Epithelial and hematopoietic cell chimerism in intestinal allografts

Background In intestinal transplantation recipient lymphocytes infiltrate the allograft soon after reperfusion. Recently, it has been demonstrated that long-surviving small bowel transplants bear enterocytes of recipient origin. We investigated whether epithelial cells (enterocytes) persisted in long-term allografts based on studies of biopsies. Methods The biopsies of four male intestinal transplant recipients of female grafts with a previous graft biopsy positive for recipient enterocytes were examined at least 6 months after previous positive assessment. Using the FISH technique, we searched for Y-chromosome-positive enterocytes in the female allograft. Results Recipient male enterocytes were identified in all biopsies at low percentages ranging from 0.18 to 0.26. The lymphocytes within the graft were of both recipient (male) and donor (female) origin. Conclusion The four types of cells - enterocytes and lymphocytes of recipient and donor origin - coexist in long-term graft biopsies.