Published online Mar 31, 2020. doi: 10.5500/wjt.v10.i3.64
Peer-review started: December 4, 2019
First decision: December 12, 2019
Revised: February 10, 2020
Accepted: March 23, 2020
Article in press: March 23, 2020
Published online: March 31, 2020
Orthotopic liver transplantation (OLT) is the only treatment for end-stage liver failure; however, graft shortage impedes its applicability. Therefore, studies investigating alternative therapies are plenty. Nevertheless, no study has comprehensively analyzed these therapies from different perspectives.
To summarize the current status of alternative transplantation therapies for OLT and to support future research.
A systematic literature search was performed using PubMed, Cochrane Library and EMBASE for articles published between January 2010 and 2018, using the following MeSH terms: [(liver transplantation) AND cell] OR [(liver transplantation) AND differentiation] OR [(liver transplantation) AND organoid] OR [(liver transplantation) AND xenotransplantation]. Various types of studies describing therapies to replace OLT were retrieved for full-text evaluation. Among them, we selected articles including in vivo transplantation.
A total of 89 studies were selected. There are three principle forms of treatment for liver failure: Xeno-organ transplantation, scaffold-based transplantation, and cell transplantation. Xeno-organ transplantation was covered in 14 articles, scaffold-based transplantation was discussed in 22 articles, and cell transplantation was discussed in 53 articles. Various types of alternative therapies were discussed: Organ liver, 25 articles; adult hepatocytes, 31 articles; fetal hepatocytes, three articles; mesenchymal stem cells (MSCs), 25 articles; embryonic stem cells, one article; and induced pluripotent stem cells, three articles and other sources. Clinical applications were discussed in 12 studies: Cell transplantation using hepatocytes in four studies, five studies using umbilical cord-derived MSCs, three studies using bone marrow-derived MSCs, and two studies using hematopoietic stem cells.
The clinical applications are present only for cell transplantation. Scaffold-based transplantation is a comprehensive treatment combining organ and cell transplantations, which warrants future research to find relevant clinical applications.
Core tip: This systematic review analyzes the current status of transplantation treatments in place of liver organ transplantation from multiple viewpoints. We classified reports into three types: Xeno-organ transplantation, scaffold-based transplantation, and cell transplantation. Clinical application occurred for cell transplantation with hepatocytes and mesenchymal stem cells; however, the effect was limited. On the other hand, scaffold-based transplantation is a comprehensive treatment that combines organ transplantation and cell transplantation. Future research for clinical application is expected. The present article provides researchers with a summary and updated information on recent trends in alternatives to liver transplantation and support for future research.