Purified CD34+ Lin- Thy+ stem cells do not contain clonal myeloma cells.

摘要: High-dose therapy with autologous marrow or peripheral blood stem cell (PBSC) rescue has been extensively applied in the treatment of multiple myeloma (MM) patients during past 10 years resulting improved event-free and overall survival when compared standard chemotherapy. However, relapses are common cure is unlikely majority patients. Because both bone PBSCs contaminated cells it conceivable that relapse after autotransplantation originates at least part from autografted tumor cells. In this study, mobilized were examined for presence based on immunophenotyping sensitive polymerase chain reaction (PCR)-based techniques. addition, CD34+ Lin- Thy+ purified PBSC harvests MM by sequentially using counterflow elutriation centrifugation, phenylalanine methylester, flow sorting, 5-parameter gating (propidium iodide, forward scatter, side v Thy+). Virtually all unsorted preparations contained sufficient quantities (range, 10%) potentially causing a disease relapse. Stem purification led to an enrichment about 50-fold patients; approximately 90% final population expressed no evidence contamination cytometric analysis CD38bright (< 0.1%). Quantitative PCR amplification patient-specific complementarity determining region III (CDRIII) DNA sequences showed depletion clonal B 2.7 7.3 logs, highest log reduction noted samples initially containing most Our results show depletes undetectable levels up 10% present PBSCs, thus offering tool investigate whether can be reduced markedly.