title: Epithelial tissue chimerism after human hematopoietic cell transplantation is a real phenomenon.
abstract: Bone marrow transplantation in animals has been shown to generate epithelial populations, a phenomenon that has also recently been suggested to take place after human hematopoietic cell transplantation. However, reports in humans are not conclusive because they still leave open the possibility that the identified donor-derived cells are not epithelial cells but intraepithelial lymphocytes. Here, we demonstrate that donor-derived CD45(+) hematopoietic cells in close contact with epithelial tissue may be falsely characterized as donor-derived epithelial cells if the three-dimensional structure of the tissue is not considered and the hematopoietic markers are not examined. By using a rigorous three-dimensional analysis on single sections of colon biopsies triple stained with donor-specific, epithelial-specific, and hematopoietic-specific markers we demonstrate that chimerism of colon epithelium is a real phenomenon occurring constantly after human hematopoietic cell transplantation. We exclude horizontal DNA transfer or cell fusion as the underlying mechanism of our findings. Tissue damage enhances the engraftment of the donor-derived epithelial cells. The physiological and therapeutical role of the donor-derived epithelial cells after human hematopoietic cell transplantation needs further investigation. However, their identification requires stringent and unequivocal detection systems.
authors.affiliation: Department of Hematology/Oncology, Freiburg University Medical Center, Freiburg, Germany. spyridonidis@mm11.ukl.uni-freiburg.de
authors.forename: Alexandros
authors.initials: A
authors.lastname: Spyridonidis
authors.forename: Annette
authors.initials: A
authors.lastname: Schmitt-Gräff
authors.forename: Tina
authors.initials: T
authors.lastname: Tomann
authors.forename: Anne
authors.initials: A
authors.lastname: Dwenger
authors.forename: Marie
authors.initials: M
authors.lastname: Follo
authors.forename: Dirk
authors.initials: D
authors.lastname: Behringer
authors.forename: Jürgen
authors.initials: J
authors.lastname: Finke
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D015703:Antigens, CD / Q000378:metabolism; D015214:Antigens, Differentiation, Myelomonocytic / Q000378:metabolism; D005260:Female; D005455:Fluorescent Antibody Technique; D018380:Hematopoietic Stem Cell Transplantation; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007413:Intestinal Mucosa / Q000502:physiology*; D017493:Leukocyte Common Antigens / Q000378:metabolism; D008297:Male; D018613:Microscopy, Confocal; D008875:Middle Aged; D018183:Transplantation Chimera; D000097382:CD68 Molecule
chemical_list: D015703:Antigens, CD; D015214:Antigens, Differentiation, Myelomonocytic; D017493:Leukocyte Common Antigens; C067980:CD68 antigen, human; D000097382:CD68 Molecule