Mapping the Evolution of Solid Organ Xenotransplantation Research:A Systematic Review

Xenotransplantation has emerged as a promising solution to organ shortage, generating numerous publications. However, no studies have analyzed the research dynamics of xenotransplantation research. We aimed to systematically assess xenotransplantation publication activity. A systematic literature search was conducted up to November 22, 2024. Studies on xenotransplantation of solid organs and islets of Langerhans from animals to humans, or perfusion with human blood or its derivatives were included. Publication information, publishing journal, publication type, organ, donor species, and topics studied were extracted. Of 2944 publications, 706 met inclusion criteria: 41.2% original articles, 41.1% reviews, 14.2% publications without original data, 1.6% case reports, 1.3% research letters, 0.6% systematic reviews/meta-analyses. Publication activity displayed two peaks: in the 1990s, driven by the gene editing advancements, and in the early 2020s, following the first pig-to-human transplantation. The top five publishing countries were the USA with (48.2%), Germany (10.2%), UK (5.4%), Sweden (4.8%), and China (4.2%). Xenotransplantation journal accounted for 19.7% of publications, transplantation journals for 27.6%, and general medical journals for 5.4%. Islets of Langerhans were studied in 23.1% of studies, and the most studied organs were heart (21.2%), followed by kidney (17.1%), liver (12.2%), and lung (6.2%). The most represented thematic groups were rejection, immune mechanisms, overall challenges, gene editing, current research, and prospects. This first systematic assessment of xenotransplantation research highlights its growing global interest and evolving focus areas. The low proportion of publications with original data underscores the need for more original research. Limited representation in general medical journals highlights the importance of engaging a broader audience as clinical trials approach.