autologous blood and marrow transplantation - Blog Science ...

Lazarus et al. 157
difference. Furthermore, in patients with leukemia and lymphoma there is a
positive relationship between the patient's tumor burden and the amount of
contamination in the autograft. 25
Despite these difficulties, it is important to
continue to study the role of purging in the overall outcome of the patients. This is
especially true if the means to accomplish purging are relatively simple, there is no
clinically significant effect on engraftment, and the costs can be minimized.
We reported previously the successful use of autologous CD34 +
enriched
peripheral blood mononuclear cells for hematopoietic reconstitution after myeloablative
chemotherapy in patients with advanced lymphoma. 18
CD34 +
cells selected
using the CEPRATE SC System resulted in rapid engraftment of hematopoietic
function at a tempo similar to studies in which unselected PBPC were given. On
the other hand, it appeared that efforts to optimize the use of labor and the number
of immunoaffinity columns might be hampered, since overnight storage of the
product before CD34 cell selection appeared to have a negative effect on cell yield
(mean 2.4-fold fewer CD34 +
cells reinfused) and increased the time to platelet
engraftment as well.
These results, however, were inconsistent with previous reports. Storage of
PBPC for periods up to 5 days has been reported to have minimal effects on cell
count, cell viability, and granulocyte-macrophage colony-forming units (CFU-
2 6 - 2 9
GM). More importantly, overnight storage before processing had been reported
to have no effect on platelet recovery after transplant. 3031
Storage of the PBPC
product overnight before processing allows schedule flexibility as well as using
fewer immunoaffinity columns.
We designed this prospective, randomized study to systematically investigate
the apparent negative effect of overnight storage in a larger population. We
demonstrated that overnight storage did not adversely affect neutrophil or platelet
engraftment after high-dose chemotherapy. Furthermore, the overnight storage did
not affect the cell yield after the selection procedure.
In our previous nonrandomized study, we observed a loss of the association
between the number of CD34 +
cells infused and platelet engraftment in patients
whose collections were stored overnight. 18
In this study, only five patients, evenly
distributed between the two groups of the study, experienced a delay in platelet
engraftment.
Twelve patients excluded from the analysis clearly were "poor mobilizers," a
common problem noted in lymphoma patients. 32,33
This group, however,
subsequently underwent high-dose chemotherapy and autotransplant using either
unselected PBPC or a combination of selected and unselected cells.
In conclusion, CD34 +
cells can be obtained and enriched from the peripheral
blood of heavily pretreated lymphoma patients. Cells can be stored overnight
before processing to improve the efficiency of the laboratory without having an
impact on patient engraftment.