Autologous Bone Marrow Transplantation - Blog Science Connections

Autografting in Chronic Granulocytic Leukemia 201
marrow cells collected 4 months after HDM treatment, but these also failed to
engraft. However, she is still alive despite pancytopenia 9 months after the initial
ABMT. No marrow metaphases were obtained after transplantation.
Two patients who underwent autografts with marrow containing a mixture
of Ph 1 -positive and Ph 1 -negative cells experienced prompt engraftment. One
patient (patient 1, Table 1) had a minority of Ph 1 -negative metaphases (20/53)
in transplanted marrow. She had a normal WBC count 4 months after ABMT.
Cytogenetic studies revealed 50% and 40% Ph 1 -negative marrow metaphases 2
and 3 months after transplantation. The karyotype showed 96% Ph 1 -positive
marrow cells when a typical hyperleukocytosis was detected 4 months after
transplantation. This patient is still in stable chronic phase 7 months after ABMT
and 46 months after diagnosis. Ph 1 -negative marrow metaphases have
disappeared.
For the other patient (patient 2, Table 1), marrow with a majority of
Ph 1 -negative cells (33/44) was transplanted. The WBC count is still normal 18
months after ABMT. More than 500 marrow metaphases were examined
during the first 6 months following transplantation, and very few Ph 1 -positive
cells were found. But afterwards, the percentage of Ph 1 -positive marrow cells
increased slowly, attaining 64% 1 year after transplantation.
DISCUSSION
High-dose melphalan was used to treat some patients with Ph 1 -positive
CGL during the chronic phase to reduce the Ph 1 -positive contingent. No effect
was observed in two patients in whom 100% Ph 1
-positive marrow cells persisted
and in whom ABMT subsequently failed to engraft. In one patient, the number of
thawed CFU-GM cells (0.75 x 10 4
CFU-GM cells/kg) infused, was low. This
number was not abnormal for the other patient, who received 3.8 x 10 4
CFCl-
GM/kg. Such graft failures have been reported in CGL after ABMT but not after
transplantation of blood-derived stem cells (7), and the failure might be
explained by the particular fragility of CGL marrow progenitors in the freezing
process (12).
After HDM treatment, the two other patients achieved partial remission
defined by the disappearance of a substantial proportion of Ph 1
-positive marrow
Table 1. Number and Proportion of Ph 1 -Negative to Ph 1 -Positive Marrow
Metaphases After Autologous Bone Marrow Transplantation
Months After ABMT 1-2 3 4 5-6 7-9 9-12
Patient 1 5/10 12/30 1/24 — 0/31 —
(50%) (40%) (4%)
Patient 2 190/191 253/257 105/106 40/50 36/100
(99.5%) (98.5%) (99%) (80%) (36%)
Abbreviation: ABMT, autologous bone marrow transplantation.