A rapid two-step method for elimination of bcl-2/IgH positive non-Hodgkin's lymphoma cells from human blood or marrow stem cells, employing immunomagnetic purging with streptavidin-coated ferrofluids.
BACKGROUND
Follicular lymphoma cells may contaminate blood or BM stem cell collections used for autologous transplants and contribute to relapse. We report on the development of a B-cell lymphoma-purging technique, using streptavidin-coated ferrofluids (SAFF) and a high-gradient magnetic-separation device (HGMSD).


METHODS
Blood or BM samples were spiked with bcl-2 positive lymphoma cells, labeled with biotinylated B cell MAb (CD19, CD20, CD37) then purged by positive selection of CD34(+) cells, followed by negative selection with SAFF and a high HGMSD. Purging efficiency was judged by dual-labeled flow cytometry and by PCR analysis of bcl-2.


RESULTS
A 6 log purge of bcl-2 lymphoma cells could be achieved by first enriching for CD34(+) cells, followed by negative selection with SAFF and HGMSD. The use of SAFF with HGMSD alone could only accomplish a 2-3 log purge.


CONCLUSIONS
CD34 selection from blood or BM of follicular lymphoma patients, followed by negative selection of MAb-labeled cells with SAFF could achieve a 6 log purge. However, cell yields were low (10%) and purging efficacy was limited to low starting concentration of lymphoma cells (< or = 1.0%). This technique, however, may be useful for full-scale clinical purging of minimal residual disease following debulking with a cyclophosphamide or other agents.
Mangan
K F
KF
Bone Marrow Transplant Program, Department of Medicine, Temple University School of Medicine, Philadelphia, USA.
Leonardo
J
J
Mullaney
M T
MT
Terstappen
L W
LW
Rao
C
C
Liberti
P
P
D018952:Antigens, CD34 / Q000096:biosynthesis; D001402:B-Lymphocytes / Q000166:cytology; D019921:Biotinylation; D001781:Blood Component Removal; D002469:Cell Separation / Q000379:methods*; D017690:Cell Transplantation; D005434:Flow Cytometry / Q000379:methods; D050438:Genes, Immunoglobulin Heavy Chain; D006801:Humans; D018189:Immunomagnetic Separation / Q000379:methods*; D008228:Lymphoma, Non-Hodgkin / Q000097:blood* / Q000378:metabolism*; D008280:Magnetics; D016133:Polymerase Chain Reaction / Q000379:methods; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000096:biosynthesis*; D019809:Streptavidin / Q000737:chemistry
D018952:Antigens, CD34; D019253:Proto-Oncogene Proteins c-bcl-2; D019809:Streptavidin