Autologous Bone Marrow Transplantation - Blog Science Connections

690 Peripheral Blood Stem Cell Transplantation
phenomenon was observed in CFCls-GM of PBMCs in very early remission from
acute nonlymphocytic leukemia (5). These cells remained viable after 2 years of
storage in the liquid phase of liquid nitrogen, and there was speculation about
their suitability for hematopoietic restoration in man after marrow-ablative
chemoradiotherapy.
Some initial clinical results using PBMCs for restoration of bone marrow
function were discouraging. Hershko et al.(6) reported engraftment failure in a
patient with aplastic anemia after infusion of 7.1 x 10 10
PBMCs from her
identical twin sister over several days. Bone marrow stem cells from the same
donor, on the other hand, resulted in bone marrow recovery. In this case no
conditioning regimen was given. In another instance reported by Abrams et al.
(7), failure of engraftment was likewise demonstrated by PBMCs from an
identical twin donor. In this case 9.8 x 10 10 PBMCs given over several days were
ineffective in restoring hematopoiesis in a young patient with Ewing's sarcoma
conditioned with chemotherapy and TBI. Three additional patients were
reported by Juttner et al. (8) in whom PBSCs were harvested in very early
remission from acute nonlymphocytic leukemia at which time an overshoot in
circulating CFCls-GM was noted. In all three, prompt initial engraftment was
followed by a fall in counts by day 16 and a secondary but incomplete rise.
Isolated case reports following these initial accounts described successful
PBSC engraftments when the products of several leukaphereses collected in
the bone marrow recovery phase from chemotherapy were reinfused at once
following marrow-lethal doses of chemoradiotherapy (9-11). Timing of PBSC
collection—taking advantage of the CFCI-GM overshoot phenomenon—was
believed to be important in these cases to ensure hematopoietic reconstitution.
Korbling et al. (12) described a case in which rapid hematopoietic
reconstitution ensued using the product of seven successive leukaphereses in a
patient with Burkitt's lymphoma treated with cyclophosphamide and TBI. The
initial stem cell harvest in this case was performed 2 weeks after the completion
of chemotherapy. However, a definite CFCl-GM overshoot was not apparent
from cells collected during this time. Kessinger et al. (13) also described two
patients with advanced breast carcinoma treated with cyclophosphamide and
TBI followed by infusion of the products of seven leukaphereses on day 0. In
both patients prompt trilineage engraftment ensued.
We collected PBSCs from our patient in a fashion similar to that reported
by Korbling et al. (12) and Kessinger et al. (13). Perhaps most important, all
patients were transfused within a 24-hour period following high-dose chemotherapy.
The CBV regimen is usually a profoundly myelosuppressive treatment
program producing an absolute granulocyte count less than 500//il for an
average of 21 days (Table 1). In contrast, our patient recovered an absolute
granulocyte count over 500/u\ in 12 days. In addition, recovery of platelet and
reticulocyte counts compared favorably to those previously reported using
bone marrow stem cells.
In contrast to older case reports discouraging the use of PBSCs for