부산대학교 도서관

In the use of autologous PBPC transplantation in patients with multiple myeloma, contamination of PBPC with myeloma cells is commonly observed. Enrichment for CD34+ cells has been employed as a method of reducing this contamination. In this study the reduction of myeloma cells in PBPC was accomplished by the positive selection of CD34+ cells using immunomagnetic bead separation (Isolex 300 system). PBPC were mobilized from 18 patients using cyclophosphamide (4.5 g/m2) and G-CSF (10 μg/kg/day). A median of two leukaphereses and one selection was performed per patient. The median number of mononuclear cells processed was 3.50 × 1010 with a recovery of 1.11 × 108 cells after selection. The median recovery of CD34+ cells was 48% (range 17–78) and purity was 90% (29–99). The median log depletion of CD19+ cells was 3.0. IgH rearrangement, assessed by PCR, was undetectable in 13 of 24 evaluable CD34+ enriched products. Patients received 200 mg/m2 of melphalan followed by the infusion of a median of 2.91 × 106/kg CD34+ cells (1.00–16.30). The median time to absolute neutrophil count >0.5 × 109/l was 11 days, and sustained platelet recovery of >20 × 109/l was 14 days. We conclude that immunomagnetic-based enrichment of CD34+ cells results in a marked reduction in myeloma cells without affecting engraftment kinetics.