In HLA-mlsmatched or aploidentlcal aHogeneic progenitor cell (PC) transplantation, T cell removal can control graft vs host disease, and B cell removal might reduce the incidence of some viral diseases. In autologous transplantation, purging of contaminating neoplastic ceKs might reduce the incidence of relapse. To study a new two step PC purging procedure combining positive and negative selection, PC were collected by apheresis from cancer patients, and an aliquot was first processed through CellPro columns for CD34+ cell positive selection. On some occasions, PC samples were deliberately contaminated by 1-5% breast cancer oeH lines CG5 and CAMA-1. After this first positive selection step, mean CD34+ cell recovery was S6±12%, and CD34+ cell purity was 63±12% At this Urne. CD3+ and neoplastic cell depletion (assessed by APAAP staining of 1x107 cells) were 2 10.7 and 1 8±0 6 logs, respectively. CD34+ cells were further processed through the StemSep(tm) negative selection device for immunoaffinity removal of T and B cells by means of anti-CD3 and anti-CD19 antibodies (n-6) or of breast cancer cells from contaminated PC samples by means of 5E11 antibody (n=4). After the first and the second step, results were as follows: CD34+ recovery CD34+ purity log depletion T and B cell removal 4719 94±B 4.8±0.4 Breast cancer removal 52±11 73±15 4.3±0.4 This new procedure is associated with an acceptable loss of CD34+ cells and a T/B and neoplastic cell purging of 4.5 logs, ie significantly superior than methods previously described.
|Number of pages||1|
|Publication status||Published - 1996|
ASJC Scopus subject areas
- Cancer Research
- Cell Biology