Chinese expert consensus on organ protection of transplantation (2022 edition)

Cutting edge of genetically modified pigs targeting complement activation for xenotransplantation

In the quest to address the critical shortage of donor organs for transplantation, xenotransplantation stands out as a promising solution, offering a more abundant supply of donor organs. Yet, its widespread clinical adoption remains hindered by significant challenges, chief among them being immunological rejection. Central to this issue is the role of the complement system, an essential component of innate immunity that frequently triggers acute and chronic rejection through hyperacute immune responses. Such responses can rapidly lead to transplant embolism, compromising the function of the transplanted organ and ultimately causing graft failure. This review delves into three key areas of xenotransplantation research. It begins by examining the mechanisms through which xenotransplantation activates both the classical and alternative complement pathways. It then assesses the current landscape of xenotransplantation from donor pigs, with a particular emphasis on the innovative strides made in genetically engineering pigs to evade complement system activation. These modifications are critical in mitigating the discordance between pig endogenous retroviruses and human immune molecules. Additionally, the review discusses pharmacological interventions designed to support transplantation. By exploring the intricate relationship between the complement system and xenotransplantation, this retrospective analysis not only underscores the scientific and clinical importance of this field but also sheds light on the potential pathways to overcoming one of the major barriers to the success of xenografts. As such, the insights offered here hold significant promise for advancing xenotransplantation from a research concept to a viable clinical reality.

Current Status and Trends in Lung Transplant Research Funded by the National Natural Science Foundation of China

OBJECTIVES

This study aimed to analyze research projects on lung transplant funded by the National Natural Science Foundation of China from 1986 to 2022 and to provide a scientific reference for lung transplant research.

MATERIALS AND METHODS

We identified research hotspots and frontiers in the field of lung transplant research using CiteSpace visualization.

RESULTS

From 1986 to 2022, the National Natural Science Foundation of China funded 93 projects related to lung transplant, with an average of 2.51 projects and ¥0.94 million annually. The National Natural Science Foundation of China funded 30 institutions across 20 provinces, with general and youth science foundation projects comprising 45.16% and 41.93% of the total projects, respectively. The main categories of disciplines included H0113 respiratory intervention, tracheal reconstruction, and lung transplantation; H1105 organ transplantation and transplant immunization; and H0109 acute lung injury and acute respiratory distress syndrome. The research hotspots mainly included ischemia-reperfusion injury, gene regulation, obliterative bronchiolitis, rejection reaction, T cells, and stem cells. The 6 main research clusters were ischemia-reperfusion injury, immune tolerance, obliterative bronchiolitis, stem cells, pulmonary fibrosis, and rejection reaction. The main key word bursts in the past 5 years were "vein endothelial" and "ex vivo lung perfusion."

CONCLUSIONS

In the past 37 years, National Natural Science Foundation of China-funded projects have significantly advanced the clinical application and basic research of lung transplantation. However, compared with developed countries and other solidorgan transplantations, several problems still require attention and improvements in lung transplant research in China.