THE FRED HUTCHINSON CANCER RESEARCH CENTER 
AND THE UNIVERSITY OF WASHINGTON SCHOOL OF MEDICINE 
DEPARTMENT OF MEDICINE, DIVISION OF ONCOLOGY 
(06/15/92) 
1. A Trial of G-CSF Stimulated Peripheral Blood Stem Cells for Engraltment in Identical Twins. 
INVESTIGATORS: C.D. Buckner, M.D., Professor of Medicine, UW, Member, FHCRC (667-4453) W. 
Bensinger, M.D. Associate Professor of Medicine, UW, Associate Member, FHCRC, (667-4933); F. 
Schuening, M.D., Assistant Member, FHCRC (667-4410); J. Singer, MJD.; R. Storb, M.D., Professor of 
Medicine, UW, Member, FHCRC, (667-4407); S. Rowley, MJD., Associate Member, FHCRC, (667- 
5914); P. Martin, M.D., Professor of Medicine, UW, Member, FHCRC, (667-4798); L Fisher, Ph.D., 
Professor of Biostatistics, UW, Member, FHCRC, (667-4567). 
Emergency (24 hour) Phone: 667-5001 
2. Introduction. 
Peripheral blood contains hematopoietic progenitor cells capable of marrow repopulation after 
marrow ablative therapy. There is good evidence that peripheral blood contains committed 
hematopoietic precursors capable of early marrow repopulation and circumstantial evidence that these 
cells contribute to long-term engraftment. However, it. is not proven that long-term engraftment is due 
primarily to infused peripheral blood progenitor cells rather than to residual endogenous stem cells. In 
the absence of a genetic marker this issue has remained unresolved. Therefore, patients entered on this 
study will be eligible to participate in protocol 691 which evaluates the contribution of genetically 
marked peripheral blood progenitor cells to long-term engraftment. For convenience, in this protocol 
the term peripheral blood stem cells (PBSC’s) will be used to denote late and\or early marrow 
repopulating cells. 
Autologous transplants can be achieved with PBSC’s but in the steady state the quantity of these 
cells in the circulation is small and offer no advantages over the use of marrow due to the difficulties of 
collecting adequate quantities with multiple apheresis procedures, except in situations where marrow is 
unobtainable. 
At this institution we have demonstrated that administration of recombinant human granulocyte 
macrophage colony-stimulating factor (GM-CSF) following high dose cyclophosphamide or Granulocyte 
colony-stimulating factor (G-CSF) alone causes an increase in the number of PBSC’s as measured by 
CD34+ cells, CFU-GMs and more recently by long-term-marrow culture-initiating cells. Based on the 
quantities of these cells that can be collected after G or GM-CSF administration enough PBSC’s can be 
obtained from 2-4 apheresis procedures to theoretically achieve autologous or syngeneic engraftment. 
The goal of this protocol is to determine if PBSC’s collected after G-CSF administration to a normal 
twin results in prompt and durable engraftment when infused following chemo or chemo-radiotherapy 
in the twin with malignant disease. 
There are several reasons for pursuing this line of investigation: 
A. Engraftment achieved by PBSC’s is likely to be more rapid than that observed with 
marrow alone with fewer days of pancytopenia. This could result in fewer days of 
infection, lower transfusion requirements and possibly a shorter hospital stay. 
B. Marrow aspiration with its attendant morbidities and the small but definite risk of life- 
threatening complications can be avoided. 
C. This is an ideal setting to evaluate the contribution of PBSC’s to long-term engraftment 
with genetic marking of normal PBSC’s as outlined in protocol 691. 
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Recombinant DNA Research, Volume 16 
