Does Endothelial Chimerism Correlate With Renal Allograft Rejection?

BackgroundThe blood vessels of a transplanted organ are an interface between the donor and the recipient. The endothelium is believed to be a major target for graft rejection. After transplantation endothelial cells of a transplanted organ may be of recipient origin.ObjectivesIn this study we sought to determine whether endothelial chimerism correlates with graft rejection.MethodsBiopsy samples from 34 renal transplants of female recipients who received kidneys from male donors were studied for the presence of endothelial cells of recipient origin. Formalin-fixed, paraffin-embedded tissue sections of renal biopsy samples were examined by fluorescence in situ hybridization (FISH) for the presence of endothelial cells containing two X chromosomes, using a biotinylated Y-chromosome probe and digoxigenin-labeled X-chromosome probe.ResultsThe FISH methods identified endothelial cells of recipient origin. Endothelial chimerism was common, irrespective of rejection. Its presence was focal with these elements, coexisting in the biopsy.ConclusionsWe observed no correlation between the percentage of recipient endothelial cells among vascular elements and the type of graft rejection (P > .05).