[1552] Looking for Recipient Cells in Donor Tissue: Do Recipient Cells Transform To Become Hepatocytes in Allograft Liver?

OA Adeyi, M Selzner, N Selzner, D Grant. University Health Network, Toronto, ON, Canada

Background: If the recipient uncommitted stem cells were shown to assist with regeneration/repopulation of hepatocytes post-transplant, some marginal organs would be more easily acceptable as a solution to organ shortage. Studies from bone marrow transplant patients, although inconclusive, suggest donor cells differentiate to mature hepatocytes, but no evidence exists that recipient bone marrow cells contribute to liver allograft hepatocellular regeneration. This study aims at investigating this concept using Fluorescent in-situ hybridization (FISH) methods.
Design: Male-female mismatched recipients were identified in the Toronto General Hospital liver transplant record. FISH staining was performed on the most recent post-transplant biopsy for X-Y chromosome markers. HepPar-1 staining was superimposed on FISH to identify hepatocytes. Working on the concept that X/Y-carrying hepatocytes in male recipients of female organ implies contribution by recipient cells in post-transplant hepatocyte repopulation, 200-500 hepatocytes were evaluated per specimen.
Results: Study set includes native liver biopsies, one each from one male (N-M) and one female (N-F) patients; 9 allograft biopsies from male recipients of female (whole or split liver) organs (F-M); and one allograft biopsy from a female recipient of female organ (F-F). The native biopsies confirm specificity of the FISH method, F-N showing only X chromosomes while M-N shows both X and Y chromosomes in hepatocytes. The studied F-M and F-F biopsies were performed 6-102 months post-transplant, and all show only X chromosomes in hepatocytes confirming donor origin. Non-hepatocyte cells (HepPar-1 negative) however show both X and Y chromosomes in M-F samples.


Conclusions: Recipient non-parenchymal cells expectedly infiltrate liver grafts post-transplant but there is no evidence based on X-Y chromosomal study that these cells differentiate into hepatocytes in whole liver grafts up to 8½ years post-transplant.
Category: Liver & Pancreas

Tuesday, March 23, 2010 9:30 AM

Poster Session III # 246, Tuesday Morning

 

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