Polyclonal hematopoiesis with variable telomere shortening in human long-term allogeneic marrow graft recipients

Donor-derived hematopoiesis was assessed in 17 patients who received alloge neic marrow grafts from HLA-matched siblings between 1971 and 1980. Complet e blood counts were normal or near normal in all patients except one. Chime rism analyses, using either dual-color XY-chromosome fluorescence in situ h ybridization (FISH) or analysis of variable number tandem repeat loci, indi cated that 15 out of 16 patients had greater than 97% donor-derived hematop oiesis, whereas 1 patient had indeterminate chimerism. All 12 recipients of grafts from female donors exhibited polyclonal hematopoiesis by X-linked c lonal analysis with the use of molecular probes. Of the 17 recipients, 9 ex hibited a less than 1.0-kilobase shortening of granulocyte telomere length compared with their respective donors, according to terminal restriction fr agment analysis or flow-FISH with a fluorescein-labeled peptide nucleic aci d probe. These data suggest that under standard transplantation conditions, the stem cell proliferative potential is not compromised during hematopoie tic reconstitution. (C) 2000 by The American Society of Hematology.