Personal reflections in transplantation

Kidney transplantation: The journey across a century

The Journey of kidney transplantation began a century ago with animal experiments and xenotransplants. The initial attempts of human to human kidney transplant were made by Yuri Voronoy, Jean Hamburger and several others between 1930 and 40s, but most of these were unsuccessful. The first successful live related kidney transplant between identical twins was performed at the Brigham Hospital in Boston in December 1953, by Joseph Murray and John P. Merrill, which paved the way for future live transplants. With the gradual improvement in the understanding of immunity and tolerance, the use of immunosuppression was attempted using irradiation and steroids, which gradually evolved over the decades to include azathioprine and cyclosporine. Discoveries of human leukocyte antigen by Dausset, complement dependent cross match by Paul Terasaki, and other developments in transplant immunology improved outcomes of kidney transplant. This journey was marked by new discoveries and improvements in surgical techniques including laparoscopic and robotic transplant surgery, better and safer immunosuppression, advances in transplant immunology, advent of the concept of brain death and deceased donor transplant program, and complicated transplants like transplants in highly sensitised recipients and ABO incompatible transplants. India was not far behind the rest of the world, and after a few unsuccessful attempts, the first successful transplant was done in CMC Vellore in 1971, which was followed by advancements in kidney transplants keeping in pace with the rest of the world.

Evaluation and Treatment of Acute Rejection in Kidney Allografts

Advances in immunosuppressive therapy have drastically improved acute rejection rates in kidney transplant recipients over the past five decades. Nevertheless, it should remain high on any differential diagnosis of unexplained graft dysfunction because of the potential negative effect on graft longevity. Understanding the pre- and post-transplant risk factors for acute rejection can help estimate the probability of immunologic graft damage, and accurate identification of the type and severity of acute rejection will guide appropriate treatment. Tissue biopsy remains the gold standard for evaluating immunologic graft damage, and the histologic definition of acute rejection has evolved in recent years. Intravenous steroids and T cell depletion remain the standard therapy for T cell-mediated rejection and are effective in reversing most cases. Plasma exchange and intravenous Ig, with or without rituximab, are most commonly used for the treatment of antibody-mediated rejection and several newer agents have recently been investigated for severe cases. This review aims to provide the general nephrologist caring for transplant recipients with an approach to immunologic risk assessment and a summary of recent advances in the diagnosis and treatment of acute graft rejection.

Anesthesia for bench surgery

Surgical removal of the kidney tumor outside the body, (ex vivo renal bench surgery) followed by auto transplantation is an emerging and often done procedure to reconstruct the urinary tract. It possesses immense challenges to both the anesthesiologists and the surgeons. The risks are multiplied if you are performing the surgery on a solitary functioning kidney. Here, we are describing the anesthetic management of 70-year-old male post nephrectomy patient undergoing renal auto transplantation by bench surgery. Our primary goals for perioperative management were to maintain a stable hemodynamics throughout the procedure, to reduce fluid overload during the period of extracorporeal surgery, to maintain perfusion for the transplanted solitary kidney, to control bleeding to a minimum, and to provide adequate analgesia for the patient. We made use of a balanced anesthetic technique and stringent monitoring standards to bring forth a successful outcome for the patient. At the end of his hospital stay, patient went home with a healthy, normally functioning kidney.

Immunosuppression for kidney transplantation: Where are we now and where are we going?

Advances in immunosuppression have propelled kidney transplantation from a scientific curiosity to the optimal treatment for patients with end stage kidney disease. Declining rates of acute rejection have led to improvements in short term kidney transplant survival, culminating in incrementally better long term patient and allograft outcomes. Contextualized around established immune-suppressing drug targets, this review summarizes the history of the clinical science and highlights the pivotal trials that have led to present-day treatment standards at the level of both individual agents and multidrug regimens for kidney recipients. Finally, recently approved and emerging therapies are discussed, with an emphasis on challenges faced by clinicians managing this increasingly complex patient population.

Metastable tolerance in nonhuman primates and humans

It is clear that both humans and nonhuman primates can do without immunosuppression for long periods of time before rejecting their allogeneic organ transplants. Immune cell depletion, particularly lymphocyte depletion, is an effective clinical strategy for achieving a tolerant state. Based on nonhuman primate and human studies, evidence suggests that metastable tolerance develops over time in a donor-specific manner and is mediated at least in part by donor antigen-specific regulatory T cells. Suppression of effector T cells by CD8+ and CD4+ T-regulatory cells is mediated by transforming growth factor (TGF)-beta or interleukin 10, and the presence of CD4+ TGF beta(latent) T-cell infiltrates may be a useful diagnostic marker for metastable tolerance. Loss of these cells has been shown to correlate with loss of tolerance. Future efforts to withdraw immunosuppressive drugs and establish a tolerant state will depend importantly on development of such diagnostic immunologic monitoring tools. Some of the reasons that tolerance remains such a challenging goal in clinical transplantation are discussed herein.

Transplantation

The history of solid organ transplantation is traced from its beginnings in the 19th century to the beginning of the 21st century. Surgical techniques, advances in immunology, and a review of major immunosuppressive milestones are reviewed. Over the last 50 years, transplantation has moved from experimental to accepted clinical therapy. The technology of transplantation has been widely disseminated throughout the United States. This paper reviews the major ethical and social problems that still need to be addressed in regards to transplantation. These include organ supply, organ distribution, access to care, funding, and xenotransplantation.

Segmental auxiliary liver transplantation: a new approach to an old problem

Long-term results after a new technique of partial heterotopic auxiliary liver transplantation carried out in pigs are presented. There are three main characteristics of this technique: (1) hemihepatectomy on the bench to solve the problem of space, (2) laterolateral vena cava anastomosis through which it is possible to fix the graft to the host's inferior vena cava. The above anastomosis is fashioned as close as possible to the right atrium and (3) partial diversion of the portal blood through the graft, while maintaining adequate portal blood for the host liver. Of the four animals that underwent transplants, three survived for more than 12 hr. One animal died after 1 day and another was sacrificed after 82 days. At this time, one animal is still alive, 8 months following transplantation and appears to enjoy a normal life. The present technique appears to anticipate the problem of space, of graft congestion, of graft atrophy, and mainly, the problem of functional competition between the graft and the host liver.