Blood, 15 March 2001, Vol. 97, No. 6, pp. 1876-1878
BRIEF REPORT
Replicative stress after allogeneic bone marrow transplantation:
changes in cycling of CD34+CD90+ and
CD34+CD90
hematopoietic progenitors
Ian Thornley,
D.
Robert Sutherland,
Rakash Nayar,
Lillian Sung,
Melvin H. Freedman, and
Hans A. Messner
From the Division of Hematology/Oncology, The Hospital
for Sick Children, and the Department of Medical Oncology and
Hematology, University Health Network, University of Toronto, Ontario,
Canada.
To further characterize hematopoietic "replicative stress"
induced by bone marrow transplantation (BMT), the cell-cycle status of
CD90+/
subsets of marrow CD34+ cells obtained
2 to 6 months after transplantation from 11 fully chimeric recipients
was examined. Cycling profiles, derived by flow cytometry after
staining with Hoechst 33342 and pyronin Y, were compared with those of
14 healthy marrow donors. Primitive CD34+CD90+
cells represented a smaller proportion of CD34+ cells in
recipients (10% ± 4% versus 19.6% ± 5.3% in donors; P < .0001) and were more mitotically active, with the
proportion of cells in S/G2/M nearly 4-fold higher than in
donors (15.6% ± 3% and 4.4% ± 1.6%, respectively;
P < .0001). By comparison, there was a modest increase
in the proportion of CD34+CD90
progenitors in S/G2/M after BMT (10.9% ± 1% vs
9.6% ± 2% in donors; P = .04). Replicative stress
after BMT is borne predominantly by cells in a diminished
CD34+CD90+ population.
