Autologous Bone Marrow Transplantation - Blog Science Connections

682 Peripheral Stem Cell Transplants
and cryopreserved early in the disease course. When the leukemias transformed
into an acute phase, all patients were treated with cytotoxic drugs and
some received whole body irradiation; this therapy was followed by infusion of
the previously collected stem cells. Engraftment was demonstrated in 19 of
these patients by a return of the disease to the chronic phase. Later this series
was expanded to 50 patients; 94% demonstrated engraftment (6).
Although autologous peripheral stem cell transplantation resulted in
engraftment in patients with transformed CML, two reports of unsuccessful
syngeneic peripheral stem cell transplantations appeared in 1979 and 1980
(7,8). The number of circulating stem cells in patients with CML was known to
be greatly increased over the number in a normal population (6). Therefore
concern continued about the ability of peripheral hematopoietic stem cells
from nonleukemic patients to restore hematopoietic function until successful
autologous peripheral stem cell transplantations were reported some years
later for patients without CML (9-15).
Autologous peripheral stem cell collections have been described in two
distinctly different settings. In the first, peripheral stem cells are collected at a
time when their numbers are augmented. The number of granulocytemacrophage
colony-forming units is known to be 25-fold higher than in
normal subjects in patients with acute myelogenous leukemia just as marrow
recovery begins following induction therapy (16). Peripheral stem cells
collected at that time have restored hematopoietic function following highdose
therapy for patients with acute leukemia and lymphoma (9,12-15).
In the second setting, peripheral stem cells have been collected when
marrow function was in a relatively steady state and no augmentation of
numbers was anticipated; these cells have restored hematopoietic function
following high-dose therapy for patients with lymphoma and breast cancer
( 10,11 ). This report updates our experience with transplantation of autologous
peripheral stem cells collected at a time when augmentation of their
numbers was not anticipated.
PATIENTS AND METHODS
Between June 8, 1984, and October 31, 1986, 10 patients received
autologous peripheral stem cell transplants. Six patients had advanced breast
cancer, three had refractory Hodgkin's disease, and one had refractory large
cell lymphoma. Characteristics of the transplanted cells are listed in Table 1.
Patients were eligible for this study if the only feature disqualifying them
for high-dose cancer therapy and autologous marrow transplantation was
metastatic malignancy in bone marrow. Methods used for peripheral stem
cell collection and cryopreservation have been published (11). Each patient
underwent eight 4-hour leukapheresis procedures no more than three times
weekly. Autologous marrow was harvested and cryopreserved to serve as a
backup in the event engraftment with peripheral stem cells did not occur or
was not durable.