medicine including diagnosis, delivery systems for the cell, drug or gene, and cells protection system. In this study, the basic concepts and recently studied aspects of cell delivery systems based on nanoscale biomaterials for transplantation and clinical applications are highlighted. Nanomaterials may be used in combination with cell therapy to control the release of drugs or special factors of engineered cells after transplantation.

Basic Sciences in Development: What Changes Will We See in Transplantation in the Next 5 Years?

Over 3000 delegates attended the 26th International Congress of the Transplantation Society in Hong Kong, which marked the 50th anniversary of the society. In his presidential address, Professor Phil O'Connell from the Westmead Hospital in Sydney, Australia, commented that a major challenge for the future is improving long-term outcomes after solid organ transplantation. He highlighted that 40% of transplanted organs are lost within 10 years, and that a high proportion of patients suffer from immunosuppression-related side effects. These 2 issues are the key drivers for basic scientists in the field of transplantation. A deeper understanding of the biological mechanisms involved, and more accurate identification of patients at risk for poor outcomes or drug-related adverse effects, will ultimately help to address these problems and improve graft survival rates and patients' quality of life. The research was more diverse than ever before, reflecting the variety and complexity of the many processes which underlie outcomes after transplantation, and the need to broaden our thinking when seeking solutions to the wide-ranging complications which face the transplant team. This article explores the latest developments in basic science presented at the Congress which may offer new insights and solutions to the current challenges in organ transplantation. With so many interesting papers presented, it is impossible to discuss everything, but some key areas are considered.

What Clinical Changes Can We Expect in the Next 5 Years? A Review of the 26th International Congress of The Transplantation Society.

Scientific presentations at the 26th International Congress of The Transplantation Society held in Hong Kong from August 18 to 23, 2016, highlighted accomplishments, challenges and opportunities in contemporary clinical organ transplantation. With nearly 1600 original abstract submissions, this review summarizes notable presentations in addressing a diversity of issues including deceased and living organ donation, improving allograft survival and unmet clinical needs in organ transplantation.

Transplantology: Challenges for Today.

Clinical transplantology in Poland had its 50th anniversary this year. With the early and long results comparable to the best achieved in the world leading centers, we face old and completely new challenges for this medical speciality. Main and growing challenge is insufficient number of available organs. With less than 15 donors/mln population/year Poland stay in the lower row of European countries in this measurement of transplant activity. Donation system is not efficient enough and we lose a big number of potential donors still. Living donation (with the exception for the fragments of the liver) remains low despite of different initiatives made so far on the national and local levels. Donation after cardiac death is possible from the point of Polish juridical regulations, but since last 3 years had not showed real impact on country donation rates (only three procedures done). Methods of tissue typing remain slow and cause relatively long times of cold ischemia for kidney programs. Second main challenge is chronic rejection causing loss of organs in the long-term follow-up and no efficient treatment employed. The emerging possibility of tolerance induction despite of plenty of new protocols proposition in the publications does not show up a clinical everyday practice in work. The same is with xenotransplantation promises; even we were informed recently that till 2030 such genetically modified porcine organs will be available. The next challenge is production of organs and tissues from own recipients cells installed on the different scaffolds or 3D printed. Other challenge is the personnel working in this field. We observe like in the other European countries lack of new candidates for work in this field together with serious problems of nursing staff, being a catastrophic perspective in country medical service in general, not only in transplant centers. The last but not least challenge is financial side of transplant programs.