Autologous Bone Marrow Transplantation - Blog Science Connections

Double Autografting in Acute Leukemia 117
Sepsis during the aplastic phase was the primary cause of death in five
patients.
Five of 62 patients (7.1%) had significant hemorrhagic complications and
two patients died of intracerebral hemorrhage despite platelet support. During
ABMTII, one patient with ALL in first CR died of cardiac arrest, for which no
cause could be identified at postmortem examination.
DISCUSSION
Double ABMT may be considered as an in vivo variant of the ex vivo
purging of marrow that is under investigation in various centers (3,4). The
potential role of ex vivo manipulation of bone marrow to eliminate residual
disease remains unclear (5).
Our results, which showed the better disease-free survival from AML in first
remission for patients who had two grafts over those who had one, must be
interpreted with caution. The patients proceeding to ABMT II were the fittest
patients in whom engraftment was quick and who did not relapse early after
ABMT I. It may be that rapid hematologic recovery is a manifestation of a
"healthy" marrow uncontaminated by residual disease. Moreover, ABMT II was
carried out between 50 and 100 days after infusion of the first marrow, as soon
as the patient had a neutrophil blood count higher than 1.5 x 10 9 /l and a
self-sustaining platelet count of more than 100 x 10 9 /1. The patient's general
fitness was also taken into account before reharvesting. This means that most
patients going through ABMT 11 had been in remission about 8 months, making
them an even more select group in terms of survival. Survival of this group
should therefore be considered in comparison with that of chemotherapy
patients who have already had 8 months of disease-free survival after remission.
The practicalities of double ABMT for patients with AML in first remission
are such that only 41 % of patients have achieved a second graft. Nonetheless,
the few patients in this group who are able to have ABMT II seem to do well.
Hematologic recovery, particularly platelet recovery, after ABMT II is delayed.
The disappointing results of this chemotherapeutic approach for firstremission
ALL patients, using either a single or a double graft, may be
interpreted in various ways. The high procedure-related mortality occurring in
this group, as opposed to that of AML first-CR patients, makes interpretation of
this small group's results even more difficult. Nonetheless, the patients seem
not to have benefited. First, induction with CIKALLIX may leave too high a yield
of minimal residual disease to be ablated by high-dose chemotherapy and
ABMT. Second, chemotherapy ablation for ABMT in ALL appears less effective
than total body irradiation, considering the European Bone Marrow Transplant
Group results (5).
For patients beyond first remission who have either AML or ALL, this
chemotherapy protocol with either a single or a double ABMT appears
unsuitable. The ablative procedure is clearly inadequate to remove underlying