Autologous Bone Marrow Transplantation - Blog Science Connections

36 ABMT in ALL
compared the results with those obtained in a group of patients autografted
with unpurged marrow.
PATIENTS AND METHODS
Data on 27 ALL patients (16 CR1 and 11 CR2) who received autografts
with purged marrow and 6 ALL CR1 patients who received transplants with
untreated marrow were collected from eight Italian institutions. The criteria
for CR1 patients in this study were: the hypercellularity at diagnosis (leukocyte
count >100 x 10 9 /D. chromosomal abnormality, L 3
French-American-
British subtype, extramedullary disease (with or without CNS involvement),
and the patients' poor response to induction therapy with difficulty in
achieving CR. The induction, consolidation, or maintenance therapy was
heterogeneous in all patients; however, the median interval from the onset of
CR to marrow collection was 2.5 months (range, 1 -4 months). The characteristics
of ALL patients are summarized in Table 1.
Preparative Regimen
The majority of patients (90%) received cyclophosphamide and total
body irradiation (TBI) as a pretransplant ablative regimen: 60% received
fractionated TBI (3 Gy x 4 days) and 40% received TBI (single dose of 10 Gy).
The cyclophosphamide was administered at 200 mg/kg within 4 days (48% of
patients) or 120 mg/kg within 2 days (52% of patients).
Bone Marrow Collection and Purging
Cells were aspirated from multiple sites on the posterior iliac crests of
patients under general anesthesia. At least 2-3 x 10 8
cells/kg body weight
was collected. The suspension was filtered and then centrifuged at 2,500 rpm
for 15 minutes. The buffy coat was removed, and the cells were counted and
resuspended in 20% autologous plasma and 80% TC 199 medium. To purify
bone marrow suspension from the malignant cells, we used mafosfamide at a
final concentration of 80-100 ug/m\.
Cells were resuspended at a concentration of 2 x 10 7 /ml with the hematocrit
ranging between 6% and 15%. Mafosfamide (80-100 ug/ml) was added
to the bone marrow cells and the suspension was incubated for 30 minutes at
37° C in a water bath; the cells were kept at 4°C for 5 minutes and then
centrifuged at 3,000 rpm for 10 minutes. The pellet was gently resuspended,
and the cells were counted and diluted at a final concentration of 4 x 10 7 /ml in
55% autologous plasma, 35% TC 199 medium, and 10% dimethyl sulfoxide
for cryopreservation. Cells were transferred to Gambro hemofreeze bags for
cryopreservation and frozen in a Nicool 316 programmed biological freezer
at 1 ° C/minute until they reached 4° C, 2° C/minute until they reached 40° C,
and finally, 5° C/minute until they reached 140° C. The bags were then stored
in the liquid phase of a liquid nitrogen freezer.