The effect of graft-versus-host disease on skin endothelial and epithelial cell chimerism in stem-cell transplant recipients.

ABSTRACT

BACKGROUND: Recent evidence indicates that bone marrow-derived cells contribute to endothelial and epithelial cell renewal in recipients of an allogeneic stem-cell transplantation (SCT). Controversy remains on the biological significance of these donor-derived cells. METHODS: This study investigated the occurrence of endothelial and epithelial cell chimerism in relation to the conditioning regimen, time interval after SCT, and development of acute and chronic graft-versus-host disease (GVHD). Fifty-five skin biopsy samples from 35 female patients transplanted with a male donor were screened for donor-derived endothelial and epithelial cells using in situ hybridization for Y chromosomes in combination with immunohistochemical cell-marking techniques. RESULTS: Endothelial cell chimerism was found in 25% of the biopsies and increased in time after SCT. Its appearance was increased in patients with acute GVHD more than 2 weeks before biopsy. Epithelial cell chimerism was found in 85% of the biopsies. Appearance of epithelial cell chimerism was not correlated with the time interval after SCT or with tissue damage caused by GVHD. CONCLUSION: From these results, we conclude that donor-derived endothelial cell chimerism results from repair of damaged endothelium and maintenance of vascular homeostasis. In contrast, epithelial cell chimerism follows a more uniform pattern of engraftment, not influenced by tissue damage.