Lung Transplantation: Controversies and Evolving Concepts

John A. Belperio, MD

Scott M. Palmer, MD

Lung transplantation is now a therapeutic option for patients with end-stage lung and pulmonary vascular disorders. Since the inception of the first lung transplant, there has been substantial progress made in both the clinical and basic science realms. More specifically, we have expanded the donor pool by using postcirculatory death lungs and through the use of ex vivo lung perfusion (EVLP). We have also expanded the recipient pool via the use of extracorporeal membrane oxygenation (ECMO). In parallel, advances have been made in candidate selection via our ability to prognosticate outcomes of various lung diseases and though the implementation of the lung allocation score (LAS) system. This system has resulted in decreased mortality for patients on the lung transplant waiting list. Additionally, risk factors have been identified for poor outcomes post–lung transplant with a better understanding of the physiological, cellular, and molecular mechanisms responsible for primary graft dysfunction (PGD), infectious diseases, acute rejection, antibody-mediated rejection, lymphocytic bronchiolitis, organizing pneumonia, obliterative bronchiolitis, restrictive allograft syndrome, and other forms of chronic lung allograft dysfunction (CLAD).

While early posttransplant survival has improved due to better surgical techniques and perioperative care, the problems of severe PGD, infectious diseases (e.g., bacterial, viral, fungal, mycobacterial), and allograft rejection continue to be common causes of morbidity and mortality. Thus, there is a need to extend our current understanding of how PGD, infection, and acute and chronic rejection interrelate and lead to the demise of the lung allograft.

This issue of Seminars in Respiratory and Critical Care Medicine is dedicated to lung transplantation and integrates both basic and clinical science, providing a comprehensive perspective on determining which patients need a lung transplant, how the LAS improves waiting times, factors contributing to PGD, the contribution of PGD to morbidity and mortality, diagnosis and treatment of acute rejection, lymphocytic bronchitis, infectious diseases, and CLAD. Dr. Vos goes over the current controversies and new developments in the selection criteria for lung transplantation. With the waiting list for lung transplants far outnumbering the availability of donors, Dr. Chan reviews the literature on the LAS and its relevance. With regard to expanding the donor pool, Dr. Keshavjee evaluates donation after cardiac death (DCD) and donation after brain death (DBD) lungs, marginal lungs, and EVLP. Dr. Bacchetta describes the role of ECMO as a bridge to lung transplant, while Dr. Diamond explores PGD, its new criteria, pathobiology, and treatment. Other insults the lung allograft has to face include infections and rejection. Dr. Mitchell tackles the impact of resistant bacterial pathogens including Pseudomonas aeruginosa and Burkholderia on lung transplant outcomes. Dr. Friedman looks at Mycobacteria and its influences on who to transplant and post–lung transplant outcomes, while Dr. Sweet evaluates community-acquired respiratory viruses posttransplant. Dr. Kennedy defines the role of fungal infection during the lung transplant process. Both acute and antibody-mediated rejections are covered by Dr. Martinu and Dr. Hachem, respectively. Dr. Weigt evaluates the causes of CLAD, its new criteria, phenotypes, pathogenesis, and treatment. Dr. Stevenson gives an overview on skin cancer in the immunosuppressed lung transplant recipients.

We would like to thank all the contributors for their hard work in preparing this issue of Seminars in Respiratory and Critical Care Medicine dedicated to lung transplantation.

Publication History

Article published online:
24 May 2021