title: Donor type microchimerism is an infrequent event following liver transplantation and is not associated with graft acceptance.
abstract: Donor-type microchimerism, the presence of a minority population of donor-derived haematopoietic cells following solid organ transplantation, has been postulated as a mechanism for induction of donor-specific graft tolerance. The stability, frequency, and relevance of microchimerism with respect to long-term outcome, however, remains uncertain. Using a polymerase chain reaction (PCR)-based method of microsatellite analysis of highly polymorphic short tandem repeat sequences (STRs) to detect donor-type cells, DNA from 11 patients was analyzed prospectively at specific time points for 12 months following liver transplantation, and from a further six patients retrospectively 2 years after liver transplantation. Using a panel of STRs, transient peripheral blood donor microchimerism was detected in 2 of 11 patients at a single time-point following transplantation, but persistent evidence of donor-derived cells was not observed during the study period. Analysis of DNA extracted from skin and duodenum in two patients likewise failed to show donor-type cells at these sites. None of the six patients in the retrospective arm showed donor microchimerism, resulting in an overall detection rate of 1.58%. These results suggest that donor microchimerism following liver transplantation is an infrequent event, and that the generation of graft tolerance is independent of microchimerism.
authors.affiliation: Liver Unit and Education & Research Centre, St. Vincent's Hospital, Dublin, Ireland.
authors.forename: S
authors.initials: S
authors.lastname: Norris
authors.forename: M
authors.initials: M
authors.lastname: Lawler
authors.forename: S
authors.initials: S
authors.lastname: McCann
authors.forename: J
authors.initials: J
authors.lastname: Hegarty
authors.forename: C
authors.initials: C
authors.lastname: O'Farrelly
mesh_terms: D002678:Chimera; D006084:Graft Rejection; D006801:Humans; D016031:Liver Transplantation / Q000276:immunology*