SMALL-BOWEL TRANSPLANTATION IN CHILDREN - AN IMMUNOHISTOCHEMICAL STUDY OF INTESTINAL GRAFTS

Seven children with short bowel syndrome underwent small bowel allogra fting. Episodes of early rejection were observed in five patients who received a graft from paediatric or adult donors but not in two patien ts who received a neonatal graft. This study aimed, firstly, to define immunohistochemical parameters accompanying rejection and, secondly, to compare immunohistochemical parameters in neonatal grafts with thos e in grafts from older donors. An immunohistochemical analysis was per formed on 85 intestinal biopsy specimens taken for monitoring the tran splants. Acute histological rejection was associated with pericryptic infiltrates of CD3+-TcR alpha beta+T cells containing clusters of CD8 cells, numerous CD25+ cells, and increased numbers of CD68+ macrophag es. These changes were associated with the appearance of major histoco mpatibility (MHC) class II antigens on crypt enterocytes and with an a ppreciable increase in the expression of E-selectin on mucosal endothe lial cells. Immunohistochemistry was useful in predicting rejection by showing the appearance of pericryptic CD25+ T cells 48 hours before t he first histological lesions of crypt necrosis. Comparison of neonata l grafts with grafts from older donors did not show any significant di fference in the density of CD68+ macrophages or in the endothelial exp ression of intercellular adhesion molecule-1, vascular cell adhesion m olecule-1, or E-selectin. In contrast to grafts from older donors, how ever, neonatal grafts did not express MHC class II antigens on epithel ial cells and contained very low numbers of intraepithelial lymphocyte s. These data indicate, firstly, that immunohistochemistry is useful f or monitoring intestinal transplants and, secondly, that the better cl inical tolerance of neonatal allografts may be related to the lower im munogenicity of the neonatal epithelium.