Allogeneic peripheral blood stem cell transplantation following CD34(+) enrichment by density gradient separation

GVHD is a significant cause of morbidity and mortality following allogeneic peripheral blood stem cell transplantation (AlloPBSC). CD34(+) cell select ion could reduce GVHD by negative selection of T cells. In an attempt to re duce the T cell content of alloPBSC we carried out a trial in which 11 pati ents with hematologic malignancies received alloPBSC from HLA-matched sibli ngs following density gradient separation using an isotonic colloidal silic a solution (BDS 60; Dendreon Corporation). Cyclosporine and methylprednison e were used for GVHD prophylaxis. The mean yield of CD34(+) cells was 69 +/ - 15.6% with a purity of 2.9 +/- 1.7%. The mean number of CD3(+) cells infu sed was 1.0 +/- 1.2 x 10(7)/kg, representing a 1.3 log depletion. A high ri sk of acute GVHD was observed: grade II-IV in 7/11 (64%) and grade III-IV G VHD in 5/11 (45%) patients. Nine of the 11 (82%) patients died with a media n survival of 68 days. Cytokine expression in PBSC was compared pre and pos t processing. Interferon-gamma was detected only following density gradient separation while IL-8 expression increased 3- to 6-fold post processing. T herefore, processing with this device may augment production of pro-inflamm atory cytokines.