The transplanted liver has been shown to be capable of inducing tolerance. It is thought that this may be due to the presence of chimerism.
|Endothelial cells of recipient origin were found in 14 of the 16 donor livers.|
Cells of donor origin have been found in recipient tissues after solid organ transplantation. However, evidence for the presence of cells of recipient origin within the transplanted liver is very limited.
In this study, researchers from the Netherlands investigated whether nonlymphoid cells of recipient origin are found within human liver allografts.
The team evaluated 5 male patients who had received a liver transplant from a female donor, as well as 11 patients who received an HLA-I mismatched liver transplant.
They confirmed their observations by using 2 different techniques in combination with double-staining techniques. In order to identify male cells in female liver transplants, the researchers used in situ hybridization for sex chromosomes. To identify specific HLA class I antigens of recipient origin, they used immunohistochemistry with HLA class I-specific antibodies.
The researchers performed double staining to discriminate different cell lineages and inflammatory cells.
The team found endothelial cells of recipient origin were found in 14 of the 16 donor livers.
They determined that bile duct epithelial cells of recipient origin were found in 5 of 16 cases.
However, hepatocytes of recipient origin were seen in only 1 of the 5 studied sex-mismatched donor livers.
Dr Rogier ten Hove's team concluded, "Our study provides evidence that cells of recipient origin can replace biliary epithelial cells, endothelial cells, and hepatocytes within the human liver allograft".
"This is consistent with the concept that circulating pluripotent progenitor cells exist, capable of differentiating into endothelial cells, epithelial cells, and hepatocytes".